Modern Thomistic philosophy: an explanation for students

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MODERN
THOMISTIC PHILOSOPHY

AN EXPLANATION FOR STUDENTS

BY

R. P. PHILLIPS, D.D., M.A.,

Professor of Philosophy, S. John's Seminary, Wonersb

IN TWO VOLUMES

Vol. I.
THE PHILOSOPHY OF NATURE

" Vidit scalam stantem super terram
et cacumen illius tangene caelum."

(Gen. c. 28, v. 12.)

THE NEWMAN BOOKSHOP
Westminster, Md.

NIHIL OBSTAT:

Georgius Joyce, S.J.
Censor deputatus.

IMPRIMATUR :

S. Canonicus Banfi,
Vicarius generalis.

SOUTHWARCI,

1934.

NOTE AS TO THE METHOD OF QUOTING
ARISTOTLE AND S. THOMAS

The references to Aristotle's works are, in accordance with the
usual practice, numbered according to the pagination of the edition
of Bekker (Aristotelis Opera. Berlin, 1831-1870. 5 Vols.). Since
the Greek text in this edition has a consecutive pagination through-
out, it is a simple matter to find any passage referred to. Thus, the
first number given refers to the page, the letter a or b to the first or
second column of that page, and the final number to the line of the
column in which the quotation is to be found. So, e.g. 952a26 refers
to a passage beginning on the twenty-sixth line of the first column of
page nine hundred and fifty-two. The same numeration is followed
by the Oxford translation of Aristotle. (The Works of Aristotle,
translated into English. Ed. J. A. Smith and W. D. Ross. 11 Vols.
Clarendon Press, Oxford.)

With regard to S. Thomas, the method of reference is as follows :
The references to the Sumrna Theologica give first the part of the
Summa from which the quotation comes, i.e. I., the first part ; I. II.,
the first part of the second part ; II. II., the second part of the second
part ; and III., the third part. Then follows the number of the
question, after which is given that of the article referred to ; and
finally, if necessary, the number of the objection or its answer, to
which reference is made. Thus : I. II. ,77, 5, ad 3 would mean that
the passage is to be found in the answer to the third objection to the
fifth article of the seventy-seventh question of the first part of the
second part. The disputed questions are referred to by name, e.g.
De Veritate, followed by the number of the question and article. So,
De Veritate 3,2, ad 6 refers to the answer to the sixth objection to the
second article of the third question of that work. The Summa contra
Gentiles is referred to by the number of the book and chapter. So,
II. CG. 12 refers to the twelfth chapter of the second book. In the
commentaries on Aristotle the number of the lecture in which the
reference occurs is given.

PREFACE

The purpose of this book is to present a simple explanation
of the philosophy usually taught to Catholic students. No
attempt has been made to introduce novel doctrines, but
merely to set out, as clearly as possible, the meaning of those
which are commonly received. Since such teaching at the
present day is predominantly on the lines of the system
originated by S. Thomas Aquinas, it is this system, as
developed by modern Thomists, which it is the object of this
book to explain. It is clear that in a single work it would be
impossible to give a full account, and absurd to try to
vindicate the truth, of the various philosophical systems
which are included under the generic name of Scholasticism ;
so that no systematic exposition is attempted of even the
chief of the non-Thomistic systems, those of Scotus and
Suarez. The divergencies of their doctrines from those of
S. Thomas frequently throw light on the precise meaning of
the Thomist contentions ; so that to make some mention of
them is not foreign to our purpose. Similar considerations
will apply to our treatment of those other philosophical
systems which diverge still more widely from the Thomistic
plan, such as those of Spinoza or of Hegel. It appears to be
as unreasonable to expect, in an exposition of Thomism, a
full account and refutation of Hegelianism, for example, as
it would be to look for such an account of Thomism in Hegel's
Logic. Consequently, all that seems necessary to be done in
this direction is to notice the principal divergencies of
modern philosophies from the Thomistic, so bringing into
higher relief its positive teaching ; and, as far as space allows,
to meet the more urgent of the reasons that have been
advanced against its truth.

The questions which were most prominent in S. Thomas'
day are not so much to the fore at present, while many of

vii

viii PREFACE

those most debated ^iow, were, in the Middle Ages, hardly
discussed. The emphasis and accent, therefore, of a modern
presentation of Thomism must be different from those of the
expositions of a John of S. Thomas or a Goudin ; though
the basic principles may remain the same. These principles
contain a view of the universe ; and no decision can be
reached as to the truth or falsity of this view, by considering
merely the arguments which may be advanced in support of
particular doctrines, but only from a consideration of it as a
whole. Just as in circumstantial evidence for a crime each
item taken separately may be insufficient to make certain the
identity of the criminal, yet if a large number of facts of
different kinds all point in a particular direction, the con-
clusion is almost irresistible ; so, in judging of the validity of
a philosophical system, conviction is reached when it is seen
that, from all sides, our consideration of the various elements
of the universe converge to establish it. For the philosopher
is, as Plato says, a ' synoptical man,' taking a unified view
of all knowledge. The world- view of S. Thomas is essentially
such a unity, and must, therefore, be judged as a whole.
Consequently, an attempt has been made, in the following
pages, to keep the main principles of it in the foreground,
and to show that from every side the roads of thought lead
up to them. To do this at all adequately a discussion of moral
philosophy ought to be added, but this would have necessi-
tated making the book impracticably long. Fortunately,
Fr. Cronin has already given us all that can be desired in
this way ; while an account of the Cosmological and Meta-
physical sections of Thomistic philosophy is not available in
English in a handy form. The only single work of this kind
is the translation of the Manual of Modern Scholastic
Philosophy, compiled by professors of Louvain University,
but this includes, in addition to these subjects, Logic, Ethics,
and the history of Philosophy, so reducing considerably the
amount of space available for those which we are to deal with.
It is hoped, therefore, that a somewhat more detailed
explanation in English, of Natural and Metaphysical philo-
sophy, contained in a single book, may be found useful by
those who are professedly making a study of Scholastic

PREFACE ix

philosophy ; and possibly also by others who have not the
time or opportunity for reading the several volumes of the
Stonyhurst series, or the very full expositions by Dr. Coffey
of some of the subjects here dealt with, but who, at the same
time, would like to know something of this philosophy as a
whole.

CONTENTS

PAGE

Preface .......... vii

I. INTRODUCTORY

Section I. The Definition of Philosophy . . . i
To be Looked for in Philosophy as an Existing
Fact — In its History — Thales and the Ionic School
— The Pythagoreans — The Eleatics — Heracleitus —
The Atomists — Anaxagoras — Socrates and Plato —
Aristotle — Conclusion .

Section II. The Division of Philosophy ... 20

II. THE PHILOSOPHY OF NATURE

Part I. Cosmology : The Philosophy of Inanimate

Nature ....... 22

Introduction.

Chapter I. Mechanism ...... 25

History of the Theory — Its Essential Character —
Criticism.

Chapter II. Dynamism ...... 30

Its Nature — Theories of Leibniz, Boscovich and
Kant — Criticism .

Chapter III. The Thomistic Theory of the Nature

of Matter . . . . . -36

Nature and Data of Question — History and Explana-
tion of Hylomorphism — The Reasons Advanced to
Support it — Additional Explanations of the Meaning
of ' Matter ' and ' Form ' — Some Difficulties Con-
sidered.

Chapter IV. Quantity ...... 54

The Distinction of Quantity and Substance — Des-
cartes' View — Reasons for Affirming the Distinction —
The Nature of the Distinction — The Nature of
Quantity in Itself — Its Effects — Opinions — The
Usual Thomist View — Reasons in its Favour — A
Difficulty Considered — The Separability of Quantity
and Substance : Substance without Quantity,
Quantity without Substance — A Peculiarity of
Quantity.

Chapter V. The Continuum ..... 67
Notion of Continuity — Zeno's Arguments — The Divisi-
bility of the Continuum — Is it Composed of Indivi-
sible Elements ? — Is it Infinitely Divisible ? — The
Parts of the Continuum — The Indivisibles of the
Continuum — Solution of Zeno's Arguments.

xii CONTENTS

PAGE

Chapter VI. Place and Space .... 78

I. Place — Localisation — Kinds of Location

II. Space — Its Nature — Opinions — Absolutist, Sub-

jectivist, Intermediate Theories — The Void —
Conclusion as to the Nature of Space.

III. The Occupation of Space — Impenetrability —

Multilocation.
Chapter VII. The Limits of Quantity . . . 103

The Infinite — Its Kinds — The Possibility of Actually

Infinite Quantity — Of an Actually Infinite Multitude.
Chapter VIII. The Quality of Bodies ; or Motion 109

The Nature of Motion — Action at a Distance — The

Nature of Gravitational Action.
Chapter IX. Time . . . . . . 117

Duration — Eternity, ^vum, and Time — Division of

Time — Non-Thomistic Views as to the Nature of

Time — Newton, Kant, Leibniz, Bergson.
Chapter X. Substantial Change in General . 128

Meaning of Substantial Change — The Plurality of

Forms — The Source of the New Substantial Form in

Generation.
Chapter XL Substantial Change in Chemical Com-
position : The Question of Mixtures . 141

Current Scientific Views — Philosophical Views —

Thomist Opinions as to the Permanance of the

Elements and Qualities in Mixtures.
Chapter XII. The Individual . . . -151

Its Nature — Opinions — Explanation of the Thomist

View — Reasons in its Favour — Meaning of ' Materia

Signata ' — Some Difficulties Considered.
Chapter XIII. Some General Characteristics of

the Inanimate World . . . .164

Physical Laws and Theories — The Formation of the

Material Universe — The Infinity and Eternity of the

Universe.

Part II. The Philosophy of Animate Nature . . 173
Introduction.

Division I. Life in General . . . . .178

Chapter I. Vital Operations . . -179

Vital Operations in General — Their Distinctive
Characteristics — Different Kinds of Vital Operations
— Vegetative, Sensitive, Intellectual.

Chapter II. The Principle of Life . . .185

Is it One Only in Each Individual ? — A Difficulty —
Opinions on the Divisibility of the Life-principle —
Answer to the Question.

CONTENTS xiii

PACE

Chapter III. The Vital Powers . . . .191
Are they Distinct from the Soul ? — How are they
to be Distinguished from One Another ?

Chapter IV. The Unity of the Living Individual 196
Opinions — The Thomist View — Definitions of Life.

Division II. Vegetative Life ..... 200
Chapter V. The Nature of Vegetative Life . 201

Opinions — Mechanism, Vitalism, Thomism — Reasons
in Favour of the Thomist View.
Chapter VI. The Transmission of Vegetative Life 207
Reproductive Processes — Thomist View of Repro-
duction.

Division TIL Sensitive Life . . . . .211

Chapter VII. Cognition . . . . 1 . 212

Nature of Cognition — S. Thomas' View — The Materi-
alist and Idealist Views — The Thomist View Further
Explained.

Chapter VIII. The Process of Knowledge . .218

Necessary Conditions for Union of Subject and Object
— Their Assimilation Involves Change in Both — The
Intentional Species — Why they are Necessary — And
Universally Necessary — The Two Kinds of Species :
Impressed and Expressed — Their Nature and Mode of
Production — Their Precise Function — Are Expressed
Species Present in Every Cognitive Act ?

Chapter IX. Sense Knowledge .... 229
The Senses are Organic — Their Distinction and Num-
ber— Where Sensation Takes Place — The Objects of
the Senses — Immediate and Mediate Sense Objects —
Can we be said to Sense the Externality of an Object ?
_^~ — The Inversion of the Retinal Image — Internal Sen-
sibility— The Sensitive Appetite.

Chapter X. The Nature of the Life-principle in

Animals . . . . . . .241

What We Mean by ' Animal ' — Have they Sensation ?
— Opinions : Descartes, Loeb — The Thomist View —
Is Sensation Peculiar to Animals ? — The Life -principle
in Animals Essentially Sensitive, and their Substan-
tial Form : so One Only — Belonging to the Material
Order, yet Specifically Distinct from that of Plants
— Summary.

Division IV. Intellectual Life . . . -251

Chapter XL The Nature of the Intellect . . 252

Views as to its Immateriality — S. Thomas' Primary
Reason for Holding it to be So — Its Objects :
Common Formal Object, and Proper Formal Object —
Further Reasons for Regarding the Intellect as Imma-
terial— The Question of Its Activity — Our Knowledge
of Individuals.

xiv CONTENTS

PAGE

Chapter XII. The Origin of Ideas . . . 264

The Empiricists — Innate Ideas — The Transcendental-
ists and Hegel — The Difficulty of the Question — The
Thomist Solution — The Active Intellect — Its Neces-
sity and Function — Summary of the Intellectual
Process.

Chapter XIII. The Intellectual Appetite ; The

Will ....... 272

Its Existence — Nature — What Necessity is — Freedom
of the Will — History of the Problem — Summary of
Opinions — Arguments in Favour of Liberty — The
Limits of Liberty — Views on the Nature of Liberty —
The Answer to Indeterminism — The Answer to
Psychological Determinism — Summary of results
arrived at.

Chapter XIV. The Nature of the Intellectual

Soul in Man ...... 296

Its Substantiality — Its Spirituality — It is the Substan-
tial Form — Simple — And One Only — Differing Specifi-
cally from that of Other Animals — Reasons for this
View.

Chapter XV. The Union of Soul and Body in Man 304
Views on the Question — Monism — Psycho-physical
Parallelism — Accidental and Essential Union— Reasons
for the Thomist View — The Mode of the Union — How
the Soul is Present to the Body.

Chapter XVI. The Origin and Destiny of the

Human Soul ...... 312

Origin — Not by Generation or Emanation, but by
Creation — The Transmigration of Souls — The Thomist
View of the Succession of Forms in the Individual —
Immortality — Opinions — Reasons for Thomist View
— The Metaphysical Argument.

Chapter XVII. The Origin of Life . . .321
The Origin of Life on Earth — Opinions — Spontaneous
Generation — Two Forms of the Theory — Their Possi-
bility.

Chapter XVIII. Transformism .... 328

Preliminary Remarks — Sketch of Evolutionary The-
ories— Lamarck — Darwin — The Materialist Theory —
Reasons which Exclude It — Consideration of Evolu-
tionary Theories in General.
Conclusion ......... 344

MODERN
THOMISTIC PHILOSOPHY

I. INTRODUCTORY
SECTION I

THE DEFINITION OF PHILOSOPHY

To be Looked for in Philosophy as an Existing Fact — In Its
History — Thales and the Ionic School — The Pythagoreans —
The Eleatics — Heracleitus — The Atomists — Anaxagoras — Soc-
rates and Plato — Aristotle — Conclusion.

Most people have the vaguest ideas, if any, of what philo-
sophy is, or of what the word philosophy means. It is
commonly used only in such expressions as : 'he took the
affair philosophically,' in which, no doubt, it is implied that
philosophy helps a man to bear up against misfortune, and
that philosophers are calm and unexcitable people ; though
why they should be so does not appear. Consequently, we
are not much nearer any knowledge of what philosophy is
in itself. It is, however, essential for the student to have,
at the start, some notion of the nature of the subject which
he is about to study ; though it is evident that it can only
be a rough and provisional one. He will have to determine
for himself at the end of his study (if that ever comes)
whether it is finally satisfactory. The definitions which the
text-books of Scholastic philosophy put on their opening
pages are often hurled at the reader's head without much
proof that they are correct, so that they have to be taken
on faith, on the authority of the author. They thus fail to

2 MODERN THOMISTIC PHILOSOPHY

satisfy the mind or arouse the interest. It seems desirable,
therefore, that a man should be led to discover for himself
what philosophy is in fact. Now, everyone will agree, that
if we want to discover the nature of a thing the right way
to do so is to examine it. To do this in the case of philosophy,
we must see what subjects are discussed by it, i.e., examine
it in the course of its history. It will hot, however, be
necessary to review its entire history, but it will be sufficient
if we see what its character was during the period of its
formation, which is that of the Greek philosophers till the
time of Aristotle.

Though it may well be that further precision might be
imported into our definition by continuing our enquiry
down to the present day, nevertheless, if it be granted that
the thought of Aristotle and his predecessors is philosophy
in process of formation, we shall, by examining it, be able
to discover what the essential character of philosophy is.
Just as the child is the father of the man, and retains the
same nature throughout his life, so Greek philosophy is
the father of modern, and thus in its nature the same.
By following this a posteriori method we shall avoid the
danger of making philosophy out to be what we think it
ought to be ; and at the same time the glimpse which will
thus be caught of the beginnings of philosophy will be a
help and a guide in the subsequent study of it.

The reason of our choice of Greek philosophy for our
enquiry is, that it was in Greece that philosophy first
appeared as an autonomous science, distinct from religion,
so that it can be examined there in a more or less pure state.

Tholes.

According to Aristotle, whose opinion on this point is
generally accepted, Greek philosophy begins with Thales of
Miletus (c. 624-550 B.C.). He and his immediate successors
were engaged on the problem of discovering the nature of
the visible world ; and this is natural, for as soon as a man
begins to think, that which first attracts his attention is
the world as presented to him in sensation, as being the
most obvious aspect of it. The opinions of Thales, as far

THE DEFINITION OF PHILOSOPHY 3

as we know them from tradition, since he left no writings,
are summarised in two propositions : first, that water is
the principle of all things ; and secondly, that the earth is
a flat disc floating on water. Strange and crude as these
statements sound, they have a considerable importance for
our purpose, since they show that what Thales tried to do
was to explain the material constitution of the universe
by the aid of reason alone, without appealing to religious
myths, or the intervention of the gods ; whose action was
then normally invoked to account for anything whose
origin was obscure. He and his successors were seeking
what was later called the material cause of the universe.
All the pre-Socratic philosophers followed the line suggested
by Thales, viz., that under the multiplicity of phenomena,
of the wond as perceived by sense, there must be some one
permanent principle. Just as Thales asserted that this
principle is water, so his successors advanced other theories
as to its nature. For Anaximander it is indefinite matter,
for Anaximenes air, for the Pythagoreans number, Jor the
Eleatics being, for Heracleitus fire, for Empedocles the four
elements, and for Democritus atoms.

The Ionic School.

Thales was the founder of what is known as the Ionic
School, from the fact that its three principal representatives,
Thales himself, Anaximander and Anaximenes, were all
men of Ionia. They have been called materialists, though
they were not so in the modern sense of denying the existence
of anything but matter : they were simply concerned to
discover what the material world was made of. Just as a
child might pull a toy to pieces to find out what it is made of,
so these philosophers tried to pull the world to pieces with
their wits, and having discovered the answer, as they
thought, asked no further questions about it.

The Pythagoreans.

The next attempt to discover the primary constituent of
the material word which calls for notice is that made by
the Pythagoreans.

4 MODERN THOMISTIC PHILOSOPHY

Pythagoras was born at Samos at some time between
580 and 570 B.C. ; and in middle age settled at Crotona in
Italy, where he founded the Pythagorean Society, which
was primarily a religious and moral order, not a philosophic
school. It was closely connected with the Orphic Sect, from
which it took the doctrine of Metempsychosis, which would
be better named Metasomatosis, since it is the theory that
souls pass from one body to another. The philosophy of the
Pythagoreans is the philosophy of number, for they held
that number is the stuff of which the world is made. They
were probably inclined to this strange opinion by their
mathematical researches, for which Pythagoras himself was
remarkable. It is thought that the first book of Euclid is
substantially attributable to him, and he is said to have
sacrificed an ox in honour of his discovery of the 47th proposi-
tion. Observing the world about them the Pythagoreans
remarked that we recognise objects by means of their
qualities. The various classes of things have, however,
different qualities, and it seems at first sight that there is
none which is common to all. Further examination shows
us, nevertheless, that there is one characteristic which is
possessed by everything, that of quantity or number. All
things are numerable, and can be counted. We are reminded
of the saying of Galileo : ' Philosophy is written in the great
book which ever lies before our eyes — I mean the universe
— but we cannot understand it if we do not first learn the
language in which it is written. This book is written in the
mathematical language ' ;x though the ideas of the Pytha-
goreans were much more primitive, and enveloped in an
atmosphere of mysticism. They concluded, indeed, from
the universal character of number and from the order and
harmony of the universe, not merely that number is a most
important element in it, but that it is its very essence, that
the universe is made of number, just as Thales had said it is
made of water. Number is the ultimate, the only reality.
Further, from the opposition of the determined and the
indeterminate or infinite, are derived all the fundamental

1 Galileo Opere, Vol. IV, p. 171, quoted by Burtt. Metaphysical
Foundations of Modern Science, p. 64.

THE DEFINITION OF PHILOSOPHY 5

contrarieties : equal and unequal, one and multiple, left and
right, male and female, rest and movement, light and dark-
ness, good and evil. These dominate the nature and activity
of things, so that every essence has its number, and every
essence is a number. This doctrine, fantastic as it is — though
it has marked affinities with the way in which the universe is
regarded by modern mathematical physics — is nevertheless
some advance on the teaching of the Ionians, since it declares
that the ultimate material of the universe is something more
abstract and so more universal than was allowed by them. It
belongs, however, to the same type of enquiry as that of the
lcnic School — the enquiry, namely, as to the stuff of which
the material universe is, in the last resort, constructed.
Consequently, it is on sense knowledge that all these tl inkers
rely, for it is by the senses that we are made acquainted with
material things ; so that the first stage in philosophy is
similar to the first stage in the development of the individual
mind, when the child is filled with curiosity as to the things
around him, trying to find out what they are made of by
sucking them, sticking his fingers in them, and pulling them
to pieces ; but hardly asking the reason of them or using his
intellect about them. This will be the next stage in his
mental life, and so it was also in the growth of philosophy ;
for the group of thinkers who now claim our attention try to
investigate the reason of things, and not merely the stuff of
which they are made. They ask not merely what things are
made of, but why they are as they are. In this way they are
of importance for our present purpose since they add a new
feature to the conception of philosophy.

The Eleatics.

These philosophers are known as the Eleatics, since their
school was situated at Elea in Southern Italy. The founder
of this famous school is said to have been Xenophanes, a
kind of troubadour, but its chief representative is Parmen-
ides, who was born about 514 B.C. His reflections take their
rise from the observation of the changing character of things.
Since everything about us is constantly changing, it seemed
to him that no knowledge of it was possible. Just as in

6 MODERN THOMISTIC PHILOSOPHY

sense knowledge, it is impossible, when looking at a rapidly
revolving wheel, to have knowledge of the spokes, since they
have passed on before they can be seen, so knowledge in
general demands that its object should be momentarily, at
least, at rest, in order that it may be seized. If, then, there
is to be knowledge at all, there must be some unchanging
reality underlying this shifting surface of the world. This
reality cannot be known by the senses which tell us only of
this superficial aspect of the world. If it is to be known at all
then, it must be by the intellect, which penetrates beneath
the surface, and what this sees everywhere in things is that
they are, is their being. This, then, must be the reality of
things, and all that is not being is unreal. Being is (i.e. is
reality) — not-being is not : the first formulation of the
principle of identity, the supreme law of thought. As he
considered further this underlying reality of pure being,
which is wholly unmixed with not-being or becoming, Par-
menides saw that it must be perfectly one and completely
immutable : it has no beginning or becoming ; for if it has,
it must come either from being or not-being. If from being,
it does not come to be, since it already is : and from not-being
or nothing, nothing comes. To maintain this position, how-
ever, he was forced to deny the testimony of the senses,
which show us being in a state of change, of becoming, and he
does not scruple to do so. He thus makes a distinction which
is henceforth to be of fundamental importance for philosophy,
the distinction between sense and reason. True being is known
to us only by the reason, the senses present to us a world
which is false, which is appearance only, and an illusion. By
a curious inconsistency, however, which was apparently
unnoticed by himself, Parmenides conceived of this one
Being as material, as occupying space, finite and spherical.
That this is an inconsistency is clear, for Being is a purely
abstract intellectual concept, and cannot have any material
characteristics : for it would thus be amenable to sense
knowledge and so be not-being, and like all else that is
sensed, an illusion. Nevertheless, this inconsistency in his
doctrine was the reason why, in fact, there issued from it the
two opposing schools of intellectualism and materialism.

THE DEFINITION OF PHILOSOPHY 7

Since Being neither arises nor passes away, if we adhere
closely to his doctrine that Reality is to be known only by
the reason, and not by the senses, we shall conclude that
there is only one Being which has no material or sensible
qualities, but is eternally the same — an absolute Monism of
a type which has become familiar in modern philosophy. If,
on the other hand, we accept his statement that Being is
material, we are led to the doctrine of the absolute indestruc-
tibility of matter ; matter has no beginning and no end,
which is materialism. The first aspect of his doctrine
represents, however, his most striking and original contribu-
tion to philosophy, and therefore we rightly see in him the
founder of Intellectualism and Idealism.

Zeno.

The most outstanding of the disciples of Parmenides was
Zeno (born about 489 B.C.), who, in support of the theory
that Being is immutable, developed some famous arguments
to show that motion is impossible, and that the very idea of
it implies contradiction. The best known of these arguments,
which are dealt with in Cosmology, is that of Achilles and the
tortoise. Achilles and the tortoise run a race, and if the
tortoise is given a start, Achilles can never catch it up. For,
first, Achilles has to run to the point from which the tortoise
started. When he arrives there, the tortoise will have moved
to a further point ; and when Achilles reaches this, the tor-
toise will have gone on still further. This process will be
indefinitely repeated, in such a way that the distance
between the two will be always diminishing, but never wiped
out ; so that Achilles will never catch up the tortoise. This
and similar arguments are meant to show that essential
contradictions are involved in our ideas of space and time.

Heracleitus.

The antithesis of this static philosophy of the Eleatics is
found, at about the same time, in the dynamic philosophy of
Heracleitus (c. 535-475 B.C.). He was an aristocrat of
Ephesus, a sardonic man, who despised not only the common
run of men, but even men of great reputation, such as Homer

8 MODERN THOMISTIC PHILOSOPHY

and Hesiod. As Parmenides had done, he sees that all the
world around us is perpetually changing ; but instead of
rejecting this appearance of change as illusory, and asserting
that the reality must be other, he accepts it, as itself the
basic reality. For him there is no stability in the universe,
but all is change. His view is summed up in the laconic
phrase vavra pit. Beneath this flux there is no principle
which is stable and permanent, so that we must not shrink
from affirming that the thing which is, the changing thing,
at the same time is not, since there is nothing which remains
even for a moment beneath the change. This movement,
this Becoming, which is pictured by Heracleitus under the
form of Fire, is all there is, and all differentiations of things
merge into it. Thus, no less than Parmenides, Heracleitus,
the originator of the philosophy of change, is led to a pure
monism ; the assertion that all reality is one and undiffer-
entiated.

This fact suggests two important points with regard to
the nature of philosophy :

i. The human mind tends to reduce all things to a simple
unity ; and that this must be so, we shall see, is accounted for
by S. Thomas' theory of its working. Hence philosophy is
the business of accounting for the many by the one, of bring-
ing particular cases under general laws, and in the last resort
of accounting for all things by one principle, cause and
ground. This effort, pushed to an extreme, ends in Pan-
theism or Monism, and it is so pressed in the two philosophies
we have just been considering. Extremes meet. '

2. But though they are extremes, yet they are antithetic-
ally opposed, since one denies all motion, the other all rest ;
and between these, philosophy has oscillated ever since.
Both owe their attraction to what is, in fact, their weakness,
viz. the denial of one of the elements in the problem. They
are attractive, being clear cut : weak, being inadequate.

This suggests a further point, viz. that the truth is likely
to be found in neither of these, but in a synthesis which com-
bines them, and, in fact, the main trend of philosophy has
been in the direction of such a synthesis, the broad lines of
which were marked out by Plato and Aristotle.

THE DEFINITION OF PHILOSOPHY 9

Empedocles.

A synthesis of this kind was indeed attempted, almost at
once, by Empedocles (c. 495-435 B.C.), who seized on Par-
menides' principle of the unchangeable character of Being,
and, interpreting it in a materialistic sense, asserted that
matter is indestructible and eternal. On the other hand, he
admitted the truth of the assertion of Heracleitus that
change is a reality ; in which case, the change of matter must
be, not an absolute coming into being of it, which would be
contrary to the Eleatic principle, but a simple mixing and
unmixing of it, to form various bodies. There are, according
to him, four fundamental kinds of matter which, unchanged
in themselves, combine to form the various kinds of bodies.
These ar,e earth, air, fire and water, which were later known
as the four elements. This theory marks a transition from
the more or less idealistic doctrines of the Eleatics and Hera-
cleitus to a fully developed mechanical and materialistic
philosophy, elaborated by Democritus and the Atomists.

The Atomists.

According to Democritus (c. 470-361 B.C.), if we could
divide matter far enough, we should ultimately come to
indivisible particles which, though extended, are too small
to be perceptible by the senses ; these he called atoms.
Now, since they fill space and have no interstices they consti-
tute the Plenum, and correspond to the ' Being ' of Par-
menides. Side by side with the atoms, which have no
qualities except to fill space, Democritus acknowledges
another reality, the Vacuum, which is also extended. That
he must allow the reality of this is clear, since he admits the
reality of change, which is nothing but the motion of the
unchangeable atoms in space. Hence space must exist and
be real, and indeed it has all the reality of atoms, which is
nothing else than extension. This Vacuum corresponds to
the ' Not-Being ' of Parmenides. Thus, according to Demo-
critus, both Being and Not-Being are real, and are extension.
All the motion in the world is determined by the nature of
the atoms, which is their size, or weight, since there are no
holes in them. Hence the bigger atoms fall faster from the

io MODERN THOMISTIC PHILOSOPHY

necessity of their nature : and thus, Democritus is led
explicitly to rule out any idea of freedom, or directing inten-
tion in the constitution of the world, or its development.
All comes about by a blind mechanical motion. It originates
by chance, and it develops by the necessary law of its nature.
In these theories the question as to the origin of the world is,
at least obliquely, answered. How did it come to be ? It
did not, since matter is eternal and indestructible, and the
force which moves it is simply natural to it.

Anaxagoras<

This answer, however, did not satisfy Anaxagoras (c. 500-
428 B.C.) ; for he saw that blind forces and mechanical
motion could not .produce such an ordered and harmonious
universe as that which we see. Nature, moreover, shows
design : all, or many, of its operations being directed to the
production of ends. Such order and purpose, he thought,
could only be produced by an agent which is rational, non-
physical and incorporeal — an intelligence or Nous. Aristotle
praises him for this entirely original contribution to philo-
sophy : ' he seemed like a sober man in contrast with the
random talk of his predecessors.'1

He is thus the first to show that philosophy must include,
beside the discussion as to the composition and genesis of
bodies materially speaking, an investigation as to the ulti-
mate final and efficient causes of the universe ; and more-
over the first to make clear the distinction between mind
and matter, and between blind mechanical chance and
purpose.

Thus closes the first period of philosophic thought in
which philosophy has chiefly concerned itself with the
attempt to discover the composition of the material world ;
and the discussion of its most obvious elements, matter and
motion. Thus philosophy, in its infancy, took stock of the
world of sense about it, and hardly gave a thought to itself,
to man who observes this world, and the mind by whose
means he does so. The consideration of these things was

1 The Works of Aristotle, translated into English, Vol. VIII. (Oxford,
1908.) Metaphysics, Bk. I, 98^18.

THE DEFINITION OF PHILOSOPHY n

now to be the main business of Greek philosophy, and
the link between the new and old is to be found in the
introduction of the all-ordering Intelligence postulated by
Anaxagorus.

The Sophists.

Philosophy did not, however, pass at a bound from child-
hood to mature manhood ; it had first to pass through a
period of stagnation and even of decadence — to sow its
wild oats.

This is the period of the Sophists, for whom philosophy
was a meie means of getting on in the world. It became
therefore their slave instead of their mistress, and they did
not aim at discovering truth, but only at finding arguments
which would flatten out any opponent. This led naturally
enough to Scepticism — or doubt as to the possibility of
arriving at any knowledge — and Subjectivism — the con-
tention that that is true which appears so to me, or to any
individual. Among the Sophists perhaps the most famous
are Protagoras and Gorgias. The propositions which the
latter undertook to prove : (i) that nothing exists, (2) that
if anything exists, it cannot be known and (3) that if it can
be known, the knowledge of it cannot be communicated,
were typical of Scepticism ; and the dictum of Protagoras,
' man is the measure of all things ; of what is, that it is ; of
what is not, that it is not ; ' of Subjectivism. These two,
Scepticism and Subjectivism, are twin diseases to which
philosophy ever since has been subject.

Socrates.

A new era of health and vigour opens with the teaching of
Socrates after this short period of decadence ; for the Greek
mind was still young and strong, and could not long succumb
to the enervating cynicism of the Sophists. The spokesman
of the revolt was an artisan, a rough and ugly fellow, who
loved to argue at the street corners and let the wind of com-
mon sense sweep away the pretensions and high-flown
arguments of the Sophists. This Socrates, unlike the earlier
philosophers, was not so much concerned with the nature,

12 MODERN THOMISTIC PHILOSOPHY

origin and working of the material world, as with man hin>
self. He regarded philosophy as the means which a man
should use in order to lead the life which will satisfy his
highest aspirations — it was to serve as the guide of life, just
as Christianity, in so far as it lays down a moral law, is
intended to do for us. His interest in it, therefore, was
much more poignant and personal than that of the somewhat
academic speculations which we have just reviewed. Now,
in order that we may lead the ' good life,' we must know
what good is : and Socrates maintained that all knowledge
is knowledge through concepts. Concepts, moreover, are the
notions we have, not of particular things, but of the essences
or natures of things ; and these concepts we express in
definitions which are absolutely fixed and unchangeable.
Hence the Sophistic notion that the truth will vary according
to the mind of the individual is altogether repugnant to
Socrates ; and he insists that it is to be judged by an
absolute standard, not by any subjective impressions. Just
as in measures the State enforces a standard of measurement;
and a draper is not able to assign any number of inches
which he pleases to a yard ; so in the realm of thought we
shall have an absolute concept of Good, by means of which
we are to test the goodness of any particular action. Since
it is absolute and unchangeable it cannot be identified with
what seems to be good for a particular man at a given moment,
viz. what is useful or pleasant for him, but must be equally
applicable to all men at all times ; and so may clash with
what seems good at the moment. He thus vindicated the
supremacy of absolute Good. We know what this good is if
we think rightly. Now, no man can desire what is evil or
bad for him ; if he does but come to the knowledge of the
good, by right thinking, he will follow it. Virtue, therefore,
is to be identified with knowledge, and sin with ignorance.
Hence the attainment of knowledge is of supreme importance,
and consequently, it is necessary to discover the laws of
knowledge in general. The attempt which Socrates made to
do this paved the way for the systematic Logic of Aristotle.
He thus brings within the realm of philosophy three regions
unclaimed, and unexplored, by it before : the investigation

THE DEFINITION OF PHILOSOPHY 13

of the essences or natures of things, the enquiry into the
workings of the human mind, and the discussion of right
conduct for man. It remained for Plato and Aristotle to
perfect and systematise his investigations in these three
regions, and so to develop fully what are now known as the
sciences of Logic, Psychology, Metaphysics and Ethics.

A short account of the work of these two great thinkers is
required in order that we may have a comprehensive idea of
what philosophy meant to the Greeks.

Plato (427-347).

Though Plato is one of the greatest philosophers in the
history of the world, his genius and originality did not only,
or even chiefly, consist in the introduction of new ideas ; but
rather in the co-ordination and transformation of the work
of the earlier thinkers. What is true of Plato in this respect
is true also of all the great philosophers, with the possible
exception of Kant. Their originality always shows itself
rather in the new perspective in which they viewed the
problems which had been discussed by their predecessors,
and the developments which they gave to them, than in the
propounding of novel doctrines. At the first glance, the
history of philosophy seems to be but a record of conflicting
opinions without any unity ; but a closer scrutiny will show
that there has iDeen all through it a development of certain
great central ideas, though, of course, with setbacks and
aberrations. All the great philosophical systems have their
roots deep in the past, and embody a uniform tradition.
This tradition is first found clearly and explicitly in Plato
and Aristotle ; and consequently this philosophy has rightly
been called the ' philosophia perennis.'

So Plato, standing as it were on the shoulders of Par-
menides and Socrates, sees even more vividly than they had
done, that the philosopher's work is to contemplate being,
and the essences of things. Now the characteristic of these
essences is that they are universal. The idea and the nature
of Man, of Triangle, and so on, apply to all men, all triangles,
regardless of their individual differences. But Plato asks :
are these ideas merely in our minds, or have they some reality

14 MODERN THOMISTIC PHILOSOPHY

apart from them ? He is convinced that they have, though
not in the world known by the senses, for there they are
found particularised and limited. Thus he concludes that
their reality must lie in some super-sensible world where the
Man-in-Himself, the Triangle-in-Itself must subsist in their
own right. This the realm of the Ideas which alone is truly
real : and it follows that the individual things which we
see and handle are not real except in so far as the Ideas are
reflected in them. They are feeble and deceitful copies of
reality, and the object, not of science, but of opinion. They
are a number of mirrors reflecting images in the sky, and
indeed distorting ones, such as those convex and concave
ones seen at fairs ; for matter, indeed, distorts the Ideas —
the Reality itself is immaterial — matter is illusory, and is,
in a sense, that which is not. This theory of the Ideas
involves consequences in other directions ; and especially in
Psychology. For if, as is the fact, we have knowledge of the
Ideas, this knowledge cannot have come to us by way of the
senses, which tell us only of the illusory material phenomena,
and must, therefore, have come directly from the Ideas
themselves, i.e. the Ideas must be already in our minds
before we begin our sense life, before we were born. In a
former life, before the soul was imprisoned in the body, it
contemplated the Ideas, and has brought fragments of this
knowledge with it into the world.

Our birth is but a sleep and a forgetting ;
The soul that rises with us, our life's star,

Hath had elsewhere its setting,

And cometh from afar.

(Wordsworth. Ode, " Intimations of Immortality.")

We are thus led to a psychological dualism — man is a soul,
or mind, forcibly united to a body.

Plato, therefore, appears first and foremost as a meta-
physician, considering the fundamental reality and being of
things ; his psychological and cosmological theories being, in
the main, corollaries which followed from his metaphysical
one. Nevertheless, he did not regard metaphysics as mere
speculation, for he had a profound belief that, by philosophy,
man can be enabled to live the perfect life. Thus he expanded

THE DEFINITION OF PHILOSOPHY 15

and amplified the moral teaching of Socrates, showing that
' the good life ' is to be found, not in pleasure, nor even in
virtue, but in union with the Idea of Good ; and it is to this
that metaphysical contemplation is directed. So, in the light
of his metaphysical principles, he discusses individual and
social morality, and the constitution of the perfect society
or Republic, where, since the parts are for the good of the
whole, all the individuals will be absolutely subordinated to
the State.

Aristotle (385-322).

For our purpose, which is to discover the nature of philo-
sophy from the conceptions which the great Greek thinkers
formed of it, it will not be necessary to set out in detail the
various doctrines with which Aristotle enriched it ; but it is
sufficient to show that, in his view, the aim of philosophy is
to get to the very heart of things ; his doctrine, wide as it is
in its scope, being still more remarkable for its profundity.
The subject of philosophy, he says, has always been, is now,
and always will be the question what is being, what is sub-
stance, or as we should say nowadays, what is reality ? In
answering this question, philosophy cannot be satisfied with
any reply which leaves some being unexplained ; it must
reach down to the first causes and reasons of being — of all
being, whether material or mental, universal or particular,
mutable or immutable. Thus the earlier philosophies had
considered material being exclusively ; Parmenides and
Heracleitus excluded mutable and immutable being respec-
tively ; even Plato had extruded the world of sense and the
individual from reality, pronouncing it illusory. So according
to Aristotle being is of many kinds, and not all one, as Par-
menides would have it. To justify this he works out his great
doctrines of the analogy of being, and the categories, which
will exclude Pantheism ; of potentiality and act, which will
account for motion and change ; of the four causes among
which the final cause is first and dominant. It is end which
makes the agent act, and determines the form or nature of
the thing produced, which form in its turn puts its impress
on matter, making it of a certain kind. Now the end to be

16 MODERN THOMISTIC PHILOSOPHY

attained is not something material, but is mental : it is an
idea, as is clearly seen in the case of the sculptor carving a
statue ; and it is one and the same idea in different states
which makes him work, which guides his action, and is
embodied in the finished sculpture. Here, then, we see that
Aristotle agrees with Plato in asserting that the primary
constituent of reality is form or idea, but now it is incarnate
in material things, not subsisting separated from them. It
is for this reason that Aristotle has been counted as the
opponent of Plato : but, though he criticises severely the
subsisting forms of Platonism, his aim is not to break down
the essential features of Platonic idealism, but rather to
complete his master's work. Both agree that reality is
fundamentally ideal or mental. Plato, however, since he
divorces his Ideas from the world of sense in fact removes
all reality from it also, while Aristotle by embodying forms
in matter restores reality to material things ; but is obliged
to admit that the forms are, when in this state, limited and
imperfect. Both form and matter, moreover, owe their very
being to the fact that they are directed to the same end, to
something other, and more perfect, than themselves, to
something which is more detached from matter, more formal
and more actual ; and so in the last resort to something
wholly formal, wholly actual and perfect, which has, there-
fore, the nature of mind, or rather of thought. This is the
Aristotelean God, from which the whole world hangs sus-
pended by desire : Being, which desires nothing but itself,
and thinks nothing but itself, for it is wholly perfect. It is
in this way that Aristotle arrives at the ultimate cause and
ground of all reality : to search for which is, in his view, the
proper business of philosophy.

Since the Thomist philosophy, with which we are to deal,
owes more to Aristotle than to any other single thinker, it
may not be out of place to add a few details with regard to
the life of the man whom S. Thomas calls, without qualifica-
tion, the Philosopher. Aristotle was born in 385-4 B.C. at
Stagira, a seaport of Chalcidice. His father was court doctor
to the King of Macedonia, but died while his son was still a
boy. He was later sent by his guardian to study at Athens,

THE DEFINITION OF PHILOSOPHY 17

where, at the age of seventeen, he joined the Academy —
Plato's school there. Here he remained as Plato's pupil and
disciple till the latter's death. He was twice married, and
for five years was tutor to Alexander the Great. Possibly it
was his life at court which made him more careful of his
personal appearance than are the generality of philosophers,
for it is said that he was noticeably well-dressed. On
Alexander's succession to the throne of Macedonia he returned
to Athens, where he established a philosophic school in a
place called the Lyceum. Here his habit of walking up and
down among the trees, discussing abstruse philosophical
questions with his pupils, gained the name of Peripatetics
for his disciples. In the evening he explained less difficult
subjects to a larger audience. In 323 there was an outburst
of anti-Macedonian feeling at Athens : and Aristotle, having
been so closely associated with the Macedonian court, was in
some danger. He therefore retired to the fortress of Chalcis ;
to prevent the Athenians committing another crime against
philosophy, as he said, referring to the execution of Socrates.
He died at Chalcis in the following year.

Conclusions.

We are now in a position to draw together the facts which
we have noted in our account of the genesis of philosophy,
and so to determine what philosophy really was in the time
of the Greeks ; which will tell us what it is, in its essence,
to-day. Now it is evident, in the first place, that all these
investigators were seeking, not a method of making or doing
something, as an artist or an engineer might be, but some sort
of knowledge. Knowledge in itself, and for its own sake,
seems to be their aim, and they range over a wide tract of
country in their hunt for it. The Ionians want to know what
the material world is made of ; and answer : material stuff
of one sort or another, which is the uniform basis of all
bodies. The Pythagoreans, in answer to the same question,
say it is a universal quality of matter : the Eleatics, examin-
ing it more searchingly still, say it is the unchangeable being
of matter ; Heracleitus, the constant movement and
becoming of it. Empedocles and the Atomists try to reconcile

18 MODERN THOMOSTIC PHILOSOPHY

these last two answers, while Anaxagoras points out that
there is something in the material world which is not
material, viz. order. This must tend to some end and be
produced by some mind. So for the first time a new field is
opened up for examination by philosophy : it must know
what mind is. But man has mind, says Socrates, so philo-
sophy must ask what man is. With Plato the interest of
philosophy centres in this question of the nature of mind,
and of concepts — of the immaterial ; while with Aristotle
the balance is restored and material nature, man, mind and
God all come within the scope of the enquiry.

None of these men, it is to be noted, tried to answer these
questions by an appeal to any revelation, to myth, or religi-
ous knowledge of any kind ; but attempted to extract the
answer by using their reason ; and they used it almost with-
out reference to sensible observation and experiments. Why
was this ? Clearly because they were convinced that the
thing they sought lay deeper in the heart of the world than
the superficial aspect of things, of which alone the senses
could tell them. They were seeking the underlying causes
of things, and this is the special point of view from which
philosophy discusses its multifarious objects, which are dealt
with from another aspect, by special sciences, such as chem-
istry, biology, zoology, and so on. It intends to go further
into their nature than these do, and not to rest content until
it has uncovered the absolutely fundamental reasons of them
all. Thus the early philosophies were not concerned to find
out, e.g., of what the world, as at present constituted, is
composed, as chemistry is ; but what were its primary
constituents : or again, in the case of man, they were not
concerned, for example, with his anatomy, but whether, in
the last resort, he is spiritual or material, intelligent, and so
on. So philosophy is distinguished, on the one hand, from
any knowledge which may be gained through religion ; and
on the other, from that which may be gained from what we
now call the Natural Sciences. Secondly, it uses in its
investigations only natural reason, not faith, nor yet sensible
experience as such. Thirdly, it excludes nothing from
its examination, but includes all things in heaven and

THE DEFINITION OF PHILOSOPHY 19

earth, man and God, in its enquiry ; and yet is dis-
tinguished from all the special sciences which study any of
these things, by its special point of view, which is to discover
the basic reason of all : and thus philosophy is not to be
identified with any of them singly, or all of them together.
All this can be summed up in the one phrase, which is the
real definition of philosophy : It is the scientific knowledge
of all things gained through consideration by the natural
light of reason, of their fundamental reasons or causes.
Books to consult :

W. Stace, A Critical History of Greek Philosophy. (Mac-
millan.) To which the foregoing account owes much. It
also includes a discussion as to the nature of philosophy.

J. Maritain, Introduction to Philosophy. (Sheed and Ward.)

Burnet, Early Greek Philosophy. (Macmillan.)

W. D. Ross, Aristotle. (Methuen.)

A. E. Taylor, Plato : the Man and his Work. (Methuen.)

SECTION II

THE DIVISION OF PHILOSOPHY

Aristotle discusses the division of the sciences in the first
chapter of the sixth book of the Metaphysics. Here he divides
them into three great classes : practical, productive and
theoretical (i025b25). The first seek knowledge for the
conduct of life ; the second in order to make something
which is either useful or beautiful ; the third seek knowledge
for its own sake. If Logic had to be put within this scheme,
it would rank as a theoretical science, but Aristotle considers
it to be not a science on its own account, but a necessary
preliminary to all knowledge, for, as he remarks : aroirov

ajxa farelv €iri(TTTJ[j.-qv kcu rpoirov eiruTTrjiArjs — ' it IS absurd to

seek at the same time knowledge and the way of attain-
ing knowledge ! ' (Met. 995ai3.) Since, as we have seen,
philosophy is scientific knowledge, it will come under
the classification given above, though it is evident that
philosophy is not productive. The theoretical sciences are,
according to Aristotle, physics, which deals with all things
which are inseparable from matter, but not unchangeable ;
mathematics, which deals with things that are unchangeable
though probably not separable, but embodied in matter,
and metaphysics, which deals with things that are both
separable and unchangeable.

Now Aristotle treats the whole body of knowledge which
can be gained of these subject matters as philosophical, since
experimental science, as we now have it, had not then been
constituted ; but, in process of time, sciences have one by
one detached themselves from their parent, philosophy, and
set up business on their own account. So Mathematics,
Biology, Astronomy, and, last of all, Psychology are now
reckoned as independent sciences, leaving behind them,

THE DIVISION OF PHILOSOPHY 21

however, sciences which treat of their various spheres purely
philosophically ; so that we have, for example, mathematical
philosophy, which considers the basis or foundations of
Mathematics ; and the philosophy of life and mind which
considers the ultimate origin and nature of these. With
certain modifications, then, the general scheme which Aris-
totle lays down for the classification of the philosophical
sciences still holds good, and we shall see later that it is the
most scientific division which can be made. For this reason,
and because it is fairly generally adhered to by Scholastic
writers, it will be convenient for us to follow it. We thus
begin by considering the material world in general, and then
the two great classes of material things, the inanimate and
living ones. The first two sections here are often grouped
together under the name of Cosmology ; while that of Psy-
chology is given to the third. As Mathematical Philosophy
is never treated separately by Scholastics of the present day,
it will be unnecessary for us to devote a special section to it,
but several questions which really belong to it will be ex-
plained in Cosmology. The last part of our explanation
deals with Metaphysics. Since this explanation is confined
to speculative philosophy, it takes no account of Ethics,
which is evidently ' practical ' in Aristotle's sense of the word.
(For this last, see Cronin, The Science of Ethics. — Gill.)

II. THE PHILOSOPHY OF NATURE

Part I.— COSMOLOGY : THE PHILOSOPHY OF
INANIMATE NATURE

INTRODUCTION

As we have seen, Aristotle regards as the object of our study
in this part of philosophy, not so much material things qua
material, but qua changeable ; for it is this characteristic
particularly which differentiates them from the objects of
mathematics. In this he is followed by S. Thomas, who says
that physics deals with mobile being, i.e. being which is
subject to motion or change. The first question we shall
have to ask, therefore, is : What is this mobile or changeable
being ? On taking a general view of the world of nature,
that which strikes us immediately in it is its variety : the
innumerable forms of plant and animal life, the changing
clouds, the very stones and kinds of soil are all different. If
we look up to the starry sky, the same variety and multi-
plicity are evident. It is this aspect which is emphasised in
the name changeable, or mobile, being which is given to the
object of Cosmology, for without variety there could be no
change, so that to call this being changeable supposes it to
be various. Is this epithet, applied to nature, a correct one ?
Such is the first question which we must ask ; and as we
have seen, it met with an unhesitating negative from Par-
menides. It is, in fact, the central question of Cosmology,
and recurs all through it. It will only be completely answered
when we have considered it in all its forms, so that at this
stage we cannot give more than a preliminary and tentative
reply. It is worth doing this, however, in order to strike at
the very start the key-note of the whole discussion, and to
bring into prominence the principles which must be taken

COSMOLOGY 23

into account in any solution of the cosmological problem.
Our reply at this stage will be on the level of ordinary
common sense ; and it might be thought that, from this
point of view, it is unnecessary even to ask whether the
world is composed of a variety of things or not, since it
seems obvious that it is ; as Stevenson says :

The world is so full of a number of things,

That I'm sure we should all be as happy as kings.

This common-sense view is known, in philosophy, as plural-
ism. It is, however, not accepted by a great number of those
who have given attention to this subject ; who say that all
things in the world are of the same kind, and even that they
do not differ from one another as units ; so that there are
not, for example, many trees, but one tree. This last which,
when thus baldly stated, sounds quite absurd, is in fact
based on certain theories as to the nature of reality, such as
Pantheism, which we shall have to consider later ; when the
denial of the numerical distinction of bodies will evidently
stand or fall with the theory on which it is based. We may,
however, notice at once that we have the testimony of our
own consciousness to vouch for our distinction from other
men, since we are conscious of initiating our own actions and
of doing so, sometimes at least, without any dependence on
other men. If, then, we are independent in action, we must
be also independent beings, so that there are at least some
bodies, viz. our own, which are numerically distinct from
each other.

We are here more directly concerned with the opinion
that all bodies are of the same nature, than with that which
maintains that they do not differ as individuals, for the
former view is founded on observation of the material world,
not on some preconceived theory of reality. It is an opinion
which has been widely held since the advent, or rather the
popularisation, of evolutionary ideas. Darwin's theory of
the gradual development of one species from another has
naturally been extended to the whole world, and an attempt
been made to show that everything is but a superficial modi-
fication of some primordial matter. This doctrine goes by
the name of Materialistic Monism, and was expounded as a

24 MODERN THOMISTIC PHILOSOPHY

scientific theory by Haeckel, and as a philosophical one by
Herbert Spencer, to name two out of many. It is also
sometimes called Naturalism.

As has been remarked, it is impossible at this stage to do
more than to meet this theory at the level of enlightened
common sense, and to point out a striking fact of our daily
experience. Observing the material world about us, we see
groups of bodies which are endowed with characteristics
which are found in them, and them only, and which are
sharply marked off one from another. Thus living things,
with their powers of growth and nutrition, animals, with
their characteristics of sense and intelligence, men, with
their mark of reason, are striking examples of such groups.
Now it is impossible that this distribution of characteristics
should be accidental or arbitrary, for unless there were some
essential connection between them, and the natures of the
things, we should sometimes come across a member of one
group which possessed the characteristics of another, e.g. a
stone which was able to feed itself and grow. This we never
do, however, so that we may conclude that these character-
istics spring from the natures of the things themselves, or
are, what the the Scholastics call, their properties, and since
they are distinct from one another, so also will be the natures
which give rise to them.

These simple considerations at least suffice to show that
there is a prima facie presumption that the world is not as
simple as Materialistic Monism would have us believe ; and
we can thus turn to a more detailed consideration of the
various theories which have been advanced as to its
composition, and the constitution of matter.

CHAPTER I

MECHANISM
History of the Theory — Its Essential Character — Criticism.

The first of the theories with regard to the constitution of
matter to engage our attention is that generally known as
Mechanism. In scholastic text-books it is more usually
called Atomism, but since this term is ambiguous, for it
might be supposed to apply to the Atomic Theory, and the
scientific doctrine of atoms, it is better to relinquish it and
use the philosophically more appropriate name of Mechan-
ism ; of which the distinctive feature is the denial of specific
differences, or differences of nature, between bodies.

The origins of all Atomic and Mechanistic theories are to
be found in Leucippus and Democritus. In their view, the
question of the divisibility of matter is regarded as of capital
importance. Extended concrete substance cannot, it is con-
tended, be infinitely divisible. What, then, remains when
it is divided as far as possible ? Not unextended points, for
then the extended would be composed of the unextended :
nor yet nothing at all, for then bodies would be mere appear-
ances. Therefore, there must remain some extended and
indivisible particles, which particles are called atoms. The
existence, however, of atoms is not the distinguishing
characteristic of the atomic theories ; this consists in the
denial that the atoms differ from one another in kind, or if
there exist different species of atoms, at least they do not
gain or lose anything in combination, but the mere fact of
their conjunction and consequent interaction produces an
apparent transformation in the composite bodies, as com-
pared with the simple atoms. The theory accounted for
everything in the world, including force and intelligence, as

25

26 MODERN THOMISTIC PHILOSOPHY

the product of extension and the passive movement of the
atoms. Such a theory rules out all purpose which, as we
shall see, is so marked a feature of Aristotle's view of nature ;
and, moreover, avoids the dualism of mind and matter, since
it is purely materialistic. It was developed with this object
in view by Epicurus, and revived in the first century B.C. by
Lucretius, who shared with Epicurus the desire to banish
superstitious fear of the gods, and their action on the world
from men's minds. After this time, however, such material-
istic theories practically disappeared from philosophic
thought under the influence of Aristoteleanism, and we do
not find any recrudescence of them till the fifteenth century,
when they again arose in connection with the metaphysical
speculations of Nicholas of Cusa (1401-1464) and others. It
was, however, the theories of Giordano Bruno, in the next
century, which had the most important influence on the
later developments of philosophical atomism ; and which
may be taken as the connecting link between the ancient
mechanistic theories and the modern.

This modern period opens with the purely mechanistic
physics of Descartes (1596-1650) and Gassendi (1592-1655),
and with it the reaction against the Aristotelean cosmology
comes to a head. According to Descartes all physical pheno-
mena are to be traced to extension and motion, the nature
of body being identified by him with spatial extension. He
was not, however, an Atomist in the same sense as Demo-
critus, for he regarded all space as one fundamental substance
which is infinitely divisible. If, then, body and extension are
identical, there will be no vacua within the material universe,
since these would be extended, and so be body, not vacuum :
and, moreover, the material universe must itself be infinite,
since, if it were finite, there would be a vacuum outside it,
which would, in its turn, be extended, and so a body, thus
forming part of the material universe. Further, if we are to
have an absolute plenum, all movement must be rotatory,
otherwise there would be a diminution of material substance
in one place, and an increase in another. In this rotatory
motion particles become rounded, and so produce three
elements, elementary fire, air, and earth from which the

MECHANISM 27

different parts of the universe are derived. Gassendi, a
contemporary of Descartes, had, meanwhile, returned to the
theory of the ancients with regard to the atomic structure
of the world. In his view, the only principles in nature are
empty space and atoms, the latter being composed of one
and the same substance, and distinguished only by differ-
ences of magnitude, shape, and weight. He found the
explanation of all the physical properties of bodies in the
motion of the atoms. The English philosopher, Thomas
Hobbes, another contemporary of Descartes, expressed
similar views.

These general mechanistic theories were greatly strength-
ened by the practical experiments of Robert Boyle (1626-
1691), on the basis of which he attempted to explain all
chemical changes mechanically. He insisted on the quanti-
tative determination of weights, thus preparing the way for
the modern chemical theory of elements, since he recognised
specific weight and chemical reaction as the distinguishing
marks of any particular substance.

It is obvious that the main purpose of all these mechanistic
theories is to simplify our ideas of matter, by accounting for
everything by means of indestructible material units which
are all of the same kind, and local motion communicated by
impact, thus rendering obsolete all discussion as to the
natures and qualities of particular bodies. The idea of a
body exerting some active force of its own cannot be em-
braced in such a scheme ; both because force cannot be
regarded as corpuscular, and because it is, moreover, a
qualitative, rather than a quantitative, conception. New-
ton's discovery of the law of gravitation necessarily led,
however, to the idea that the atoms exert an attractive force
on one another at a distance ; and though this notion was
resolutely opposed both by Newton himself and many others,
it came gradually to be accepted, and the simple picture of
the great world-machine painted by the earlier Atomists was
destroyed. It would, nevertheless, be a mistake to suppose
that the mechanical view of nature, according to which all
material happenings are ruled by a strict mathematical
necessity, perished along with it ; for though the conception

28 MODERN THOMISTIC PHILOSOPHY

of force is not amenable to mathematical treatment, its
effects can be quantitatively expressed ; and thus a mechan-
ical theory, modified by the introduction of dynamical con-
ceptions, for long continued to hold, and probably still does
hold, the field, as the orthodox philosophy of matter,
especially among scientists. The theory so modified will be
considered in the next chapter.

Reduced to their simplest form the earlier mechanical
theories are seen to consist of two propositions :

i. All bodies are composed of material elements of
essentially the same kind — matter is homogeneous.

2. All corporeal properties can be explained by local
motion which is governed by mechanical laws.

When stated in this way the theories are evidently open
to the objections urged against Monism in general, for we
find, both in the organic and in the inorganic world, a variety
of constant and stable types of bodies. We see bodies which
are distinguished from one another by definite and unchang-
ing characteristics : so bodies are by nature liquids, solids,
and gases, under determinate, but different, conditions.
They have differing though constant weights, as, for example,
zinc is lighter than lead. These weights are also known
scientifically to be constant and different for each one of the
chemical elements. Further, the boiling and freezing points
of the different elements exhibit a constant difference. Such
differences, therefore, cannot arise from the circumstances
in which the bodies are placed, but must belong to them by
nature, and be their properties, so that to deny difference
of nature, or specific differences, is to make these bodies
inexplicable.

The second dogma of mechanism is that all the apparent
changes of bodies, and all corporeal phenomena, are to be
explained by the local movement of the atoms. Now, such
local motion alone cannot be a sufficient explanation of the
phenomena, since one of the most striking of these is the
activity or force of bodies. Local motion, however, is a
result of activity, and so cannot be its cause or explanation.1
Moreover, local motion, as such, cannot be communicated

1 Cf. Nys, Cosmologie, Vol. I, Sec. 125. (Louvain, 1928.)

MECHANISM 29

from one body to another, for, as M. Meyerson says : ' There
can be no movement without a substantial substratum,
without something which moves. Movement is in no sense a
substance, the most that we can do is to consider it as a
state. Supposing we accept this latter notion, and consider
that this state must last indefinitely, as the principle of
inertia requires, how can it break away from one body to
attach itself to another ? It would be necessary, as Lotze
has very rightly remarked, that this state should exist of
itself, between the two, for a moment, even if this moment
be infinitely short, becoming thus a true substance, which is
absurd. It is consequently quite impossible to conceive of
the transmission of movement from atom to atom without
the intervention of a special faculty, a mysterious agent.'1
So it would be like the grin of the Cheshire cat — a grin
without a cat.

Lastly, as a philosophical theory, mechanism is inaccept-
able, since it does not go to the root of the matter ; for, in
fact, it does not explain the constitution of either simple or
compound bodies : not of simple bodies, since these are the
atoms themselves, and no attempt is made to explain the
atom : nor of compound bodies, which are homogeneous,
having different properties from their elements, as water
has different properties from those of oxygen and hydrogen.
Neither of these facts is explained by Mechanism, since from
the atoms, as conceived of by the Mechanists, there cannot
arise a homogeneous compound, for they are complete in
themselves, and combine by mere juxtaposition, remaining,
in themselves, the same. Nor can a mere juxtaposition of
the elements give rise to entirely new properties, but will
only give the sum of the properties already existing in the
elements.2

1 E. Meyerson, IdentiU et Realite (1912), p. 332.
* Cf. Nys, op. cit., Sect. 78-88.

CHAPTER II

DYNAMISM
Its Nature — Theories of Leibniz, Boscovich and Kant — Criticism.

Since our concern is only with philosophical theories as to
the nature of matter, we can omit any consideration of the
various modifications which have been imported into
Cartesian Mechanism, considered purely as a physical
theory ; and turn our attention to the group of philosophical
theories which are often generically known as Dynamism.
The characteristic tenets of this school are :

1. The assertion of the essential activity of material
substance, and indeed of all substance.

2. The denial of extension to the basic principles of bodies.

3. The consequent assertion that all bodies, and all cor-
poreal phenomena, are produced by the grouping and inter-
play of simple unextended forces.

In virtue of this last view, Dynamism joins hands with
Mechanism in holding that bodies are merely aggregates of
elements which are in themselves simple, i.e. not having
parts of different kinds, and which do not change intrin-
sically in combination. In all other respects, however,
Dynamism is the opposing extreme to Mechanism, since, for
the former, the basic principles of the material world are
active forces which have no extension, while for Mechanism
extension is the very essence of body, and force, which is
variable, active, and tending to definite ends, is incompatible
with the tenet that all change arises from local motion only.

The initiator of Dynamism is generally acknowledged to
have been Leibniz (1646-1716).1

He was first ' charmed ' by the mechanical explanation of

1 Though Fr. Hoenen, S.J., thinks that Dynamism should not be
attributed to him. Hoenen, Cosmologia, p. 414.

30

DYNAMISM 31

the world, but soon came to see ' that the notion of extended
mass taken alone is insufficient, we must also employ the
notion of force, a very intelligible notion, though its source
may be metaphysical.'1 Thus he came to abolish extension
and matter altogether out of reality. So, in opposition to
the ideas of Descartes, who considered the constituent of
body to be something passive, viz. extension, he maintained
that body is essentially active. From the principle ' that
which does not act does not deserve the name of substance '
he soon passed to the statement that active force is the very
essence of material beings. He thus spiritualised matter,
and decomposed it into an infinite number of infinitesimally
small ' bodies ' or elements, which are unextended and
simple, i.e. without parts. These he called Monads. They
are essentially active, and, in fact, always in action : they
can, however, only act internally, not on one another, or on
anything outside themselves, since otherwise they would not
be simple.2 He expressed this in the saying : ' The monads
have no windows by which anything can enter or go out.'
Every being is composed of a whole world of these little
' souls ' : 'A world of creatures, living beings, animals,
entelechies, souls, exists in the minutest part of matter.
Each portion of matter may be conceived as a garden full of
plants or as a pond full of fish. But every branch of a plant,
every limb of an animal, and every drop of the fluids within
it, is also such a garden, such a pond. . . . Thus there is
nothing arid, sterile or dead in the universe.'3 But since
the Monads are simple and unextended, it seems impossible
to explain extension and movement by their means. Hence
Leibniz denies the reality of these ; they are appearances.
Thus in perception we produce the appearances of things
which we represent as outside one another. For this
representation we have need to construct the fiction of
extension ; so that extension is not what we perceive, it is the
background which we construct in order to represent indivi-
duals as outside one another. ' It is the artifice by which in

1 Leibniz, Art. in Le Journal des Savants (1695), quoted by Wildon
Carr. Leibniz, p. 78. (Benn, Leaders of Philosophy Series.)

2 Leibniz, Monadology, No. 7. * Ibid., Nos. 67, 69.

32 MODERN THOMISTIC PHILOSOPHY

perceiving a multitude of distinct individuals we represent
their togetherness.'1 It is clear, however, that the Monads
act harmoniously in concord, as if, in fact, they acted on one
another ; so the earth, air, water, etc., all appear to contri-
bute to the growth of a plant, and the plant to grow con-
tinuously and harmoniously : and the same is true of the
working of the universe as a whole. If, then, the Monads do
not, in fact, interact, how is this harmony and apparent
efficient causality to be accounted for ? Not being connected
intrinsically they must be held together extrinsically by a pre-
established harmony, which God, the supreme Monad, had
imposed on the universe at its creation, so that the Monads
all developin concord and give the appearance of mutual
help and dependence. As if we had a number of clocks all
striking in turn it might be thought that each set the next
one on, though, in fact, their striking has been arranged to
occur in this order ; in either case we should have a series of
chimes such as that in ' La Boutique Fantasque.'

A somewhat similar theory was proposed in the middle of
the eighteenth century by the Jesuit, Boscovich. This very
remarkable man was rather a scientist and mathematician
than a philosopher, and his system is less complete from a
philosophical point of view than that of Leibniz. According
to him matter consists of a swarm of atoms, each of which
occupies a geometrical point of space, is capable of motion,
and possesses a certain mass, so that a definite force is
required that each atom may acquire a given acceleration.
The atoms attract one another, if separated by anything
more than a small distance, with a force varying inversely
as the square of the distance between them. At small dis-
tances, the force is supposed to be alternately attractive and
repulsive ; and in order to avoid the difficulty of two atoms
coalescing in the same place, Boscovich imagines that for all
distances below a certain minimum the force is repulsive,
and increases indefinitely in proportion as the distance
diminishes. Thus, all actions are actions at a distance, and
there is no such thing as actual contact. It was the idea that

1 Wildon Carr, Leibniz, p. 91. Leaders of Philosophy Series. (Benn,
1929.)

DYNAMISM 33

the atoms act thus at a distance which led him to abandon
the notion that they are extended, since, without contact,
the conception of extension seemed unnecessary : and this
view was continued by Ampere and Faraday, who regarded
the atoms as unextended, or simple centres of force. Here
we see clearly that the scheme put forward by Boscovich
was rather a scientific hypothesis than a philosophical theory.

The theory of Kant is akin to these, but differs from them
in two respects : (i) In accordance with his general prin-
ciples, he does not allow that we can know what are the
constituents of bodies in themselves, but only as they are
conceived of by us ; and (2) he will not admit the possibility
of a vacuum. As conceived of, then, body, according to
Kant, is something mobile which fills a space ; and this
filling of space implies a resistance to anything which would
penetrate into this space. Now, since all resistance pre-
supposes a force of resistance, and all motion a force which
moves, body can only fill a space by means of a motive force,
which must consist in a kind of elasticity, and which Kant
calls a force of expansion and concentration. It is these
plastic forces which constitute bodies as conceived of by us.

The views on the constitution of bodies held by various
schools may be exhibited in the following scheme :

Bodies are composed according to :

S. Thomas
of two elements : one potentially extended, and one

unextended

Mechanists Dynamists

of one extended element of one unextended element

Kant

I
two elements in idea.

34 MODERN THOMISTIC PHILOSOPHY

So S. Thomas combines mechanism and dynamism in a
positive synthesis : Kant in a negative one.

Criticism of Dynamism in General.

i. There can be no doubt that bodies appear to us to be
extended, and any theory which is to claim to be satisfactory,
must take account this fact, and offer some explana-
tion of it, either by allowing that they really are so, or if it
denies this, by advancing some feasible reason to account
for their appearing to be so. The first course is not open to
the Dynamists, and they cannot offer a satisfactory explana-
tion of the appearance, which will be in accord with their
notions as to the nature of bodies ; for their appearance of
extension must have some cause. Now this cause cannot be
the senses themselves, since, on the Dynamist hypothesis,
these are also unextended, and so contain nothing which
would cause their objects to appear as extended. Nor can
the cause of this appearance be external agents, since these
also labour under the same disadvantage : in a word, since,
according to the Dynamists, there is nothing in the universe
which is extended, there is equally nothing in the universe
which could be the cause of an extended appearance. Leib-
niz's suggestion that we produce it in order to represent a
numberof distinct things together is clearly untrue, since
the notion of distinction and external position are quite
different, that of distinction being wider ; and, moreover,
we do not always represent distinct things as outside one
another in space as, for example, a series of numbers, or our
various thoughts and desires, or immaterial beings, such as
angels, or even God and the material world.

2. According to Dynamism, matter is composed of simple
forces. Now these forces must be either in contact or not in
contact. If they are not in contact they will coalesce, form-
ing one force at a geometrical point, as Boscovich rightly
observed. For it is clear that a certain extension is required
for contact : if a tangent of a circle touched it at one point
only, it would not touch it at all. In this case the plurality
of bodies would disappear. If, on the other hand, they are
not in contact ; in any one body, the many monads or forces

DYNAMISM 35

which compose it will be entirely distinct one from another,
as regards their entity, even though they be supposed to act
on one another across a vacuum. Hence the unity of such a
body will be wholly destroyed. This is also true if they are
supposed to coalesce in a point, since this point, which will
be the only body, and therefore the only unified body, will
be composed of a multitude of forces which will preserve
their own entity in it. In either case, therefore, it is imposs-
ible to maintain the unity of bodies, on the Dynamist
hypothesis. Now, not only is this result in direct contradic-
tion with experience but, if no body is a unity, we can gain
no notion of the nature of any body, since it will not have
one ; and a fortiori shall be unable to determine the nature of
body in general, but shall say it is force, which will be a term
without any one meaning, and so a mere word to cover our
ignorance.

CHAPTER III

THE THOMISTIC THEORY OF THE NATURE OF MATTER

Nature and Data of Question — History and Explanation of Hylo-
morphism — The Reasons Advanced to Support it — Additional
Explanations of the Meaning of ' Matter ' and ' Form ' — Some
Difficulties Considered.

The problem of which we are to attempt to find the solution
is : what, in the last resort, is the nature of matter or of
bodies ? Not of this or that body, but of material things in
general ; nor yet of what chemical elements bodies may be
composed, for even if we were successful in showing that all
bodies were compounds of one element, such as hydrogen, or
one force, such as electricity, as has been sometimes suggested,
the question would still remain what is the nature of hydro-
gen and electricity, and we should have our original problem
still on our hands. The question, therefore, is not a physical
one merely, but both physical and metaphysical. It is
physical, since the starting point of our enquiry must be the
properties and behaviour of bodies as made known to us by
common and scientific observation. The experimental or
empirical investigation of material phenomena is the work
of the physicist : and we could take his results as they stand
as the basis of our investigation, were it not that, unfortun-
ately, he often imports theories of a philosophical kind into
them. Moreover, as we shall see later, there is much dis-
agreement among scientists, and, what is worse, undoubted
error in the views of some of them, as to the nature of scien-
tific investigation. For it should be observed at the start
that it is impossible for the scientist, as for the philosopher,
to deal with ' brute fact,' i.e. mere disconnected happenings
in the material world : he is bound to connect them by a
meaning of some kind, bringing them all under a general

36

THOMISTIC THEORY OF MATTER 37

law, and it is here that exaggerations and aberrations are
apt to creep in. So Newton observed the movements of
bodies, and from a mass of observations concluded to the
general law that they move as if actuated by a pull which is
directly proportionate to their masses and inversely to the
square of the distance between them. It was an easy jump,
then, to stating that they were attracted, or pulled together,
by a force of this kind ; though such a transition from
observation to theory was, strictly speaking, more than the
facts warranted. It follows that it is not possible for the
philosopher to assume that physical laws and theories, as
enunciated by scientists at any particular epoch, are philo-
sophically true ; but in his enquiry he will take as the basis
of his investigation the best knowledge available about the
material world ; and this will include both the knowledge
obtained by common observation and that gained by scien-
tific enquiry, the latter being accepted by the philosopher
only provisionally, and under certain conditions. For it is
to be noticed that scientific knowledge must always be an
extension of, and dependent on, common observation, for
though the scientist, by reason of the refinement of his
instruments, may be able to extend the latter, he must in
the last resort rely on his five senses and intellect in using
them ; so that the philosopher could not accept from the
scientist a law or theory which is in contradiction with the
evidence of the senses. It is clear, therefore, that this
enquiry has a metaphysical as well as a physical side. It
must check the empirical observations of the scientist, and
of the senses, by considerations of a purely intellectual
character, for the object in view is not merely to investigate
the phenomena, i.e. those things which can be known by the
senses, but something which is outside the sphere of pheno-
mena or appearances, viz. the very nature of things which so
appear, and this is knowable only by the intellect. Thus
any theory as to the essential constituents of bodies must
satisfy four general conditions :

1. It must explain the inner nature of all bodies.

2. It must explain not only the unity, but also the essential
diversity of bodies.

38 MODERN THOMISTIC PHILOSOPHY

3. It must explain the dualism of bodies : why they are
both active and passive, changing and unchanging (their
stability), one and multiple, alike and different.

4. It must take its rise from, and be in full accordance
with ascertained facts obtained by observation.

The Thomistic answer to the question : what are the
essential constituents' of bodies, can be summed up in three
statements :

1. There is in bodies a substantial material principle, and
substantial formal principle.

2. Both these principles are incomplete substances.

3. The material principle has the same relation to the
formal as potentiality to actuality.

What is meant by material and formal principles, or
matter and form can be seen roughly by means of an example:
the flour, raisins, eggs, etc., are the material principles of the
plum pudding, but these have to be combined in the proper
proportions, mixed and boiled in a certain way in order to
obtain a plum pudding. The result of such combination,
mixing, etc., is the formal principle of the pudding, making it
a Plum Pudding, differing from all other kinds of pudding.
Similarly at the start we may take an example to illustrate
what is meant by potentiality and actuality ; as when we
say : ' John can read,' i.e. has the capacity or potentiality of
reading, and ' John is reading,' i.e. is in the act of reading, is
reading actually. We shall shortly see the meanings of these
terms more scientifically and precisely ; but before we do
this, and pass to the proof of the Thomistic theory, it will be
useful to glance at its origin and history.

The History of the Theory of Matter and Form.

Matter. The theory of matter and form, or, as it is often
called, Hylomorphism, is due to Aristotle. It is true that
Plato had already introduced a notion from which that of
matter was derived, in the Timaeus, viz. that of Xu>pa or
' space.' This is conceived of by him as the screen on which
the images of the Ideas or Forms are thrown. In itself it has
no form, no determination, no features of any kind. It is
not empty space, nor yet in any way the single underlying

THOMISTIC THEORY OF MATTER 39

substance of the universe, it is the reality on which the
appearances show, its sole attribute being to support them.
Since Plato affirms that the Forms alone are real, he must
consequently deny reality to this background of appearances,
and so he sometimes calls it ' nothing,' tu p) 6V, inasmuch
as it is altogether other than the forms. But since it also in
some way exists, it is a nothing or not-being, which, in some
way, is. It is thought of as being in existence prior, with at
least a logical priority, to its determination by the impress of
the Forms ; and so may perhaps be compared to the chaos
of Genesis, which is itself something, prior to the possession
of any definite nature. This obscure being, though far enough
removed in some respects from Aristotle's ' matter ' ; since it
is altogether immovable and unchangeable, and contrasted
with reality which is Form only ; is nevertheless in other
ways akin to it, in so far as it suggests the root idea which
underlies the Aristotelean ' matter,' of a not-being which in
some way is.1 So long as this entity is thought of as ' other
than ' reality, no intelligible meaning can be attached to this
phrase ; and Aristotle working on the Platonic notions insists
that it too must be real, though formless. Though it can
have no existence of its own, yet where it exists owing to
form being joined with it, it is not identified with form, but
has its own reality. For reality and existence, though com-
monly confused, are, as we shall see, two very different
things. Aristotle therefore defines it in two ways : positively
and negatively. The positive definition, given in the
Physics (io,2a3i), is : matter is the first subject of each thing,
from which, since it is intrinsic, something which is not per
accidens comes into being.

By the word first, it is differentiated from second matter,
which is what we ordinarily mean in English when we speak of
matter, for this, though the subject of accidents, is yet not the
first subject, since there must have been a prior subject of the
substantial nature : e.g. cloth can be neither white nor black,
till the nature of cloth has been embodied in matter. Cloth
in the abstract is of no colour.

The words ' being intrinsic ' show that it is not privation,

1 Cf. R. P. Omez, O.P., La Notion de x^Pa- Revue des Sciences Philo-
sophiques et Theologiques (1925), pp. 433 ff. Taylor, A. E., Plato, pp. 456 ff.

40 MODERN THOMISTIC PHILOSOPHY

but a positive principle which enters into the composition
of the complete being.

Lastly, the phrase ' something which is not per accidens
comes into being ' indicates that the compound of matter and
form is not an accidental, but a substantial unity, the two
together making up a complete nature, and being joined in
one nature ; not as in the case of an accidental union each
retaining as its own nature, as, e.g. glass and water in the
case of a glass of water. The second and negative definition
which he gives is : ' By matter I mean that which in itself
is neither a particular thing, nor of a certain quantity, nor
assigned to any other of the categories by which being
is determined.' (VII Met., i02o,a20.) This definition has
received a traditional Latin form as : materia prima secundum
seipsam non est quid, neque quale, neque quantum, neque
aliquid eorum quibus ens determinatur.

It is not any particular thing, for in this case it would be a
specifically complete substance ; nor is it in any of the
categories, since all presuppose a pre-existing substance,
while matter is absolutely first as a subject. Yet, though it is
not in any of the categories (i.e. the general classes into
which things can be divided) directly, it is reducible to
that of substance.

. First matter must therefore be carefully distinguished
frorn what is commonly called matter, and which the
Scholastics name Second Matter ; since first matter is incom-
plete in itself, and cannot be known in itself, or by the
senses. It can only be known indirectly, by means of form,
and cannot be touched, seen, or smelt, being something dis-
coverable only by the intellect. This does not prevent it
from being a real substantial entity, though an incomplete
and potential one.

The word used by Aristotle (vA.77) means literally timber,
and more specifically ship's timbers. Prof. A. E. Taylor
suggests that its selection may be due to a reminiscence of an
old Pythagorean fancy which looked on the universe as a
ship. It is most nearly rendered in our language by the word
'stuff.'

Form. The difference between the Platonic and Aris-

THOMISTIC THEORY OF MATTER 41

totelean conceptions is as marked with respect to their
notions of Form, as it is with respect to those of matter.

Though both used the same word for form (efSos), Plato
conceived of it as a nature which was self-subsistent, and
separate from matter, though imaged or ' participated ' in it ;
while Aristotle strongly maintained that forms must be an
integral part of the things to which they give a determinate
nature, immersed in the matter of such things, and incapable
of being separated from it. In a word, the Platonic forms
are essentially discarnate, and immaterial ; while for Aris-
totle they are incarnate in matter ; so that matter is never
found without form, and form is the correlative of matter.

The Aristotelean description of form is therefore : First
Act, which constitutes, when joined with first matter, a being
which is one in essence, and complete.

The word act signifies that form is a positive perfection,
and first that it is immediately joined to matter in contra-
distinction to accidental form which presupposes an already
constituted thing, which it modifies.

The theory that all bodies are composed of a permanent
featureless element, which is matter, and positive determin-
ing elements or forms, arose historically speaking from the
consideration of the conversion of one substance into
another, as in the case of a mixture, such as beer, which
apparently has a different nature from that of any of its
ingredients, or in the case of conversions of one substance
into another, as water into steam, wood into ashes under the
influence of fire, or in the case of organic conversions such as
that of water and other elements into the juice of the grape.
Such changes are known as substantial changes. In recent
times doubt has been thrown on the existence of such
changes, modern chemical and physical theory seeming to
show that they are in fact merely new accidental combina-
tions of the original atoms. Some Scholastics, therefore, as
Pere Descoqs, S.J., would abandon the classical argument
from substantial change, which has always been used to
establish the theory of matter and form. It seems, however,
that the theory stands or falls with the reality of such
changes, the alternative to accepting them being a denial of

42 MODERN THOMISTIC PHILOSOPHY

all essential or specific difference between things. It is to
this denial that the current scientific theories would naturally
lead, and it is a denial which no Scholastic would make : for,
as has been pointed out, the backbone of the philosophy of
nature, as conceived by Scholasticism of any type, is the
maintenance of the essential differences between bodies, and
the rebuttal of monism. Those writers who wish to abandon
the argument from substantial change suggest that the series
of chemical elements are such specifically distinct natures :
but this contention is based on precisely the same grounds
as those which lead the Thomists to say that compound
natures, such as water and oil, are specifically distinct, viz.,
that they exhibit constant and sharply distinguished proper-
ties.1 Further, the whole tendency of natural science is to
reduce all the chemical elements to a single base, such as
hydrogen ; and if scientific results be taken as being applic-
able as they stand to philosophical discussion, a man who is
ready to give up specific differences among compounds, on
the ground that science does not recognise them, should also
be ready to abandon specific differences altogether, even
between simple bodies, if science should not acknowledge
them.

The Aristotelean and Thomistic theory as to the constitu-
tion of bodies therefore maintains, as we have seen, that their
constituents are two principles, which are intrinsic and dis-
tinct, viz. matter and form ; and to prove it S. Thomas
appeals in the first place to the fact of substantial change,
for it is clear that every change implies a subject which
changes, and a substantial change, i.e. the change of one
substance into another, a substantial subject ; otherwise we
should have annihilation and creation, not change. Now,
since this subject is to be common to two specifically distinct
substances, it must not of itself possess the specific character
of either, and will therefore of itself be altogether undeter-
mined and featureless. Such a subject or substratum is what
we have called first matter. Similarly, if bodies are sub-
stantially mutable, they must include a second principle

1 Cf. P. Geny, S.J., De doctrina Hylemorphica. Divus Thomas (Plac),
January 1925.

THOMISTIC THEORY OF MATTER 43

which completes and specifies this quite undifferentiated and
potential subject, otherwise they would have no definite
character, and so could not change from one character to
another. It is further clear that these two principles are
really distinct, from the fact that they are separable and
separated in the process of change, since the potential
subject remains the same, while the form is altered, the prior
form disappearing from the subject, which thereupon receives
a new form. Hence the subject and the form are separated
and distinct.

The a posteriori foundation of the theory remains, how-
ever, still to be proved, viz. that substantial changes actually
occur : or that bodies are substantially mutable. It is
necessary to prove this for all bodies, both organic and
inorganic, though not that such changes actually occur in
every body, since our purpose is to show that it is the nature
of body to be capable of such change, even if, as may happen,
they have not been subject to it, or the change has not been
observed in them. Now, if we prove our general rule for
organic bodies, this will afford an a priori presumption that
it holds good for inorganic bodies also, otherwise, the organic,
as mutable, would be inferior to the inorganic which would
be immutable. For the immutable is more perfect than the
mutable, since that which is absolutely perfect must be
wholly unchangeable, and change lessens as perfection grows.

1. Taking, then, the case of organic bodies we have the
very simple and evident fact that plants and animals die,
and the no less clear fact that the animal and its dead body
are specifically distinct, since their operations differ essen-
tially, those of the one being immanent, springing from an
intrinsic principle and being directed towards the good of
the whole animal, whereas those of the other are transeunt
only, the term of decomposition being the disintegration and
destruction of the body. Clearly, however, they could not
act in these essentially different ways unless they were essen-
tially different in themselves. Similarly, organic things
transmute inorganic ones into their own substance in the
process of nutrition. Hence, it follows that in the organic
realm as a whole, substantial change occurs ; since the

44 MODERN THOMISTIC PHILOSOPHY

organic bodies either change themselves, or produce substan-
tial changes in the inorganic bodies which they absorb.

2. Passing now to the realm of inorganic matter, we observe
the continued formation of elements into new compounds, the
elements and compounds being specifically distinct. That
the latter part of this statement is true is shown from finality,
for things which have different finalistic inclinations or ten-
dencies must be specifically distinct, since such tendency is
nothing else than nature itself which is tending to a definite
end : hence, where it is different, it follows we have two
different natural tendencies, which must therefore be imman-
ent in the things themselves (since nature is immanent), and
constitute them as naturally or specifically distinct.

That such different finalistic tendencies do exist in the
elements and their compound is an obvious fact of experi-
ence ; for all simple bodies act in a certain definite way, and
combine according to certain ascertained laws ; and, similarly,
composite bodies have their own distinctive actions and laws
which differ from those of the simple ones. To take the
obvious case of water and its elements to illustrate this, we
know that oxygen and hydrogen produce their own distinc-
tive effects, and combine only in certain proportions. Water,
however, which is their compound, has its own action which
is quite different from either of theirs, and in some ways in
opposition to their actions, and it also obeys its own proper
laws. Thus all bodies have their own distinctive finalistic
tendencies.

3. Another argument to show the fact of substantial
change is derived from the unity of bodies.

It is indubitably true that a thing which possesses one,
and only one, nature cannot be made of a number of things
possessing different natures. Now, if we consider nutrition
in plants and animals, we see that they absorb into them-
selves many things which before absorption have a complete
and independent nature of their own, a nature which is lost
when they are taken up into the body of the animal or plant
which feeds on them : for if not, it would follow that the
living thing was but the sum total of the things on which it
feeds, and not a complete essential unity on its own account.

THOMISTIC THEORY OF MATTER 45

If, then, it is such an essential unity, it is clear that the sub-
stances on which it feeds undergo a substantial change.
Hardly anyone would doubt the essential unity of living
things, since all their functions and activities are directed
towards the good of the plant or animal as a whole, not to
that of some particular part of it. In nutrition, for example,
the whole being feeds and is nourished, not the mouth,
stomach or any particular organ in isolation. In man, whom
we know more intimately than we do any other animal, this
is particularly clear, for we say the man, e.g. John, thinks,
feels and eats : not that John's brain thinks, John's hands
feel, and John's stomach eats. If John were not a unity, but
a mere collection of elements and organs, such an attribution
of all these functions to him would be altogether illegitimate.
We are conscious, however, that it is not so, and the whole
human race agrees with us.1

Besides this classical argument from the fact of substantial
change, there are two other metaphysical arguments which
are ordinarily used by Scholastics to prove that bodies
are composed of matter and form, i.e. of an undetermined
principle which is capable of becoming anything : which
S. Thomas calls a potency or potentiality ; and a perfecting
and determining one, which he calls act.

These arguments for their full understanding need more
precise acquaintance with metaphysical notions than is
possible at this stage ; it is nevertheless worth while to note
them here owing to their demonstrative character.

1. The first of these arguments is based on the fact of
extension, for it is clear, that since all bodies are extended,
they can be divided into parts of the same nature as the
original body, as slices of bread are still bread. It is clear,
then, that all bodies have a certain capacity for division, or
what is the same thing, for multiplication. (Cf. II Contra
Gentiles, c. 65, Arg. 3.) Such a capacity is, however, what we
call a potentiality or potency, and it follows that all bodies
possess an element which is potential. They are nevertheless
not entirely composed of this element, for they are always

1 This is more fully discussed in the Psychological section later. Vied
Ch. IV and Ch. XV.

46 MODERN THOMISTIC PHILOSOPHY

definite bodies of some kind, i.e. they possess an actual
element also ; in other words, all bodies are composed of
potency and act, i.e. of matter and form.

2. Again, if we consider a whole species instead of an
individual body, we shall be led to the same conclusion : for
it is clear that in order that one and the same specific nature
may be found in several individuals, it must be differentiated
in them in some way, i.e. there must be something which is
added to the specific nature in each of them. If each were
simply the specific nature, and nothing more, they would not
be different individuals. Now, the nature itself is a definite
determined thing, i.e. a perfection or an act ; and therefore
the individual must possess an element which is different
from this act, and at the same time is capable of receiving it.
Such a capacity, however, is what we mean by potency, and
so the individual is composed of two elements, an actual one
and a potential one, i.e. form and matter.

The reason why, in both these arguments, we identify
the actual and potential elements in the individual with
substantial form and first matter, is that the individual must
be a unity and an essential unity, for it is certainly one thing,
not two. Now the greatest amount of division that is possible
in a unity of this kind is the division into a potency and its
immediate act, for if the potency were made actually a sub-
stance, any further act would only modify the already exist-
ing substance, i.e. it would be an accident ; and the union
would be accidental. Undetermined and unactuated potency,
such as this, is precisely what we mean by first matter, as the
definition given above shows, while its immediate act is sub-
stantial form. Consequently, in order to preserve the essen-
tial unity of the individual it is necessary for us to say that
its potential element is first matter, and its actual element
substantial form.

A Further Consideration of Matter and Form.

We now pass to a consideration of the two principles of
bodies, taken individually.

What exactly are first matter and substantial form ? In
the first place we ask with regard to first matter : is it pure

THOMISTIC THEORY OF MATTER 47

potentiality ? By pure potentiality is meant that which does
not contain any act as a part of itself, and that which has not
the nature of act in any real order. Now, there are two real
orders, those, namely, of essence and existence, and so a two-
fold act : act of essence and act of existence, or, as they are
often called, formal and entitative act. The first determines
what the thing is, the second places the thing outside the
state of mere possibility, making it an actually existing
thing. So, in the case of a child, every child whether possible
or existing is a certain kind of animal, an animal which is
capable of loving, thinking, laughing and talking ; of a par-
ticular physical shape and organisation, and so on ; but
before such a child is conceived it is possible only, it may be
born ; but when it is born or conceived, it has not only the
formal act which belonged to it when it was still only
possible, but in addition the act or perfection of existing, by
whose means it makes its appearance in the world, as an
actually existing member of a family.

That matter is pure potentiality in the order of essence is
universally admitted by Scholastics, i.e. all agree that it has
no determined nature of its own, being a mere capacity for
receiving form, or in technical language, that it is free of all
formal act, and so has no element of form in it, nor is it to
be thought of as form, either in itself, or relatively to any
real subject which is naturally prior to it. So, no material
element, however all-pervasive, or capable of being a sub-
stratum in various substances, as oxygen for example, nor
even any definite force, such as electricity, can possibly be
identified with first matter ; since all have their own original
nature or form.1 It has therefore an unlimited capacity for
receiving all material forms ; though not, of course, for
receiving those which are wholly immaterial, if there are any
such, since these would not be in any way correlative to it.
Just as a quart measure can receive any quantity up to a

1 How easy it is to be entirely mistaken as to the meaning of first
matter is exemplified in the following astonishing statement (Haas, The
New Physics, p. 71) : ' In the modern system of physics electricity no
longer stands alongside of matter : it has taken the place of matter. The
new physics can descry in electricity that unadulterated primordial
something for which scientists sought through thousands of years, and
from which all things amenable to sense perception are formed.'

48 MODERN THOMISTIC PHILOSOPHY

quart, so that, to this extent, its capacity is unlimited ; so
first matter is like a vessel which should be capable of receiv-
ing any amount however great ; which would nevertheless
not be capable of receiving anything which was not quantita-
tive. It has an indefinite internal capacity, though externally
it is limited.

Here, however, agreement ends ; for many hold that there
is in matter some entitative act, while others will not allow
it to have any of itself. This question is closely connected
with the more famous one with regard to the real distinction
between essence and existence. Those who deny the real
distinction must hold that the essence of matter is its exis-
tence, and since existence is necessarily actual, that this
essence is an entitative act, though an incomplete one. For
they say that it is impossible to conceive of anything being
real, unless it has existence which is identified with itself.
This is the opinion of the Scotists, Suarez and others. For
those who hold, with S. Thomas, the real distinction, the
question can only be, whether matter has some existence of
its own, independently of form ; in other words, whether
matter is related to existence immediately, without form
intervening, or whether it receives existence only by the
mediation of form. This latter view, which is universal
among Thomists, is an integral part of the Aristotelean notion
of form, since, for him, existence belongs to form of itself (per
se), to matter by means of something else, viz. form (per
aliud). The Thomists therefore have to prove that matter
has no existence of its own. To do so they argue once more
from the essential unity of the individual, for if matter has
its own existence, form can only give it an added or secondary
existence, which therefore cannot make it simply existing,
but merely existing in a certain new way. In other words,
it will not make it exist as a substance, but confer an added
accidental existence, so that matter and form together will
not be substance, but substance and accident.

Further, an essential unity cannot have two substantial
existences, which would be the case if matter has its own
existence, as well as form. So, from both points of view, it is
clear that if matter has its own existence, the compound

THOMISTIC THEORY OF MATTER 49

resulting from matter and form will not be an essential, but
only an accidental unity.

This same truth can also be proved as follows : It is clear
that if matter can only receive existence by the mediation
of form, it has no existence of its own ; and that this is, in
fact, the case, we see if we consider that existence can only
belong, of itself, either to a complete essence, or, at most, to
some actual principle of essence ; since a thing which exists
must be a determinate and definite thing, otherwise, we
should be in the absurd position of asserting that something
altogether indefinite exists. It is, however, clear that matter
is neither a complete nature, nor yet an actual principle of
nature, since it is defined as a capacity for receiving form,
i.e. as a potential principle of nature. It follows, therefore,
that we cannot consistently maintain that matter has any
existence of its own.

That matter has no formal act, on which all Scholastics
agree, is simply another way of stating the definition of it :
' neque quid, neque quale, etc' ; and it is clear that unless this
fundamental notion of matter is adhered to, it is useless to
employ the notion at all, since matter which includes formal
act will be a mixture of matter and form, so that either we
must go on for ever with a series of matters which include
form, or else say that at last we come to a matter free from
formal act, which is what Aristotle and the Scholastics
understand by the expression ' first matter.'

If, then, it be granted that first matter is pure potency,
certain other conclusions with regard to it immediately follow :

1. It is metaphysically impossible for matter to exist
without form, since it receives its existence by the mediation
of form.

2. From which it follows that matter is unknowable apart
from form, since that which cannot be, or exist, cannot be
known. So all our knowledge of first matter is derived from
some compound of matter and form, and Butler rightly
derides the pseudo-philosopher who asserts that :

' He had first matter seen undressed ;
He took her naked all alone,
Before one rag of form was on.'1
1 Hudibras, Part I, Canto I.

50 MODERN THOMOSTIC PHILOSOPHY

So matter being a correlative of form is only intelligible
with relation to it, we must know of what it is capable if we
are to understand its capacity ; just as a Fiji Islander, if
confronted with an electric accumulator, and asked what its
capacity was, would reply, in all probability, that it could
hold about two pints, not knowing that it had a capacity for
storing electrical energy, and that this was what it was made
for. He could only understand the accumulator if he under-
stood that of which it was capable.

3. We must further conclude that if matter receives
existence from substantial form only, there can be only one
substantial form in one compound. This is a much-debated
question, about which more will be said later.1 Here it is
sufficient to note that there are three main opinions with
regard to it. The first is that of Scotus, who contends that a
living body possesses, besides the soul which is united to it,
an incomplete and subordinate form, called corporeality
(corporeitas). The second view is that of Albert the Great,
who was S. Thomas' master, and some modern writers,
according to whom the soul would be the primary form of the
body, and the forms of the chemical elements would be sub-
sumed by it, retaining their natural reality. The third
opinion is that there is only one substantial form in one com-
pound, and is that of S. Thomas and all Thomists.2

As M. Nys says, the reasons given by S. Thomas appear
to be decisive.

He argues : one thing has only one substantial being, but
substantial being is given by substantial form (as we have
just seen), therefore one thing has only one substantial form.
Secondly, there is no mean between substantial and accidental
form, hence, if there is a first form which gives substantial
being, any other which is added to it will find the subject
already constituted as a substantial being, and consequently
will be accidentally united to it.3

4. Since, then, matter is pure potency, and form, act
which confers existence on matter, and makes the material

1 Vide pp. 129 ff., Ch. X, Qu. 1.

2 Cf. Remer, Cosmologia, pp. 87 ff. (ed. 4a, 192 1).

3 Summa Theol., Part I, Q. 76, Arts. 3, 4 ; de. Potentia, Q. 3, Ch. 3, et 9
ad 9.

THOMISTIC THEORY OF MATTER 51

thing a being, it follows that form of itself actuates matter,
and makes the compound of matter and form a unity. In
other words, there is no need, in order that matter and form
should be made one, of any unifying medium distinct from
them, just as in cabinet-making when parts are dovetailed,
there is no need of glue to join them.

From all that has been said of substantial form, it will be
obvious that it is not the same as what is commonly called
form, in everyday language, as when we speak about the
form of a vase. This really means its shape, though there is
no doubt a vague reminiscence of the old meaning of form,
as that which gives a thing its definite character.

The question is often asked whether this theory of matter
and form is compatible with the results of modern science,
since spectroscopic investigation has proved, from a scientific
point of view, that the chemical elements remain in the
molecule, or larger body, intact, and so are not substantially
changed, and, even in living things, scientific investigation
seems to show that elements absorbed in the process of
nutrition are not changed in their natures, but merely used
by the living thing to build up its tissues, etc. ; which results
would destroy our first argument. What is, perhaps, even
more serious, though all of a piece with the denial of sub-
stantial change, is that science does not recognise the con-
tinuity of matter, nor the unity of bodies ; since, in the
scientific view, the atom itself is made up of discontinuous
electrons and nuclei, the abandonment of the old notion of
the ether making this discontinuity still more apparent. If,
however, there is neither continuity nor unity in matter our
other two arguments fall to the ground.

To answer these difficulties completely, a treatise on the
nature and scope of scientific theories would be required ;
but it will be sufficient for our present purpose to note the
following considerations :

1. The scientist does not approach the investigation of the
physical world with the same aim as the philosopher, for he
wishes to observe the phenomena accurately, not to discover
the ultimate nature of the bodies whose appearances they
are. Thus his theories or pictures of bodies, if he presents

52 MODERN THOMISTIC PHILOSOPHY

any, are all directed to the elucidation of the phenomena
themselves, not of what lies behind them, if anything does :
whereas it is the nature of the underlying reality which is
precisely that which interests the philosopher.

2. Exact science can only speak in terms of quantity,
neglecting all else, such as nature and quality ; whereas the
philosopher has to take every aspect of the physical universe
into account.

3. From the account given above of the Thomistic theory
of matter, it will be clear that it is essentially a metaphysical
theory, which enunciates the elements which bodies must
possess if we are to give an intelligible account of matter and
motion ; taking all bodies, including our own, into consider-
ation. Such a view is evidently much wider and deeper than
the special one of physics, and it follows that the scientific
theories and conclusions cannot be transported bodily, and as
they stand, into the philosophical theory. Further, the fact
that science with its special aim, and using its own proper
methods, does not find essential change or continuity in the
material world, does not prove that these do not exist there,
and if reason demands that we should assert their existence,
our conviction of the truth of this assertion is not weakened
by the fact that the description which science gives of
matter, for its own purposes, does not confirm it : nor would
it be strengthened if science did so confirm it. So Fr. D'Arcy
says : ' Whatever scientific hypothesis of nature be accepted,
evolutionary or static, the principles of S. Thomas find a
ready application. They serve to explain the presuppositions
of fixity and change, and disclose the two factors which must
be assumed and included in any intelligible account. The
physical theory of S. Thomas need be taken ... as only a
framework into which a variety of scientific theories can be
fitted. It is primarily metaphysical.'1

4. If we examine, in the light of these principles, the
particular instances in which we have asserted the reality of
substantial change and continuity, we shall see that the

1 M. C. D'Arcy, S.J., Thomas Aequinas, pp. 196 flf. Benn, Leaders of
Philosophy Series (1930). Cf. P. Geny, S.J., Art. in Divus Thomas (Plac),
January 1925, pp. 73 flf.

THOMISTIC THEORY OF MATTER 53

conclusions of science, in so far as they seem to point to a
denial of their reality, are, in fact, based on a consideration
of the facts, which is only partial. So, substantial change
would be denied chiefly on the ground that spectroscopic
analysis shows that the elements of the molecule remain in
it ; and continuity, because different properties are found
in different parts of the molecule or atom. No consideration
is taken, however, of the further fact that the molecule
operates as a whole, and as a whole has properties which are
quite distinct from those of its elements, nor of the fact that
whatever might be said of the discontinuity of inorganic
matter, it is impossible to deny that living bodies, at least,
are unities. If we take these considerations into account we
shall conclude, not to simple heterogeneity, which would
exclude substantial change and continuity, but to a sub-
stantial unity accompanied by accidental heterogeneity ;
for it is not a sufficient criterion for the real discontinuity of
bodies to point out that the parts of them have differing
properties, we must also show that there is no solid ground
for supposing them to be continuous. Thus, a horse and his
rider exhibit different properties, and there is no reason
why we should suppose them to be parts of one substance,
so we conclude they are different and discontinuous, whereas
a man's blood and the rest of his body, though exhibiting
different properties, are nevertheless not judged to be
different substances, or discontinuous, since the man is
evidently a unity : all the constituents of his body, including
his blood, working in harmony for the sake of the whole.

We conclude, therefore, that the theory of S. Thomas, with
regard to the nature of bodies, remains unaffected in its
essentials by modern scientific investigations ; and that, in
fact, all bodies are composed of matter and form.

CHAPTER IV

QUANTITY

The Distinction of Quantity and Substance — Descartes' View —
Reasons for Affirming the Distinction — The Nature of the
Distinction — The Nature of Quantity in Itself — Its Effects —
Opinions — The Usual Thomist View — Reasons in its Favour —
A Difficulty Considered — The Separability of Quantity and
Substance : Substance without Quantity, Quantity without
Substance — A Peculiarity of Quantity.

After the discussion on the nature of material things,
logical order leads us to consider their primary character-
istics, which are quantity and quality : for, as S. Thomas
says, " The first accidents which follow substance are
quantity and quality, and these two are proportionate to
the two essential principles of substance, viz. form and
matter."1

Quantity is usually denned by the Scholastics as : ' an
accident, which makes the subject have parts outside parts.'
They further distinguish two kinds of quantity, continuous
quantity, or extension, and discrete quantity or number.
Now, it is evident that things are actually numerable in so
far as they are separate, and they are separated by division.
So that discrete quantity is a derivative of continuous,
brought about by the separation of one part of it from
another ; by cutting it up, in fact, in the way in which from
one loaf of certain dimensions (continuous quantity) we get
a number of slices of bread (discrete quantity). However,
as is clear from this, continuous quantity is the primary
kind of quantity, and so we shall, here, be principally
interested in it.

Two questions immediately suggest themselves when we
look at the definition given above : first, is it true that

1 IV Sent. dist. XII, Q. i, a. i.
54

QUANTITY 55

quantity is an accident, or is it to be identified with the
substance of body ? Secondly, what precisely do we mean
by saying that it makes the subject have parts outside
parts, i.e. what is the precise nature of quantity ? This
question is expressed in Scholastic language by asking :
what is its primary formal effect ?

Question I. 7s Quantity Distinct from Substance ?

Some philosophers, as was to be expected, hold that
quantity is really distinct from substance, and some that it
is not. Among those who admit, at least to some extent, the
truth of the Aristotelean notion of two distinct realities in
bodies, substance and accident, there are still some who
make an exception in the case of quantity. Thus Descartes,
while acknowledging a modal distinction between accident
and substance, i.e. that some accidents affect substance
variably, nevertheless asserted that the nature of physical
body is extension in three dimensions, and so identified its
substance with extension.1 The distinction of substance
from quantity is also evidently denied by those who do not
recognise the distinction between substance and accidents in
general, as Hume and the Phenomenalist School, together
with the Monists, and the majority of modern philosophers.
The dispute, however, is, in this case, clearly not confined to
the question of quantity.

That substance and quantity are really distinct is the
opinion of all Scholastics, with the possible exception of the
Nominalists ; though they differ in the way in which they
understand this distinction.

Various arguments are used to prove the reality of the
distinction, among which are the following :

i. In order that quantity may be the same as substance,
it is necessary that it should be the same, either as the sum
of the essential parts of corporeal substance, or, at least, as
one of these parts taken separately. This is not the case,
however, for the essential constitutive parts of corporeal

1 Principes de la philosophic Partie I, Ch. LX-LXII. CEuvres, Tom. IX,
ed. Adam-Tannery. Everyman ed., Vol. 570, p. 188. Cf. Principes,
Partie I, CEuvres, II, ed. Napoleon Chaix, p. 55, in Everyman ed,, Sect. 53,
p. 185.

56 MODERN THOMISTIC PHILOSOPHY

substance are matter and form. Now, it is clear that quan-
tity is not to be identified with matter, since matter is pure
potentiality, while quantity is evidently actual ; for it either
confers something actual on a subject (if it be distinct from
its subject), or is itself actually extended. Nor can quantity
be identified with substantial form ; for the characteristic
of such form is that it informs the whole of its matter in pre-
cisely the same way, since its function is to make the body
to be of a particular kind, and so, all of the same kind, other-
wise we should have two species of bodies, i.e. two forms.
Although form may be divided, yet, since it makes the thing
what it is, the whole of any simple body has one and the same
form throughout, whereas it evidently does not have the
same quantity throughout. A part is not equal to the whole
in quantity, but it is the same in form. Lastly, quantity
cannot be identified with matter and form taken in conjunc-
tion, since together they do not compose some third thing,
other than matter and form ; for, as we have seen, the union
of matter and form is immediate (cf. p. 50, No. 4) ; and
quantity cannot be made up of two elements, one of which is
potential and identical with matter, while the other is actual
and identical with form ; since, as we saw above, quantity is
necessarily and wholly actual. Hence, in no way can quan-
tity be identified with corporeal substance.

2. Another simple but convincing argument is the
following :

If quantity were the same as corporeal substance, i.e.
were of the very essence of corporeal substance, quantity
could not be varied without the nature of the body being
varied. In other words, a change in quantity would entail a
specific change in the body ; since the change of an essential
element must necessarily change the nature of the body. It
is clear, however, that quantity can alter, both in different
individuals of the same species, and even in the same
individual body, by means of addition and division, as well
as by condensation and rarefaction, without any such
change in the nature of the body following, as a necessary
consequence. So a drop of water is water, just as much as a
bucketful, or a lake, from which it comes, though evidently

QUANTITY 57

the quantity of water in one drop is not the same as that in
the lake ; or again, a man remains a man even though he
may grow stout or lean. His quantity changes, but his
nature remains the same.

Granted, then, that quantity and substance are not the
same, we have now to consider the way in which this dis-
tinction is to be understood ; for some who allow it, yet
regard as properties of substance itself, characteristics
which, others maintain, only accrue to it from the influence
of quantity upon it. Thus :

i. Some think that both quantity and substance have
some extension of themselves, and so have this element in
common, though in different ways. Thus they say that sub-
stance has entitative extension, i.e. that corporeal substance
has, in itself, integrating parts ; parts, that is, which taken
together make up the whole ; so that it has such parts before
the coming of quantity to it, the function of quantity being
merely to make these parts capable of filling a place, so
giving impenetrability to the body. This is the view of
Suarez.1

2. Others, while agreeing that substance has entitative
extension before the coming of quantity, maintain that the
special function of quantity is to put the parts in order. So
John of S. Thomas.2

3. The Thomists, generally, hold that though substance
has no parts of itself, yet it obtains parts on the coming of
quantity to it.

(Note : The ascription by some text-books of the view
that substance does not obtain parts even under quantity to
the Salmanticenses and others, seems to be a mistake.
Cf. Salm., Vol. XVIII, pp. 380 ff.)

The truth of the second part of this statement, inasmuch
as it affirms that quantified substance has parts, is evident,
since quantified substance is extended substance, which,
clearly, has parts. To prove the other part of their statement,
viz. that substance has no entitative parts before the coming
of quantity, the Thomists argue that, if it had, it would be

1 Disputationes Metaphysical, Disp. XL, Sect. 4.

3 Cursus Phil. Logica, Pars. II, Q. 16, A. 1 (ed. Vives, p. 466).

58 MODERN THOMISTIC PHILOSOPHY

formally quantified, for to have entitative parts can mean no
less than to have parts which are situally distinct, i.e. distinct
with respect to position, or order of the parts with respect to
the whole, though not necessarily with regard to place, that
is to say, with regard to their relation to surrounding
bodies ; as the head of a man would not be his feet, even
though they were not supposed to have different relations to
surrounding bodies. To have parts which are situally dis-
tinct, in this sense, is to be formally quantified ; since the
proper function of quantity is to introduce into a body a
merely numerical distinction of parts, and such merely
numerical distinction can only come about by a mere dis-
tinction of the parts with respect to their position with
regard to the whole. It follows, then, that a substance
with entitative parts would be formally quantified, which is
clearly impossible when quantity is absent. Thus they
contend that to speak of parts which are not produced by
quantity is unintelligible. In fact, it seems probable that
those who maintain that substance has parts before the
coming of quantity, are really making use of an awkward
and ambiguous expression, and do not really disagree with
those who deny it. For, since both parties agree that cor-
poreal substance is composed of matter and form, and that
matter has a positive capacity or potentiality for receiving
quantity, or parts, they both allow that it is not simple, in
the way that a spiritual substance is, which is absolutely
indivisible. To say, however, of a substance whose divisi-
bility consists in a mere passive capacity for division, and
so is in itself undivided and indivisible, that it has parts,
entitative or other, is clearly an awkward and ambiguous
expression ; since to speak in this way implies some actual
divisibility, such as is found in a yard of cloth, and even
division ; which is a meaning certainly not intended by
those who use the expression. It is therefore better to avoid
it and say that substance apart from quantity has no parts,
and is indivisible, as S. Thomas does.1

1 Cf. II Sent. dist. Ill, Q. i, a. 4 ; and Quodlibet, IX, a. 6.

QUANTITY 59

Question II. What is the Nature of Quantity in Itself?

The question we have just reviewed, on the distinction
between substance and quantity, has, of course, shown us
that quantity has the nature of accident, and the latter part
of it, that its peculiar nature, as distinguished from the other
accidents, is to give parts to substance. We now have to
try and see in what way it does this ; and, if we do so, we
shall have arrived at its definition, since all accidents must
be defined by means of the effects which they produce on
substance ; and strictly speaking by means of their primary
formal effects, i.e. the first effects which they naturally
produce. In fact, in ordinary affairs, this is the way in which
we judge of the nature of accidents, as a doctor judges the
nature of a disease by observing the effects which it pro-
duces in his patient — its symptoms — and we are here trying
to find the peculiar ' symptoms ' of quantity. We must not,
however, suppose that its nature consists in the actual posit-
ing of this effect ; since, in common with all other accidents,
it is that which is naturally fitted to be in some subject, not
that which actually is in it, and actually affects it. For the
nature of a thing is unaffected whether it is actually existing
or not ; whiteness would still be whiteness, even if there
were none left in the world. Since, in spite of this, the only
means we have of judging of its nature is by observing its
actual effects — for we have no intellectual X-ray, so to
speak, by which we can penetrate into the very heart of it —
it is these which we must examine. What, then, are its
characteristic effects ?

Consider such an object as a cube of sugar. Since it is
quantitatively extended, it occupies a certain three-dimen-
sional portion of space. This extension is measurable and
also divisible. Since the cube occupies a certain portion of
space, it prevents any other body from occupying it, i.e. it
is impenetrable. Now, all these effects presuppose parts in
the cube, and parts which are not coincident, but outside
one another, and in a certain order ; this being an essential
condition for the occupation of space. Thus we have seven
characteristics which accompany extended quantity in a

60 MODERN THOMISTIC PHILOSOPHY

material substance, viz. plurality of parts, the order of these
parts among themselves, their capacity for filling a space,
actual occupation of a space, divisibility, mensurability, and
impenetrability.

We want to discover which of these is the first and essen-
tial characteristic of quantity ; and it is not easy to do so,
since each one of them has some claim to be so considered.
Thus, John of S. Thomas holds the view that quantity con-
sists in the ordering of parts among themselves, while Suarez
maintains that it is the capacity of the parts for filling a
place. The opinion which makes the primary formal effect
of quantity to be impenetrability is reahy the same as this :
since a body which is capable of filling a place is ipso facto
capable of excluding another body from the same place.
Neither of these views, however, can be maintained if we
accept what was said above as to the absence of parts in
substance before the coming of quantity, since to unite parts
in order, and, still more to make such parts capable of filling
a place, presupposes the existence of such parts.

The same reason rules out the notion that mensurability is
the nature of quantity, an opinion said to have been held
by S. Albert the Great ; for, in order that a thing may be
measurable by an extended measure, such as a foot-rule, it
must be extended in itself, i.e. composed of parts which form
a continuous body. Scotus is said to have thought that the
nature of quantity consisted in divisibility ; this, however,
could not be true, as a thing is divisible because it is quantita-
tive, rather than quantitative because it is divisible.

In the minds of all Scholastics, when dealing with this
question, there is present a constant theological preoccupa-
tion with the dogma of the Eucharist ; and this is particu-
larly evident in their treatment of the view of Durandus
that the nature of quantity consists in the actual occupation
of a place ; in connection with which they note that, since
Christ's body in the Eucharist does not occupy a place, it
would be necessary to deny that it is quantitative, a view
which they stigmatise as at least erroneous and temerarious,
if not heretical. Apart from the theological reason, it is
easy to see that the actual occupation of a place by a body

QUANTITY 61

is a consequence of its being extended, and having parts in
itself, and that, therefore, such occupation cannot be the
primary formal effect of quantity, and constitute its nature.

Only one conception of its nature therefore remains, viz.
that it consists in its capacity for giving to substance a
plurality of parts, in doing which it will ipso facto put them
in order with regard to the whole compound, though not
necessarily with regard to place. In other words, the parts
will be situally distinct, though not necessarily distinct
locally.1 Some writers, as Remer and Hoenen, call this
effect of quantity actual extension of substance, but since
this expression might lead to confusion, it is perhaps better
avoided ; though the view, intended to be expressed by it,
is that now generally held by Thomists ; with the exception
of Gredt, who follows John of S. Thomas.2

A strong presumption in favour of this Thomist view is
already afforded by the manifest insufficiency of all the pro-
posed alternatives, and, if we look at the matter directly, we
can see that the primary formal effect of quantity must be
that which is the reason and source of all the other properties
or effects, which may proceed from it ; for this is what we
mean by primary effect. For example, if we were enquiring
what was the primary effect of alcohol on the human system,
we might reply it is the deadening of the nerve-cell junctions
(or synapses, as they are called), which, in turn, causes
resistance to the passage of nervous energy, and so partial
dissociation of the brain ; causing, in its turn, loss of control
of the emotions by the intellect, which results in boisterous
conduct ; and, progressively, loss of control of the limbs and
sense faculties, eventually ending in entire suspension of

1 The two words ' situs ' and ' locus ' have different meanings in the
Scholastic vocabulary. The first indicates the distinction and arrangement
of the parts of a body among themselves, as for example the arrangement
of a man's limbs in sitting or standing ; whereas the word ' place ' implies
a relation of the body to external ones, as will presently be explained (cf .
Chap. VI, pp. 78 ff.). Of course, in the ordinary way, a change of situs
would involve a change of location, since if the parts of a body are differently
arranged among themselves, they will also be differently arranged with
regard to surrounding bodies ; but this need not happen, as we shall
shortly see, and in any case it is evident that situation and location in
the Scholastic sense are not the same.

2 Gredt, Elementa Philosophies, Sect. 315 (ed. 4, 1926).

62 MODERN THOMISTIC PHILOSOPHY

them, in a heavy sleep.1 All these latter effects result from
the obstruction of the synapses, which, therefore, is primary.
We are asking here, not only what is the primary effect of
quantity, but what is its primary formal effect, and that will,
evidently, be that which proceeds from quantity, and from
no other accidental form. Now, these two conditions : that
the effect we are looking for must be the source of all other
properties proceeding from quantity ; and that by which
quantity is distinguished from any other form, are satisfied
only in the case of that effect of quantity which is the giving
to substance a plurality of parts, on which follows, immedi-
ately, their order with respect to the whole ; for it is clear
that no other accident gives substance a plurality of ordered
parts, and so this property is distinctive of quantity, or
formal ; and, moreover, it is primary, since, as we saw above,
the other properties of quantity, viz. capacity for filling a
place, divisibility, mensurability and impenetrability follow,
once the substance has been given such a plurality of parts,
and presuppose it. Thus it is evidently the primary formal
effect of quantity.

The difficulty of this view is, no doubt, chiefly to be found
in the fact that we cannot imagine a thing with parts which
are numerically distinct one from another, and yet, not dis-
tinct as regards place. Undoubtedly, a body which has such
parts, which are outside one another as regards itself, is ipso
facto in a state which makes it able to fill a place ; but in
order that it may actually do so, two further conditions are
required : (i) that there actually exist other bodies which
constitute the place, and (2) that their internal dimensions
be actually applied to the external dimensions of the body
which is to be in place. For it must be borne in mind that
the state of being in a place arises, not from something
internal to a body, but from something extrinsic to it, viz.
the proximity and juxtaposition of other bodies. Hence, if
either of the conditions, mentioned above, is not fulfilled,
the body will be extended in itself, and yet not be in any
place. So, if we suppose that there existed only one body, it
could not be in place, since, owing to the absence of all others

1 Cf. McDougall, Abnormal Psychology, pp. 67-74.

QUANTITY 63

which might surround it, the extrinsic relation of being
situated with respect to them, i.e. of being in place, could
not arise. Similarly, if a body, which was one of many,
were yet not related to them by means of its extension, they
would not surround it by means of extension, and so it would
not fill the extended place which they form. The difficulty,
therefore, is due to the imagination, for we cannot imagine
one body joined to another by any other means than by the
application of the extension of the one to that of the other,
since this is the only union of which the senses tell us. We
can, however, understand that there is nothing necessary
about this particular mode of union, since it is not necessary
that the extension of a body should have any relation to the
extension of others, if it is present to them in some other way.
It is also extremely clear from the consideration of the
unique body (the only one in the world), that for a body to
be actually in place is a condition totally distinct from that
of being extended in itself.

If, then, as is certainly the case, to be in place and to fill
a place is an extrinsic relation added to the nature of extended
body, it follows that the exclusion of another body from a
place already occupied, is, though a natural consequence of
such occupation, as experience shows, nevertheless not a
necessary formal effect of extension or quantity. This is
another way of saying that such impenetrability is not of
the very nature of extended or quantified body, and it is
possible to have an extended thing which is not im-
penetrable.

From our conclusions as to the relationship of substance
and quantity, certain other results also follow. First, tha
since quantity is not of the essence of material substance,
absolutely speaking, it would be possible to have such sub-
stance without any quantity, since we can take away from a
thing some attribute which does not belong to its nature,
without destroying that nature. Substance, however, in
this case, would still retain its natural requirement to be
quantified, and, in certain cases, it is impossible to conceive
of an unquantified, i.e. unextended material substance, as in
the case of living things which must be organised, i.e. have

64 MODERN THOMISTIC PHILOSOPHY

parts, in order to live. If quantity were removed from
material substance in this way, the body would not be reduced
to a point, as some have supposed, but would simply have no
relation to extension ; whereas a point is the beginning of an
extension.

A more difficult question arises when we come to consider
the possibility of the existence of quantity divorced from
substance, for though we might summarily assert that it can
so exist, in common with all other accidents (since an
accident requires substance only for its support, and con-
sequently if supported, in some other way, can dispense
with it), yet certain difficulties peculiar to quantity remain.
For quantity immediately affects material substance, and
indeed results from the nature of matter.1 We must, by all
means, avoid thinking of material substance as something
inert and passive, on which quantity is imposed from without,
like a coat of whitewash on a wall. On the contrary, quan-
tity, like the qualities of bodies, grows, as it were, from them ;
as a plant grows from the ground, being enabled to do so by
the nature of the soil. It seems, then, that the whole raison
d'etre of quantity is to produce extension in substance, and
consequently it cannot exist if it does not do so, which would
be the case if it were separated from substance. Now, as we
saw, the primary function of quantity is to give extension to
substance, but in order to do this, it must be extended in
itself. This accidental extension, therefore, is its true nature,
and it may still have a function to fulfil even if deprived of its
primary one.

In order to bring out the meaning of the statement that
quantity can preserve its nature, and a certain function, even
if deprived of the possibility of exercising its primary function
owing to the absence of substance, we may, perhaps, be
allowed to make use of an illustration, though it is not to be
supposed that the two cases are parallel. The primary
function of a doctor is to cure the sick, and in order to do
this he must be versed in the medical sciences. Now, suppose
he were in some ' brave new world ' where there were no sick
people to cure, he would still continue to be a doctor so long

1 Cf. Summa Theol., Pars I, Q. 77, a. 6., o. et ad lum et 311m.

QUANTITY 65

as his scientific competence remained ; and he would also
have a function to fulfil, though not his primary one, in so
far as he assisted the people to preserve their health, or even
to get healthier and healthier. Just as quantity cannot
quantify substance if there is no substance, so the doctor
cannot cure disease if there is none, but quantity preserves
its nature of accidental extension, and the doctor his of
medical scientist, and both fulfil a derivative function ;
quantity, in virtue of its own essential extension, giving
extension to other accidents, and the doctor, in virtue of his
medical knowledge, preserving the health of the healthy ;
prevention, in his case, being the substitute for cure. If,
then, we imagine a case in which it was necessary that the
accidents of some substance should remain and be known,
when the substance had disappeared, quantity would still
have a necessary role to fill, viz. to make them extended,
impenetrable, and so on. Hence, it would still have a reason
of being. If it be further objected that quantity detached
from its subject will not be any particular quantity, since it
is not the quantity of anything ; and that, therefore, it is
impossible to conceive of it as existing, since only concrete
singular things exist ; we notice that quantity is peculiar,
among the accidents, inasmuch as it is by quantity that things
are distinguished as numerically different, i.e. as individuals.1
Unlike qualities, such as colour, say the colour white, which,
if abstracted from its subject, would give us whiteness, not
this white thing ; quantity, even in abstraction, is of a certain
definite amount, since its extension is proper to itself, and
does not depend on its subject, whereas whiteness, and such-
like qualities, are only made individual, particular and
definite by being the whiteness, and so on, of a particular
subject.

Quantity, then, in our hypothetical case, could exist
without its subject, since it would retain its definiteness and
individuality, and have a function to perform, even though
deprived of its primary one.

1 Cf. Remer, Cosmologia (editio sexta), p. 143, Resp. ad 2am diff.
Summa Theologica, Pars III, Q. 77, a. 2 ; IV Sent. dist. XII, Q. I, a. I,
Sol. 3, ad 2um, et ad 311m ; V. Metaphysica, Lect. 15.

66 MODERN THOMISTIC PHILOSOPHY

These considerations throw a little more light on
the difficult question of the nature of quantity, and,
of course, have their special application in theo-
logy, in the question relating to the Eucharistic
accidents.

CHAPTER V

THE CONTINUUM

Notion of Continuity — Zeno's Arguments — The Divisibility of the
Continuum — Is it Composed of Indivisible Elements ? — Is it
Infinitely Divisible ? — The Parts of the Continuum — The
Indivisibles of the Continuum — Solution of Zeno's Arguments.

We have already noticed, what is indeed obvious, that there
are two kinds of quantity, continuous and discrete, of which
continuous quantity is a primary kind, while discrete is a
derivative of it. It is, therefore, a natural sequence to pass
from the consideration of quantity in general to that of con-
tinuous quantity. No doubt, the analysis of continuous
quantity, or the continuum, was first suggested by observa-
tion of the material world, since bodies are, at least in appear-
ance, continuous. The philosophical discussion of it, how-
ever, leads us into a region more abstract than that of natural
philosophy ; and indeed this section, like the preceding,
really forms part of the science of mathematical philosophy.
What, then, is the essential feature of continuity ? To
answer this question we notice in the first place the distinc-
tion which exists, and which Aristotle points out, between
the continuous and the contiguous ; for two things, or two
parts of the same thing, are continuous, if the extremities in
which they join are the same ; and contiguous, if their
extremities are together, i.e. in the same immediate place.
They are then said to be in contact.1 Thus the continuum
is a reality which is actually one in extension, stretching out
without any intervals, e.g. a geometrical line. So, to consti-
tute the continuum mere juxtaposition is insufficient, the
parts must be united by a common term. As we consider, by

1 Aristotle, Physics, 226b34, 227a27, 23ia2i, io68b26, 1069*14 ; and
S. Thomas in V Phys., Lect. 5 ; VI Phys., Lect. 1 ; in XI Met., Lect. 13,
ed. Cathala, n. 2404-15.

F 67

68 MODERN THOMISTIC PHILOSOPHY

abstraction, one, two, or three dimensions, we arrive at
three species of continuum : the line, the surface, and the
volume (cube or solid). In the line points are in some way
present. Since the point is indivisible, points are called the
indivisibles of a line. Both lines and surfaces are indivisible
in some respect, the line, namely, with respect to breadth and
depth, the surface, with respect to depth only. Thus lines
are said to be the indivisibles of surfaces, surfaces of solids.

It is advisable to notice here that there are two genera of
continuum, viz. the permanent and successive. The first is,
again, of two kinds, the physical continuum, which is natural
body ; and the mathematical, whose species, solid, surface,
and line, we have just enumerated. The successive con-
tinuum is of two kinds : motion and time.

If we now examine this notion of the continuum as
uninterrupted extension, it seems that since it is an extension
it is divisible without end, in which case it appears that we
might have an actually infinite multitude, an hypothesis
which few accept, and which presents grave difficulties.
(Cf. pp. 107 ff.) If, on the other hand, the continuum is not
infinitely divisible, we must come finally to indivisibles, so
that in the last resort the divisible continuum will be com-
posed of indivisibles, the extended of the unextended. This
difficulty was first recognised, though obscurely, by Zeno,
who argued on the assumption that the continuum is com-
posed of indivisibles, and so constructed his famous proofs of
the impossibility of motion, which have been referred to in
our Introduction (p. 7). Though one of these, the Achilles,
may be invalidated by his ' ignorance of the theory of infinite
convergent numerical series,' as Whitehead suggests,1 the
others are unassailable, if we admit his premise ; but they
stand or fall with it. Thus if we prove that the continuum
is not composed only of indivisibles, we shall ipso facto refute
these arguments.2 They are as follows :

1. The Dichotomy. In order to travel a distance, a body
must first travel half the distance : and half the distance

1 Process and Reality , p. 95. The suggestion was first made by Descartes.
Vide CEuvres (Adam and Tannery), Tom. IV, p. 445.

2 Aristotle, Physics, 239^11-^30 ; S. Thomas in VI Phys., Lect 11. ■

THE CONTINUUM 69

remains to be travelled. Again, since the first half is divis-
ible, it must first travel half of that half, and so to infinity,
since a magnitude is divisible to infinity. Infinities, how-
ever, cannot be traversed in a finite time, therefore the body
will never arrive, nor even can it move from one place to
another.

2. The Achilles. Achilles and the tortoise run a race. If
the tortoise is given a start, Achilles can never catch it up.
For, first he must run to the place from which the tortoise
started. When he gets there, the tortoise will have gone to a
point further on. Achilles must then run to that point, and
the tortoise will have gone still further. This will go on for
ever, the tortoise always being ahead, so that Achilles will
never catch him up. Since this seems absurd, it is better to
say that nothing moves. (Aristotle and S. Thomas omit the
picturesque details.)

3. The Arrow. Everything which is in a place either
moves or is at rest. Now an arrow in its flight would, at each
moment of it, be in its place : therefore at each moment it
would either move or be at rest. But it cannot move, for
then it would not be in one place, but in two. Therefore it is
at rest. If, therefore, it moves at no moment, it does not
move in the whole time, and so is at rest.

There is also a fourth argument called the Road. Strictly
speaking, only the first two concern us here ; and both
assume that the continuum is actually composed of indivis-
ibles. We will therefore first consider this question.

Section I. On the Divisibility of the Continuum.

Question I. Is the Continuum Composed of Indivisible
Elements ?
That it is not, is admitted by all philosophers of all schools,
with the possible exception of the Pythagoreans, and some
Scholastics of the seventeenth century ; for it is, in fact,
very obvious that it cannot be so composed. Clearly the
indivisibles, inasmuch as they are indivisibles, are unextended.
An extended continuum, however, cannot be composed of
unextended elements. Moreover, such elements would either

70 MODERN THOMISTIC PHILOSOPHY

be at a distance from one another, in which case they would
not form a continuum, or in contact, in which case they would
be coincident ; since, having no extremes nor middles, they
must touch in their totality if at all. So, again, they would
not form an extended continuum, whose parts must be out-
side one another. In other words, if we suppose that an
extended continuum is composed of indivisibles which are
outside one another, continuity disappears, and if they are
not outside one another, extension disappears, so that in
neither case can the continuum be composed of indivisibles.

It is useless to suggest that the indivisibles are infinitely
small : for though, in Mathematics, we may speak of an
innitely small quantity, we mean a quantity whose magni-
tude is indeterminable. That such quantities cannot be
infinitely small, in the philosophic sense, is clear from the
fact that they are not nothing, and so must have a finite
magnitude, though an indefinitely small one. That they
have such a magnitude is seen from the fact that they can be
further divided, which in itself disallows the suggestion that
the indivisibles are of this kind.

Further, the very impossibilities which result from Zeno's
arguments confirm our contention that his hypothesis, viz.
that the continuum is composed of indivisibles, is false ; for,
if it were true, the slowest and quickest movers would move
at the same speed : since the quickest could not pass over
more than one indivisible element of space in less than
one indivisible element of time, i.e. in less than one instant,
since by hypothesis an instant is the least time there is,
otherwise it would be divisible : nor could the slowest take
more than a single instant to pass over less than one indivis-
ible element of space, since this is, by hypothesis, the least
space. Consequently, they would both pass over one
indivisible element of space in the same time, viz. one instant,
and so would travel at the same rate.

Question II. Is the Continuum Infinitely Divisible?'

This conclusion, that the continuum is not composed of
indivisibles, carries with it an important corollary : for if we
never come to ultimate indivisible elements when we divide

THE CONTINUUM 71

the continuum, it must be divisible to infinity. Now, just as
philosophers are practically unanimous in asserting that the
continuum is not composed of indivisibles, so they also agree
that it is divisible to infinity. It is as well to recall here the
distinction between the continuum formally considered,
i.e. as it is one real extension — the mathematical continuum,
and the physical or material continuum, viz. the actual
bodies in the universe, which are extended and endowed
with a variety of accidents. Those who consider the physical
continuum only, hold that it is not infinitely divisible : and
this we do not deny, but rather affirm with S. Thomas : for
the mathematical or abstract continuum is divided into
proportional parts, i.e. parts which are some proportion of
the whole, as halves or thirds, which can again be divided
into halves or thirds ; and it is clear that we can go on for
ever taking a half of half, or a third of a third, and so on, so
that this continuum is infinitely divisible. A priori we can
see that this may not be true of the physical continuum,
and experience shows that, in fact, it is not : for the physical
continuum is composed of what are known as aliquot parts,
determined ones, namely, which when added together make
up the whole. These have a determinate extension, and so
cannot be further divided. The reason of this is that in the
physical continuum we come to a minimum quantity of
matter which is necessary to support a given form, such
minima, for example, as the molecule or atom would be.
Now, if this minimum be further divided we get a body of a
different nature, i.e. the original form disappears, and another
takes its place. So S. Thomas says : ' Corpus mathematicum
est divisible in infinitum, in quo consider atur sola ratio quanti-
tatis in qua nihil est repugnans divisioni infinites. Sed corpus
naturale, quod consideratur sub tota forma, non potest in
infinitum dividi, quia, quando jam ad minimum deducitur,
statim propter debilitatem virtutis convertitur in aliud. Unde
est invenire minimam carnem, sicut dicitur in I. Physicorum,
nee tamen corpus naturale componitur ex mathematicis.'1

1 De Sensu et Sensato, Lect. 15. Cf. Summa Theol., Pars I, Q. 48,
a. 4, ad 3um ; I. II., Q. 85, a. 2.0 ; II Sent. dist. XXX, Q. 2, a. 2.0 ;
III Phys., Lect. 10, a. 9 ; de Potentia IV, a. 1, ad 5um ; IV Sent. dist.
XII, Q. 1, a. 2, Sol. 3.

72 MODERN THOMISTIC PHILOSOPHY

Thus in the physical continuum we come to ultimate parts
which cannot be further divided ; so that this continuum is
not infinitely divisible. This seems to be what Fr. Leslie
Walker suggests, though he charges Aristotle with denying
it : and what is worse, with being ' led astray by appear-
ances.'1 Thus with regard to the abstract or mathematical
continuum, which alone concerns us here, there seem to be
few or no philosophers who do not allow that it is divisible
to infinity.

That it is so, is seen from what was said above, for we can
go on for ever taking a half of a half, and so on. Moreover, it
is clear that the whole continuum can be divided, being an
extension, and the quotient will be an extension and so
divisible, and the same will hold good in all further divisions,
so that no end can be put to them.2

Section II. The Parts of the Continuum.

If, then, the continuum is not composed of indivisibles, it
must be composed of divisibles, i.e. of extended parts, such
as halves, quarters, etc. The name ' parts ' is applied
exclusively to such extended portions, and not to the
indivisibles. Since, then, such parts exist in the continuum,
they may exist there either actually or potentially, i.e. in
such a way that they can be made actual parts by division.
There are, therefore, two main views corresponding to these
two possibilities, while some have tried to reconcile them.

Thus : A. (i) Many teach that the parts exist in act.
Plato held this view, according to Prof. Ross, who agrees
with him and adds : ' to cut a. ball in two is not to bring into
existence the common plane of its halves, it is to drive your
knife along a plane that is already there.'3 Similarly, John
of S. Thomas, Goudin, and Gredt. These maintain the
actual existence of parts without any reservation.
■ (2) Others say that though the parts are not actually
divided, yet they are actually distinct : existing formally as
parts joined together by continuing indivisibles. So, Suarez,
and others.

1 Aristotelean Society's Proceedings, 1922-3, pp. 98-9.

2 Cf. Leibniz, Ep. ad P. des Bosses.

* Ross, Aristotle's Metaphysics, Vol. I, Introd., p. lv.

THE CONTINUUM 73

B. Many others, however, teach that the parts exist only
potentially in the continuum : inasmuch as there are in it
no actual limits, which serve to separate one part from
another. This is the view of Aristotle, as can be seen in
VII Met., I039a3 ff. ' The double line consists of two halves
— potentially : for the actualisation of the halves divides
them from one another.' S. Thomas agrees, as in his com-
ment on this passage (Lect. 13) ; also in Lect. 16, and Bk. V,
Lect. 21 : ' Partes sunt in potentia in toto continuo ' ; and
VII Phys., Lect. 9 : ' Pars auteni prout est in toto, non est
divisa in actu, sect in potentia tantum ' ; and IV. Sent. dist. X,
Q. 1, a. 3, qa4, sol. 3 ad ium. : ' Partes alicujus homogenei
continui ante divisionem non habent esse actu sed potentia
tantum,' and many other places.1

C. Some try to reconcile these two views, saying that
though the parts are not actually in the continuum con-
sidered formally as parts, yet considered as realities they
are actual in it. So Donat, and Hugon.

The argument which Aristotle and S. Thomas use to prove
their opinion is of extreme simplicity and clarity. The first,
and most essential characteristic of the continuum as a
species of quantity is its unity. If the continuum were not
essentially one, we should have, not continuous, but discrete,
quantity. This being so, it is impossible that the parts
should be actual, since the least that this could mean would
be that they are already actual entities, and so actual
unities. A number of such unities, however, even if in juxta-
position, could never constitute an entity which was essen-
tially one. It may be useful to quote the very words of
S. Thomas,2 which are lucidity itself : ' Sicut aliquid est ens,
sicut et unum : unum autem est quod est in se indivisum et ab
aliis divisum : pars autem prout est in toto, non est divisa in
actu sed in potentia tantum, unde non est actu ens neque una,
sed in potentia tantum.' So we may express this simple truth
by saying that if the parts are actual entities, they will be
actually many, and so cannot at the same time be actually
one, or a continuum.

1 I de Ccelo, Lect. 3, Sect. 6 ; I Phya. Lect. 9. Sect. 8 ; Summa Theol.,
III Pars, Q. 76, a. 3, ad ium ; I Pars, Q. 85, a. 8, ad 2um ; Quodlibet I,
a. 21. 2 VII Phys., Lect. 9, Sec. 5.

74 MODERN THOMISTIC PHILOSOPHY

It is worth noting that those who take the middle view
contend that the matter of which the parts are composed is
actually present in the continuum before division, which
nobody denies ; consequently, their effort at reconciliation
is unsuccessful, for they do not, by this means, solve the
question, which is whether the parts considered formally as
distinct entities are actual before division. Since, however,
they deny that they are actual, their opinion seems to be
that of S. Thomas, and the distinction introduced by them
only serves to obscure the real nature of the dispute. A
confirmatory argument in favour of this same view is derived
from the infinite divisibility of the continuum, since if the
parts were actually present in the continuum, they would
have to be either infinite or finite in number. They cannot,
however, be either ; for if they were infinite in number we
should have an actually infinite multitude in the genus of
quantity, which, as we shall see, is impossible ; and, more-
over, they would not be parts but indivisible points, since, if
they had any extension, however small, when they were
multiplied an infinity of times, they would constitute an
infinite magnitude : so that any body, even the smallest,
would have an infinite magnitude, which is absurd. Now we
have proved, and Suarez agrees, that the continuum is not
constituted of indivisibles. So, it is impossible that the parts
should be infinite in number. Nor can their number be finite,
for, in this case, the continuum would not be divisible to
infinity, which we have seen that it is. Hence, it is imposs-
ible that the continuum should be composed of actual parts.

Section III. The Indivisibles of the Continuum.

In order to complete our analysis of the nature of the con-
tinuum, something must be added as to the other elements
which are conceived of as being in it, in addition to its parts,
viz. the indivisibles. Now, these indivisibles are of two
kinds, the terminating indivisibles which are thought of as
actually limiting the continuum, such as the points at the
end of a line ; and the continuing indivisibles which are
thought of as being within the continuum, and joining
together the parts which can be separated at them. We ask,

THE CONTINUUM 75

then, whether indivisibles of these two kinds are actually, or
only potentially, present in the continuum.

1. There can be little doubt that the terminating indivisibles
are actual, since, if the continuum is limited at all, it must
be by means of an actual limit. There is, however, difference
of opinion as to the nature of this limit, for some regard it as a
mere negation, the negation, that is, of further extension,
while others think that it is a positive reality, being the reality
of the limited body, in so far as this connotes the negation of
further extension. A much more general view, however, is
that they are something positive, really distinct from the
continuum which they terminate, the distinction, of course,
not being that of one quantitative thing from another, but of
the determinator from the determinated, and so a modal dis-
tinction, i.e. that which obtains between an entity and some
mode of it. This seems, on the whole, to be the most prob-
able opinion, though since all agree that the terminating
indivisibles are actually present, for the reason given above,
the question is one of lesser importance. The reason for
saying that they are positive realities is that where a con-
tinuum begins there is something real and positive which
was not present before, and where it ends something positive
and real ceases. Consequently, the terminating indivisibles
being the beginning and end of the continuum, they must be
something positive and real. For contact too, it is necessary
that bodies should touch by means of indivisibles, otherwise
they would interpenetrate. They cannot, however, touch in
a negation, for to do so would be, in fact, not to touch, and
since the contact is to be real, the indivisibles must be real
also. Further, they must be distinct from the continuum
itself, since this is divisible, and they are indivisible.

2. With regard to the continuing indivisibles, the Nomin-
alists hold them to be a mental fiction, while some sixteenth
and seventeenth century writers, such as John of S. Thomas,
whose opinion in recent times has been espoused by others, as
Gredt, think that they exist in act, and are really distinct
from the parts which they unite. There is little doubt that
neither of these views accords with that of Aristotle and
S. Thomas, for it seems clear that these considered that they

76 MODERN THOMISTIC PHILOSOPHY

do not exist in act, but only potentially. It is, indeed, only
another way of saying that the parts of the continuum are
potential only, and not actual, since it is clear that if the
continuing indivisibles were actual, they would actually
determine the parts, and make them actual. So, if the parts
are not actual, as we have already seen to be the case,
neither are the continuing indivisibles.

Section IV. The Arguments of Zeno.

We are now in a position to see what answer can be made
to the arguments of Zeno, against the possibility of motion.
In effect, Zeno argues : You rnaintain that the continuum is
infinitely divisible. Now, the only things of which there can
be an infinity in a lineal continuum are points, and in general,
in any continuum, indivisibles ; for if we suppose that there
are an infinite number of extended parts in a continuum,
the resultant of these parts will also be infinite. Hence, a
line must be composed of an infinity of points (the Dichotomy
and Achilles), time of an infinity of instants (the Arrow).
Now, we have proved that the continuum is not composed of
indivisibles ; and not only this, but that though it is infinitely
divisible, it is not actually divided at all, and finally that the
indivisibles are not actual, but only potential in it. If this
be conceded, Zeno's arguments at once break down, for there
will not be an infinity of indivisibles actually in the con-
tinuum ; such indivisibles as there are being only potentially
present, and consequently there will be no point which is
actually the halfway point of a distance which is being
traversed, no actual point in the motion of Achilles where the
tortoise was before, no moment in the flight of the arrow
actually. Thus the mover does not divide its trajectory into
an infinite number of actual parts, whether proportional or
aliquot ; but into two indeterminate parts, that already
traversed, and that .about to be traversed ; which are both
continually changing. If, however, we admit actual indivis-
ibles, and actual parts in the continuum, it seems that the
arguments are insoluble, even if it be contended that the
number of such parts is finite ; for the parts must be either
extended or unextended : if they are extended, they are

THE CONTINUUM y7

divisible, and if they are unextended, in traversing them a
body will not move. So we shall have either an infinite pro-
cess, or the absence of motion. On S. Thomas's theory, on
the contrary, a moving body never arrives at the halfway
point, but passes through a potential point, the hero never
arrives at the points in the path of the tortoise, but passes
through infinity of potential points, the arrow is never at
any one point of its flight.

Though it would be true to say that an infinite distance
could not be traversed in a finite time, yet it is not true that a
distance which is only potentially infinite cannot be traversed
in a finite time ; for both space and time are infinitely
divisible, but not infinitely divided ; so that it is possible to
pass over an infinitely divisible space in a finite time, since
this time is itself infinitely divisible.

CHAPTER VI

PLACE AND SPACE

I. Place — Localisation — Kinds of Location. II. Space — Its Nature
— Opinions — Absolutist, Subjectivist, Intermediate Theories —
The Void — Conclusion as to the Nature of Space. III.
The Occupation of Space — Impenetrability — Multilocation.

At the beginning of our discussion of the continuum, we
noticed that it is of two kinds, permanent and successive.
We must now examine these separately. Now the permanent
continuum is concerned with the extension of bodies, and
bodies, in so far as they are extended, are said to be in space ;
and as occupying a defined portion of it, are said to be in
place. It is necessary therefore to analyse these two notions.

Section I. On Place.

Though the notion of place is, in a certain sense, included
in that of space, and dependent on it, yet being one which is
clearer and more familiar to us than that of space, it will be
more convenient to consider it first.

Place is defined by Aristotle as : T6 tov wepuxovros ^v0?
dxivrjTov TrpQrov, i.e. the first unmoved limit of the container.1
The word ' unmoved ' indicates that the surface, which
is said to be unmoved, is so formally as a limit ; not
that the interior surface of the container, viz. this or
that vessel which contains the thing which is in place, is
unmoved. Thus, in the case of a ship anchored at sea, though
the water is constantly moving round it, yet the containing
limit of the water, as such, may remain unmoved. How are
we to tell whether it is or not ? Evidently, we must gauge it
either with reference to something which is absolutely immov-
able, or which at least is unmoved for all practical purposes.
Now, we do not know of any body in the material universe of

1 Phys., 212* 20.
78

PLACE AND SPACE 79

which we can say that it is absolutely immovable, but for
practical purposes the poles and the centre of the earth are
unmoved, and consequently we calculate the place of a body
with reference to them. So, S. Thomas says : ' Although
this container may move, in so far as it is this body, never-
theless as it is considered with respect to the relation which
it has to the whole body of the heaven, it is not moved, for
any body which succeeds it, has the same order or position
with respect to the whole heaven, which the body, which
earlier passed away, had.'1

Modern Scholastics often distinguish between external and
internal place. The former is that of which we have just
been speaking, while by the latter they mean the capacity
which is circumscribed by the exterior surface of the body,
i.e. it is the portion of space which the body occupies, and
which exactly corresponds with its real volume. It seems
doubtful, however, whether this distinction can be main-
tained, as it appears that such internal place would not be
real.2 When the word place is used, then, it is to external
place that reference is made.

Aristotle distinguishes between the proper and common
place of a body : proper place being that which immediately
surrounds the thing which is in place, so that it is in con-
tact with it alone ; while common place is that which does
not immediately surround the thing, but surrounds it in
common with other things ; as in a nest of Chinese boxes,
each one containing a smaller one, the proper place of each
might be said to be the box next greater than itself, while
the common place of all, but the outermost but one, would
be the outside box of all.

The accident resulting in a located thing from the fact
that it is subject to external place is called ' ubi ' or localisa-
tion. As to the nature of this accident opinions differ, for
some think it is a mere mental relation, and not real at all ;
for they think the body must be the same in itself whether it
is in one place or another, so that by local motion it acquires

1 IV Phys., Lect. 6. No. 9.

2 But cf. Nys, La Notion de I'Espace (pp. 236-278), who argues at length
in favour of this distinction, and the reality of internal place.

8o MODERN THOMISTIC PHILOSOPHY

nothing but a change of position relatively to other objects.
This, indeed, seems to us nowadays the obvious view to take,
and accords well with the Cartesian theory of motion men-
tioned above ; and is probably, as Whitehead suggests, ' the
very foundation of the seventeeth century scheme of nature.'1
Nevertheless, local motion seems to imply more than a mere
change of position ; for, supposing, while a body was in
motion, all others were to be annihilated ; according to this
theory, since it could not change its position relatively to
them, its motion would cease : a conclusion which can hardly
be accepted since the motion was not caused by the presence
of other bodies, and could not therefore be destroyed by
their removal. Further, the relation which the located body
has to its environment is certainly a real one independent of
our thought of it, and consequently requires a real founda-
tion.2 Now, this foundation cannot be the quantity of the
body, as is suggested, for, though it is true that the body is
located by means of its quantity, yet it can have different
locations while retaining the same quantity. There must,
therefore, be, in the body, some additional reality over and
above quantity, which is the foundation of this or that
localisation, i.e. application of the body to this or that place.
For, in so far as contact is made with a second place, a new
relationship is acquired by the body. The fact that the
foundation of this relation is in the located body, even
though the relation is derived from without, owing to the
presence of the surrounding bodies, is in no sense a contradic-
tion ; for the foundation and the relation arise simultaneously ;
the foundation being the formal cause of the relation, i.e. that
by which the relation is constituted, the extrinsic circum-
scription by the other bodies being the efficient cause of this

1 Whitehead, Science and the Modern World, p. 72.

2 As will be explained more fully later, the Scholastics recognise three
elements in a relation : the subject, the term, and the foundation ; all of
which, in the case of a real relation, must be real. The subject is that
thing in which the relation is present, the term that towards which it is
directed, and the foundation that by which the relation is constituted,
i.e. the reason why the subject is related to the term. So in the relation
of sonship, the subject is the boy who is generated, the term is the parent,
and the foundation the fact of being generated. Here, then, the foundation
is caused by the act of generation of the parents, while it constitutes the
son as standing in a certain relation to them.

PLACE AND SPACE 81

foundation. It would, however, be absurd to rush to the
other extreme, and say that this accident was something
absolute, intrinsic to the located body, for it clearly arises as
a result of its quantity being commensurate with those of its
particular surroundings, and hence is something which comes
to it from without, and so is not ' secundum substantiam, vel
secundum aliquam intrinsecam dispositionem substantia n —
such as quantity or quality — as S. Thomas says repeatedly.
It seems, therefore, that it is a real mode which comes to the
body from without. This theory does not, as the one men-
tioned above seems to do, render the admission of motion in
a completely empty space impossible, for change of localisa-
tion is not here identified with motion, but is considered to be
an effect of it, so that even if there were no localisation, and
consequently no change of it, motion could still continue.2

It is worth noticing that the reality of local motion is safe-
guarded by both these theories, since in the first there is a
succession of real contacts, and in the second a connected
succession of real modes by whose means the different real
contacts are effected.

The Scholastics point out that there are several ways in
which a thing may be in place.

First, there is the way of which we have just been speaking,
viz. circumscriptive location, which is predicamental location.
This is the passive circumscription of a body which arises
from its actually being surrounded by a place.

But a thing may also be in place ' not circumscriptively,'
and this either naturally or praeternaturally. Naturally
either by operation, i.e. by acting on a place, as an angel
may do ;3 or by informing a body, which is circumscriptively
in place, as the human soul does. The theologians enumerate
three preternatural modes of being in place, viz. eucharistic-
ally, infernally, and hypostatically.

A thing is said to be definitely in place, if it is so limited to
one place as not to be able to be at the same time in another.
Evidently it is only bodies which are in place circumscrip-
tively, and, as we shall see shortly, they must also be in

1 XII Met. S. Thomas, Lect. 7 (ed. Cathala, 2530).

2 Cf. Nys, op. cit., pp. 254, 264 f.

8 Summa Theol., Pars I, Q. 52, a. I.

-82 MODERN THOMISTIC PHILOSOPHY

place definitively, i.e. they cannot be in two places at
once.

Owing to the importance of the subject, we may perhaps
be allowed to notice that the body of Christ in the Eucharist
is in place neither circumscriptively nor definitively, as is
plain from the definitions given. It is only metaphorically
that we say that It is in place ; indeed it is only those things
which are in place circumscriptively, which are in place
properly speaking, so that an angel, or the human soul are
only in place metaphorically, in somewhat the same way as
when we speak of a discussion or remark being ' in or out of
place,'1

From what has been said, it will be seen that there is a
very close connection between the notions of place and space ;
and we are thus naturally led to consider the latter.

Section II. On Space.

Although the greatest divergence of opinion is to be found
among philosophers as to the nature of space, yet these
opinions are linked together by the degree of reality which
they attribute to it ; and may be classified under three heads :
the theories (i) of those who emphasise this reality, (2) of
those who emphasise its ideal character, and (3) of those who
preserve the balance between the two. The last group of
opinions will have a prima facie claim to be preferred as
being a mean which preserves the truths pointed out by both
the other groups.

The difficulty of the question consists in this, that if we
make something real of space in itself, we shall be logically
led to say that space without bodies is something real, or
that absolute space is something real, which is a purely
gratuitous assertion, based on no evidence ; and one, more-
over, which would make space itself unintelligible ; since, if
all bodies are removed, leaving real space behind, this space
must be immaterial. It is, however, the function of space to
be the location of bodies, and apart from this function we
seem to have no conception of it. It is, moreover, clear that
the material cannot be located in the immaterial, and so by

1 Cf. Salmanticenses, De Angelis, Vol. IV, pp. 83 S.

PLACE AND SPACE 83

making space real we deprive it of its only meaning, and
render it unintelligible. On the other hand, if we say that
space is not real, we shall seem to contradict common sense,
to speak in a way which is in disagreement with scientific
language, and to deprive the material world of its objectivity.

Can these and similar objections on one side, or the other,
be met, or must we try to reconcile the two views ? Such is
the question to be answered.

I. Turning, then, to the first group of opinions, of those,
namely, who insist on the reality of space ; we find among
the Greek philosophers some who regarded space as absolute.

1. Thus Democritus, and others who took a similar view
of nature, taught that space is the vacuum, or a universal
receptacle, which is distinct from bodies, but in which they
move. Similarly, some Peripatetics taught that space is a
kind of immense sphere which surrounds all bodies. Gassendi,
in the seventeenth century, reviving the old Atomism,
adopted this view of space, but tried to rid it of some of its
absurdities, by denying to it the character of absolute
necessity, which had been given it, and saying that it has a
reality which does not come within our categories, being
neither substance nor accident. Locke (1632-1704) also
seems to incline to the ultra-realist opinion, which would
substantialise space, though his way of speaking is by no
means free of ambiguity.1 He, like Gassendi, suggests that
space may be thought of as a substance, granting that ' sub-
stance ' be taken in a different sense from that in which we
ordinarily use it. The word, he says, has already three
different senses as applied to God, spirits, and bodies : why
not add a fourth to apply to space ?

If we examine these notions one by one we shall see that
all of them involve inconsistencies. So the suggestion that
space, the receptacle of bodies, is the vacuum, is untenable,
since the bodies are extended, and so their receptacle must
be extended also. The vacuum, however, of the Atomists
was unextended, and so cannot be space. Even if it were
thought of as extended, it would need a further receptacle

1 Cf. Essay on the Human Understanding, Bk. II, Ch. XIII, Nos. 5 ff.,
especially No. 22 ; and Nys, op. cit., pp. 37 ff.

84 MODERN THOMISTIC PHILOSOPHY

or vacuum to contain it, and so we should have an unending
series of vacua containing one another, without ever arriving
at an ultimate space. This last objection militates equally
against Gassendi's view, for whom the receptacle of bodies
was extended, and the very reason which, in his opinion,
makes it necessary to imagine a first receptacle, viz. that an
extended thing must be received in something, would apply
with equal force to this receptacle itself, and so on to infinity.
Further, this space was thought of as eternal independent
being. Such being, however, would be unproduced, and pure
act, which is in direct contradiction with the notion of space
as the receptacle of bodies, which must necessarily imply a
universal potentiality for receiving them.

2. Such views as these seem to deify space, and this idea
that space is an attribute' of the Deity, is found explicitly in
the opinion of Newton and Clarke, though the latter, under
the pressure of the objections of Leibniz, modified his original
position to some extent. Thus Newton identifies it with
God's omnipresence, and Clarke with His immensity. So, in a
curious passage, Newton writes : ' Is not the sensory of
animals that place to which the sensitive substance is present,
and into which the sensible species of things are carried
through the nerves and the brain, that there they may be
perceived by their immediate presence to that substance ?
And these things being rightly dispatched, does it not appear
from phenomena that there is a Being incorporeal, living,
intelligent, omnipresent, who, in infinite space, as it were
in his sensory, sees the things themselves intimately, and
thoroughly perceives them, and comprehends them wholly
by their immediate presence to himself ; of which things the
images only (i.e. on the retina) carried through the organs of
sense into our little sensoriums, are then seen and beheld by
that which in us perceives and thinks.'1 Now, if there is one
thing which is clear about the divine attributes, such as
omnipresence and immensity, it is that they must be iden-
tical with the divine nature, and so an absolute unity. This
is in evident conflict with that most fundamental character-

1 Opticks, pp. 344 ff. (quoted by Burtt, Metaphysical Foundations of
Modern Science, p. 258).

PLACE AND SPACE 85

istic of space which is its extension and divisibility. More-
over, such a theory would lead straight to Pantheism, since
space is an attribute of bodies, and so can only be held to be
also an attribute of God by Pantheists.

This is, in fact, the view adopted in the pantheistic philo-
sophy of Spinoza, Starting with the Cartesian notion that
the nature of bodies consists of their triple extension, he
follows him also in asserting that there is only a logical dis-
tinction between space and extension. There are, he con-
siders, two aspects in which space is viewed by us. In the
first place, we imagine it as composed of parts, and so divis-
ible, and, in fact, divided : its parts being what we call
bodies. Secondly, the intellectual consideration of space
shows us that it is, in fact, a common reality, viz. substantial
extension in three dimensions, which is everywhere the same,
absolutely indivisible, and positively infinite. Such an
entity can be nothing else than an attribute of God.1 Now,
we cannot concede the second part of this theory, since it is
clear that extension implies a non-coincidence of parts, and
is therefore essentially divisible.

A theory having marked affinities with those of Newton
and Spinoza has recently been evolved by Professor S.
Alexander in his work, Space, Time and Deity, according to
whom the whole universe, whose reality is Space-Time,
which is progressively evolving, is to be identified with God.2
This idea is open to the objections raised against Spinoza,
and, in addition, God is represented as progressing or evolv-
ing, and, in fact, never coming to be. Such a ' Being ' is
evidently imperfect and finite, so that the name God is
applied to it equivocally, i.e. in a wholly different sense to
that intended by Theists when using the word. Alexander's
God is not their God.

II. The Second Group. The Ultra-Sub jectivist theories.

1. If the Absolutist views of space thus fail to satisfy us,
perhaps we may find a more adequate idea of it among the
Subjectivist theories. The first of them to claim our atten-
tion is that of Kant. According to him, we cannot know

1 Spinoza, Ethica, Pars I, Prop. 15, Scholium.

2 Vol. II, pp. 428 fif.

86 MODERN THOMISTIC PHILOSOPHY

whether the external world has those characteristics which
we attribute to it, and so whether ' things-in-themselves '
are extended, distant from one another, and so on : all we
can say is that they appear to be so to us. Now this spatial
appearance might derive either from the things, or from us.
Just as to a man crossing to France in a Channel steamer the
sea might appear yellow ; and this appearance might be
caused either by the flood waters of some river running into
it and discolouring it, or to the disturbed state of the man's
liver ; so, in the case of space, the spatial appearance might
be due either to things sensed being spatial, or to the consti-
tution of our senses ; and Kant argues that we see that this
latter supposition is the true one from the fact that space is a
general form, which applies universally to the whole material
world. Now, the thing-in-itself is singular, and so cannot
contain, or transmit to us the universal. Hence this form
must be part of the constitution of our minds or senses.
What, then, is space ? It is a part of the pattern of our
senses, and so Kant calls it an ' a priori form of the sensi-
bility.' It is a priori, in a way somewhat similar to that in
which the shape of a ' castle pudding ' may be said to be
given a priori : it is that particular shape because of the
mould in which it is made. So the senses, having a particular
mould (of space and time), turn out the objects marked with
this mould or pattern. It is seen to be a priori, since it
logically precedes any sensible experience ; in saying which,
Kant wishes it to be clear that he does not think that it
really precedes it, as if we could know space before we know
sense-objects : but it is present in the sensibility in a similar
way to that in which an image on a photographic film may
be said to be present in it before the film is developed : as
soon as the acids are applied to it the image will come up.
Similarly, as soon as the sense-objects are applied to the
sensibility, the forms of space and time will, as it were,
develop up. Further, he calls it ' pure,' since it is not derived
from any experience ; and finally, it is necessary, as being
an essential condition of all sensible experience.

The most fundamental criticism of this view is that which
shows the inconsistency in Kant's distinction between

PLACE AND SPACE 87

appearance and reality, between phenomena and things-in-
themselves ; for, according to Kant, not only is space
phenomenal and a priori, but the same is true of the notions
of cause and existence, which he calls a priori categories of
the mind. The reality, therefore, can be neither a cause nor
existing. If this be so, we are faced with a contradiction, for
our sensations, though not their forms, are in Kant's view
caused by the thing in itself ; which must therefore exist.
But, according to him, as we said, it can neither exist nor
cause, if existence and causality apply only to phenomena.
Further, on Kant's theory, it is impossible to give any
coherent account of the change and movement which we
perceive among bodies. For this movement, even if it is
only phenomenal, is at least a real phenomenon which must
therefore have some cause. This could only be the a priori
form of space, or some influence external to the senses. Now,
Kant's theory will not admit of either of these explanations
of its source ; for, in the first place, the a priori form is
logically prior to all phenomena, and essentially static, since
it is a form of our nature, from which it receives its function
of making the phenomena appear as extended in three
dimensions, and only three. Hence, though it may imply
relative position, it cannot give us change of position,
direction, distance, etc., which are things quite extraneous
to the form of space as such ; which would equally well be
preserved in an entirely static world, implying, as it does,
nothing more than three-dimensional extension. In the
second place, it is even more impossible that the appearance
of spatial change should be derived from external influences,
for, in this case, the a priori character of the space-form
would be destroyed.1

2. A second view of the ultra-sub jectivist type is that of
Leibniz, who thought of space as ' something purely relative
... as an order of coexistences. Space denotes, in terms of
possibility, the order of those things which exist at the same
time, in so far as they exist together ; leaving on one side

1 Cf. Nys, op. cit., p. 79. For a detailed criticism of Kant's theory see
Pritchard. Kant's Theory of Knowledge, Chaps. Ill and IV, and Nys,
Ch. II.

88 MODERN THOMISTIC PHILOSOPHY

their way of existing. Whenever we see several things
together, we are conscious of such an order of the things
among themselves.'1

Consistently, therefore, with his cosmological theory,
according to which the world is composed of unextended
monads, he banishes space altogether from reality, and makes
of it something purely mental or ideal.2

We already noticed one radical defect of this theory, when
we showed that it is impossible for the notion, or appearance,
of extension— and so of space — to arise in our minds unless
there be some spatial extension somewhere in reality : but
we may mention here some difficulties which belong peculiarly
to this view of space. For, in the first place, the coexistence
of things, and a fortiori the order of coexistences, presupposes
space, since they are said to coexist precisely because they
appear to exist together in different parts of space. Con-
sequently, since the order of coexistences presupposes space,
it cannot constitute it. In the second place, the attributes
of space must apply to the order of coexistences if these two
are identical. Now, space is said to be full, empty, and equal
to the located thing, none of which predicates can be applied
to the order of coexistences, since an order, or relation,
cannot be full, empty or equal. In the third place, things
which coexist must be bound together by some common link,
which cannot be true of the Leibnizian coexistents, seeing
that they are simple monads without extension. In Leib-
niz's view the monads do not interact in any way, but are
like the puppets in a marionette show, which appear to bow
and speak to one another, but are, in fact, controlled entirely
by the showman : they are not related to one another, but
to the man behind the scenes. In a similar way, the monads
have no connection with one another, but only with God,
who destined them by pre-established harmony to act in a
certain way. So there is no common link between them, and
they cannot be said, in any direct sense, to coexist. Leibniz,
in fact, recognised the gravity of this difficulty, and tried to
meet it — and other cognate ones — by his elusive doctrine of

1 Correspondence with Clarke, third letter of Leibniz, No. 4.
* Cf. Nys, op. cit., pp. 121 f. Wildon Carr, Leibniz, pp. 156 ff.

PLACE AND SPACE 89

the ' vinculum substantiate,' a. real substantial link, and a
reality other than the monads, from which alone continuity
is said to arise. This seems rather to add to the difficulty,
than diminish it, since it is not easy to see how it can be
reconciled with the independence of the monads, which is a
central doctrine of Leibnizianism. The notion of the
vinculum substantiate was introduced in an attempt to
reconcile his theory with the Scholastic idea that bodies,
e.g. of animals, are unities per se, not mere aggregates.1

Lastly, space would still be preserved if there were only
one body in the world ; but, evidently, in this case, there
would be no order of coexistences, and consequently these
cannot be identified.

III. The Intermediate Theories. We now turn to the
intermediate theories, which make space neither a reality on
its own account, nor yet wholly ideal.

1. The first of these is the view of Descartes, Balmes, and
Palmieri, which identifies space with extension. They say
that when we think of space, we abstract from the extension
of bodies, and give to space a generic unity, without division,
so that we can speak of bodies moving in space. Conse-
quently, our notion of space has no counterpart in nature,
but is nevertheless based on something found in nature, viz.
the extension of bodies.

Hence, space is, according to these philosophers, abstract
extension. We have called this an intermediate view, and
indeed it does seem to try and mediate between the extreme
realists and the extreme idealists. Unfortunately, however,
like so many peacemakers, it only succeeds in receiving the
blows which the rivals aim at one another. For, if space be
identical with corporeal extension, it will certainly be real,
and in Descartes' system, an absolute reality ; since there
can never be a vacuum ; and so matter must be indefinitely
extended. Space, then, from this point of view, will be an
absolute, infinite, real being, and open to all the attacks
which the idealists make on the ultra-real views of space,
such as those of Clarke and Spinoza. On the other hand,

1 Cf. Epistola ad Pattern des Bosses, 29 May, 1716; and Latta,
Monadology, etc., pp. 118 ff. (Oxford Univ. Press.)

90 MODERN THOMISTIC PHILOSOPHY

since this theory denies that our conception of space corres-
ponds to anything found in nature, it seems to make of space
something purely mental, and so falls a victim to the blows
which the realists aim at the idealists, such as Leibniz or
Kant. Apart from the awkward position in which it finds
itself, as combining the disadvantages of both the other
theories, the notion that space is to be identified with exten-
sion will not bear investigation, for though it is true that
there are many characteristics, such as stretching out, being
measurable, divisible, and so on, which belong both to space
and extension, yet space has at least one characteristic which
is contrary to that of extension ; for we conceive of space as
that which is filled and occupied by bodies, while extension
is that by means of which a body fills or occupies space.
Consequently, far from being formally identified, space and
extension are formally opposed, as the filled and the filler,
the occupied and the occupier. The truth, therefore, is that
these two are not identical, but that the notion of space
includes that of extension.

2. The second of these intermediate opinions is that of
Suarez and many other Scholastics, as de Backer, Dario, and
others, according to whom space is a logical being with a real
foundation. They conceive it, in itself, as an empty recep-
tacle which is capable of containing bodies, real space being
that portion of absolute space which is occupied by real
bodies. This opinion, like the last, is attacked from two
sides ; since Nys,1 as it seems justly, accuses it of taking
away all reality from space, while others say that it gives it
too much. For, according to Suarez, absolute space is not
real, and what is called real space in this theory is merely a
portion of this absolute or imaginary space ; and so will be
as ideal as it is, since the portions of such ideal space cannot
become real from the mere fact that real bodies are present
in them, nor from any of their properties, since in this view
the parts of space are carefully distinguished from any of the
realities of the bodies which occupy them. Space, then, on
this view, appears to remain a purely ideal entity, a con-
ception which seems irreconcilable with the notion of space
1 Cf. Nys, op. cit., pp. 177 ff.

PLACE AND SPACE 91

as the receptacle of bodies, and the field of their real
motion.

On the other hand, Hoenen maintains that the theory is
ultra-realist, as making a reality of absolute or imaginary
space, since, in this opinion, it is held that a single body
would have in itself a determinate localisation in space,
irrespective of any extrinsic relations to others, so that even
if there were only one body in the world, it would be localised
in space ; and so could, properly speaking, have local motion
through the variation of this intrinsic location.1 There is,
in fact, an inconsistency in this theory, for either absolute
space must be allowed to be real, in which case Hoenen 's
criticism is justified ; or else, as is, in fact, done by those
who hold this view, its reality must be denied, and it then
becomes impossible to say that a single body will of itself be
really present in any part of it ; and space will be something
wholly ideal. Since, then, absolute space is not allowed to
be real, it seems that the criticism of Nys is justified.

3. We now pass to the opinion which regards space as the
interval between bodies. Even here we have a divergence
of views, for some hold that space is the interval between
the confines of a single body, others that it is constituted by
the relation of distance which holds between several bodies,
which relation rests on the accidents which localise these
bodies. The latter is the view of Nys, and can be explained
as follows :

(a) Since all are agreed in conceiving space as the recep-
tacle of real bodies, we start our investigation with this
conception. Now, it seems clear that such a receptacle must
be a three-dimensional relation of distance containing them,
i.e. a three-dimensional relation of distance which connects
the related terms ; and so is such a relation between real
bodies, the foundations of this relation being the localising
accidents which give to the bodies a certain situation in the
universe. That the receptacle must be three-dimensional is
clear, since it must be able to contain the bodies, which are
themselves three-dimensional. This condition is not only the
necessary one for such a receptacle, it is also sufficient, since

1 Cf. Hoenen, Cosmologia, pp. 109 f.

92 MODERN THOMISTIC PHILOSOPHY

to contain or surround a body requires nothing but such
extension, the composition of the receptacle in other ways
being irrelevant.1

Apart, however, from the difficulty, touched on when we
were dealing with place, of allowing that the accidents which
localise a body are something which it has of itself intrinsic-
ally, and which are not derived from its relation to others
(and of such a kind are supposed to be the foundations of the
relation of distance in this theory) there is another difficulty
in it, inasmuch as it would follow from it that a single body
was not in space, which seems to be at variance with the
common view of space, and our ordinary expressions with
regard to it, as when we say : ' This street ' or ' this room is
spacious.' To this it might perhaps be replied that though
we may imagine a single body to be in space, yet, in fact,
considering the essential elements of the notion of space,
viz. that it is a receptacle, and a distance capable of being
traversed, neither of these conditions would be fulfilled in
the case of a single body : for, being single, it could not be
received in anything, since there is nothing else, and a thing
cannot be received in itself ; nor would the distance included
between its limits be capable of being traversed, for it would
either have to be traversed by some body other than itself,
which is impossible, since, by hypothesis, no other body
exists, or else by some part of itself, in which case the body
would be broken up and would no longer be one body.
Neither of these replies is, however, really satisfactory, for
even though a single body could not be actually traversed
owing to the absence of anything to traverse it, yet this
evidently arises from something extrinsic, and not essential
to the body itself, which, as being extended, still retains its
capacity for being traversed. So it would be as absurd to
say that an absolute desert was incapable of being traversed
because there was nothing to traverse it ; as that a man
living alone in a hermitage had lost the power of speech
because he had no one to talk to. Further, with regard to
the non-fulfilment of the second necessary condition, viz.
that it must be received in something, we notice that its

1 Cf. Nys, op. cit., pp. 216-287.

PLACE AND SPACE 93

outside surface would afford a receptacle for it ; for this,
though only modally distinct from the thing itself, is yet
sufficiently distinct for our purpose, since this surface can
be considered as a container instead of part of the content ;
and we are all agreed that space is not a receptacle, which is a
reality, on its own account, apart from the bodies which it
contains.

(b) We turn, therefore, to the second way of regarding
space as an interval of distance. This is that space is form-
ally constituted by the dimensions of the containing body
in so far as the relation of distance is considered in them.
This theory follows directly from the idea of space as the
receptacle of bodies ; since a receptacle of a body is that
whose dimensions are of sufficient extent to circumscribe it :
so that space will be constituted by the dimensions of the
containing body, considered as enclosing an extension, i.e.
precisely with reference to the relation of extension.

What may be considered to be a serious objection to this
theory is that it makes the existence of the void not only
physically, but even metaphysically impossible ; for it is
clear that a body cannot contain nothing ; since to assert
this would be equivalent to saying that it does not contain —
it is not a receptacle — which is to deny the initial concept of
space. Hence, in a void space would vanish, and with space
distance. So, if two bodies were separated by a void, they
would be separated by no distance, and so would not be
separated ; so that the existence of a void becomes meta-
physically impossible.

On the Void.

This question of the void has been one of the most con-
stantly discussed problems in the history of natural philo-
sophy, and it is therefore worth while examining it a little
more fully. Both Plato and Aristotle rejected the idea that
there is, in fact, any empty space in the world : and the
latter seems to have regarded it as impossible that there
should be. Most of his arguments are based on his mistaken
idea of ' natural movement ' ; according to which ' light '
and ' heavy ' are qualities belonging to different kinds of

94 MODERN THOMISTIC PHILOSOPHY

bodies, so that some bodies naturally move upwards, others
downwards ; and both these, and his other, arguments are
all directed to show that it is physically impossible that there
should be a vacuum. S. Thomas, as it seems, shared these
views, and even added one reason which might be taken to
mean that he regarded a vacuum as metaphysically impos-
sible, for he says : ' Cum de ratione vacui sit, quod sit sfiatium
corporis prater corpora, sequitur quod vacuum non sit ,J — in
other words, the notion of a vacuum is self-contradictory.
Since, however, in the whole of this section, the view of the
Platonists, which he regards as mistaken, is being considered,
it is not clear that this statement should be taken absolutely,
but it may be only ' ad hominem.' The absolute impossi-
bility of a vacuum was, without doubt, of necessity main-
tained by Descartes, since he identifies extension with body,
so that any extension will be ipso facto corporeal. He was
followed in this view by Spinoza and Balmes, and also by
Leibniz, though for a different reason.2

Apart from the false Cartesian presuppositions as to the
nature of body, it is clear that if the material universe is
finite, an hypothesis which is faced by no metaphysical con-
tradiction, there must be a certain kind of void outside it,
which some call a negative void ; so that a void is possible,
absolutely speaking. The discussion here, however, is con-
cerned with the possibility of a void within the confines of
the material universe, and regarding the matter without
prejudice, there seems to be no conclusive reason for saying
that such a void is impossible ; since it would only imply
that there should be no matter within a certain area, this
area remaining, nevertheless, surrounded by bodies. Against
this it is argued : (i) that in this case the interior surfaces of
the body (or bodies) which surrounded the void would come
together, or (2) if not, at least there would be no determinate
distance across the void. The first consequence clearly does
not follow, since bodies are not kept apart by the matter
which separates them, but simply are apart by being
localised at different points in space. Neither is the second
a necessary consequence of a void, for since, if there was one

1 IV Phys., Lect. 10, No. 8. 2 Cf. Nys, op. cit., p. 386.

PLACE AND SPACE 95

there would be a determinate circumference round it, there
would also be a determinate distance diametrically across it.
We are, then, led to the conclusion that an internal void is
possible.

Whether there is, in fact, any void within the material
universe is a question which is even less easily answered.
Generally speaking, physicists from the time of Aristotle
down to the present day have agreed in saying that there is
not. The pre-Newtonian scientists held this opinion, either
on the grounds put forward by Aristotle, or later, on the
basis of the Cartesian mechanics. Even when this latter
view was not accepted in its entirety, a void was rejected, as
it was by Newton, on the ground of the impossibility of
action at a distance. Consequently, modern scientists have
supposed that there is an all-pervading ether, which acts as
the carrier of light, and electro-magnetic, waves. Even
though, in the universe of Einstein, the hypothesis of a
luminiferous ether is no longer necessary, its place will be
taken by Space-Time. It would, nevertheless, be unwise to
build up a philosophical theory on the basis of these specu-
lations, and therefore rash to assert, on their authority, that
there is no void in the material universe. In any case, it
seems clear that a theory which makes the void metaphysic-
ally impossible cannot be regarded as a satisfactory account
of the nature of space. If, then, the second view, given
above, is to be taken literally, it is ruled out ; and it seems
that a modification of the first view is required. We wish,
then, to construct a theory which will allow of a single body
(if there were only one in the universe) being spatial or in
space, since there seems to be no valid reason for denying
that it would be : and, secondly, to eliminate the intrinsic
localising accidents which, according to the first theory, are
the foundations of the relation of distance which constitutes
space, while admitting with this theory, or at least not
excluding, the possibility of a vacuum. To satisfy these
conditions, we shall refuse to say that space is a relation of
distance between several bodies, and at the same time admit
that it is a relation, not something absolute, as the second
theory maintains. It will, therefore, be a relation which will

96 MODERN THOMISTIC PHILOSOPHY

hold as well in a single body as in several. Moreover, there
is no doubt that the basis of our concept of space is extension.
Hence, it will be a relation of extension or distance. Now, it
is clear that the only relation of distance which is to be found
in a single body is that between its extremities ; and space
being conceived as the receptacle of body, it will be, as it
were, an envelope enclosing the extremities of the body, and
will be formally constituted by the three-dimensional rela-
tion of distance between the extremities of real body. Thus,
from the point of view of the concept which we form of it,
space will be distinct from the body which it encloses, though,
in fact, their extent will be the same, and an empty space
will be identical in extent with the interior dimensions of the
bodies which enclose it. This explanation thus seems to
include all the data which we have as to the nature of space,
for it will be a receptacle of real bodies, it will be found as the
container of a single body, and empty space will be not
impossible ; being constituted by the relation of distance
between the extremities of the real body or bodies which
enclose it. The space of a single body (if there were only
one) would be constituted by the relation of distance between
its own extremities, considered ideally as enveloping or con-
taining it. It is clear that, if this view be taken, space will
be a logical being, not a reality on its own account ; having,
nevertheless, a basis in reality, since there is, in nature, real
extension, or continuous quantity. The relation of distance,
as conceived of, is not however found in nature, and is the
absence of contact, a condition which is verified both in a
vacuum and a plenum. That space is indeed such a logical
being is very generally held by Scholastics.

Section III. On the Occupation of Space,
(a) On Impenetrability.

If one body occupies a portion of space in such a way as
to fill it, it seems clear that it will exclude another from
occupying the same portion. We are familiar enough with
such impenetrability in ordinary life, for we know that we
cannot occupy the same place as another man, or any other
solid object. The question, considered philosophically, is,

PLACE AND SPACE 97

however, much wider than this, since it is the question
whether it is possible for two bodies to occupy the same
place at the same time, i.e. whether compenetration is
possible. Thus, we are not concerned with what is usually
known as penetrability, which occurs when one body enters
into the pores or interstices of another, as when a sponge is
filled with water ; for, in this case, the body which is pene-
trated does not occupy the space of its interstices, and there-
fore there is no question of two bodies occupying the same
place. Nor is our question confined to any particular kind
of bodies, such as solids or liquids, but is quite general,
relating to any kind of bodies.1

As a preliminary to dealing with the possibility of com-
penetration, something must be said as to the question of
fact ; viz. whether it is a fact that any matter is continuous,
for if it is not, the whole question of the possibility of com-
penetration falls to the ground, since it is clear that if no
body has continuous extension, none will occupy a place, so
that we cannot ask whether any other can occupy it at the
same time.

That the question comes to be asked at all is due to current
physical theories, in which matter is regarded as composed
of discontinuous molecules, molecules of discontinuous atoms,
atoms of discontinuous electrons and protons. The electrons
within the atom are said to be such that they cannot have
both velocity and position in an exact sense.2 It seems,
therefore, that they cannot have continuous extension, and
the same would be true, no doubt, of the nucleus ; and so,
in this theory, all continuous extension appears to be taken
away from the world.3 On the other hand, we have a theory
which is the antithesis of this, and asserts that all through
the universe there is an absolutely continuous ether which

1 Fr. McWilliams in his Cosmology (p. 94) says that compenetration
. . . means the presence together of two absolutely solid bodies in the same
place.' If this were to be taken to mean that the question is confined to
solids, as opposed to liquids or gases, it would no doubt be a mistake.
But the context seems to show that his meaning is that the question does
not relate to solids in this sense, but to continuous bodies, or, to the parts
of discontinuous, or porous ones, which are continuous.

2 Eddington, Nature of the Physical World, pp. 220 ff.

3 Cf. Whitehead, Science and the Modern World, pp. 122 ff.

98 MODERN THOMISTIC PHILOSOPHY

is thought of as the carrier of light, and electro-magnetic
waves. This ether pervades the atom, and even the nucleus
and electron of which the atom is composed. These, then,
may be either knots or coagulations in the ether itself, in
which case there would be only one body in the world — the
ether — and so no chance of compenetration ; or else they
may be bodies other than the ether, in which case compene-
tration is a fact. Science, therefore, in different moods, or
in accordance with different theories, seems to say : (i) that
the question of compenetration is illegitimate, since there
are no extended bodies, i.e. having continuous extension,
(2) that it cannot occur, since there is one continuously
extended body, and only one, and (3) that it does occur.
The apparent contradictions here are reconciled by taking
now one view of matter, now another ; and by denying
material character to the ether.1 This last denial would
clear up the affair, if we knew what matter itself is, for it is
clear that we cannot attach any meaning to the statement :
' the ether is not material,' unless we know what the predi-
cate means. Now, this is just what we do not know ; and
we therefore have to be content to use that theory which
suits us best, i.e. which is simplest, in investigating any
particular class of phenomena. But whatever may be the
divergences of view as to the nature of matter and the ether,
all the theories agree in making the elements of matter
separate from one another in space, i.e. in saying that there
is a distance or extension between them. Now, it is clear
that if the ether were supposed to be material, we should
have a number of continuously extended portions of it ;
and so some continuous body in the universe ; and if it is
not material, it is impossible to measure it by physical means,
since all our measuring instruments are, of necessity,
material ; so that it would be illegitimate to assert that it is
extended. It seems to be a curious position to deny exten-
sion to material objects which can be measured, and to
assert it of an immaterial one which cannot. From the
point of view of physics, therefore, the position is not unsatis-
factory, for we can use any hypothesis which suits us at the

1 Cf. Eddington, op. cit., pp. 31 f.

PLACE AND SPACE 99

moment ; but from the point of view of philosophy, if these
hypotheses are to be taken as telling us of the nature of
bodies, it is intolerable, and lands us in contradictions ; and
our only course would be to deny any extension at all to the
physical world ; since it is absurd to assert that unextended
points, having no position, are separated from one another
in space. If bodies, or their elements, are not extended,
the spaces between them cannot be either. In this case,
however, we are faced with the insuperable difficulty of
explaining the illusion of extension, as it is then thought to
be, and all the other difficulties of the Leibnizian theory.
We are therefore compelled to reject the notion that there is
no extension in the world, and to assert the continuous
extension of both simple and compound bodies, unless such
extension can be shown not to exist in a particular case. In
doing so, we shall not be rejecting the scientific theories, as
scientific, i.e. as giving the simplest and most comprehensive
account of phenomena yet discovered, but we shall be reject-
ing them as philosophical ones, which they were never
intended to be : and we do so for the excellent reason that
they are, in this sense, contradictory in themselves, and lead
to impossible conclusions. If it be true, then, that some
bodies have continuous extension, it is possible to ask
whether two of them can occupy, i.e. make their dimensions
exactly correspond with the same place at the same time.
That they actually do so, and therefore, that it is possible for
them to do so, is held by some scientists, as Lodge, who con-
sider that the ether is a kind of matter which permeates other
bodies j1 but there is here almost certainly some confusion
of ideas. Among philosophers, apart from the Dynamists,
who deny the legitimacy of the question, none hold that
bodies actually do compenetrate, and almost all that it is in
some way, either physically or metaphysically, impossible
for them to do so.

Descartes and his school necessarily thought that it is
metaphysically impossible, for, if the nature of body is

1 Cf. Lodge, Ether and Reality, Ch. II, pp. 38 ff. Though he seems to
deny that the ether is ' matter,' yet he says that material particles are
probably formed out of it. So the ether is other than the particles, and
yet the particles consist of ether.

ioo MODERN THOMISTIC PHILOSOPHY

extension, where there is a single extension there must be a
single body, so that two bodies occupying the same place
would ipso facto be one : in other words, the supposition is
unthinkable.

Locke thinks it physically impossible, since ' this resis-
tance, whereby it ' (i.e. a body) ' keeps other bodies out of
the space which it possesses, is so great, that no force, how
great soever, can surmount it.'1

Though among Scholastics there is general agreement as
to the possibility, absolutely speaking, of compenetration,
there is considerable difference of opinion as to the nature of
that property of bodies which makes them naturally impene-
trable. Some consider it to be an active force, as Palmieri
and Hoenen, others as a simple consequence of continuous
extension ; and this latter opinion is that of the majority,
following S. Thomas. Indeed, this view seems much more
consonant both with common sense and the present state of
knowledge than the other ; with common sense, since it is
difficult to see how a body can preserve an unbroken con-
tinuity of its boundaries if another one, which is also con-
tinuous, forces its way into it ; and with our knowledge of
nature, for in fact no compenetration is known in nature,
but only the passage of small bodies through the pores of
other bodies, and, moreover, the smallest scientific bodies,
atoms and electrons (a-particles , etc.) are said to vary in their
power of penetration. So the a, (3, and y rays are progres-
sively more penetrating, and this in proportion as they
possess more of the character of waves, and less of corpuscles.
This would seem to accord better with the idea that the cause
of impenetrability is the corpuscular or continuous nature of a
body rather than the activity exerted by the body to be
penetrated.

Whatever interpretation is to be put upon the facts, in so
far as they are known, philosophical considerations seem
clearly to indicate that impenetrability naturally results
from the extension of bodies ; since if, as we have seen, it is

1 Locke, An Essay concerning Human Understanding, Bk. II, Ch. IV,
Sect. 3. Fr. Dario, S.J., and Fr. Hugon, O.P., represent Locke as holding
it to be metaphysically impossible, but this does not seem to be the case.
Vide Dario, Cosmologia, p. 143 ; Hugon, Cursus Phil., Vol. II, p. 197.

PLACE AND SPACE 101

the function of quantity to give material substance parts
outside parts, it will naturally follow that one part will be
outside the place of another. Now, this relationship of the
parts of quantity with regard to place is evidently something
extrinsic to quantity itself, since the nature of quantity is
merely to have parts outside parts in the whole, without
reference to place. Consequently, absolutely speaking, no
contradiction is involved in this natural consequence of
quantity, which is impenetrability, being removed ; for the
essential character of quantity, the having parts outside
parts would still remain, even though the parts of the quan-
tities of the two bodies would occupy the same place. Hence
compenetration, though naturally impossible, is not meta-
physically so, and consequently could be effected by an
agent who had sufficient power, such as God ; granted that
the distinction of the bodies, which is ordinarily secured by
distinction of place, could be preserved ; a condition which
is capable of fulfilment in the case of bodies of different
material constitution ; though impossible for purely geo-
metrical volumes, which, if equal, can only be distinguished
by position.

(b) On Multilocation.

If two bodies cannot naturally be in one place together ;
what is to be said on the question whether one body
can be in two or more places simultaneously ? Is such
multilocation possible ? This question admits of solu-
tion much more easily than the last. We must bear
in mind the distinction made above (pp. 81 f.) between
circumscriptive and non-circumscriptive presence in a
place. That non-circumscriptive presence (which, as we
have seen, is only analogically called location) by a
thing in several places at once, is possible, is universally
admitted, for there is clearly no contradiction involved in a
body being circumscriptively in one place, and yet joined to
another in some other way. With regard to circumscriptive
presence, on the contrary, there is a difference of opinion, for
Suarez holds that it is not absolutely or metaphysically
impossible, in which view he is followed by Dario, among

102 MODERN THOMISTIC PHILOSOPHY

recent writers. The opinion of S. Thomas is quite clear,
since he says plainly that bilocation involves a contradiction,
which is to say that it is metaphysically impossible.1 The
reason for this latter view seems absolutely convincing, since
it is quite impossible for a thing, while retaining its own
dimensions to be twice, or three times, as large as it is.
That this would be the case, if a body were circumscriptively
in more than one place at the same time, is clear, since cir-
cumscriptive location is brought about by the dimensions of
the located body corresponding with those of the containing
one ; so that if a body were in several places at once, its
dimensions would correspond with those of several contain-
ing bodies at once ; and its dimension, say A, would be at
the same time A + B, . . . which is contrary to the
principle of identity. If we want to bring this vividly before
the imagination, we may picture a man sitting in two con-
tiguous places at once. The space occupied by him would
thus be double what it was when he was sitting in the usual
way, and yet his dimensions would remain the same, and so
could not occupy more space than they did before. Without
swelling out he is twice as big, which is absurd.

1 Quodlibet III, Arts, i and 2 ; IV Sent. dist. XLIV, Q. 2, a, 2, sol. 3,

ad 4um.

CHAPTER VII

THE LIMITS OF QUANTITY

The Infinite — Its Kinds — The Possibility of Actually Infinite
Quantity — Of an Actually Infinite Multitude.

One question still remains to be discussed with reference to
quantity, viz. whether it is necessarily limited, or is it
possible for it to be infinite ; for the infinite is that which
has no term or limit. In order to grasp the exact bearing of
this question, we must first see the various ways in which
this term ' infinite ' can be understood.

1. So the Scholastics distinguish in the first place between
the privative and negative infinite, the former being that
which, though capable of being terminated, yet is not actually
terminated ; while the latter is that which is incapable of
being terminated ; which incapacity may be due to its entire
perfection, when we have what is sometimes known as the
positive infinite (or to its imperfection).

2. Again, they divide the infinite into the categorematical
and syncategorematical. The first is that which is unlimited
in act, and so is called the actual infinite ; and the second,
that which is capable of receiving one act after another
without end. So it is finite in act, and infinite potentially
only, and is called the potential infinite, or the indefinite.

3. A third division is into the infinite simply speaking,
and in some particular respect (secundum quid). The infinite
simply speaking is that which is altogether unlimited, and
possesses every possible perfection. It is known also as the
absolute infinite. The infinite secundum quid is that which
in some direction has no term, and thus possesses some par-
ticular perfection in an unlimited degree. This is also called
the relative infinite.

The question we are asking here is whether it is possible
to have an actual infinite with respect to quantity.

103

104 MODERN THOMISTIC PHILOSOPHY

That the syncategorematical infinite, both in magnitude
and multitude, is possible, is sufficiently clear, for no reason
can be assigned why we should stop at any particular magni-
tude in a series, and say there could not be a greater ; and the
same applies to a series of individuals — there could always
be one more ; and we have seen, too, that the continuum is
divisible to infinity. Our question, therefore, is confined to
the possibility of the categorematical infinite.

Aristotle defines the privative infinite, of which we are

here Speaking, as follows : arrtipov /i«v ovv «rriv ov xaT<*
Trocruv kaLjifidvovo-iv cuei ti \af3elv ccttiv e£o) (207a7)»1 which

may be rendered : ' so then the infinite is that of which
any quantity being taken, there always remains some-
thing to be taken outside ' (this quantity) ; a definition
which is approved of by S. Thomas, who rejects with
Aristotle the definition of infinity which makes it ' that
outside which there is nothing ' : since what is essential to
infinity is that it should be inexhaustible, not that there
should be nothing greater than it. It has been suggested2
that this is rather the definition of the indefinite, but this
does not seem to be the case, for in the indefinite, when a part
has been taken, there does not remain something more to be
taken, but only something potential ; and it is that which is
potentially, not actually, inexhaustible.

There is no general agreement as to the possibility of an
actually infinite magnitude and multitude within the genus of
quantity, but the majority of Scholastics following Aristotle
and S. Thomas deny the possibility of either.

(a) That an actually infinite discrete quantity, or number,
is impossible, is easily seen, since every actual number is
closed by its last unit, for if it had not a last unit, it would
not be actual but potential ; as the series of ordinal numbers,
ij 2, 3, 4, etc. ... w. is a potential whole, not an actual
one ; and so is potentially infinite, or indefinite, not actually
infinite. What is actually infinite cannot be closed by a last
unit, or it would not be infinite, and consequently no number
can be actually infinite.

1 Cf. S. Thomas in III Phys., Lect. II.

2 Vide Dario, Cosmologia, p. 114.

THE LIMITS OF QUANTITY 105

(b) Turning to the question of an actually infinite con-
tinuous quantity, or magnitude, we notice that this might
be an attribute either of natural or mathematical body.
But it can be seen that the supposition that either has such
an attribute leads to contradiction.

1. Considering natural body, we see that its quantity is
an intrinsic accident, which will therefore take its rise from its
substantial form, since it is this which gives a thing its
intrinsic nature. Now, it is clear that every natural body,
when it is actual, will have a certain determined substantial
form, since form is its act, and that a determined form cannot
be the source of what is not determined, but infinite. Hence,
no natural body can have an actually infinite extension or
quantity.

2. Just as natural body, when actual, has a certain deter-
mined form, so has mathematical body, though, in this case,
the form is its shape. Now, shape is the outline of the
mathematical figure, and is therefore its termination or
boundary. Consequently, every mathematical body is ter-
minated and finite, and the supposition that it is not, is in
contradiction with the very notion of mathematical
body.1

We see, then, that it is impossible to find actual infinity
either in number (multitude within the genus of quantity),
or in magnitude.

Though, strictly speaking, we are here concerned only with
the possibility of an actually infinite quantity ; since we
have spoken several times of multitude within the genus of
quantity, it is implied that we might have a multitude outside
that genus, and the question suggests itself whether such a
multitude could be actually infinite ; so that it is convenient
to discuss it here.

By a multitude we mean a collection of distinct beings ; if
these are quantitative, it will be a multitude within the genus
of quantity ; if not, it will be outside it. Now, quantity is
an accident found only in material substances, so that a
collection of quantitative beings will be a collection of material
ones. Hence, the question here asked is whether we can

1 Cf. S. Thomas, Summa Theol., Pars I, Q. 7, a. 3.

106 MODERN THOMISTIC PHILOSOPHY

have a collection of immaterial beings which is actually
infinite.

The earlier Thomists, as Capreolus,1 affirm that the notion
of an actually infinite multitude involves an intrinsic contra-
diction ; and this seems to have been the generally accepted
view among the great Thomist writers, such as John of
S. Thomas ;2 though there is always much doubt whether
they are not speaking only of quantitative multitude. In
any case many recent writers, as Hugon,3 are definitely
opposed to the possibility of any kind of actually infinite
multitude. Nevertheless, the contrary view has lately begun
to find favour, as with Mercier,4 Nys,5 Remer,6 and Geny.

The opinion of S. Thomas is not altogether clear, but it
seems that we can trace a development of his thought in
this matter. In the Summa he denies the possibility of an
actually infinite multitude.7 This was written8 in the years
1 267-1 268. Nevertheless, the argument on which he founds
this assertion is pronounced by him, two years earlier, in his
commentary on the Physics (III Phys., Lect. 8, circa 1265)
to be a probable one only. Thus it is not surprising to find
that in the Questiones Quodlibetales (IX, a. i, XII, a. 2),
written in 1264-1268, he distinguishes between the absolute
and ordinated power of God, and seems to allow that, with
respect to the former, an actually infinite multitude is not
impossible, though he says that the view which denies its
possibility ' seems truer.' Finally, in the essay De JEternitate
Mundi (1270), he absolutely p-^irms that no proof of the
impossibility of an actually infinite multitude has yet been
given : ' Et tamen non est adhuc demonstratum quod Deus non
possit facer e infinita esse in actu.' With regard to the state-
ments in the Summa, we may perhaps apply to them the
distinction made in the Quodlibets, and say that they ' should

1 Capreolus (ed. Paban-Pegues), Vol. II, p. 537.

2 John of S. Thomas, Cursus Phil. Phil. Nat., Part I, Q. 15, a. 3.
8 Hugon, Cursus Phil., Vol. V, pp. 193 ff.

4 Mercier, Metaphysique Generate, pp. ic , ff.
6 Nys, La notion d'Espace, pp. 335 ff.

6 Remer and Geny, Cosmologia, Nos. 119 ff.

7 Summa Theol., Pars I, Q. 7, a. 4 ; Pars I, Q. 7, a. 3, ad 411m ; 1.46,2,
ad 6 and 7.

8 The chronology of these writings is that of Mandonnet, Bibliographie
Thomiste, pp. xii ff .

THE LIMITS OF QUANTITY 107

be understood not absolutely, having regard to nothing but
the power of God which is limited only by the principle of
contradiction, but bearing in mind the normal conditions of
quantitative beings, and the action of God, which pre-
supposes the concord or harmony of all His attributes.'1

The chief argument against the possibility of an actually
infinite multitude is that such a multitude could not be added
to, being infinite, and yet since it is actually infinite, it
must contain a definite number of individuals, otherwise it
would be only potentially infinite, not actually so ; it would
be indefinite. If, however, it contains a definite number of
individuals, we could always add one more ; so that it both
could and could not be added to, which is absurd. Further,
if we supposed that there existed an actually infinite multi-
tude of spiritual beings, there would be a still greater multi-
tude of their thoughts, volitions, etc., so that we should have
two infinities of which one was greater than the other ; so
that the lesser could not be infinite. The idea, then, of an
actually infinite multitude is, it is argued, self-contradictory ;
since such a multitude, though infinite, must contain a
definite, i.e. a limited or finite, number of individuals.

The fallacy of this argument seems to be that we are not
here dealing with individuals which are numerable, and con-
sequently the idea of number introduced into the argument is
out of place.

In favour of the possibility it is argued :

1. That the ideas of infinite and multitude are not contra-
dictory ; since the second implies only a collection of dis-
tinct individuals, while the first denies that this collection
has any limits.

2. God knows all possible things, actually and distinctly.
There is, however, an infinity of possibles, so that God knows
an actually infinite multitude, distinctly and actually.

3. If creation from eternity is possible, there seems to be
no reason why there should not be an actual infinity of
creatures. This series would be infinite a parte ante, though
limited a parte post, i.e. at the ' now ' ; just as the series of
our thoughts and volitions, on the hypothesis of individual

1 Pegues, Commentaire Litterale de la Somme Thiol, in I. ,7, 3, and 4.

108 MODERN THOMISTIC PHILOSOPHY

immortality, is infinite a parte post, though limited a parte
ante, if our souls were created at our conception.

Whatever is to be said on this difficult problem, we must
certainly avoid confusing multitude with number. As
Cardinal Mercier says : ' The question of the possibility of
an infinite multitude is certainly open to dispute, but the
debate cannot be cut short by the summary consideration that
every collection of unities is essentially finite. To confuse
multitude and number is to solve the question by begging it.'1

Note : S. Thomas remarks in the Contra Gentiles (Bk. II,
Ch. 81) that Aristotle in the Physics (III Phys, V, 13 ff. :
S. Th. Lect, 9), and in the De Ccelo et Mundo (I De Ccelo,
V ff. ; S. Th. Lect. 9 ff.), proves that there is no actually
infinite multitude of corporeal beings, but not that there is
none of incorporeal ones. This was written between 1258
and 1260.

1 Mercier, Metaphysique Generate, p. 196.

CHAPTER VIII

THE QUALITY OF BODIES, OR MOTION

The Nature of Motion — Action at a Distance — The Nature of
Gravitational Action.

Section I. On the Nature of Motion.
After the consideration of the quantity of bodies, we now
turn to that of their common quality, which is change. The
word ' motion ' was used by Aristotle and S. Thomas to
express this ; but its signification is evidently not the same
as that of mutation, or the transit from one state to another,
for mutation may be either intrinsic or extrinsic ; and in
both cases there are some kinds of mutation which cannot
properly be called motions. For extrinsic mutation may be
either metaphysical, as creation and annihilation, which are
not motions properly speaking, since in both there is only
one term : or physical. In this latter case the change may
be either substantial or accidental ; the first being of two
kinds : generation and corruption ; while the second
embraces both instantaneous change, which is accidental
generation and corruption, and which again, not being con-
tinuous is not motion properly so called ; as well as succes-
sive, which includes local motion, alteration, and increase (or
growth).

Motion, in the sense of successive physical mutation, is
defined by Aristotle as ' the act of that which is in potency
as such.'1 Obviously, when a thing is merely in potency to
something it has not begun to change ; when it is actually
something, it has ceased to change, if it ever has changed ;
so that in order that it may be in motion it must be neither
wholly actual, nor wholly potential, but in some intermediate

1 III Phys., i ; 20iaio.
109

no MODERN THOMISTIC PHILOSOPHY

state, i.e. will be the actualisation of that which is in potency,
or of the potential. But this is not sufficient for actual
present change, for it may have begun a motion towards
some term, and never attained it, but have stopped half-
way. In this case, though it is in potency to the term, and
in process of being actualised, it is not changing. Hence,
the words ' as such ' are added in the definition, meaning
that the potency is being actualised, or is actually tending
to some further act.1

Now motion, which is confined, strictly speaking, to that
kind of change which is successive — since, as S. Thomas
says,2 it requires time — is always produced by some agent.
So we are led to the consideration of action, of which the
correlative is called ' passion.' Action, moreover, is of two
kinds : immanent, whose source and term are in the agent,
and transeunt, which produces an effect in something other
than the agent.

There was, in the Middle Ages, a vigorous dispute as to
the subject of action, some maintaining that action was in
the agent, others that it was in the thing acted on — the
patient ; the first view being held by the Scotists, Cajetan,
and others ; the second by the majority of Thomists, such
as Capreolus, and by Suarez. It is not necessary for us to
enter in detail into this discussion, which seems to be largely
a controversy about words and phrases ; since Scholastics
now generally agree that the contending views can be recon-
ciled, and all the factors of the situation satisfactorily
accounted for, by saying that there are in action two form-
alities, one by which the agent is actuated, and another
which is in the term, and actualises the patient ; so that the
complete formula, with regard to the subject of action, will
be that action is initially in the agent, and completely in the
patient. It is, in fact, clear that the agent is the cause of
action, and originates it ; and no less clear that it is the
patient which is altered, and so, that the action, as producing
its effect, which is action properly so called, is in the patient.
So S. Thomas says : ' An act, which is in reality the same,
belongs to two things in different ways : for it belongs to

1 Cf. Ross, Aristotle, p. 81. 2 V Phys., I, Lect. i.

THE QUALITY OF BODIES in

the agent inasmuch as it is from it, and to the patient
inasmuch as it is in it.'1

Section II. On Action at a Distance.

Having determined the way in which it is most correct to
speak of the subject of action, we next have to consider its
necessary conditions. Now, it is suggested that presence is
not such a condition, but as this matter has given rise to a
good deal of controversy, it is well to see what can be said
about it.

Preliminary Notions.

It is obvious that when we say that two things are present
to one another, we mean that they are not separated from
one another in some particular respect. If we are dealing
with quantitative things, this non-separation, with regard to
quantity or extension, is called contact.

Now, presence is of two kinds : virtual and formal ; for,
as between an agent and its effect, it may happen, either
that the very substance of the agent is present to the effect,
when we have formal presence, as in the case of the soul and
the body which it informs ; or that the agent is present to
the effect, not in its own substance, but by means of its
power, as in the case of a man whose thoughts produce effects
in others, such as those of a statesman, a philosopher, or a
religious teacher. The Scholastics call the presence, in these
two cases, immediacy of suppositum, and immediacy of
power, respectively.

Quantitative presence is divided in a similar way. So we
have mass contact when the extremities of two bodies are
together, and virtual contact, when there is immediacy of
power only, between two things.

It is clear that mass contact can only occur in the case of
two bodies, whereas there may be virtual contact between
two things, of which one is quantitative, or corporeal, and
the other not quantitative, or spiritual.

The statement ' action at a distance is impossible,' may be
taken in one or other of two senses as meaning either that we

1 III Phys. Lect. 5, 10.

ii2 MODERN THOMISTIC PHILOSOPHY

cannot have action between two bodies without mass con-
tact, or that such action is impossible without either mass or
virtual contact. The word ' cannot ' is also ambiguous, since
it may imply physical impossibility, i.e. that we have no
warrant in nature for saying that it can occur, or meta-
physical and absolute impossibility. How easy it is to con-
fuse these meanings can be seen in a remark by Dr. Schiller :
' Such action ' (i.e. at a distance) ' our scientists persist in
regarding as impossible. ... If metaphysics had been con-
sulted, it would have been obvious that no special medium
was required to make interaction possible between bodies
that coexist, seeing that their coexistence is an ample
guarantee of their connection and of the possibility of their
interaction.'1 This, at least, is obvious, that Schiller is main-
taining that such action is metaphysically possible, and the
scientists that it is physically impossible — opinions by no
means incompatible.

Three distinct views may therefore be held on this
subject :■

i. That action between bodies without mass contact is
both metaphysically and physically impossible. This appears
to have been the view of Aristotle and S. Thomas, though the
latter, at any rate, does not seem to have stated it explicitly.
It was also held by Suarez,2 and is still maintained by modern
Scholastics.

2. That action without mass contact between bodies is
physically impossible, but that its metaphysical impossi-
bility has not been proved. This is the view put forward
by Nys.3

3. That such action is both physically and metaphysically
possible.

Those who hold this last view, further maintain that such
action occurs ; and it is an opinion which has found favour
both with great scientists such as Faraday, as well as with
philosophers as Leibniz.

That mass contact between bodies is a metaphysically

1 Schiller, Riddles of the Sphinx, p. 66.

2 Suarez, Metaphysical Disputations, Disp. 18, Sect. 8, nn. 1 and 13.

3 Nys, Cosmologie, Vol. I, Sect. 199.

THE QUALITY OF BODIES 113

necessary condition of action appears to be a proposition
incapable of proof ; nevertheless, arguments derived from
our knowledge of natural laws seem to show that action does
not take place between two bodies without such contact : in
other words, that, as far as our knowledge of nature at
present extends, it is probably true to say that mass contact
is physically necessary. That some kind of contact is
absolutely necessary for action of any sort between two
things is really a truism, as we shall see ; and it seems to be
in this sense that the axiom ' action at a distance is impos-
sible ' should be understood.

With regard to the physical necessity, there are some
probable arguments which show that the laws of nature, as
at present known to us, are not consistent with the view
that action between bodies can take place without mass
contact.

First, we may argue from the law of the inverse square,
which governs the actions of bodies in such a way that the
intensity of the action varies inversely as the square of the
distance between them, and so diminishes as the distance
increases. It follows that they cannot act on one another at
a distance, i.e. without mass contact, since a material force
can only be diminished by a material resistance which, in this
hypothesis, would be lacking, since the bodies would be sup-
posed to act across a space void of matter. Since, then,
there would be nothing to diminish the force with which
they act on one another, it would not be diminished ; unless
we are ready to posit an effect without a cause, or invoke
spirits, or other unknown forces to account for the
unaccountable.

Secondly, such action is not a natural mode of action, since
bodies are naturally in a place, and just as the being of a body
is naturally circumscribed by a definite place, so also is its
action, on the basis of the general principle that the mode of
action of anything corresponds to its mode of being.

As against this opinion the following objection may be
urged. Gravitation is propagated instantaneously, or, at
least, with a velocity which has been estimated to be at least
fifty million times that of light ; all bodies appear to be

ii4 MODERN THOMISTIC PHILOSPOHY

absolutely transparent to gravitational action ; and it is
not subject to any kind of reflection or refraction. It seems
also to be independent of the structure, or the physical and
chemical conditions of the bodies between which it acts : its
energy is unchangeable and inexhaustible. Hence, it appears
that gravitation acts without being in any way affected by
the medium through which it may appear to pass ; i.e. that
it acts at a distance.

This serious difficulty may perhaps be met on the lines of
the classical physics by supposing that gravitation is due to
waves in the ether of space, which, by hypothesis, is omni-
present ; waves which can penetrate intervening matter
even more easily than can the long waves of wireless tele-
graphy.1 Another solution, however, has been suggested by
the theory of Einstein. The connecting link between the
two is to be found in a sentence written by Fitzgerald in
1894 : ' Gravity is probably due to a change in the structure
of the ether, produced by the presence of matter.'2 In the
developed theory of Einstein there are in space-time natural
paths, along which bodies move naturally ; the structure of
space-time being such that it will only allow of certain
definite configurations. Such a state of affairs is familiar to
us in bodies with which we are constantly dealing in every-
day experience, as in the shapes taken by liquids in motion,
or to use Eddington's example, in a piece of cloth which is
gathered into puckers ; the part between the puckers being
capable only of a definite configuration, or, conversely, if the
part between the puckers is to lie flat, the puckers themselves
must be of a particular kind.3 Similarly, in this view space-
time allows of certain curvatures only, and since these curva-
tures are the matter in it, the bodies must be so arranged in it
that they will not create any unallowable ones ; or, it would
be better to say that they will appear to arrange themselves
in this way. Their doing so is their falling to the earth, their
passage round the sun, and so on, So, in following the in-
trinsic laws of space-time, and of matter, they will naturally

1 Cf. Lodge, Ether and Reality, pp. 44, 60, and Ch. IV.

2 Scientific Writings, p. 313.

3 Eddington; Nature of the Physical World, pp. 127 f.

THE QUALITY OF BODIES 115

move in certain paths. Just as in Newtonian physics we
imagine bodies to move naturally along straight lines in
three-dimensional space, when not acted on by any forces,
since such paths will be the shortest distance between two
points ; so in the curved four-dimensional continuum of
space-time, the bodies will still tend to take the shortest
track, but this track will no longer be a straight line, but a
curve. Hence, the earth circling round the sun, the stone
falling to the ground, are not, according to this view, pulled
out of their natural paths by some force, but are simply fol-
lowing that path in space-time which is the shortest, and
does not entail their inducing in it any unallowable curva-
ture. So gravitation is not a force which acts between bodies,
but the appearance of pull is simply due to the fact that in
the regions near matter space-time is curved, and the
natural paths of bodies are therefore curved also. This way
of regarding gravitation, therefore, describes it, not by way
of cause and effect, as Newton did, but simply as the state-
ment of a situation : space-time being of a particular kind,
and only amenable to certain configurations, bodies move in
a definite fashion. So the idea of gravitation as a force is
got rid of, and with it the objection that it is a force which
acts at a distance ; for it is clear that if there is no gravita-
tional action between bodies at all, there cannot be action at
a distance which is gravitational.

To turn to the proposition : ' some sort of presence is
required for action between things,' it can hardly be denied
that we are justified in calling it a truism. For, if one thing
acts on another, it influences it in some way, and so has some
connection with it, or is not altogether separated from it.
To say that a thing can act at a distance in this sense is an
obvious absurdity, since it is equivalent to saying that it can
influence the thing on which it acts, while it remains in every
way separate and disconnected from it, and so not influencing
it. That, if there is not mass contact, there must be some
medium through which the action shall pass is not, and
cannot be, proved by this and similar arguments.

So, in a word, we may say that there seems to be no meta-
physical impossibility involved in action between two

n6 MODERN THOMISTIC PHILOSOPHY

bodies without mass contact, but that physically it is prob-
able that the laws of nature do not allow of it.

For the whole question, see Nys, Cosmologie, Vol. I,
pp. 256 ff. Also : Hugon, Cursus Philosophies Thomisticce ,
Vol. VI, pp. 142 ff.

Note : The explanation given above of Einstein's account
of gravitation is, of course, entirely inadequate. All that is
necessary to grasp here is th?t, according to Einstein, gravi-
tation is not regarded as a pull or force, and so cannot be an
example of a pull which acts at a distance. A fuller explana-
tion is given by Eddington in the work referred to, and this
is probably the most intelligible account of a non-technical
kind. (Eddington, Nature of the Physical World, Chaps. VI
and VII.)

CHAPTER IX

THE MEASURE OF MOTION, WHICH IS TIME

Duration — Eternity, Mvum, and Time — Division of Time — Non-
Thomistic Views as to the Nature of Time — Newton, Kant,
Leibniz, Bergson.

The word ' motion ' no doubt means, properly speaking,
successive motion for which time is required, by which
motion itself is measured ; and so the consideration of
motion naturally leads us to that of time. The whole ques-
tion as to the nature of time is a very thorny one, for as soon
as we begin to submit it to analysis, time, which seems such
an obvious fact of our lives, eludes us, and has ' softly and
silently vanished away.' This is due to the nature of our
thought which can only deal with things which are fixed and
permanent, whereas time is essentially fluid and impermanent
Nevertheless, though we cannot give a clear-cut answer to
the question — what is time ? — and, indeed, such an answer
would be its own refutation — we can discover a good deal as
to its nature by careful consideration.

First, then, it is clear that time is a species of duration :
and to say a thing endures is to say that it continues to
exist, so that duration is permanence in existence, and it
might be thought that duration is either to be identified with
the thing which endures, or, if not, at least is the same as its
existence. Neither of these opinions, however, is tenable
without qualification, for, in the first place, the hold which
anything has on existence is not something which belongs to
it of its very nature, otherwise, so long as its nature was not
altered, it could not cease to exist, which is contrary to
experience ; since things do come into being and pass away,
which they could not do if existence was their very nature.
It is clear that this conclusion would not be conceded by

117

n8 MODERN THOMISTIC PHILOSOPHY

those, such as Suarez, who identify essence and existence ;
but, even if this be done, duration is, in the second place,
not precisely the same as existence, and so, as the nature of
the thing, for to say that a thing exists durably or per-
manently is to say more than that it simply exists.

Whatever differences of opinion there may be as to the
relation of duration to the enduring thing, the Scholastics all
agree in distinguishing three kinds of duration : eternity,
aevum and time ; the first being the duration of a thing
which is altogether unchangeable, the second that of a thing
which is subject to accidental change, though it remains
immutable in its substance, the third the duration of a
thing which is subject both to substantial and to accidental
change.

Eternity is defined by Boethius as ' interminabilis vitce
tota simul et perfecta possessio.'1 The words ' tota simul ' ex-
clude the idea of succession, and the word ' perfecta ' the
idea of the temporal ' now,' in which possession of life and
existence is imperfect, since it is essentially transitory.
Eternity is, strictly speaking, interminable, since it has
neither beginning nor end. Since there is absolute immuta-
bility in eternity, it is clear that there is no succession in an
eternal being, nor even are things which succeed one another
successive with regard to it, since, having no beginning or
end, it includes and embraces them all. ' Just as,' says John
of S. Thomas, ' if there were a tree of such a size as to stretch
out over all the waters of a river, it would coexist with all
the parts of the river together, even though these succeeded
one another.'2 Time, on the other hand, is intimately con-
nected with succession, of which we get our first notion when
we notice local motion, since the moving thing passes through
a succession of places. Now, it is clear that such movement
takes place in time, and at first sight it might seem that time
is simply the motion of some body. So the day seems to be
the revolution of the earth on its axis ; and the year its
passage round the sun. But a little reflection will show us
that though time and motion are closely connected, yet they

1 Philosophies Consolatio, Lib. V, Ch. VI, io.
* Phil. Nat., Q. 18, A. i, diff. 3.

TIME 119

are not to be identified, and this for two reasons : first,
because motion is something which belongs to the thing
which is moving, whereas time affects all things everywhere ;
and, secondly, because motion can be fast or slow, but time
is not.1 If time varied with the movement, as it would have
to do if they were the same, we could never say of anything
that it moved quickly or slowly ; and the fact that we can
do so shows that we compare the motion with time, for we
say that one motion is quicker than another, if it takes a
shorter time to traverse the same distance. Hence motion is
measured by time.

Again, though time implies succession, this latter is not
the same as time, since some successions are non-temporal,
e.g. the succession in the series of ordinal numbers. Never-
theless, since time implies succession, we shall have to state
its successive character in our definition of it. All these
elements were included in the Aristotelean definition of time,
which was adopted by S. Thomas, and is now generally
accepted by Scholastics, viz. : Time is the number of move-
ment in respect of before and after, tovto ydp eo-nv 6 xp°voi><

api9p.hs KivTjcrecos KaTa to Tporepov kou vo-repov.2

The word d/nfyxos here (i.e. number) is equivalent to
measure, for all quantity is measurable, and measure is
expressed by number. Time is the measure of movement
only, that which is immobile is not in time ; and, further, by
this phrase we affirm that time is not the same as movement,
since it is its measure.

Lastly, the words ' in respect of before and after ' indicate
that time does not apply to movement precisely as move-
ment, but in so far as it is successive. Hence the words do
not merely repeat the notion of time which they are intended
to explain, as Plotinus thought,3 but indicate expressly its
successive character.

In this definition, as indeed in our everyday conceptions,
time is thought of as a unity ; but it is difficult to see on
what such a unity can be founded, for the motions of which
it is the measure are multiple. The Aristotelean physics

1 Cf. Aristotle, Physics, 2i8bg. 2 Aristotle, Physics, 2igbi.

8 Inge, The Philosophy of Plotinus, Vol. I, p. 171.

120 MODERN THOMISTIC PHILOSOPHY

gave, at least, a partial answer to this question, since Aris-
totle regarded motion in a circle as the primary kind of local
movement, and thought that the celestial sphere moved
uniformly. Hence, in his view, there is one uniform motion
which dominates all others, and so one from which the unity
of time can be derived. * It is from this notion that we derive
our way of speaking of time, and the changes of human affairs,
as cyclical. It is, however, clear to us at the present day, that
there is in nature no known movement which is absolutely
uniform, and consequently none which can be taken to
standardise and unify time. Nevertheless, such a movement
can be readily conceived of, and was, in fact, used in New-
tonian physics, under the name of mathematical time. It is
evidently a mental fiction.

If, then, we must abandon the hope of finding any absolute
time, we nevertheless are well acquainted with relative times,
and so can continue, with regard to the things whose motion
is measured by them, to speak of them as being in time.

What, then, are these things which are in time ?

As Aristotle points out, ' to be in time,' may have three
senses : (i) to be when time is, (2) to be a part or attribute of
time, and (3) to be measurable by time.2 The first of these
senses can obviously be ruled out at once, it is simply an
ambiguity of expression. Of the other two senses the second
applies to past, present, and future, which are, in a wide
sense, parts of time ; the third to events which are measur-
able by time ; i.e. all things whose being is mutable or sub-
ject to change.

The Division of Time.

There are two kinds of time : imaginary and real, the first
being external to the material universe, and containing
within itself all durations. The second is the measure of real
motion. We have seen that this absolute imaginary time is a
mere mental fiction, and we shall shortly see what is to be
said as to the extra-mental existence of ' real time.' This

1 Aristotle, Physics, 223^12-22 4a2 ; cf. S. Thomas, loc. cit., and in
IV Phys., Lect. 17, No. 4.

2 Aristotle, Physics, 22137 sqq. ; S. Thomas in IV Phys., Lect. 15, No. 3.

TIME 121

last is of two kinds : time as duration, and time as a measure.
The first is also called intrinsic, and the second extrinsic,
time. Extrinsic time is also of two kinds : primary and
secondary. Primary time is the measure of the motion of
the earth, secondary being the measure of any particular
motion, such as that of a clock, or clock-time. Primary time
is again divided into sidereal, apparent, and mean time. The
sidereal day is the interval between two consecutive south-
ings of a particular star. Apparent time is derived from the
motion of the sun, the solar day being defined as the interval
between two consecutive southings of the sun. This interval
is by no means constant, owing to the inclination of the
ecliptic to the equator, and the lack of uniformity in the
velocity of the sun. The mean time is the average of
the apparent time, the maximum divergence being about
sixteen minutes.

We are now faced with the difficult question of the extra
mental status of time. Aristotle raised the question whether
there would be time if there were not soul (mind), but gave
no definite answer to it.1 We have to enquire as to the
objectivity both of time as a duration — which is the con-
tinued existence of motion — and of time as a measure, whose
definition is the number of movement in respect of before
and after. At first sight it appears as if time as a duration
were something which exists quite apart from the mind, but
a little reflection shows that all that can be said to exist in
this way is the moving thing and its successive states ; the
continued existence of motion not being found in nature.
For it is clear that a car running along a road, though its
motion is continuous, is yet to be found in reality at only
one potential point of its course at any one (potential)
moment ; whereas to have continued or enduring existence
it would either have to be fixed at one point, not passing
through a potential point, or stretching out from one point
to another, in which case it would be in two places at once.
There is a striking passage in S. Thomas' commentary on
the Physics, which deserves to be quoted.2 He says : ' The
notion ' (the word used is ' ratio,' which means both nature

1 Aristotle, Physics, 223321-29. 2 In III Phys., Lect. 5, No. 17.

122 MODERN THOMISTIC PHILOSOPHY

and notion) ' of movement is made complete, not only by
what there is of motion in nature, but also by what the mind
apprehends. For, of motion, nothing more exists in nature
than an imperfect act, which is a kind of beginning, in the
thing which is moved, of a perfect act. Thus, in a thing
which is turning white, there is already some whiteness. In
order, however, that such imperfect act should have the
nature of movement, it is further required that we should
conceive it as a mean between two extremes, of which the
preceding one bears to it the relation of potency to act, and
the one which follows it that of act to potency : which is the
reason that we call motion the act of that which is in potency.'
Thus the duration of motion is not a reality found in
nature apart from the mind. It is our mind, which is endowed
with memory, which gives unity and so being to motion, and
to the duration of motion, as a whole. Further, its duration
is the foundation of time as a measure, since only in so far
as it is an enduring whole does it lend itself to measurement.
This conclusion is strengthened by considering the attempts
that have been made to account for the existence of time :
for some, as Suarez, have maintained that time exists by
reason of its parts, the past and future, which continually
flow on. It is, however, difficult to see how a thing can exist
by reason of parts which do not exist themselves ; for the
past is already dead, and the future is not yet born. Con-
sequently, S. Thomas and his school affirm that in so far as
time exists, it does so by reason of the present instant,
which is not a part of time, but the indivisible link of its
parts, the past and future. This instant must exist since it
is the measure of unity of a definite state of the moving
thing, and without such definite state the moving thing itself
could not exist. It is, however, present only in so far as it is
considered by the mind in relation to the past and future ;
and it is clear that it cannot make the past and future exist,
since the past cannot exist in the present, and to speak of the
present presupposes that the future is not yet existing. So
we are brought back to our former conclusion that neither
time as a duration, nor time as a measure, exist, or are real,
apart from the mind. This, however, should not blind us to

TIME 123

the fact that there is an element of time which has such extra-
mental existence, viz. the indivisible of time, the instant.
So S. Thomas says : ' If motion had some fixed existence in
things, as a stone or a horse have, it would be possible to
say absolutely that just as, even if the soul does not exist,
there exists a number of stones, so, even if the soul does not
exist, there would be a number of motion which is time. But
motion has no fixed existence in things, and in things there
is found nothing actual of motion, except a certain indivisible
of motion, which is the division of motion : but the totality
of motion is comprehended through the consideration of the
soul which compares the former to the latter disposition of
the moving thing. So, therefore, time also has no existence
outside the soul, except with regard to its indivisible, but
the very totality of time is comprehended through the order-
ing of the soul which enumerates before and after in motion.'1
So, he adds, time has an imperfect existence only, apart from
the mind, just as motion itself has.

Taken then as a whole duration or measure, it exists in the
mind only.2 In this delicate doctrine as to the existence of
time, it is essential not to overlook either the objective or
subjective element in it : both of which must be preserved
in their proper proportions. Those who dissent from the
Thomist view do so, in fact, because they ascribe undue
weight to one or other of these elements, and so fall into two
classes which may, for convenience, be called Ultra-Realist
and Subjectivist.

Non-Thomistic Views of the Nature of Time.

Though it does not come within the scope of this explana-
tion to set out extraneous opinions for their own sake, yet, in
this case, a short review of the principal ones will serve to
clarify the meaning, and emphasise the balance and sanity
of the Thomist view.

I. The Ultra-Realist view is represented in the first place
by Gassendi, who, basing his theories on those of Epicurus,
considered time to be something which is neither substance

1 In IV Phys., Lect. 23, No. 5.

* Cf. Nys, La Notion du Temps, pp. 59 f., No. 38.

124 MODERN THOMISTIC PHILOSOPHY

nor accident, and which is eternal and uncreated. Newton
and Clarke, in a somewhat similar way, held that time is a
divine attribute. Gassendi, however, as a theist, was in an
impossible position, since there cannot be two uncreated and
eternal beings ; and the Newtonian view is faced with the
difficulty that the divine attributes are immutable, and there
is no succession in them, whereas time is essentially successive.
The elaborate theory of space-time put forward recently by
Professor Alexander seems to have affinities with these views.
He considers it to be the fundamental stuff of the universe
from which Deity is progressively emerging. It seems diffi-
cult to regard this view as other than pantheistic, though its
author has repudiated this interpretation of it.

II. The Subjectivist Views.

1. Kant regarded time as an a priori intuition of the sensi-
bility, something, that is, which belongs to the very texture
of our senses : so that, for him, it is purely subjective. This
is evidently false if we recognise motion as a real foundation
of time ; and moreover it is contrary to experience, since, in
observing some extended sensible object, such as a landscape,
our observations are successive, while the landscape appears
as a static whole. If, however, succession were something
which directly affected our sensibility alone, both it and its
objects ought to be affected by it, or neither of them ; so
that, on Kant's hypothesis, it should be impossible for us to
have a successive knowledge of a simultaneous whole.1

2. Leibniz at least inclines to over-emphasise the subjec-
tive character of time : for he defines it as the ' order of
successions/2 He remarks that a thing of which no part
ever exists cannot exist ; and in the case of time, nothing
exists except the present instant, which is not a part of time ;
and concludes that time cannot be other than an ideal being.
It will be seen that this view has close affinity with that of
S. Thomas ; for they are at one in recognising the purely
mental character of absolute time, and also that the only
element of time which exists in nature is the instant.

1 Cf. Nys, op. cit., p. 226, No. 138.

s Cf. 3rd letter to Clarke and 5th letter to Clarke (on Par. 10).

TIME 125

S. Thomas, however, notices what Leibniz overlooks, that this
instant is the number of the motion of the body, and corres-
ponds to the indivisible of motion, which, though the only
actuality in motion, is at the same time potential to the
further process of motion, so that time exists as a perfect and
actual being ideally only, but as an imperfect and potential
one in things. It seems, therefore, not unjust to Leibniz to
say that his teaching on this point is not so well balanced as
that of S. Thomas, and that his theory is of the subjectivist
type, though not of so extreme a kind as that of Kant.
Further, in his definition and view of time, Leibniz loses
sight of its essential continuity ; for the definition does not
take account of the fact that time requires continuous
motion, as well as the permanence of the thing which moves.
Order does not necessarily imply either of these, for there
can be order among discontinuous things, and, consequently,
apart from the permanence of the thing which is subject to
order. Hence, Leibniz's definition does not discriminate
between that by which the motion of material things is
measured, and that which applies to the motion of pure
spirits : which latter is discrete, not continuous.

Lastly, to define time as the order of successions is a loose
way of speaking, for order is a consequence of succession, and
so of time, rather than constitutive of successive duration,
or time. There is order in the succession of things because
of the motion by which the things succeed one another, not
conversely : for it is not true to say that there is motion
because there is order.

III. Bergson's Theory of Time.

According to Bergson, there are two kinds of time, homo-
geneous and heterogeneous. The latter is the time of our
experience, and is named by him ' la durie,' to which no
English expression exactly corresponds. Homogeneous
time, which is what we ordinarily mean when we use the
word time, is, in his view, merely space, on to which the mind
projects psychological time, the succession of our conscio1- '
states, thus making it appear to be a successive and con-
tinuous reality. In fact, it is nothing but an illusion for there

126 MODERN THOMISTIC PHILOSOPHY

is no true succession in things which are said to be measured
by time, since one state has entirely disappeared when
another appears. So he writes : ' Doubtless exterior things
change, but their moments only succeed one another with
respect to a consciousness which remembers them. We
observe outside us, at any given moment, a collection of
simultaneous positions ; nothing remains of the former
simultaneities.'1

Hence, the only time which is not illusory, and which he
regards as real, is the heterogeneous time, or succession,
which accompanies the development of our conscious states.
Such development is purely qualitative, and its parts can only
be qualitatively, never quantitatively, distinguished, so that
they are absolutely heterogeneous ; for it is clear that all
our psychic acts are unextended — it is impossible to have a
yard of thought — and so if distinct their distinction can be
qualitative only.

There can be no question as to the subjective character of
this theory ; and to make of time an affection of our con-
scious states is to contradict completely the common-sense
notion of it, which undoubtedly attaches it to bodies. What
is more, it is only the permanent which changes, and the
permanent endures : so that it is inconsistent to admit that
things change and to deny their duration. Moreover, if time
attaches only to our conscious states, each one of us will live
in his own time, and there will be no unique sense in which
two events can be said to be simultaneous. This, however,
is to deny time, not to explain it, for the notion of time
surely implies, at least, the possibility of comparing the
position of two events in the world process. Without this
capacity, it is altogether useless. Of the characteristics of
time, as all men conceive it, viz. as measuring events, as
having parts, past, present, and future, and as continuous,
the only one which is, in the end, retained by this theory is
the last, and that illegitimately ; for Bergsonian time is, in
fact, the series of irreducible different qualities, which, there-
fore, can never form a unity or continuity. Much more
might be added in criticism of the theory, but these remarks

1 Essai sur les donnes de la conscience, p. 173.

TIME 127

may suffice to show that it is irreconcilable with common
sense, and inconsistent in itself ; though highly ingenious,
and devised with the best of intentions, viz. to rescue living
things, and especially conscious processes from the grip of a
deterministic mechanism.

(For a fuller discussion, see Nys, La Notion du Temps.)

Note. The theory of Einstein with respect to the relativity
of space and time is well known : but it would be to go beyond
the limits of a simple explanation of Scholastic philosophy
to attempt to explain and comment on it here. The reader
may be referred to Einstein's own explanation of it in his
book, The Theory of Relativity (Methuen) ; and there are
many other explanations of it in English, such as those
given by Professor Eddington in various works, e.g. The
Nature of the Physical World. Scholastic comments on it
can be found in Nys' monographs on Space and Time, cited
above ; and a good discussion of it from a metaphysical
point of view is contained in Maritain's Reflexions sur
V intelligence. The Prcelectiones Cosmologice, by Fr. Dario,
S.J. (Paris : Beauchesne) can also be consulted.

CHAPTER X

SUBSTANTIAL CHANGE IN GENERAL

Meaning of Substantial Change — The Plurality of Forms — The
Source of the New Substantial Form in Generation.

In considering the quality of the material world (mobile
being), which is motion, we have seen what is meant by
motion in general, and how material beings are affected
extrinsically by their motion through space. We now turn
to that motion, or change, which is intrinsic to them. Such
change is of two kinds : substantial, by which their very
nature is changed, and accidental, by which their qualities
are altered. There are two questions which require separate
treatment with regard to substantial change, that of sub-
stantial change in general, and that of the particular kind of
substantial change which occurs when two or more simple
elements combine to form a chemical compound.

With regard to substantial change in general, we notice
that the changing of one substance into another involves
both the appearance of a new substance, and the disappear-
ance of the old. It is therefore called by Aristotle generation
(yfveo-is) and corruption (<f>dopa).

Generation is defined as the change by means of which
some real subject, which before the change did not have
existence, receives it ; while corruption is the change by
means of which some real subject, which before the change
had existence, loses it. The real subject referred to in both
cases is the compound of matter and form. So, for example,
assuming for the moment that wood and the carbon which
results from burning it are substances of different natures,
we have the carbon receiving existence, which it did not
have before, and the wood losing that which it had. The
coming-into-being of the carbon is the passing-out-of-being

128

SUBSTANTIAL CHANGE IN GENERAL 129

of the wood, so that the Scholastics say that the generation
of one thing is the corruption of another. Thus, that which
is produced by generation is the concrete thing, in our
example, the carbon. This carbon is, moreover, a certain
nature which exists, and one which comes into being as a
result of generation ; so that it is clear that the nature of
carbon is itself a product of generation ; not, however, as
that which is directly generated in itself, but as a constituent
of the concrete thing. So the Scholastics call it the ' terminus
qui generationis ' as contrasted with the ' terminus quod,'
the thing which is generated. The nature itself is made of a
definite and specific kind by the substantial form, which is
therefore also a terminus qui of generation. It is clear,
further, that there is no moment of time between the dis-
appearance of one nature, one form, and the coming of
another, since the disappearance of one is the appearance of
the other. Nevertheless, in substantial change the first form
does disappear entirely, according to the teaching of S.
Thomas ; so that, in his view, matter is stripped of all
substantial form in this process. The truth of this opinion
has been, and still is, hotly contested ; and we must pause
to consider it more fully.

Question I. On the Plurality of Forms.

Whether we admit S. Thomas' view or not will depend
on whether we allow a plurality of forms in one being. Until
the time of S*. Thomas the possibility of there being many
substantial forms in a thing, which still remained essentially
one, and indeed that there actually were many such forms,
was generally admitted by Scholastics. S. Thomas, however,
always held firmly to the opposite opinion,1 being, as Pro-
fessor Taylor says, ' too sound an Aristotelean ' to admit
such plurality.2 The views of his opponents on this question,
and so on the process of substantial change, were of two
kinds, of which the first is that some substantial form does
remain throughout the change. So Avicebron (Ibn Gebirol) ,
according to S. Thomas,3 held that in a man there would be a

1 But cf. Fr. Roland-Gosselin's edition of De Ente et Essentia, pp. no ff.

2 Platonism and its Influence, p. 127.
8 De Spiritualibus Creaturis, Art. 3.

130 MODERN THOMISTIC PHILOSOPHY

hierarchy of forms, beginning with the form of substance, to
which is added that of corporeality, then of vegetative life,
then of sensitive life, and finally of intellectual life. Scotus
admitted a form of corporeality in living things, and taught
that it remains on the departure of the soul ;x while Albert
the Great held that the forms of the elements remain in a mix-
ture, subsumed under the form of the mixture, which is
new ; as the Greeks in the Trojan horse were subsumed
under the form of horse, though they did not lose their own
forms, if we may use a very inadequate example. A similar
view was held by Avicenna and Averroes.

The second way of regarding this process of change is that
of Suarez, who, though allowing that no substantial form
remains throughout the change, yet, since he holds that
accidents are individuals of themselves, not by reason of the
substances in which they inhere,2 is able to grant that the
accidents of the generated thing are the same individual
ones as those which were found in the corrupted thing. Apart
from this, his opinion is practically the same as that of
S. Thomas. Those who differ from S. Thomas maintain
that his position is unintelligible, for they say that if there
be no form remaining, we shall have absolute indetermina-
tion, which is the same as nothing. This is, in fact, the denial
of the reality of pure potency : and as we have already seen
neither Scotus nor Suarez is willing to admit that matter is
pure potency without any act (cf., p. 48). Further, they
object that when one form disappears there will be a moment,
if not in time, at least in the order of intelligibility, when the
subject of the first form, lacking that form, will vanish ;
since the Thomists admit that matter cannot exist without
form. Hence, in order that we may have a common subject,
it must be furnished with a form independent of those which
it loses or acquires in the change. Apart from these theor-
etical objections, it has recently been urged by Fr. Descoqs,3
and others, that the facts show that the subject of change is
not first, but second, matter.

1 In IV Sent. dist. XI, Q. 3, A. 2.

2 Disputationes Metaphysiccz, Disp. V.

8 Essai Critique sur I'HyUmorphisme, pp. 31 fl.

SUBSTANTIAL CHANGE IN GENERAL 131

The Thomists reply that they are compelled to adhere to
their doctrine that at the moment of change no substantial
or accidental form remains by irresistible metaphysical
arguments. With regard to substantial form, it is evident
that if it be true that there can be only one substantial form
in one compound, since change of substance or nature must
mean that the old nature passes away and a new one takes
its place, and substantial form is that which makes a thing
to be of a definite kind substantially, this too will pass away
at the moment of change, and if it is the only one, none will
be left. The question, therefore, resolves itself into that
concerning the plurality of substantial forms in a body
which is an essential unity ; as we have already stated.
Though we mentioned shortly, at an earlier stage (vid. p. 50),
the reasons which S. Thomas gives for excluding a plurality
of forms, as a corollary to our discussion of the potentiality
of matter, it is necessary to examine the question rather
more fully here, as it is one of the main arches of the Thomist
structure, and is a characteristic architectural feature of it.

There are two questions to be asked : first, What do we
mean by the phrase : ' a being which is essentially one ' ?
and, second, Are there any such beings ?

Can we say, in answer to the first question, that we mean
a being whose nature is itself a compound of several, so
that E, its nature, is compounded of E1} E2, E3, . . . etc. ?
This is surely impossible, for the thing will have these
natures Ex, etc., either all at once or in succession. If it has
them all at once, it clearly has a number of natures, since,
by hypothesis, they are different, and therefore cannot have
a single nature. If it has them successively, when it has
nature E2, it will already be a definite and determinate kind
of being ; and so cannot be made a definite being by having
a nature E2 added to it. For, just as it is true to say that
nothing gives what it has not already got, so also is it true
that nothing gets or receives what it has already. This is
true even in the accidental order, as for example, it is imposs-
ible to make a man a millionaire if he already is one ; and it
is certainly true in the substantial, a man cannot be made a
man, a determinate nature cannot be made a determinate

132 MODERN THOMISTIC PHILOSOPHY

nature. To doubt this would indeed be to doubt the prin-
ciple of identity — being is being — from which follows the
principle of Parmenides : ' from being, being cannot come
to be, since it already is,' which, with the precision imported
into it by Aristotle, becomes : ' from being in act, being in
act cannot come to be.' And this is precisely the case in
point, since being which has an essence is an actual being,
and so by the addition of another essence cannot become
one. It is already constituted as a substantial nature, so
that any addition to it can only modify that nature, not
constitute it. So S. Thomas says : ' Quod advenit alicui post
esse completum, advenit ei accidentaliter .' (Contra Gentiles,
Lib. II, c. 58.) So it is clear that by essential unity we must
mean that the thing which has it, has one nature only, for no
kind of compound of natures will satisfy the conditions.
But it might be said : ' No doubt in the abstract essential
unity means that there is a single nature, but in the concrete
existing thing is it not possible that several natures should so
fit in with one another that all should be united in the bond
of a single existence, thus giving us a substantial unity ; in
other words, that though there may be several substantial
forms in a body, yet it may exist as a unity ? ' If we con-
sider this we see that it is impossible to agree with this sug-
gestion, for substantial form is that which, when it is joined
to matter, makes a compound which is capable of receiving
existence, neither form nor matter being capable of doing
so in separation, since they are only principles of being. If,
then, the compound receives existence — as it must do in
order to be a concrete thing — the existence which it receives
will be existence without any qualification or addition,
making it pass from the realm of mere possibilities to that of
actual existing things, for if it does not do this the thing will
not pass out of the abstract order. If, however, it does do it,
any further existence cannot do it, since it is already done,
and so any further existence will be only existence of a par-
ticular kind, as to be white, etc. Hence, in order to have a
single substantial existence, and so a substantial unity we
must have one substantial form, and one only.1

1 Cf. P. Geny, S.J., Gregorianum, 1925, Vol. VI, pp. 126 f. ; and Divus
Thomas (Plac), 1925, pp. 72 f.

SUBSTANTIAL CHANGE IN GENERAL 133

But, are there in the world any beings which possess
essential unity of this kind P1 We must certainly answer
this affirmatively, both because of our consciousness which
affirms that we are such unities ourselves, and the intolerable
consequences which follow from splitting up human nature
into two or more natures — from what is called psychological
dualism — and because in the world of inanimate matter, if
we were to deny such essential unity to everything, it is
clear that nothing could be quantitative, since, having no
one nature, there could not be parts of one nature, and
nothing would be quantitative and extended. The hypo-
thesis of Leibniz was precisely that of the plurality of monads,
of substantial forms, and we agree with him that this must
logically lead to a denial of extension : a denial which we
have seen to be impossible, and which, in any case, no
Scholastic, not even those who hold the doctrine of the
plurality of forms, would admit. Thus, the individual in the
organic and inorganic worlds must be granted to have a
unity of nature, an essential unity, otherwise the world as we
know it becomes inexplicable.

S. Thomas argues against the plurality of forms in the
following passages, among others :

Summa Theologica, Part I, Q. 76, Arts. 3, 4, 6, ad ium, 8 ;
Part III, Q. 1, A. 5, ad ium. Contra Gentiles, Lib. II, Caps.
57> 58. Questio Disp. De Spiritualibus Creaturis, A. 1, ad
o,um ; A. 3 ; Q. Disp. de Anima, A. 9 et 11 ; Quodlibet I,
A. 6 ; Quodlibet XI, A. 5 ; de Substantiis Separatis, Cap. 6 ;
from the last of which the following passage may be quoted :

' To make an end of the matter, the aforesaid position '
(i.e. that there are a plurality of forms) ' destroys the first
principles of philosophy, by removing unity from individuals,
and consequently both true entity, and the diversity of
things. For if another act supervenes to something which
exists in act, the whole will not be a unity per se, but only
per accidens, for the reason that two acts or forms are in
themselves diverse, and agree only in the subject ; to be
one, however, through the unity of the subject is to be one
per accidens.'

1 Cf. Geny, Divus Thomas, loc. cit., p. 74.

134 MODERN THOMISTIC PHILOSOPHY

Thus he always appeals to the principle : ' substantial
form gives existence simply speaking ' ; so that anything
added can only give accidental existence, with the result
that nothing can have more than one substantial form.

It follows immediately from this that the opinion of Suarez,
that the same individual accidents remain throughout a
substantial change, cannot be maintained ; for if substantial
form disappears at the moment of change, the subsistence of
the first subject which constitutes its capacity for sustaining
itself also disappears, since this is caused by substantial form.
So, evidently, if the substance ceases to be self-sustaining, it
ipso facto becomes incapable of sustaining or supporting
anything else, such as accidents, which must therefore
disappear also ; to suppose the contrary would be like sup-
posing that you could hang your hat on a nail that wasn't
there.

Are we, then, to suppose that nothing at all of the sub-
stance which undergoes substantial change is to be found in
the new substance which comes into being, with the excep-
tion of the absolutely undetermined first matter ? This
does not at all follow, for we can see that though the replace-
ment of one substantial form by another is instantaneous,
yet the process which leads up to this change is a gradual
one : since the first substance is gradually changed by the
modification of its qualities until it arrives at the state in
which the new substantial form, which is to take possession,
is required as the source of these modified qualities. The
accidents introduced in this way into the changing substance
are called by the Scholastics the previous dispositions, since
they dispose the subject to be informed by a new form ; and
these remain virtually through the change, since the matter
which has been brought, by their means, to the point at
which it calls out, as it were, for the new form, remains
throughout the change. It never has the chance to fall into
complete indetermination, since the new form takes posses-
sion of it as the old one disappears. They are like children
playing ' musical chairs,' where one child holds on to the
coat-tails of another, so as to be able to occupy immediately
the chair which the other has vacated. Consequently, the

SUBSTANTIAL CHANGE IN GENERAL 135

new form will produce in the substance accidental disposi-
tions which are the exact counterpart of those which the
subject had, immediately before the change, when the old
substantial form was present. These dispositions will, how-
ever, be numerically distinct from the previous ones, since we
now have a new subject. They are called the proximate
dispositions. Can these latter be said to precede the sub-
stantial form ? The answer is, that, regarded from different
points of view, they precede and follow it. Inasmuch as
they prepare the subject for the reception of the substantial
form, they precede it ; for, from this point of view, they are
the same as the previous dispositions, which affected the
matter which the new substantial form takes possession of ;
but they follow it, inasmuch as it is due to the new sub-
stantial form that they are able to be supported as entities of a
certain nature. Thus they precede it in the genus of material
disposing cause, and follow it in the genus of formal cause :
according to the general principle : ' causa ad invicem sunt
causes in diverso genere ' — causes which are mutual causes are
causes in different genera. From the point of view of time,
they neither precede nor follow the new substantial form, but
are contemporaneous with its coming, since this occurs instan-
taneously. Hence, we see that matter is never left wholly
undetermined, even for a moment, whether in the order of
time, or that of intelligibility. If difficulty be experienced
in conceiving how a thing may both precede and follow
another, and yet be simultaneous with it, the following
example, though inadequate, may be a help. In an ecclesi-
astical procession the dignitaries walk at the rear of it, and
so follow it ; nevertheless they precede all the other mem-
bers of the procession in dignity, and are at the same time
simultaneous with them all in walking, since the whole pro-
cession moves together at the same time. Thus they follow
in space, precede in dignity, and are simultaneous in time.

Question II. The Source of the New Substantial Form in
Generation.
What has been said about the ' dispositions ' introduced
into the changing body will suggest that the new substantial

136 MODERN THOMISTIC PHILOSOPHY

form takes its rise from the changing material thing itself ;
and this is, in fact, the Thomistic opinion, which is expressed
in the phrase : ' material forms are produced (educuntur)
from the potentiality of matter.' The process may be
likened — if proper care be taken not to press the comparison
too far — to the felling of a tree. Little by little, as the axe
bites into the trunk, the tree becomes less capable of preser-
ving its upright position, until finally the moment comes
when it is unable to stand any longer ; a slight stroke, the
tree wavers and comes crashing down. Similarly, a body
which is undergoing a substantial change has its capacity for
preserving its original nature gradually weakened until
finally it, as it were, topples over into the arms of the new
form, which comes to it, not from without, but from within,
as a result of its natural propensities having been gradually
altered. This process is held by S. Thomas to be verified
only in the case of material forms, not of spiritual ones ;
since only the former are dependent on matter for their
existence, and consequently these alone can be dependent
on it for their actual coming into being. Evidently, also,
the process applies only to substantial generation, not to the
beginning of all things.

There are, however, two other opposing theories as to the
way in which substantial forms come to be ; between which
the Aristotelean theory stands as on an eminence, preserving
the truth of both, and filling in their lacunae.

So, some thought that all forms actually existed in matter,
but lay hid in it ; while others supposed that they were not
in matter at all, but were created whenever substantial
change occurred.

The first view is, according to S. Thomas,1 erroneous, as
we have already seen ; the error arising from a failure to
distinguish between potency and act ; since the forms are
potentially only in the matter, not actually ; while the
second is also erroneous, since it implies that a form is, in
itself, a complete being, not a principle of being. It is, in
fact, the new compound which comes to be, not form alone,
as we noticed earlier (cf. p. 129).

1 Cf. Summa Theologica, Pars I, Q. 45, a. 8 ; and VII Metaphys.,
Lect. 7, ed. Cathala, Nos. 1430 and 1431.

SUBSTANTIAL CHANGE IN GENERAL 137

It is, however, not easy to see how the new substantial
form is made actual, if, as we have just said, it is only
potentially in matter, and is not created ; for since matter
contains it only potentially, it cannot make it actual ; and
the efficient cause, or agent, by whose means the change is
brought about, seems also incapable of doing this. The
principle of causality demands that a cause must contain
the effect at least virtually, and that in a way which is at
least equal in perfection to the effect itself. This condition
is not, however, verified in the case of many of the agents
which appear to produce substantial changes, as heat or
electricity, which can hardly be said to contain virtually the
forms of the bodies produced by their means. And how can
a bullet be thought to contain virtually the forms which
appear in the dead body of the man whom it kills ? So,
neither matter nor yet the agent seem to be causes which
are capable of producing the new substantial forms. Besides
this, there is a further difficulty in supposing that the new
form is produced by the agent, since the action of an agent
is an accident, and so cannot produce substance. Aristotle
thought that the ' heavenly bodies ' exercise a general
influence on all terrestrial operations, and that they are
beings of a higher order than earthly bodies, so that their
power virtually contained all earthly forms. This view is
obviously untenable, but some Scholastics, thinking that an
absolutely general cause of a higher order to that of parti-
cular material substances is required, have substituted for
the influence of the ' first heaven ' either that of God, or of
the all-pervading ether. The first is the suggestion of M. Nys
in his Cosmologie ;x the second that of Remer.2

In M. Nys' view the Divine action is required at the
moment when the forms appear, not by way of creation,
but as giving to the generative forces the necessary perfec-
tion ; while Remer thinks that the ether of space, being the
subject of all physical action, may be considered as a universal
agent, and so as containing virtually, and on the same level
as themselves, the forms of all other bodies.

1 Nys, Cosmologie, Tome II, pp. 178 ff.

2 Remer, Cosmologia, ed. 4a (1921), pp. 83 ft'., No. 54, versus finem.

138 MODERN THOMISTIC PHILOSOPHY

Neither of these suggestions, however, seems altogether
satisfactory, for to invoke a special action of God every time
a generation takes place, and when unable to see any natural
explanation of a natural event, to cut the knot by asserting
that it must be due to the action of God, seems to make of
Him a ' Deus ex machina.' It is as if a savage, falling into a
river, and being swept away by it, were to say ' the god of
the river has got hold of me,' not knowing the law of gravita-
tion ; but what is pardonable in a savage is hardly so in a
philosopher.

Nor is Remer's theory much more probable, for even if
there be a material ether of the kind supposed, which is
highly doubtful, its characteristics are so negative, since it
is thought of merely as the medium whereby electro-magnetic
waves are transmitted, that it can hardly be considered to
be an active agent of the kind required.

The solution seems rather to be found in a careful and
strictly philosophical consideration of the parts played in the
process of substantial change by the material which under-
goes it, and the agent which modifies this material, as well as
by the active character of substance itself. According to
this view, the agent which introduces into the changing
bodies the dispositions favourable to the coming of the new
substantial forms does not produce or effect these forms, but
merely gives the matter that actuation which is necessary
for the transformation of its capacity for them into actual
possession of them. So, absolutely speaking, a sculptor has
no need formally to possess the form of the statue which he
is carving ; nor even virtually, except in the sense that he
has the power, both mental, by reason of his artistic con-
ception, and physical, so to manipulate his material that in
it the statue may appear. The statue which results depends
therefore both on the material used, e.g. whether it be
marble or wood, and on the power of the sculptor. Similarly,
in the case of natural agents, both the matter which is being
changed, and the agent which is introducing modifications
into it, concur in the production of the new substantial com-
pound, though in different ways : for the agent modifies the
substance, which, when so modified, gives birth, as it were,

SUBSTANTIAL CHANGE IN GENERAL 139

to the new form. It is, therefore, the material substance, as
modified by the agent, which possesses virtually the new
form which is to arise in it ; and the objections raised to the
virtual possession of this form by the efficient cause of the
change fall to the ground. That this is true seems to be
borne out by the fact that a random application of the effi-
cient cause will not produce the new substance ; the old
must be modified in a particular manner, i.e. the modifica-
tions must be such as to bring it to the state in which it
possesses the new form virtually. So, an electrical current
has to be applied to oxygen and hydrogen in a particular
way in order to make them combine into water ; and it is
only certain lesions or diseases which cause death. Thus, it
is not necessary to suppose that electricity or a bullet possess
virtually the forms which are educed by their means, except
in the sense that they are necessary in order to modify the
material in a suitable manner. But it will still be objected
that the actions which cause such modifications are accidents,
and cannot therefore produce substantial forms, but only
accidental ones, viz. these very modifications. This, how-
ever, is easily answered, since they are the actions of sub-
stance, and are naturally united to it, in such a way that it
acts with and through them. The power manifested in the
action of any agent is not the power of the action, but that
of the agent ; being nothing else than the power or force of
the active substance. So, as Cajetan says : ' Accidentalis vis
non sua, sed substantia est virtus ' ; so there is no reason why
it should not produce a substantial actuation. The substance
does not lie inert or inactive under accidents which act for it,
like sentries who drive away intruders from the sleeping
camp ; but they are, as Cajetan puts it, ' organa conjuncta,'
whose whole efficacy is that of the substance whose ' organs '
they are. Thus, as far as virtual possession of the new form
is concerned, we can say that this is found in the changing
material ; and as far as it is necessary that this material
should receive a new substantial actuation, passing from the
capacity for being a new substance to being it actually, such
actuation is derived from the agent, whose accidents act
with its own substantial power. So the formal or specific

i4o MODERN THOMISTIC PHILOSOPHY

character of the substantial form is educed from the poten-
tiality of matter ; while its substantial character is derived
from the substantial agent, imparting its substantial power
to its accidents.

These remarks seem to express Cajetan's view as he sug-
gests it in his commentaries on the first part of the Summa.
Cf. Comm. in lam Partem, Q. 54, A. 3 ; Nos. 8, 16, and 17 ;
in Part I., Q. yy, A. 1 ; No. 13. Cf. Goudin, Physica, Pars I,
Disp. 2, Q. 4, A. 3 versus finem.

CHAPTER XI

SUBSTANTIAL CHANGE IN CHEMICAL COMPOSITION I
THE QUESTION OF MIXTURES

Current Scientific Views — Philosophical Views — Thomist Opinions
as to the Permanence of the Elements and Qualities in Mixtures.

In the general discussion of the theory of matter and form
we noticed that some modern Scholastics refuse to admit
that substantial change actually occurs, owing to the diffi-
culties which have arisen from the discoveries made in
modern times by physical science. These difficulties are
particularly acute with regard to inorganic chemical com-
pounds, which the Scholastics call ' mixtures ' — though the
name is not absolutely confined to the inorganic realm — and
some authors who are willing to allow substantial change to
organic things refuse to admit it in the case of the inorganic.
In the present discussion we shall confine ourselves to a
consideration of inorganic bodies ; and even so it will be
impossible to consider in detail all the difficulties which can
be raised from the point of view of physical science, since we
are concerned to unwind the thread which may lead a begin-
ner safely through the labyrinth of Scholastic philosophy,
not to examine all the obscurities of its caverns ; and because
such a consideration would entail a course of physical science
which is outside the scope of a brief philosophical summary,
such as the present. We will therefore try to see what are
the main philosophical ideas and principles which lead to the
solution of these difficulties.

As is well known, all inorganic bodies are regarded by
science as aggregates of smaller ones, composite bodies being
collections qf molecules, which are themselves collections of
two or more particles of the simple elements, which are
called atoms. In both cases, therefore, gross matter, whether

141

142 MODERN THOMISTIC PHILOSOPHY

composite — what is called by the Scholastics a mixture — or
simple, which we may take for the present as meaning the
chemical elements, is composed of a number of discrete par-
ticles in juxtaposition. Even so, we have not come to the
end of the division of matter as envisaged by physics, for
the atom itself is regarded as being composed of parts : the
proton, which is a positive electric charge, and electrons,
which are negative unit charges. The number of these
electrons is held to vary in the different chemical elements ;
beginning with hydrogen, which has one electron, and so a
positive unit charge as proton, up to uranium which has
ninety-two electrons. Hence, according to this view, all
matter is fundamentally the same, being composed of a
greater or less number of electrical units.

Faced by this theory, which seems well-established
scientifically, some Scholastics thought that the traditional
view, that inorganic substances differ in kind, ought to be
abandoned, and along with it, of course, the idea of the
essential unity of inorganic bodies. Some of these writers
thought that the essential unity of organic beings (i.e. living
ones) could still be maintained, but others more logically
(e.g. P. Descoqs, S.J.) abandoned this also. For, in fact, if
the reasons which cause us to give up the idea that the
elements of inorganic matter do not remain actually in the
compound, — and so the essential unity of compounds, — are
peremptory in the inorganic realm, they will be so also when
these substances, exhibiting the same characteristics, are
found in living things, as is in fact the case. The theory,
however, that living things are not essential unities leads to
very serious difficulties both philosophical, and, as Professor
J. S. Haldane has pointed out, scientific. Nevertheless, it is
such thorough-going sacrifice of unity which the scientific
theory, if it is to be taken at its face value, seems to demand.

We are therefore led to ask whether the traditional view
may not, after all, be the true one : i.e. whether chemically
simple bodies, those, namely, which are not composed of
other chemical elements, do actually persist as such when
they join together to form a compound.

What are known by the physicists as the chemical

CHANGE IN CHEMICAL COMPOUNDS 143

elements, of which ninety-two are supposed to exist, and of
which ninety have at present been discovered, are not in
fact all chemically simple, though they are usually treated
as if they were. For our purpose it will be sufficient to con-
sider them as simple, since, if we can show that these
elements cannot retain their own nature in composition, the
same reasons will apply to the constituents of those elements
which are, in fact, composite.

Since the chemical elements naturally combine with one
another, those which do so must have a natural tendency to
do so, or, as it is called, have affinity for one another. Their
power to combine is known as their valency, so that an atom
which combines with one, two, three, etc., atoms of another
element is called mono-valent, di-valent, tri-valent, and so
on. The result of such a combination will be an equilibrium,
and the question is, how is this equilibrium to be explained
philosophically.

Broadly speaking, there are two opinions at present in
vogue among Scholastic writers. The first is that of the
pluriformists who trace their philosophical descent to S.
Albert the Great. The second is the Thomistic view, which
maintains that in many compounds the elements of which it
is made up do not remain substantially, or as such, when
mixed together. They are not present in the mixture actually
and formally, -but virtually only, by means of a persistence
of their qualities.

The opponents of this view urge, in addition to the general
scientific argument touched on above, the further considera-
tion that it is difficult, if not impossible, to see why a
chemical compound possessed of a single form or nature
which is different from those of its elements, should invari-
ably be able to be resolved again into these elements, as we
know that in fact it can be ; and moreover, why, if it is an
undifferentiated unity, different agents acting on it do not
produce different effects, whereas, in fact, such different
agents as electricity, heat, or even a blow, all produce the
same effect of resolving the compound once more into its
constituent elements. All these phenomena, they contend,
are easily and naturally explained on the hypothesis that the

144 MODERN THOMISTIC PHILOSOPHY

compound is a mere aggregate of atoms. In addition many
other arguments are brought forward against the Thomistic
opinion, such as the impossibility of accidental forms pro-
ducing substantial ones, of which we spoke above : as well
as many special difficulties relating to particular classes of
chemical substances. We must, therefore, see what answer
the Thomists make to these objections, and why in spite of
them, they are so determined in maintaining that the
elements do not remain actually in the mixture.

To explain the resolution of the chemical compound into
its elements, modern Thomists develop further what they
mean by saying that the elements remain virtually in the
mixture.

This virtual permanence of the elements may mean either :

i. That neither their substance nor their qualities remain
formally in the mixture, or :

2. That while the substances do not remain formally, the
qualities do so ; and this again may be understood in two
senses :

(a) That the qualities which remain are homogeneous
throughout the whole mixture or compound, or :

(b) That they are localised in different parts of it, so that
the compound is heterogeneous with respect to its qualities,
having one quality in one part, and another in another.

(i) With regard to the first view, it is further explained as
follows : The chemical compound is perfectly homogeneous,
and contains all the material bases of the elements, which are
moulded into a higher unity by means of the one specific
principle. This form of the compound is virtually many,
inasmuch as it takes the place of the various substantial
forms of the elements. The qualities of the elements are
thought to persist virtually in the compound in so far as
their opposing qualities are represented in it by some third
quality which is their mean, and the mean qualities so
formed are considered to be distributed evenly throughout
the whole compound, in such a way that it has a single
electrical force, a single luminous force, a single calorific
force, and so on ; which single forces represent, though, of
course, they are not the same as the corresponding forces of

CHANGE IN CHEMICAL COMPOUNDS 145

the elements. The compound is thus perfectly homogeneous,
both substantially and accidentally.

(2) (a) The second view in its first form is that put for-
ward by Fr. J. Gredt, O.S.B.1 It differs from the view just
given in that he holds that the qualities of the elements
remain formally in the compound, i.e. that the electrical
force of each of the elements occurs again in the compound,
and is not replaced by a single third quality which is their
mean. Nevertheless, it agrees with the previous view in
maintaining that these qualities are evenly distributed
throughout the whole mass of the compound. Thus the
intensity of the qualities of the elements will be diminished
until a state of equilibrium is reached, owing to the action
of the elements on one another, but the nature of these
qualities will remain the same. Hence the compound will
have a single substantial form, and a variety of qualities
which are of the same kind as those of the elements. These
qualities have a uniform intensity which is less than the
intensity of the qualities of the elements, the qualities them-
selves being found equally, both as regards their natures and
their intensities, in all parts of the compound, which will
thus be perfectly homogeneous, both substantially and
accidentally. This qualitative homogeneity is, however,
mitigated to some extent by the admission of a quantitative
heterogeneity in- the compound, i.e. a heterogeneity of
structure. \

(2) (b) The second form of the second view goes further in
the admission of accidental heterogeneity within the com-
pound ; for, while still maintaining that there is a single
substantial form in the compound, it allows that its qualities
are of the same nature as those of the elements, and, more-
over, that they are found in the mixture in groups, which are
localised in different parts of it. As regards their intensity,
it agrees with the previous view. This is the theory proposed
by M. Nys.2

The view that the qualities remain formally in the mixture,
as opposed to that which says they remain virtually only, by

1 Elementa Philosophies (ed. 4), Vol. I, Nos. 405-408.

2 Nys, Cosmologie (ed. 4), Vol. II, pp. 206 ft., Nos. 169 ff.

146 MODERN THOMISTIC PHILOSOPHY

means of some third mean quality, is now almost universally
accepted among Thomists : for the reason that it seems
impossible on the latter view to account for the reappearance
of the elements at the dissolution of the compound. For
it is a principle of hylomorphism that a form cannot appear
except in matter which is predisposed to receive it. The
theory of the mean quality, however, renders such pre-
disposition absolutely impossible, for if the compound is
altogether homogeneous, both substantially and accidentally,
it is impossible that it should be predisposed in one part in a
different way to that in which it is predisposed in another ;
and so the appearance of two or more distinct forms is
excluded.

To show that the elements do not retain their own nature
in the mixture, or, in other words, that the mixture is a new
entity with a nature of its own, distinct from those of its
components, the Thomists argue from its distinctive charac-
teristics and operations. If we find in any body, or class
of bodies, characteristics peculiar to that body or class, and
such as are found in no others, it is permissible, and indeed
unavoidable, to conclude that such characteristics are
properties of it, since, if they did not arise from the very
nature of the body — which is the meaning of the word
property — they would be without reason of being ; for, as
they are constant, they must owe their being to some con-
stant factor in the situation, and the only constant one is
the natures of the bodies themselves. Now, in mixtures,
this is just what we do find, for along with some qualities
which were present in their elements we also find many
which were not present there, and are really new ; qualities,
moreover, which attach to certain mixtures exclusively and
constantly. Such are colour, taste, scent, chemical affinities,
etc. For example, some compounds such as sulphate of
barium, are stable and absolutely inert, though its elements
are very active,1 and new characteristics are produced by
hydration, which renders acids capable of dissolving metals,
etc., which their components could not do. M. Nys says that
thousands of such modifications, which are more or less pro-

1 Cf. Nys, Cosmologie, Vol. II, p. 231.

CHANGE IN CHEMICAL COMPOUNDS 147

found, have been observed, and the reader may be referred
to his work for many more examples.1 We shall decide
whether any substance which is under consideration is a
true compound, in accordance with our observation of such
changes in particular mixtures ; and it is also to be noted
that what is important, from the philosophical point of view,
in the properties observed in compounds is not their physical
analysis, but the way in which they operate. Scientifically
speaking, all we can know of these properties is such aspects
of them as are amenable to quantitative treatment, and so
are measurable, but the philosopher ought to take into
account their operation as a whole, including the effects
which they produce on other bodies ; since their operation
and mode of working taken as a whole is the only means we
have of discovering their nature. Science, by reason of its
method, which is mathematical, does not find it necessary
to take account of the ends towards which things tend, or
their purposes, nor even why they occur in the way they do,
but philosophy must consider all these elements, if it is to
arrive at a balanced view of the natures of things. If this is
done, we shall find that the compounds often behave in a
way very different from that of their elements ; and naturally
tend to different ends. These considerations, then, as to the
operations and intrinsic tendencies of the elements and com-
pounds show that the elements are specifically distinct one
from another, and the compounds also from their elements. It
is altogether illogical to admit a specific distinction among the
elements, and to deny it as between elements and compounds,
since the same criterion which assures us of the one, viz.
diversity of operations, is equally decisive in the case of the
other.

If, then, the elements are specifically changed when they
combine, so that they do not remain in the compound for-
mally, how are we to explain the fact that the compound
shows many of their characteristics, or the sum of them, such
as weight, and is always resolvable into them again ?

As we have already seen, the Thomists agree in saying
that the qualities of the elements remain formally, i.e.
1 Nys, op. cit., Vol. II, pp. 227-239.
L

148 MODERN THOMISTIC PHILOSOPHY

retaining their original nature, in the compound. If they
did not, they would either be represented by a quality which
is their mean, or potentially only, or not at all. The last
hypothesis makes it quite impossible to explain how it is that
many qualities of the compound are merely the sum of those
of the elements, the fact that the spectrum of the molecule
shows the characteristic spectra of the elements, and the
fact that the compound is always resolvable into its elements.
If they remain potentially only, different external agents,
which dissolve the compound, would produce different results,
since the only determining factor in this case would be the
agent. This, however, is not the case, for whatever agent be
employed, the resulting elements are always the same. We
have already seen that the theory of a mean quality cannot
be maintained, and so we must conclude that the qualities
remain in the compound formally. If this be so is it sufficient,
in order to account for the facts, to say that they are dis-
tributed evenly and homogeneously throughout the whole
compound, their capacity for reappearance in the solution of
it being accounted for by its being heterogeneous in struc-
ture, i.e. that there is a difference of arrangement of parts in
one portion of the compound from that in another ? It
seems very improbable that such a heterogeneity as this is
sufficient, since it is quantitative only, and thus seems to be
inadequate as a predisposition for the appearance of sub-
stantial forms which differ in kind, and which must, there-
fore, be prepared for by qualitative differences. It does not
seem possible to regard inanimate bodies as wholly unified
and unorganised, as was done in the Middle Ages, but rather
we find in them an organisation which is comparable to that
of living things, though less elaborate. Thus, the view which
ascribes to the molecule different qualities in its different
parts appears more consonant with the known fUcts, and on
a wide view more acceptable, than that which denies it :
since we shall recognise right through the material world,
from the atom up to the highest forms of life, a continually
increasing heterogeneity of structure and quality, along with
a consistent homogeneity of nature. To maintain such a
gradual ascent is merely an expansion of the Thomistic

CHANGE IN CHEMICAL COMPOUNDS 149

notion of the scale of being of which Milton speaks in
Paradise Lost (Bk. V, lines 468 fi.) :

To whom the winged Hierarch repli'd.
O Adam, one Almightie is, from whom
All things proceed, and up to him return,
If not depraved from good, created all
Such to perfection, one first matter all,
Indu'd with various forms, various degrees
Of substance, and in things that live, of life ;
But more refin'd, more spirituous, and pure,
As neerer to him plac't, or neerer tending
Each in their several active Sphears assignd,
Till body up to spirit work, in bounds
Proportiond to each kind. So from the root
Springs lighter the green stalk, from thence the leaves
More a^rie, last the bright consummate floure
Spirits odorous breathes : flours and thir fruit
Man's nourishment, by gradual scale sublim'd
To vital spirits aspire, to animal
To intellectual, give both life and sense,
Fansie and understanding, whence the soule
Reason receives, and reason is her being.

Somewhat the same idea, though carried much farther, is
held as true by Professor Whitehead, who says : ' The doc-
trine which I am maintaining is that the whole concept of
materialism only applies to very abstract entities, the
products of logical discernment. The concrete enduring
entities are organisms, so that the plan of the whole influences
the very characters of the various subordinate organisms
which enter into it. In the case of an animal, the mental
states enter into the plan of the total organism and thus
modify the plans of the successive subordinate organisms
until the ultimate smallest organisms, such as electrons, are
reached. Thus an electron within a living body is different
from an electron outside it, by reason of the plan of the body.
. . . But the principle of modification is perfectly general
throughout nature, and represents no property peculiar to
living bodies.'1

The difficulties arising from the existence of isomeric and
polymeric substances,2 as well as the phenomena of allotropy,3

1 Science and the Modern World, pp. 98 fi. ; cf. pp. 164 fi. Cf. also
Nys, Vol. II, pp. 200 fi. ; Geny in Gregorianum (1922), pp. 458 f. ; Divus
Thomas (Plac.) (1925), p. 77.

* Cf. Nys, Vol. II, pp. 268 fi. 8 Ibid., Vol. I, pp. 240 f.

150 MODERN THOMISTIC PHILOSOPHY

can be explained on these principles ; while the assertion
that atomic weight, mass, etc., remain constant does not
affect our conclusion, since we maintain that the same matter
remains throughout the change, and so those accidents which
are quantitive, and thus directly associated with matter, will
naturally remain unchanged also.

In general it is true to say that all the facts which science
takes as proving the essential discontinuity of matter — since
this is the simplest hypothesis, and therefore for science the
truest — can equally well be accounted for by substantial
homogeneity, together with accidental heterogeneity. We
are led to adopt this latter view from the philosophical con-
sideration of the natural intrinsic tendencies of bodies and
their relations with the rest of the material universe : con-
siderations which natural science does not, and ought not,
to take into account j1 dealing as it does only with measur-
able phenomena.

1 Examples of the application of these principles are to be found in
Hcenen's Cosmologia, pp. 350-404 ; e.g. p. 368 with regard to Bragg's
experiments. See also his Summary, pp. 401 ff.

CHAPTER XII

THE INDIVIDUAL

Its Nature — Opinions — Explanation of the Thomist View — Reasons
in its Favour — Meaning of ' Materia Signata ' — Some Diffi-
culties Considered.

So far, we have been concerned with general natures ; first of
material substances, and then of its various species and
accidental characteristics ; and we now have to turn to the
individuals which belong to these species. It is with such
individuals that our knowledge begins, and the whole process
of generalisation has as its object and end the understanding
of them. It will, however, only allow us to have knowledge of
them with regard to those features which they possess in
common with other individuals, leaving us still in ignorance
as to what it is that constitutes them as individuals, or as
differentiated from other concrete substances ; for the
individual, while undifferentiated in itself, is yet distinguished
from others, as S. Thomas says.1 If what has been said
about the essential unity of the atom and molecule be true,
•these bodies, at least, when taken singly, will be true
individuals ; even if we are obliged to deny or doubt the
individuality of larger masses of inanimate matter ;2 and we
wish to discover what it is precisely which is the root of their
unity and of their distinction from other bodies of the same
nature as themselves. This question as to the root of
numerical unity is known as the problem of the principle of
individuation, and is one of the most recalcitrant and obscure
of the many difficult problems discussed in mathematical
philosophy.
The history of the consideration of this problem may be

1 Summa Theol., Pars I, Q. 29, a. 4.

* For a full discussion of this question see Nys, Cosmologie, Vol. II,
pp. 281-294.

151

152 MODERN THOMISTIC PHILOSOPHY

said to begin with Aristotle who regarded the individual as
containing reality in itself, in contrast to Plato, who looked
upon the subsisting Forms as constituting reality. The
former finds in the individual two kinds of unity, a unity of
nature, which it shares with other individuals, and a unity
which is all its own. The first is specific, and the second
numerical, unity. Specific unity is, in his view, derived from
form, since form is that which makes the substance to be
determinately what it is. What, then, is it which is the source
of the numerical unity of individuation ? Few passages, and
those ambiguous, can be cited in which individuation seems
to be ascribed to form ;x while there are numbers in which it
is distinctly attributed to matter. So he says : ' The whole
thing, such and such a form in this flesh and these bones, is
Callias or Socrates ; and they are different owing to their
matter (for this is different), but the same in species, for the
species is indivisible.'2 So it is no doubt true to say that
Aristotle thought that things which differ numerically
within the same species do so in matter only, and so by reason
of it.

The question does not make much progress till we come
to the Arabian philosophers of the Middle Ages ; though
Boethius, in touching on it incidentally, seems generally to
ascribe individuation to accidents. ' Ea vero qua individua
sunt et solo numero discrepunt, solis accidentibus distant.'3

Passing then to the Arabians, Avicenna (980-1037), or
rather his translator, first introduces us to a term which was
to become famous in discussions of this question, by using
the word ' signatum ' as synonymous with ' determinate
individual,' which thence comes to be applied to any deter-
minate reality. Thus we hear both of ' forma,' and of
' materia,' ' signata.' Since a nature, he contends, is not of
itself individual, the relation between it and individuality is
an accidental one, and therefore we must look for its source
not in essence, but among the accidents, such as quantity,
quality, place, and time. Nevertheless, a definite theory of

1 Cf. Met., I038bi4 ; 1071027-29 ; Phys., 412*6-9.
1 Met., 1034*5-8 ; cf. IOI6&32 ; I035b27~3i ; 1054334 ; 1074331-34 ;
Phys., 278*7^3.

• In Isagogen Porphyrii, ed. Brandt, pp. 241, 9 ; cf. De Trinitate, I.

THE INDIVIDUAL 153

individuation is not worked out by Avicenna, though his
dicta about it should logically lead to the conclusion that its
source lies in matter which is determined by spatial dimen-
sions. No doubt this latent conclusion was perceived by the
penetrating mind of S. Thomas : who, however, was also
much influenced in this question by another writer of the
same race — Averroes (1126-1198). According to Averroes,
known in the Middle Ages as the Commentator, from his
exhaustive commentaries on Aristotle, matter is in itself
numerically one, since being undetermined, it cannot be
many. Nevertheless, it is divisible, and that which makes it
so must be quantity, i.e. the three dimensions of the con-
tinuum. Hence matter must be conceived as carrying with
it, not this or that three-dimensional extension, but exten-
sion in general — ' unterminated extension or dimensions.'
So first matter is in potency to a determination by three
dimensions in general, which potency is logically prior to that
which it has for being determined by a specific form.

The theories of Avicenna and Averroes seem to have had a
predominant influence on the thought of S. Thomas (1224-
1274) ; which vacillates in a remarkable fashion between their
explanations. He never, as it seems, had the least doubt
with regard to the Aristotelean theory of individuation by
means of matter ; but he hesitates for some time as to the
way in which this general theory should be understood.
After accepting, at first, the expressions and theory of
Avicenna that the principle of individuation is matter
designated by determined dimensions,1 he abandons it in
favour of the Averroist opinion that it is matter affected by
unterminated dimensions which is this principle.2 He makes
considerable use of this second theory, only in the end to
throw it over and return once more to the view that the
dimensions are determined ones.3

The reason of this change of opinion is almost certainly to
be found in S. Thomas' keener realisation of all the con-
sequences which flow from the strict acceptance of the
doctrine of the uniqueness of substantial form : since the

1 De ente et essentia, Cap. 2.

4 In Boethium de Trinitate, Q. 4, A. 2, et ad 311m.

* e.g. Quodlibet, XL, a. 6, ad 2um.

154 MODERN THOMISTIC PHILOSOPHY

Averroist theory really implies some real priority of the
unterminated dimensions to substantial form.

A few words must be added with respect to the subsequent
history of this discussion in the Schools, though it is impossible
to treat it fully, or to examine non-Scholastic views of
individuation.

Scotus (i265(?)-i3o8) held that the source of individuation
is the numerical determination of the form and matter of the
compound, by which they become this form and this matter.
He maintains, further, that it is distinguished from the
nature of the thing by a formal distinction a parte rei, i.e. it
is not wholly identified as a reality with the nature. He
says it is the 'ultima realitas entis ' ;x and though not sub-
stantial form is yet of the nature of a formality as determin-
ing the thing to be ' this.' He calls it ' hcecceitas ' or
' thisness ' ; so that a thing is this by its thisness, it is an
individual by means of the last reality of its being : a
conclusion which is not very illuminating.

Ockham (c. 1300-1348), and the Nominalists generally,
necessarily regard the question as to the principle of individua-
tion as meaningless, since they do not admit as realities
independent of the mind any universal or specific natures,
but only individual things or phenomena. Hence the
individual is distinct of itself, and not multiplied in the
species, the latter being either a mere concept or a group
name.

Suarez (1548-1617) considers, in opposition to Scotus,
that the principle of individuation can only be logically dis-
tinguished from the individual being. Every being, even an
incomplete one, is individual of itself, by reason of its entity.
He is particularly determined in his opposition to the
Thomist thesis which would see in a part of the nature
only, viz. matter affected by quantity, the principle of
individuation.2

It is essential to notice that in this enquiry we are not

1 Opus Oxoniense, II, dist. Ill, Q. 2, No. 15.

* Disp. Metaph., V, Sect. 3. Cf. Mahieu, Francois Suarez, pp. 112 ff.
The greater part of the foregoing account of the history of this problem
is derived from Fr. Roland-Gosselin's masterly analysis in his edition of
the De ente et essentia ; particularly with regard to S. Thomas' opinions.

THE INDIVIDUAL 155

looking for the proximate cause of individuation, but its
root or first cause ; nor yet do we wish to discover how
individuals are to be distinguished by it, how we recognise
them as distinct individuals, but how they are distinguished
from one another in themselves.1

The Thomist school all answer this question by saying that
the principle is matter signed or sealed by quantity : which
at this stage we may take as meaning matter which has a
relation to quantity — Wicksteed describes it as ' earmarked
by quantity '2 — though later we will examine this phrase
more closely. It is necessary to discuss this question fairly
fully since S. Thomas' view on this subject is at the very
heart of his metaphysical system, to such an extent that its
abandonment would seem to involve the abandonment of
his whole conception of the universe ; and conversely a real
grasp of it will greatly help to an understanding of the
whole of his philosophy. We have already had occasion to
notice that the theory of matter and form is a particular
case of the Aristotelean division of being into potency and
act — though almost certainly not a derivative of it — and
this thesis is another special case of that theory. For multi-
plication implies a distinction, and so a restriction or limita-
tion, which limitation implies, in its turn, some imperfection
or potency ; from which it follows that an act which is com-
plete and perfect in its own order, both as a substance and as
a species, cannot be multiplied in that order ; and also that if
any form or act is multiplicable, this cannot come about
from the form or act itself ; since this in itself implies no
limitation. The multiplication must therefore come from
potency or matter.

To prove their contention that the principle of individu-
ation must be matter determined by quantity, the Thomists
argue in the first place that no other principle can be dis-
covered which will satisfy the necessary conditions, viz. to
multiply substantial individuals within the species ; since in
any material substance we can distinguish four, and only

1 Cf. Salmanticenses, Cursus Theol., Vol. I, Tract. I, Disp. I, Dub. 2,
No. 45 f.

' The Reactions between Dogma and Philosophy (1926), p. 368.

156 MODERN THOMISTIC PHILOSOPHY

four, elements : matter, form, subsistence (i.e. that by which
the thing is put in the category of substance, and made self-
supporting or existing per se, or on its own account), and
existence. The last two cannot possibly be the principle of
individuation, since they both belong to the existential
order, and so presuppose, as a necessary condition of their
own individuality, an individual nature already constituted.
The reason of this is that existence being, in itself, all of a
kind, must, if it is to be differentiated and made individual
at all, be so differentiated by something other than itself,
i.e. by nature. Moreover, we are, in fact, asking how we
can have an individual nature, so that the question is con-
cerned with the order of nature or essence, not existence.
Neither can form be the principle we are looking for, since
form differentiates things specifically, for the very concep-
tion of form implies that it is form which makes a thing to be
of a determined species : so that when form varies, the
species varies. Consequently, matter, as the only remaining
element in the thing, must be the principle of individuation.
Matter, however, does not seem to be capable of filling the
role required of it, for it is, as we have seen, altogether
potential and undetermined in itself, so that it could not
determine, or differentiate, anything else. If, then, it is to
do this, it must be in some way determined. Such deter-
mination as is required evidently cannot come to it from
substantial form, since we are looking for numerical, not
specific, determination : while the very word ' numerical '
suggests that it does come from that accident, which is most
closely united to it, and which is numbered, viz. quantity ;
which is also, as we saw, individual of itself (cf. p. 65). In so
far, then, as matter has a relation to this quantity rather
than that, it can be, and is, the principle of individuation.

Again,1 if we look at the question directly we see that two
things are required for the principle of individuation ; first,
that it should be an intrinsic substantial principle of incom-
municability of form ; and, second, that it should be the
principle whereby one body is made distinct from all others.
Now, that matter is an intrinsic substantial principle is clear,

1 For the following argument cf. Summa TheoL, Pars III, Q. 77, a. 2.

THE INDIVIDUAL 157

and moreover, being the basic and primary substratum of.
bodies it is unable to be received in anything else ; from
which it follows that any form which is received in it will like-
wise be unable to be received over again, and so will be
rendered incommunicable so far as reception in a subject is
concerned. The principle of distinction from others, on the
other hand, is not matter, since this is in itself undiffer-
entiated ; while the source of differentiation and division is
extended quantity, for a thing is rendered naturally incapable
of existing in several things if it is undivided in itself, and
divided from all others. It is clear, moreover, that it is
extension which divides substance, and so is a kind of
individuating principle, inasmuch as forms are numerically
differentiated by being in different parts of matter. That
quantity is indeed, in this way, a principle of individuation
can be seen in the order of pure quantity, inasmuch as we
can imagine several lines of the same species, differing only
by their position in space : and the same is true of other
geometrical figures. Such difference in position, however,
belongs to quantity. Hence a double principle of individu-
ation is required, matter and quantity, or matter determined
by quantity. From this we can see the way in which the
phrase ' materia signata quantitate ' ought to be understood :
a much controverted question.

Sylvester of Ferrara held that materia signata is a com-
pound of matter and the quantity which actually informs it.
This idea is perfectly clear and acceptable if we consider an
existing individual ; which, of course, has a particular
quantity ; but it is not satisfactory if we consider the
individual in the process of coming into existence, and
attempt to determine how it came to be individualised ;
since the matter could not be actually informed by a parti-
cular quantity until it had already received a substantial
form. Now, it is precisely with the individuation of this
form that our enquiry is concerned ; and so we cannot ascribe
such individuation to actually informing quantity, since
being posterior to form it cannot be, in the same order, prior
to it, and so cannot make the matter to be this rather than
that, and thus individuate form.

158 MODERN THOMISTIC PHILOSOPHY

In order to meet this and other difficulties in the opinion
of Ferrariensis, Cajetan and the majority of Thomists say
that materia signata must be explained as first matter which
has a radical requirement for this quantity rather than that :
for first matter, being the potential principle of bodies,
requires quantity.

First matter in general requires quantity in general, and
so this or that determined matter requires this or that deter-
mined quantity. Hence the radical requirement for a
determined quantity is considered as prior to the coming of
substantial form, and actual quantity, to the body. This,
perhaps, lessens the difficulty, but does not clear it up ; for
how can matter which is altogether undetermined have a
determinate requirement ? To answer this an appeal is
made to the Aristotelean principle of reciprocal priority of
mutual causes.1 According to this principle, causes, which
are causes of one another are in different genera of causality ;
and in this case, quantity, being an accidental form, is pos-
terior to substantial form in the genus of efficient causality,
but, since it is at the same time a disposition which disposes
matter to receive this form, it is prior to it in the genus of
material disposing causality. So the matter in which
the new form is about to appear, being disposed to receive
this form, is also disposed to receive the quantity which goes
along with it. This explanation, however, seems only to
give us matter with a requirement for some quantity within
the limits of the quantities which are suitable to the form in
question, as e.g. the quantities suitable to elephants as
opposed to those suitable to mice. Such quantity, it is plain,
cannot be said to be individually determinate ; in fact, the
very idea of it is of that quantity outside whose limits we
should not find a member of the species, and within whose
limits we might find any individual of it, not a particular
one. Now, as we have seen, quantity essentially consists in. a
plurality of parts, and one quantity is differentiated from
another, and is this quantity as opposed to that, by a different

1 Cf. S. Thomas in V Metaph., Lect. 2 ; de Veritate, Q. 28, Arts. 7
and 8. John of S. Thomas, Cursus Phil. Phil. Nat., P. II, Q. 1, A. 7,
and Q. 9, A. 4. Salmanticenses Cursus Theologicus, Tom. I. De Principio
Individuationis, Disp. I, Dubium 5, Sect. 3.

THE INDIVIDUAL 159

order of parts in the whole. So, in a homogeneous body
one part differs from another by its position in the whole
body, and having thus once acquired an individuality it
retains it, even if its position in the whole be changed. If we
apply this idea to a body which is about to undergo a sub-
stantial change, we see that at the instant before the change
it has a determinate order of parts, and occupies a deter-
minate ' situs ' or position with respect' to all the other
bodies in the universe. Then comes the change, and the new
form is drawn out of matter under the action of the agent,
the matter having been so modified as to be disposed to
receive just this form and no other, among such predisposi-
tions in it being that it requires to occupy a definite situs,
viz. that of the corrupted body. Thus the new body also has a
requirement for occupying this same situs, and so is made
individual. Having once gained such individuality it can
retain it, i.e. it can remain divided from every other body by
reason of its actual quantity at any given moment, and
remain unable to be subjected in any other by reason of its
matter. Being thus an individual, if, as in the case of living
things, it takes up new matter into itself and grows, thus
altering its quantity, it does not thereby lose its individual
identity, since it makes the new matter part of itself, both
specifically and individually, by a continuous process.

If this theory be correct, it is evidently in accord with
S. Thomas' requirement, in the last phase of his thought on
this question, for a determinate quantity as a co-principle of
individuation with matter ; and avoids the difficulty which
he eventually found in accepting the Averroist theory of
matter affected by unterminated quantity, viz. that such
quantity must be conceived as prior to substantial form in
the matter. According to the view just outlined, there is no
real priority of quantity, whether determined or undeter-
mined, to form, but merely a requirement in the matter for
the occupation of a determinate situs or position, owing to
the fact that the body at the instant of corruption actually
occupied that situs. Thus, no actual quantity remains
through the change, but the matter has been predisposed to
receive a form accompanied by a determined quantity. The

160 MODERN THOMISTIC PHILOSOPHY

quantity in the generated substance will not be numerically
the same as that in the corrupted one, since, like all other
accidents, it will be individuated by its subject : even
though, as we saw, it possesses a certain distinction and
individuation of its own. Its actual dimensions, qua dimen-
sions, remain the same, but they are now the dimensions of
the body B, whereas before they were those of A. The fact,
however, that they are the same ; in other words, that the
generated body occupies the same situs as the corrupted one,
and that the matter which is in each has therefore a require-
ment for this situs, enables us to say that this matter
remains the same under the change. ' This ' matter, which
is marked out as ' this ' by the requirement for a definite
position and quantity, is found both in the corrupted and
generated body : a state of affairs which seems to be
demanded by our common way of talking about such
changes, as, for example, this wood has turned into this ash ;
this dead body is the body of such and such a man, and so on. 1

It seems, then, that there can be no doubt that matter is
the principle of individuation, since, as S. Thomas says :
' Differentia quce ex forma procedit inducit diversitatem speciei '
{Contra Gentiles, Lib. II, Cap. 93), which, as we noticed
before, is a consequence of the principle that act, if it is to be
limited and multiplied must be so limited by potency.

Nevertheless, certain further difficulties arise with respect
to the theory, for it seems that if first matter has a require-
ment for a definite quantity, it is already determined to a
certain extent, or actuated, and so does not lose all its actu-
ation in substantial change, in contravention of what we
have already seen is necessarily required in such change.
This, however, is not the case, for just as first matter in
general is not a capacity for receiving all forms of whatsoever
kind, but only material ones, so that it is determined extrin-
sically, though not intrinsically, similarly ' this ' matter has a
great deal of its capacity taken away from it, but neverthe-
less, what remains is a sheer capacity, not any positive deter-

1 This theory of individuation, in so far as it attributes an important
role to situs, was proposed by Fr. Geny, S. J., Gregorianum, April 1921, pp.
290 &,, with acknowledgements to the Venetian Province of the Society.

THE INDIVIDUAL 161

mination. The Scholastics express this by saying that it has
a transcendental relation to ' this ' quantity, i.e. a relation
which is not something added to it, but is its very self ; just
as matter as such has a transcendental relation to material
form as such. They are correlatives, one implying the other.
The matter remains purely potential, but its capacity is
limited ; as in the case of two vessels of different sizes, the
smaller one's actual content would be less than that of the
larger, and yet both may be equally empty ; so, in the case
of our two ' matters,' both may be equally potential. The
matter which has a transcendental relation to a definite
quantity is no less potential than matter in general, but there
is less potentiality.

Again, it might seem that our principle, though sufficient
to account for the individual distinction of two bits of
inanimate matter, such as two stones, is hardly sufficient
when we come to things of a higher order, such as two dogs,
and still more two men. This difficulty arises, partly, from
the fact that we often confuse individuality with personality ;
but we can hardly insist too much on the distinction between
them, for they are, in fact, at the opposite ends of the scale.
Quite apart from this theory of individuation, consideration
shews, as we shall presently see, that personality is the
highest and most perfect thing in nature, whereas individu-
ality is almost the lowest.1 Further, it is to be noticed that
by individuality we mean something negative : this thing is
not that, whereas, as we ascend in the scale of beings, we get,
along with this negative character, a gradual increase of a
positive character as the things become more and more
masters of themselves. Such self-mastery is in proportion
to the capacity for action on one's own account, by and for
oneself ; in other words, in proportion to the capacity for
immanent action. Now a plant has immanent activities
which inanimate things have not, being able to nourish itself,
grow, and reproduce its kind ; animals have still more of
such immanent activity, for they direct themselves by sense,
and men most of all, being able to determine their own

1 Cf. Maritain, Three Reformers, pp. 19 ff., where this distinction is
shown at length with many of its applications.

162 MODERN THOMISTIC PHILOSOPHY

actions both by sense and reason. Thus we have a growing
centralisation and self-control, but the negative division from
other bodies which is characteristic of individuality remains
the same : and we can legitimately attribute individuation
to matter, while recognising a growing unification in the
thing itself as we ascend the scale.1

As to the way in which we distinguish one individual from
another, there is no doubt that we do so by remarking their
different accidental characteristics, such as position, dimen-
sions, shape, colour, etc. ; but though individuality is known
to us by means of these, it would be a confusion of thought
to conclude that they are therefore its principle.

If, then, the principle of individuation be matter affected
by a transcendental relation to a determined position, it
follows that material substances are not individuated
absolutely in themselves, but in relation to other individuals,
from which they are separated ; and consequently that the
principle of individuation, though intrinsic, cannot be, as
Suarez maintains, the entity of the thing considered abso-
lutely. For, if this were so, the matter of one thing, con-
sidered absolutely, would be different from the matter of
another, and so would not be common matter. This would
lead us to conclude that any two substances differ essentially
or specifically of themselves. Such a conclusion, however,
is definitely Nominalistic, since there could, in this case, be
nothing universal in nature. All things would be essentially
different, and no essential concept could apply to several of
them. On the other hand, if, with Scotus, we make individu-
ation something added to the nature of the thing, we equiva-
lently assert that nature without such addition is universal ;
and since such nature is found in individuals, the universal
as such will be found in individuals. This view, therefore,
tends towards an extreme form of Realism. In saying this
our intention is only to point out the tendencies which seem
to be implicit in the views of these two great thinkers, not to
suggest that Suarez was a Nominalist, or Scotus an advocate
of an extreme form of Realism. In any case, the balance

1 Cf. M. C. D'Arcy, S.J., Thomas Aquinas, pp. 148 ff., where this
difficulty is discussed and the notion of immanence emphasised.

THE INDIVIDUAL 163

between an extreme Realism and Nominalism is undoubtedly
preserved in the theory of S. Thomas, in which the individual
neither absorbs the universal, nor is absorbed by it. Such a
moderate realism avoids both scepticism, which is the out-
come of Nominalism, and Monism, from which extreme
Realism cannot escape. From this point of view, therefore,
this thesis may be said to be a postulate of the Thomist
theory of knowledge. Indeed, whether we look at the
change and motion in the material world, or at the multipli-
cation of individuals in it, or at our knowledge of it, the facts
force us to say that the only intelligible explanation which
can be given of them is that this world and all things in it
are composed of two elements, one of which is actual and
the other potential, and of which the latter limits the former.

CHAPTER XIII

SOME GENERAL CHARACTERISTICS OF THE INANIMATE
WORLD

Physical Laws and Theories — The Formation of the Material
Universe — The Infinity and Eternity of the Universe.

I. Physical Laws and Theories.

To enquire into the ultimate cause of the universe and the
method of its production, if it is not self-sufficient, does not
come, strictly speaking, within the scope of natural philo-
sophy, since this considers the material world in itself. At
the present time, however, it is more than ever evident that
it is subject to change, and has not always been in the state
in which we now find it. Its changes, nevertheless, must be
held to be regulated by determinate rules ; for since the
Thomistic theory of bodies recognises that they have deter-
minate natures, they must also have determinate modes of
action. Such modes of action are commonly called the laws
of nature. It is clear that such laws have a certain necessity,
since they are consequents of the natures of the bodies ; but
this necessity is said to be ' hypothetical ' ; i.e. dependent
on the fulfilment of some condition ; the condition in this
case being that the circumstances remain the same, and that
no disturbing influence comes into the system of inanimate
nature from without. If this condition be fufilled, bodies
will always act in a certain determinate fashion which follows
from their nature. We may not, however, be able to formu-
late these laws adequately, and any formulation of them will
naturally be bound up with the way in which the world is
regarded by physical science at any particular epoch, and so
with physical theories, the discussion of the character and
value of which belongs properly to Epistemology, or the
theory of knowledge. It may not, at the same time, be out

164

CHARACTERISTICS OF INANIMATE WORLD 165

of place to remark here that some writers now regard these
theories as having only a phenomenal value, with little or
no connection with the realities which may or may not underlie
them : while others take them simply at their face value,
and transport them bodily into natural philosophy. In this
latter view, atoms, electrons, protons, waves, the ether, etc.,
are treated as substances on the same terms as bodies which
fall under direct sensible observation. This view seems hardly
tenable, and in any case is not necessitated by the notions of
the physicists themselves, who certainly regard sub-atomic
elements as being of a different character to gross matter.
The other extreme seems also to be inadmissible, inasmuch
as the theories are founded on quantitative examination of
the material world, and therefore cannot be wholly uncon-
nected with the material reality of which it is composed.
From this it is clear that philosophy cannot ignore physical
theory, nor yet regard it as expressed in the same language
as that which it uses itself. To what extent physical
theories are intended to, or in fact do, represent ontological
realities, is one which must be left over for more detailed
consideration at a later stage.

II. The Formation of the Material Universe.

Since the changes which occur within the material
universe come within the limits of the subject matter of
natural philosophy, it is within its scope to examine them,
and so to consider the whole system of such changes, or the
world-process in general. In such an examination it will
necessarily be directed by rational or metaphysical principles,
such as the principle of finality, which, though it is only
in metaphysics that they are demonstrated to be absolutely
general ones, applying to all being, can yet be legitimately
employed here, since natural philosophy has established
their validity as applied to bodies, as in the case of the
principle of finality, by showing that bodies have determined
natures. Its function will consequently be rather negative
than positive, in so far as it will endeavour to see whether
the views put forward by natural science are consonant with
reason or not.

166 MODERN THOMISTIC PHILOSOPHY

The current theory with regard to the formation of the
material universe is, as is well known, the following :

It is supposed that the material universe at first existed as a
uniformly distributed gas, which, supposing the total amount
of matter to have remained constant, and calculating on the
basis of the amount of matter now existing, must have been
extremely tenuous. The first stage in the growth of the
universe would be the condensation of this gas into giant
nebulae, not stars, as Newton conjectured. Such condensa-
tions must have been started by some disturbance in the
primeval gas, and unless this motion were directed exactly
towards the centre of the condensation it would cause it to
spin. As the gas is contracting this spin will increase in pro-
portion as it does so, and the result of the process will be
nebulae rotating at different rates. This is, in fact, observed,
viz. that the nebulae are so rotating. A nebula which was
not rotating would assume a spherical shape under the force
of its own gravitation, but rotation will cause it to be flat-
tened at the poles and broadened at the equator until it
reaches the limit of such flattening, which is not a plane
surface, but a figure of the shape of a double convex lens.
After this point, since flattening cannot proceed any further,
the nebula will begin to eject matter from its sharp equa-
torial edge, and a thin layer of gas will be formed in the
equatorial plane. Any disturbance in this mass will cause
condensations in it, of which the larger ones only survive.
When the weights of the smallest condensations which could
form and be permanent are calculated it is found that most
of them are comparable with that of the sun. For this
reason, and others, therefore, it is considered that this is the
actual process by which the stars (of which, of course, our
sun is one) were formed. Thus the sun and all the stars will
have been born out of rotating nebulae. The galactic system
(the Milky Way) is supposed to have been a rotating nebula
which has gradually condensed into the Galaxy which we
now observe, and in which our solar system is situated.

Turning now to the formation of the Solar System, we see
that according to the foregoing theory it will have begun
with the sun as a condensation of the gas of the galactic

CHARACTERISTICS OF INANIMATE WORLD 167

nebula, which condensation will be in rotation since its
parent was rotating. The first serious scientific attempt to
account for the formation of the Solar System in its present
form was that put forward by Laplace in 1796. He suggested
the idea that the system was originally a nebula in rotation
which would gradually shrink, and its shrinkage making it
rotate more and more quickly, he showed that it would
flatten out and emit matter in its equatorial plane in the way
described above with regard to the formation of the stars.
Thus the planets would be left behind by the main mass
(the Sun) as this shrank continually. This view was accepted
for nearly a century, but has now been abandoned, for,
according to the theory the Sun broke up and produced the
planets owing to its excessive rotation. This, however, could
not have been the cause of their production, since it is now
known that a star which rotates too fast does not form a
system similar to the Solar System, but bursts into pieces
of nearly equal size, a result which is observed in binary
and multiple stellar systems. Moreover, on calculating the
angular momentum of the primeval sun, it is found that it
could not have been sufficient to make it break up at all ;
and, lastly, the mathematics of condensations shows that
though Laplace's nebular hypothesis would hold good with
respect to vast masses, such as the giant nebula?, it cannot
account for the formation of small bodies such as planets,
since the gas left behind by the rotatory motion of the
Sun would be too tenuous to condense, it would simply be
dissipated. Thus it appears that though, roughly speaking,
Laplace's hypothesis is applicable to the birth of suns from
the original nebula, it cannot account for the birth of planets
from the Sun.

Since there is no known method by which a single star
could give rise to a planetary system, the theory is put for-
ward that the Solar System arose through the approach of
another star to the Sun while the latter was still in a gaseous
state. This is known as the tidal theory, which suggests
that some two thousand million years ago a second star
approached near enough to the Sun to raise in it an enormous
tide of the nature of an arm of gas drawn out from the Sun's

168 MODERN THOMISTIC PHILOSOPHY

matter. This arm would be of sufficient density to allow
condensations to form within it, the larger of which conden-
sations became the planets. These will follow a somewhat
irregular orbit round the Sun, in the course of which they
may approach near enough to it for matter to be drawn out of
them in the same way as they themselves were drawn from
the Sun ; and in this way the production of their satellites
is accounted for. This idea is confirmed by the fact that the
orbital planes of the planets are different from the equatorial
plane of the Sun, a fact which is unaccountable on Laplace's
theory, but which fits in well with the notion that matter
was drawn out of the Sun by a passing star, which was not
in the plane of the Sun's equator.

Now, it is clearly not the business of philosophy to decide
what degree of probability attaches to these theories from
the scientific point of view : this is determined by the extent
to which they cover the known facts, and the simplicity of
the picture which they give. Philosophy can only say
whether, if they are taken to represent what really occurred
in the past, they involve any elements which are repugnant
to reason. Now it is clear that they all presuppose that the
evolution of the material universe came about, not at random,
but in obedience to the natures of the bodies considered,
which all have their peculiar properties and laws ; though
some laws are common to them all — such as gravitation —
and others to large classes — such as the laws governing the
condensation of gases. No account is given of the origination
of the primeval nebula, or of the first movements in it which
caused rotation, etc. So, no objection can be taken to the
theories on the ground that they violate the principle of
causality ; and since they all recognise determinate charac-
ters and laws in natural bodies, they do not violate the
principle of finality. Hence, from no point of view can it be
said that they are irrational ; and it is clear that since the
primeval gas is supposed to have had a definite constitution,
it would contain virtually the developments and evolution
which followed from it.

From a scientific point of view the general theory of the
way in which the stars were produced enjoys, at least, a high

CHARACTERISTICS OF INANIMATE WORLD 169

degree of probability ; though it should be recognised that
all we can affirm positively is that the observations show
that the known phenomena are such as they would have
been if the theory represents the actual events. The
universe looks as if it had been formed in this way.

III. Is the Universe Finite or Infinite in Extent, and in

Duration ?

(a) The first question has already been answered implicitly,
since we have seen that an absolutely infinite quantity,
whether discrete or continuous, is an impossibility. It is
thus clear that since a universe which was actually infinite
in extent would involve the actuality of both these infinities,
it is therefore impossible.

(b) The second question does not admit of so definite an
answer. It might be thought, at first sight, that we could
rule out an infinite duration of the world on the same
grounds as we do its infinite extent ; but it is clear that if
we cannot exclude such a possibility we can then ask
whether it is a fact that it has had an infinite duration.

Let us consider first the possibility of an infinite duration
of the world. If the universe were unproduced by any cause
it would clearly have such a duration, since it exists now,
and a thing cannot bring itself into existence. Hence, we
should have answered both our questions — as to possi-
bility and fact — affirmatively ; saying that it is, and so
obviously can be, eternal. If, however, the world has been
brought into existence, does it follow that it had a beginning
in time ? As is well known, S. Thomas startled his contem-
poraries by maintaining that reason was unable to prove the
necessity of such a beginning in time, even though the world
was acknowledged to have been created by God. This
assertion depends on the statement that causal priority does
not necessarily involve a priority of time ; and, in fact, in
production from nothing no priority of time can be involved,
since time only begins with the production of the world.
There cannot be a moment before the first. The universe
itself which is made is also not incompatible with infinite
duration, since it is what it is by reason of its nature, which

170 MODERN THOMISTIC PHILOSOPHY

is quite independent of time ; and this holds good whether
we consider a single static thing or a whole series of successive
ones, for in the first case the single being, in the second the
whole series, would endure from all eternity.1

If, then, we cannot exclude the possibility of the infinite
duration of the world in the past, we can only weigh the
probabilities for and against such an infinite duration having
been the fact ; and all Scholastics, together with most
theists, think that the weight of probability is on the side of a
finite duration of the material world, both in the past and in
the future. They argue that since everything of which we
have any knowledge had a beginning, it is natural to con-
clude that the world as a whole also had a temporal beginning.
They appeal, further, to the law of entropy, according to
which the energy of the world is tending towards a state of
equilibrium, and consequently since this state of equilibrium
has not yet been reached, the process cannot have been
going on for ever, since all that is required in order to reach
it is that the process should go on long enough, a condition
which would evidently be satisfied in an infinite time.
Hence, in the past, there must have been a beginning of this
process, when the available energy was at its maximum ;
and in the future there must come a time when a state of
energy equilibrium will be reached, and when the world will
cease to be in the state in which it is now.

Further, on the supposition that energy is liberated and
made available by the ' annihilation ' of matter, as is sug-
gested by many scientists, it will follow that if the law of
entropy holds good, and the material of the universe is finite,
there will be a definite limit, however remote, to the process
of the liberation of energy, and consequently there must
come a time when all the matter in the universe will have
been annihilated. Similarly, in the past, if we were to go
back to infinity, we should have to suppose that the matter
in the universe was infinite in weight, a supposition which is
said to be impossible on physical grounds.2 In accordance

1 Cf. Summa Theologica, Pars I, Q. 46, Arts. 1 and 2 ; Contra Gentiles,
Lib. II, Cap. 31-38 ; Opusculum De Eternitate Mundi.

2 Jeans, The Universe Around Us, Ch. VI.

CHARACTERISTICS OF INANIMATE WORLD 171

with these ideas Sir James Jeans says : ' the present matter
of the universe cannot have existed for ever : indeed, we
can probably assign an upper limit to its age of, say, some
such round number as 200 million million years.'1

It is clear that these arguments are not absolutely demon-
strative, both because they do not show that there is a con-
tradiction in the supposition that the world has had an
infinite duration, and because they only possess the same
degree of probability as attaches to the physical theories on
which they are founded. From this point of view the argu-
ment which concludes from entropy that the world will not
always remain in the state in which it now is, seems more
certain than that which asserts that the matter of the
present universe will come to an end. What their scientific
value is can only be estimated by physicists, philosophy
being able to point out only that, however highly they may
be esteemed in this way, they are not demonstrative ; and
that in itself the hypothesis of an eternally existing material
universe does not involve any contradiction or absurdity.

It may be well to add, in conclusion, that to speak of the
world beginning ' in time ' is clearly an inexact phrase, for it
is impossible that there should have been any time before
the world was, time being the measure of the motion of
mutable being, which therefore began, if it began at all, with
the first of mutable things. We can only speak of creation in
time in the same way as we might speak of the source of a
river being in it.

Conclusion.

With these considerations as to the beginning and end of
the material universe the Cosmological section of philosophy
closes ; and we have next to examine a special class of beings
which are found in it, viz. animate ones, the discussions with
regard to which form the second part of Natural Philosophy,
which is commonly called by the Scholastics Psychology.

1 Op. cit., p. 327.

THE PHILOSOPHY OF NATURE
Part II.— THE PHILOSOPHY OF ANIMATE NATURE

INTRODUCTION

The investigation into the nature of living beings is held by
the Scholastics to be a part of Natural Philosophy. This
fact is of considerable importance, since to overlook it would
result in a fatal confusion of this study with what is now
generally known as Psychology. The latter is, in fact, an
entirely different science ; but the name Psychology was
originally applied to the philosophical examination of the
animate world, and for the last two hundred years the
Scholastics have used it in this sense, and so as the name of
that part of philosophy which we are now beginning to con-
sider. Philosophy, as we saw, deals with the very natures of
things, and is concerned with their actions and behaviour,
only in so far as these give us insight into their natures. The
recently constituted science of Psychology, on the contrary,
is interested to discover the way in which living things, and
particularly human beings, act, and to establish, if it can,
the laws which regulate their conduct and behaviour. The
distinction, therefore, between Scholastic and modern Psy-
chology is similar to that which we have already noticed
between Cosmology and Physics. Cosmology tries to deter-
mine the inner nature of material things, while Physics is
concerned with the laws of their action ; so that the former
discusses the very essence and reality of motion, for example,
while the latter lays down its laws, or the ways in which it
is observed to occur. Modern psychology is therefore an
experimental and natural science, while Scholastic psychology
is a rational and philosophical one, dealing with the being of
living things. If this distinction be borne in mind from the
start it will prevent any false expectations being entertained

i73

174 MODERN THOMISTIC PHILOSOPHY

as to the kind of truths which may be hoped to be discovered
by means of Scholastic psychology, as it would be idle to
look for explanations of particular human actions in a
science which sets out to explain the nature of man in
general, or to seek for a discussion of abnormalities in one
which professedly deals with the normal. So our study will
deal with the nature of man and other living things and with
their powers, but will not attempt to investigate in detail all
their particular actions and behaviour, especially abnormal
ones. The distinction, moreover, takes the sting out of the
objections made to rational psychology which assert that it
deals exclusively with unobservable entities such as the
intellect or senses ; for by ' unobservable ' is meant that
these realities cannot be known experimentally in the
laboratory, and rational psychology does not profess to be
an experimental science. At the back of such objections
there is always, in fact, present the conviction or prejudice
that nothing can be known which cannot be so experimentally
observed ; but this is a prejudice which concerns the theory of
knowledge in general (it is, in fact, what is known as Nomin-
alism), and has no greater bearing on psychology than on
any other philosophical study. The discussion of it, there-
fore, would be evidently out of place here, and we must con-
tinue to trust to the common-sense belief that reason can
give us knowledge which is additional to that which we can
derive from sensible observation. If anyone should feel any
qualms about trusting to the powers of the reason before he
has examined them, perhaps the consideration that the
proposition, ' nothing can be known but that which can be
observed experimentally,' is itself not open to experimental
verification — and therefore on this hypothesis unknowable —
may be sufficient to allay them, at least provisionally.

That rational and experimental psychology are specifically
distinct sciences is undoubtedly genuine Thomistic doctrine,
as can be seen, both in particular passages where S. Thomas
distinguishes the experimental and speculative knowledge
which we have of the ' soul,' asserting their difference,1 and

1 Cf. De Veritate, X, 8, III.C.G. 46 ; and Barbado, Actus Primi
Congressus Thomistici, p. 94.

PHILOSOPHY OF ANIMATE NATURE 175

from his general principles for the distinction of the sciences
which will be discussed later.1

If, then, it be granted that there is a psychology which is a
rational or philosophical science, we can pass to a considera-
tion of its nature more in detail.

The word psychology seems to have been introduced by
Melancthon, and means literally the science of the soul, i.e.
the science of the life-principle ; and this may be taken to
be a nominal definition of it ; which, though it tells us what
is the field of its investigations, is yet too vague to enable us
to distinguish psychology from other sciences dealing with
life, such as biology.

Now we have already declared that the psychology which
we are going to consider is to be a part of philosophy, so that
we can add this to the definition, and assert that psychology,
in our sense, is the philosophic science which treats of the
intrinsic principle of life, i.e. of vital operations. According
to this view of it psychology will deal with life wherever it is
found : in man, in animals, and in plants, and indeed if we
wish to discover the nature of life in itself it would be absurd
to exclude any of its manifestations from our scrutiny. At
the same time, both because of the greater facility for study-
ing it, and because of its higher interest for us, no doubt the
life of man will occupy the foremost place. Hence we shall
have to discuss the very nature of life in general, and in its
various grades ; to do which we shall be bound to consider
the nature of vital operations, since it is only by observing
the actions of a thing that we can arrive at any knowledge
of its nature. In doing this we shall make use of our common
knowledge of vital phenomena, and also of the facts which
have been discovered by the investigations of experimental
science in this field ; to which we are to apply those rational
principles which will lead us to the further knowledge of the
primary causes which produce these phenomena.

From these remarks can be seen the distinction and
relation between this philosophic science and the experi-
mental sciences which deal with living bodies, such as
Biology, Physiology, Morphology, Anatomy, and so on ;

x Cf. Epistemology , in Vol. II.

176 MODERN THOMISTIC PHILOSOPHY

for the first of these, though dealing with the whole range of
living bodies, yet treats them only from the point of view of
discovering how they function, not of what they are in
themselves, while the others are concerned merely with
some particular aspect of them. But though distinct they
are also complementary, for rational psychology takes into
account the data which they supply, and they, in their turn,
supplement it by giving us knowledge of the way in which
living things function and behave. This behaviour of living
things in the various circumstances in which they are placed
is more particularly the province of experimental psy-
chology, which has been variously defined as the science of
psychical states and processes, or knowledge of psychic
phenomena. So Professor Stout says : ' Psychology treats
of psychical states and processes, their objects as such, and
the conditions of their occurrence,'1 Woodworth says it is
' the science of the conscious and near-conscious activities of
living individuals.'2 Ward asserts that 'it is the science of
individual experience — understanding by experience, not
merely, not primarily, cognition — but also and above all,
conative activity or behaviour ' ;3 while William James calls
it ' the science of mental life, both of its phenomena, and of
their conditions.'4 It is clear that all such definitions limit
the province of psychology to the study of the observable
manifestations of life, excluding that of the very nature of
life itself and of the fundamental causes of the activities of
living things. The discussion of these would, by most
modern writers, be considered to be metaphysical, and though
Thomists would not agree to rational psychology being
reckoned as a branch of metaphysics, since their formal
objects are different, yet they are at one with the non-
Scholastic writers in recognising that experimental psy-
chology is a natural and not a philosophical science.

That rational psychology is of the greatest utility is evident
if we consider that its aim is to understand our own real
nature. Its main problem is the relation between mind and

1 Stout, Groundwork of Psychology, p. 1.

2 Woodworth, Psychology, p. 17 (cf. p. 1).

3 Ward, Psychological Principles, p. 28.

4 James, Principles of Psychology, Vol. I, p. 1.

PHILOSOPHY OF ANIMATE NATURE 177

matter ; according to our solution of which will follow our
view as to the intellectual, moral and religious capabilities
of man. So a recent writer says : ' If we knew just how
mind affects body, and how body affects mind, we should
have the clue to many a philosophical riddle, and a clue
which would give us much needed guidance not only in
philosophy but in many a region of practical, moral, and
religious activity and experience in which our generation is
groping rather blindly and is longing very eagerly for more
light.'1

Our discussion will naturally fall into three parts dealing
with the three great realms of living things : plants, animals,
and man. This must be prefaced by some account of what
we mean by ' life ' in general, and completed by an investi-
gation of the origin of. and connection between, living things.

1 Pratt, Matter and Spirit, p. viii.

DIVISION I. LIFE IN GENERAL
CHAPTER I

VITAL OPERATIONS

Vital Operations in General — Their Distinctive Characteristics —
Different Kinds of Vital Operations — Vegetative, Sensitive,
Intellectual.

Since all living things have at least vegetative life, it will be
convenient to include under this head not only those general
philosophical conclusions which we can arrive at by a survey
of the animate world as a whole, but the more particular ones
which relate to the life of plants.

The nature of life in itself is naturally regarded by Aris-
totle and St. Thomas from the point of view of the motion
which it exhibits, since, as we saw, they regard ' mobile
being,' or things subject to motion, as the proper object of
the whole of Natural Philosophy, of which our present dis-
cussion forms part.

Now the word motion can be taken in three senses : (i) In
its strictest sense it signifies local motion ;x (2) it is applied
to any successive mutation, and is then defined as the act of
that which is in potency as such.2 This meaning, though
wider than the first, yet applies to motion properly so called.
(3) A still wider meaning is the application of the name to
any change, i.e. any transit from potency to act, even if the
change be instantaneous. A last and very loose sense is
when the word motion is made to cover any kind of opera-
tion, even if there is no transit from potency to act, so long
as we conceive of the operation as if there were such a transit.

1 Cf. Aristotle, VIII Physics, Ch. IX.
8 Cf. Cosmology, Ch. VIII, p. 109.

178

VITAL OPERATIONS 179

This last meaning applies only to the divine operations. In
speaking of motion in connection with life, we do not limit it
to any one of these senses, but it is taken to include them all,
though the second sense is more particularly applicable to
vital motions.

Section I. Vital Operations in General.

Observing, then, the motions of living things of all kinds,
Aristotle notes that their motion has a common characteristic
and peculiarity, it is self-motion — they are automatic. Even
the humblest of living things nourishes itself and grows, thus
causing itself to change ; and this power is found nowhere in
the inanimate world. Hence he defines a living thing as one
whose natural property it is to be able to move itself j1 or
rather this definition implicit in Aristotle is made explicit by
S. Thomas.2

It should be noted that S. Thomas says the living thing is
one which is able to move itself, not one which actually does
so : for it is this capacity which properly constitutes the
essence of a living thing. The Scholastics call this life in actu
primo, and oppose it to actual self -movement, or vital action,
which is called life in actu secundo.

We may notice in passing that since to move oneself is
opposed to being moved by another, self-motion, properly
speaking, consists in the production by the agent of an opera-
tion which remains in the agent, and so is immanent action.
However, we cannot at this stage be quite certain that the
action of living things is immanent, i.e. proceeding from an
intrinsic principle to an intrinsic term, since it will only be so
if they are essential unities, not two or more things accident-
ally joined together ; and this has not yet been proved.

It is clear from common observation that there are three
kinds of living things with markedly different characteristics,
viz. plants, animals, and man. If, as we shall see presently is
the case, these three kinds are distinguished specifically or
essentially, it is clear that the word life will apply to them in

1 VIII Physics, 254t>i5. Cf. S. Thomas, Summa Theol., I.i8,l and 2 ;
IaIIae.3j2, ad I.

% De anima, L. II, Lect. I.

180 MODERN THOMISTIC PHILOSOPHY

senses which are also specifically distinct ; in other words, it
is an analogical concept, used of the things to which it is
applied in senses which are simply speaking different, though
from a certain point of view, viz. that of self-motion in
general, the same.

If it be true, then, that the essential characteristic of living
things is their capacity for self-motion, an important
corollary follows, viz. that they are necessarily organic. For
all motion, as we have seen, involves a transit from potency
to act. Now it is clear that a thing cannot be both in potency
and act in the same respect at the same time ; in other
words, it cannot be capable of becoming something, and
have, at the same time, become it ; and it necessarily follows
that if we have a thing which moves itself and so makes itself
pass from potency to act, there must be one part which moves
and another which is moved ; it cannot, as a whole, both
move and be moved. x The parts, then, of a living thing must
have different functions and different activities, which will
proceed from principles of action which differ, at least
accidentally.2 Though it is clear from this that if there are
bodies which are altogether inorganic, not having qualitative
differences in their different parts, they will be inanimate ; it
does not follow that all inanimate bodies are inorganic in this
sense, and in fact we have seen reason to believe that a
rudimentary organism in this—philosophical sense is to be
found in the inanimate world as well as in the animate.3 It
was, nevertheless, the observed structural organisation of
living things — both in the single cell, as well as in more com-
plex bodies — which so struck the scientific imagination as to
make the name organism coextensive in biology with animate
bodies, while inanimate ones are known as inorganic. Though
this distinction may not be an absolutely fundamental one,
yet there is no doubt that it is one of the ways in which living
bodies differ from inanimate ones ; which differences it will
be convenient to enumerate at this stage.

1 Cf. I.C.G., c. 13 (Tertio probat).

* Cf. 13th Thomist Thesis. Revue Thomisie, 1921, pp. 276, 280.

• Cf. Cosmology, Ch. XI, pp. 148 fi.

VITAL OPERATIONS 181

(a) In the Physical Order :

i. In Internal Structure. As we have just noticed, living
things are composed of heterogeneous parts, either cells or
combinations of cells, forming organs. The cell consists of
two parts, the cell-body (protoplasm, or more properly cyto-
plasm) and a nucleus which consists of a modified protoplasm
(karyoplasm). The nucleus is spherical and denser than the
rest of the protoplasm. Such cells are found only in living
bodies ; inanimate ones not presenting such differences of
internal structure.

2. In Shape. Generally speaking, living things of different
species have a determinate shape, the varieties of species and
of shape being very numerous. The fixity of such shape
increases as we ascend in the scale of life, the lowest forms
being able to vary their shape considerably. Such deter-
mination in shape is not found in the inanimate world except
in the case of crystalline formations, but here we do not get
the immense variety of shape which is found in living things,
there being six, and only six, types.

3. In Chemical. Composition. Living things are com-
posed of many and almost the same chemical elements, of
which a number are not found in inanimate ones in nature ;
whereas inanimate bodies have, individually, only a few
chemical constituents, and differ from one another in the
elements of which they are composed. Moreover, the
elements found in living things are constantly changing,
whereas those in inanimate ones are stable.

(b) In their Mode of Being :

1. In their way of coming into being, their origin. Living
things always come to be by means of generation by another
living thing : whereas chemical action, affinity, and valency,
suffice for the production of inanimate ones.

2. In Duration. Living things need nourishment in order
that they may endure as living things ; and even so, their
powers fail and they die, no extrinsic cause being needed to
destroy them ; whereas inanimate ones endure so long as
they are not corrupted by an extrinsic cause.

182 MODERN THOMISTIC PHILOSOPHY

(c) In their Activities and Tendencies :

It is here that we see the most marked, and from the
philosophical point of view, the most significant distinction
between the two orders.

1. With Regard to Nutrition and Growth. Living things all
feed and nourish themselves, so preserving their life and
repairing waste tissues ; while they also add to their own
structure intrinsically, and grow. Inanimate bodies, on the
contrary, if they increase at all do so by the mere juxtaposi-
tion of more matter to themselves from without. In this
connection we may notice that all living protoplasm breathes,
taking in oxygen and giving out carbon-dioxide ; it also
secretes products useful to the organism and excretes those
which are useless or injurious to it. Such activities are
peculiar to living things.

2. With Regard to Reproduction. All living things increase
by reproduction, giving rise to successors, similar to them-
selves and formed out of their own substance. The most
primitive method of reproduction, as we shall see, is fission,
by which the living thing splits up into two. No non-living
things behave in this way.

3. With Regard to the Regularity of their Actions. The
actions of the living thing are rhythmic, as breathing and
the beating of the heart. Some vital rhythms are in tune
with cosmic changes such as the action of the tides, or the
changes of the seasons. This last is very obvious in plants.
Though it is clear that such rhythm is not absent from the
inorganic world, yet it is much more marked in the organic,
where it is found in all individuals, and not merely in the
mass : and like other vital actions has its source within the
living thing itself.

These observations afford us strong grounds for thinking
that living things differ essentially or specifically from
inanimate ones. We shall have occasion to return to this
question later, since it is evidently one of great importance
for philosophy, being another example of the problem of the
one and the many, which, as we saw,1 is a leading issue in
natural philosophy.

1 Cf. Cosmology, p. 22.

VITAL OPERATIONS 183

Meanwhile, in our observations of the animate world we
have noticed that there are, apparently, three different kinds
of life in it, viz. that of plants, of animals, and of man. Can
this distinction be justified philosophically ?

Section II. The Different Kinds of Vital Operations.

We examine these operations in order to discover what
are the kinds, or grades, of life. Now the Scholastics are
unanimous in asserting that there are three main grades of
life which include all others, vegetative, sensitive, and intel-
lectual. To establish this assertion they appeal to the
following consideration,1 among others :

Since it is the essential characteristic of vital motion, as
we have seen, to be always from within, or intrinsic, it will
be more perfect, or more fully vital, in proportion as this
characteristic feature is more completely found in it. Now,
in any motion we can consider three elements : the execution
of the motion, its determining form or principle, and its
object. Consequently, life will be more perfect, and so allow
us to distinguish grades of perfection in it, in proportion as
one, two, or all three of these elements are intrinsic to the
living thing. Now, observation shows us that in plant life
only the first of these elements is intrinsic, for though plants
undoubtedly move themselves, and so execute their own
motion in growth, and so on, yet, since they have no know-
ledge of the end to which their motion is directed, it is clear
that both this end, or object, and the principle of their
motion must be determined for them by nature, and cannot
be due to any" activity of their own. If we now turn to the
animal world, we see that the animals, like the plants,
execute their own motion, but they also do so with some
knowledge of what it will bring them, and it is this knowledge
which is the principle of their motion, making them move ;
though they still are apparently not capable of determining
the end to which they will move for themselves, but act
according to the instincts or natural tendencies of their
nature.- Nevertheless, it is clear that both the execution of
the motion and the principle which makes them move are

1 Cf. Summa Theologica, 1.18,3.

184 MODERN THOMISTIC PHILOSOPHY

intrinsic to the animal itself, which, by knowledge, receives
into itself, in a certain fashion, the object towards which it
moves ; and thereby causes its own motion. When we come
to man we observe that he, like other animals, moves him-
self and knows the object to which he moves, and that he
further determines for himself what this object shall be,
choosing any means he pleases for arriving at some end which
he has in view. Hence the very object of his motion itself is
constructed, as it were, by man, and his vital motion is
wholly intrinsic and so in a high degree perfect.1 Evidently
the most perfect life of all would be one in which the" vital
motion was absolutely intrinsic, not seeking anything out-
side itself at all, nor receiving the form of its motion from
without, a state of things which could only be found in the
case of an infinite being, of God.

1 Cf. also Summa Theologica, 1.78,1.

CHAPTER II

THE PRINCIPLE OF LIFE

Is it One Only in Each Individual ? — A Difficulty — Opinions on the
Divisibility of the Life-principle — Answer to the Question.

There can be no doubt that such vital actions, as we have
just been examining, must proceed from some vital principle,
since they are clearly accidental, the living thing acting now
in one way, now in another. Aristotle and S. Thomas call
this principle of life the soul, and if what we have just said
about the three grades of life be true, it follows that there
must be three kinds of life-principle, or soul, to be found
among living things. It will be convenient to note here the
definition which Aristotle gives of the soul, though we cannot
at this stage claim that the definition has been fully verified.
According to him, then, the soul is ' the first act of a physical
organic body.'1 Now first act is substantial form, and this
definition will be true if living things do indeed differ essen-
tially from inanimate ones, since it is clear that such essential
difference must proceed from the principle of life in them,
which will therefore specify them, and be their substantial
form ; and, secondly, if they are essential unities, so that
they can be said to have one, and only one, form or first act.
It is necessary, then, for us to see whether in fact the soul
is one only in each individual living thing ; and we are
immediately confronted with a fact which seems incompat-
ible with its being so. Just as when we were discussing the
unity of substantial form in chemical compounds, the chief
difficulty in the way of our asserting it was that the mixture
can always be resolved into its elements, so that it seemed

1 HEPI "I'TXHE. B.l.4l2.b.5. el 8f) ti KOivbv iirl wd<rrjs \p vxqs Set \tyetv, ( Irj &.v
evreXixeta. i] trpurr-q (rui/xaros (pvcriKou dpyaviKOV.

I85

186 MODERN THOMISTIC PHILOSOPHY

that the substantial forms of the elements remained as such
in the mixture, so here we find that in the lower grades of
life at least, and to a certain extent in the higher, a living
thing can be divided into two or more parts without losing
its life, and so without losing its substantial form. It looks,
therefore, on the face of it, as if there were many principles
of life (or cyto-dynamic principles, as they are sometimes
called) in such things. Another solution is nevertheless
possible, for it is conceivable that the life-principle, or the
soul, might itself be divided on the division of the body. But
it will at once be objected that only such things as are quan-
titatively extended can be thought to be divisible, and
quantitative extension belongs to matter, not to form. A
little consideration only is needed to show us that substantial
form is, in spite of this, divisible ; for it is clear, if we take a
bucketful of water out of a pond, we have the substantial
form of the water in the bucket, and another remaining in
the pond : the matter being divided, the form is divided
along with it. This consideration answers the objection, for
though the substantial form is not of itself [per se) either
extended or divisible, yet it is, or may be both, by reason of
the extension and divisibility of the compound of which it
forms part. It is, as the Scholastics say, ' divisible per
accidens.' It is possible, then, that the substantial forms or
souls of living things should be divisible. Is this the case, or
are we to adopt some other explanation of the fact mentioned
above that in some cases living things can be multiplied
simply by division ? Before speaking of the opinions on this
question, it will be useful to mention some instances of
multiplication. In the first place fission is a common and
normal method of reproduction among plants, and occurs in
most of them, a part of the original plant dividing off and
forming a new one. Gardeners make use of this property by
taking cuttings of plants, and we all know that a flower or
branch of a plant does not die immediately it is cut. The
same method of reproduction is found among the lower forms
of animal life, as in the case of the amoeba and of Hydra.
The same is true of the sea-anemones and many aquatic
worms. If we turn to artificial division, we find that life

THE PRINCIPLE OF LIFE 187

can be preserved in parts divided off from animals much
higher in the scale than these. We are all familiar with the
fact that if an earth-worm be accidentally cut in two it will
regenerate the cut surfaces and form two worms. Experi-
ments have also been carried out which have resulted in the
preservation of life for a time in parts dissected from highly
organised animals, such as dogs. Thus pieces of tissue have
been kept alive (nourishing themselves and growing) for
considerable periods : e.g. life was preserved for sixty-one
days by Carrel, and for eleven months by Ebeling.1

Again, parts have been transplanted from one animal to
another, e.g. a segment of the carotid artery of a dog was
transplanted on the aorta of a cat. More spectacular, though
less important from a philosophical point of view, are the
successes obtained in the preservation of the functioning of
an organ or group of organs extracted from a living animal.
So, a frog's heart has been kept beating for thirty-three days
after extraction, and for this it is necessary that the muscles
of the heart should preserve their relations with the nerves.
Similarly, nearly the whole of the internal organs of a cat
were extracted and preserved alive for periods ranging up to
thirteen hours after the death of the animal whose organs
they were.2 Since, however, nearly the whole organism is
preserved alive, while the rest dies, no question as to the
division of life arises, and the rhythmic pulsation of the heart
may be ascribed not to life but to chemical action. It does
not appear, moreover, that in any of the other experiments
we can say with certainty that the dissected tissues or parts
were truly living, since increase by means of assimilation of
nutriment is doubtful, and reproduction of the cells, i.e. the
production of really new cells by cellular division, almost
certainly absent. There is purely dimensional growth, not
organic growth. It does not appear, then, that in the higher
animals it is possible to preserve life, truly so called, with its
three marks of nutrition, growth, and reproduction, in parts
cut off from a living organism, though in the plants and little
organised animals we see that such a process is a normal and

1 Journal of Experimental Medicine, Vol. XVII, n. 3, p. 273.
* Cf. Gemelli, Religione e Scienza, pp. 134 ff.

188 MODERN THOMISTIC PHILOSOPHY

natural one. Is, then, the life-principle, or soul, of such
thing as these latter divisible ?

Four answers are given to the question : Is the soul
divisible ?

1. The first is that all souls, including that of man, are
divisible. This is, in substance, the view of materialistic
biologists, who, since they consider living things to be
merely physico-chemical compounds, maintain that, like
other compounds of this kind, such as water, they can be
divided without changing their character.

2. On the other hand, some say that no soul is divisible.
Some recent writers (as Hugon1) hold this view and explain
it as follows : They think that the vital principle is actually
one and potentially multiple. When the body is divided the
division must be such that sufficient organisation for life is
preserved, which is an indication that the soul as such is not
divided. Hence in this view the consequence of the division
is not the division of the soul, even per accidens, but the
induction of a new soul, a soul which is new in act, though it
was present before in potency, in the greatest propinquity to
act. Hence, such a process is more properly called genera-
tion than division of the soul, being the origin of a new
living thing from a previously existing one.

Mediating between these two extreme opinions there are
two others :

3. Some, as Scotus and Nys,2 think that all souls, with the
exception of the human soul, are divisible.

4. Others, including S. Thomas and the majority of
modern Scholastics, hold that while the souls of plants and
the less complex animal organisms are divisible, those of man
and the more complex animals are indivisible.

There is probably little difference between this opinion
and the second one mentioned above, except in the mode of
expression, and which mode is preferred will depend upon
the view taken of the results of the experimental work which
has been outlined ; for if it be held that life was really

1 Hugon, Cursus Philosophies Thomisticts, Vol. Ill, pp. 64 ff. Cf. John
of S. Thomas, Phil. Nat., Pars III, Q. 2, A. 1 ; and Revue Thomiste, 1923,
pp. 290 ff.

8 Nys, Cosmologie, Vol. II, pp. 30 ff.

THE PRINCIPLE OF LIFE 189

preserved in the excised tissues, we shall be led to express
ourselves as do the exponents of the second view ; but if not,
it will seem more reasonable to say that, as far as is known
at present, the souls of the more highly organized animals
are not divisible. In the case of man, it would be impossible
(since, as we shall see, his soul must be held to be simple) to
maintain that his soul was divisible ; nevertheless, if it were
proved that human tissues could be kept alive apart from
the organism, such a fact could be explained by the second
view, inasmuch as a vegetative soul could be generated in the
excised part by the power of the rational soul which gives
vegetative life to the whole organism, just as, in fact, vegeta-
tive souls are generated in those cells which naturally divide
off from the body, viz. the reproductive cells. While saying
this, it should be borne in mind that, properly speaking, it is
not such souls which are generated, but a new compound,
and, what is even more essential, that the vital principle of
this compound is not new in the sense that it in no way
existed before, but only inasmuch as what was previously
potential now becomes actual. * This way of explaining the
matter meets also the principal objection which is raised to
the second view, viz. that we cannot say that a new soul is
generated in each of the parts since this would involve the
destruction of the original soul, which consequently could
not generate ; nor yet that a new soul is generated in one
only, since often the parts are exactly alike, so that there is
no reason for asserting that one is, as it were, the ' mother '
of the other. If, however, we maintain that the potential
multiplicity of the soul is made actual in such fission, we can
see that neither of these statements need be made, since
neither soul will be wholly new, but we shall have two actual
souls where before we had a single actual one which was
potentially two. And this is the very way in which S.
Thomas speaks with regard to fissiparous generation ;2
which is well set out by Pere Sertillanges, who says : ' The
degree of organisation of some living things is so restricted
that no particular organ is essential for its life, or incapable

1 Cf. Cajetan Comm. in I P., Summ. Theol., Q. 76, A. 8, n. 10.
* De Potentia, III, a. 12, ad 5.

190 MODERN THOMISTIC PHILOSOPHY

of being regenerated by the life left in the other organs. The
vital " idea " being complete ... in each of the divisible
parts, to separate them will produce, not death, but multi-
plication. The soul, being simply the immanent " idea " of
life, can therefore pass from unity to multiplicity, because
from the start, by reason of the conditions of its support, it
was multiple potentiality. The case is, mutatis mutandis,
similar to that of the homogeneous continuum, where
division multiplies the form numerically.'1

This, then, seems the most satisfactory answer to the
question : Is the soul divisible ? Where life can be preserved
after division, the soul may be said to be divisible per
accidens : by which we mean that what was before actually
one and potentially multiple becomes, on the division of the
body, actually multiple.

As far, then, as the generic consideration of the soul is
concerned, there seems to be nothing in the facts we have just
discussed to cause us to assert that there are many souls in
any individual living thing ; and to that extent the Aris-
totelean definition of it as the first act of a physical organic
body is justified. We shall have to return later to the con-
sideration of the specific difference of living and inanimate
things, as well as to that of the positive reasons for asserting
they are essential unities. The discussion of the first of these
problems will naturally occur as part of that concerning the
lowest grade of life, the vegetative, while that of essential
unity will reappear in connection with each of the three
grades of life in turn.

1 Sertfflanges, S. Thomas D'Aquin., Vol. II, p. 88.

CHAPTER III

THE VITAL POWERS

Are they Distinct from the Soul ? — How are they to be Distin-
guished from One Another ?

So far, then, we have seen that there is, prima facie, much
justification for the supposition that living and inanimate
things differ in kind, and that the generic consideration of
life does not provide any ground for saying that the life-
principle in a single individual is multiple. We are thus
justified in asserting provisionally that it is one only, but
even so it is clear that vital activities are many, and it is
natural to ask how these two statements are to be reconciled,
and how these manifold activities come about. This is the
question concerning the powers of the soul in general, and is
suggested by the definition which asserts that the soul
informs an organic body ; for the reason why the body is
organic is that different organs are required for different
vital operations.
Two questions can be asked about these vital powers :

1. Do they exist, or are they simply the soul itself ? ; and,

2. If they do, how are they to be distinguished irom one
another ?

Question I. Are the Powers of the Soul Really Distinct
from it ?
Aristotle, S. Thomas, and the Thomists consistently
maintain such a distinction between the essence of the soul
and its powers. There is, however, a widespread opposition
to this doctrine, both on its own account, and also because,
owing to a misapprehension, it has been confused with what
is spoken of as ' faculty psychology ' by modern psycholo-
gists, and which is, as it seems rightly, regarded by them with
contempt.

191

192 MODERN THOMISTIC PHILOSOPHY

The objections to the distinction in itself proceed, in the
main, from a Nominalist point of view, and we find it rejected
by the Medieval Nominalists, like Ockham, as well as by
modern Empiricists.

All these recognise nothing but individual vital actions and
states, an attitude which clearly rules out any powers which
underlie these states or any substantial principle of them.
All such principles will, therefore, be regarded as metaphysical
phantasms. Again, if it be supposed that the faculties are
real agents, distinct and separable from the soul, the positing
of such faculties would land us in absurdities, for it is clear
that we can have no willing without a subject who wills, and
so on. This objection was expressed by medieval writers by
saying that the soul is simple, and therefore cannot be split
up into faculties. Distinction, however, does not necessarily
imply separability. Perhaps the most common objection to
faculties nowadays is that they explain nothing. So Prof.
Stout says i1 'To say that an individual mind possesses a
certain faculty is merely to say that it is capable of certain
states or processes. To assign the faculty as a cause ... of
the states or processes is evidently to explain in a circle ; or,
in other words, it is a mere failure to explain at all.' No
doubt in the decadence of Scholasticism, and later, it was
supposed that the question ' why do I think ? ' could be
answered by ' because I have a thinking faculty,' just as
Moliere's physician, in answer to the question ' why does
opium produce sleep ? ' answers, ' opium produces sleep
because it has a soporific tendency ' ; but this was not the
intention either of Aristotle or S. Thomas in asserting the
existence of faculties. They were not interested in them as
explanations, but as facts. It would be no answer to the
question ' why does a man see ? ' to say ' because he has eyes/
yet few people would on this account deny that he had eyes,
or say that it would not be nice to mention the fact in polite
society, which seems to be the attitude of the critics of the
faculties. Prof. Ross2 puts this well with regard to Aristotle.
He says that Aristotle does not evade ' the task of genuine

1 Stout, Manual of Psychology, Bk. I, Ch. Ill, p. 114.

2 Ross, Aristotle, p. 133.

THE VITAL POWERS 193

explanation of facts by referring to a mystical faculty of
doing this or doing that. He is simply taking account of
the fact that the soul does exhibit a variety of operations
and that behind each of these intermittent operations we
must suppose a permanent power of so operating.'

We ask, then, do these powers, as a matter of fact, exist,
i.e. are there such powers really distinct from the soul itself ?

By power the Scholastics mean the proximate and
immediate source [principium quo) of action as such.

In saying this they implicitly state with regard to vital
powers that these are not the fundamental sources of action,
either adequate, since this is the nature taken as a whole,
or inadequate, since this is the soul ; and, moreover, that
such powers are not to be considered as that which acts,
which is the living thing, but only as that by which the living
thing acts. Just as it is inaccurate to say ' my legs dance,'
but true that ' I dance with my legs,' so, strictly speaking, it
is inaccurate to say ' my intellect knows/ and true that ' I
know with my intellect.'

That their contention is true can be seen if we consider
that a living thing is a substance and cannot therefore be a
power which is essentially directed towards the production
of actions, which clearly are accidents, since they come and
go in the course of life ; for it is evident that two things
which are essentially related to one another in this way must
be at least of the same generic kind, otherwise they would
have no community of nature, and so would not be essentially
related. Consequently these powers must be accidental, and
so really distinct from the constitutive principle of the living
thing, the soul, which is substantial.

S. Thomas also advances a second reason which applies in
a special fashion to the soul as the substantial form of the
living thing,1 for substantial form not being an efficient cause
cannot be directed to the production of any effect beyond
the constitution of the compound of which it is the form, and
so not to that of operations. As, however, we have not yet
justified the statement that the soul is the substantial form,
this reason can only be noted in passing. The first reason is

1 Summa Theologica, 1, 77,1.

194 MODERN THOMISTIC PHILOSOPHY

sufficient and we ought therefore to recognise the fact that
the soul has powers which are accidents distinct from itself.
The recognition of this fact does not, as we saw, afford any
explanation of vital actions ; but it is useful in helping us to
classify them, as is generally recognised.1

Question II. How are the Powers of the Soul to be Distin-
guished from One Another ?
This question, which is called by the Scholastics the
question of the specification of the faculties, presents no
special difficulty, if it be granted that the soul has faculties
distinct, though inseparable, from itself. It must, however,
be clearly understood that in looking for an essential dis-
tinction between the faculties, we are considering them pre-
cisely as faculties, or powers ; by whose means the living
thing attains certain ends, as, for example, knowledge of the
colour or odour of an object. If, instead 6i this, we asked
how the faculties of man, for example, were distinguished
from those of some other animal, the answer would clearly
be that they were distinguished by being human or not, i.e. by
reason of the natures whose powers they are.2 Considered,
then, precisely as powers, they are directed towards the pro-
duction of certain definite operations, as seeing, etc., and
hence their natures must be such as will produce these
operations ; and will, therefore, be essentially different if
the operations towards which they are directed are essentially
different. Consequently, it will be by means of their opera-
tions that the powers of the soul will be specified. But we
can go further, for these operations themselves are only
intelligible and definable in so far as they are directed towards
certain objects, since what makes an action to be of a parti-
cular kind is its being directed towards a particular end.
The powers of the soul, therefore, will be immediately
specified by their operations, which being, in their turn,
specified by their objects, the powers will be mediately
specified by these. If, then, we wish to distinguish one

1 Cf. Stout, op. cit., p. 115; and McDougall, Outline of Psychology,

P- 13-

2 Cf. Cajetan, Comm. in Primam Partem Summcs Theol., Q. 77, A. 3,
No. 6.

THE VITAL POWERS 195

power of the soul from another, we shall have to seek the
source of this distinction in the objects towards which the
soul's actions are directed. It is clear that since we are
seeking a specific distinction, or distinction of nature, the
objects which will cause such distinction are not those
which differ merely materially, but those which differ speci-
fically, i.e. in nature or formally. Where we have different
formal objects, then, towards which the vital activities are
directed, we shall also have different vital powers.

Distinct powers, therefore, are necessary for different
classes of operations, as well as distinct organs, and it looks
as if the unity of the living individual were seriously impaired.
Would it not be simpler to say that a living individual is
really a collection of differing living things ? This suggestion
is confirmed by the fact, which is quite certain, that all living
things are composed of cells, which are separated from one
another by the cell-wall, and so are structurally discontinu-
ous. We see, then, that we are constantly brought back to
this question : Is the ' individual ' living thing an essential
unity, possessing one nature throughout, or should it rather
be considered to be a collection of distinct entities ?

Though we must, no doubt, consider this question in detail
later, in connection with the three great classes of living
things, it is convenient, and even necessary to see whether
we can come to any conclusion about it with regard to living
things in general, since we find ourselves hampered at every
turn through lack of an answer to it.

CHAPTER IV

THE UNITY OF THE LIVING INDIVIDUAL

Opinions — The Thomist View — Definitions of Life.

Those who hold what is called the mechanistic conception
of life, according to which a living thing, like a machine, is
composed of many parts which have each their own work to
do, and do it independently of the rest by means of energy
given to them from outside, answer our question by saying
without hesitation that the living individual is merely a
' colony ' of cells each living with its own life. The life of
the individual is thus simply the sum total of the lives of its
cells, and it has no essential unity ; and, moreover, they
suppose that the cell-life is simply a chemical process, whose
nature has not yet been discovered.

This opinion is based partly on the facts which we have
noticed, but still more on a materialistic prejudice and the
wish to bring all the facts known to us into a form in which
they can be dealt with quantitatively according to mathema-
tical methods.

Now the facts of cellular structure, and the differentiation
of the organs are only a selection from those which are known
to us with regard to living things, and a wider view will show
that not only are we not compelled by them to accept the
opinion that the ' individual ' is really a colony of cells, but
that they fit in perfectly with that which is forced on us, if
we consider the organism as a whole, viz. that it is an essen-
tial unity.

In order to understand this we are to observe that in order

that there should be essential unity it is not necessary that

there should also be material continuity in the strict sense,

i.e. that the extremities of the parts should be the same.1

1 Cf. Cosmology, p. 67, and Ch. XI.

196

UNITY OF THE LIVING INDIVIDUAL 197

In fact it is clear, quite apart from the results of microscopical
investigation, that the living thing cannot be continuous in
this sense, since, in order that one part should act on another,
it is necessary that it should be divided from it, for otherwise
it would act on itself, so that S. Thomas says1 that ' in
animals which move themselves, there is rather a kind of
binding together of the parts than perfect continuation.' If,
then, we consider the living individual philosophically, we
see that all the operations of its different parts are related
one to another and subordinated to one another in such a
way that each and all are directed towards a single end
which is the preservation and the well-being of the whole
individual. Now this co-ordination and tendency shows
that there must be in them some single unifying principle
which directs and guides the various activities of the living
thing, a principle which, in order to unify, must be one, and
since it directs the activities from within must itself be
internal and the principle of nature of the individual. In
this the difference between a living individual and a machine
is evident, for the latter is directed by some extrinsic prin-
ciple, any adjustment either of the whole mechanism or of its
parts having to be made from without, as is the original
co-ordination of the working of the various parts so as to
produce the effect for which the machine is intended. Such
an internal determining principle of nature is, as we have
seen, what the Scholastics call ' form ' ; and where the
nature is substantial, as in the present case, ' substantial
form.' So that we have good grounds for asserting that each
living individual has a single substantial form, and is there-
fore an essential unity ; so long as we take all its activities
into account, and do not confine ourselves to some arbitrary
selection made from them, such as the mere conversion of
the energy contained in foodstuffs into that of the body, or
to some isolated fact, such as that the body is composed of
cells. We shall see later that the mechanistic hypothesis,
and with it the contention that the individual living thing is
really a ' colony,' is even incapable of accounting for these

1 S. Thomas in VIII Phys., Lect. 7, No. 8.

198 MODERN THOMISTIC PHILOSOPHY

facts, since it is impossible to make sense of them unless the
whole organism be taken into account. The differentiations
of the parts, organs and powers of a living thing are so far
from being incompatible with its essential unity that their
very variety, inasmuch as they are all co-ordinated and har-
monise with one another, makes the unity of nature in the
whole much more apparent that it would be otherwise. Just
as if we see a large body of men who all act in harmony with
one another we are much more struck with their unity than
if there were only a few ; and the more various are the types
which a body comprises, the more remarkable will be their
unity. Nations exemplify this to some extent, a union of
races, such as is to be seen in America ; still more, the best
example of it in any body of men being, no doubt, the Catho-
lic Church, which includes men of all nations and types. We
can, therefore, assert without hesitation, though we shall see
as we go on much to confirm us in this view, that every living
individual, i.e. every living thing which can preserve life in
situal isolation from others of its kind, is an essential unity,
and therefore that the Aristotelean definition of the soul as
the first act (or substantial form) of a physical organic body
is justified. It follows also, since they move themselves,
that being such unities their action will be, strictly speaking,
immanent as proceeding from an intrinsic principle and
tending to an intrinsic term, and further that they will be
specifically distinct, i.e. of a different nature from inanimate
ones. The full discussion of this last point must be post-
poned to another chapter when we consider vegetative life
more in detail. To close this one it will be useful to set out
some of the definitions of life in general which have been
suggested.

In contrast with the Thomistic definition that a living
thing is a substance whose natural property is to be able to
move itself, and to act immanently, the others are very
vague and unsatisfactory. So the Oxford English Dictionary
says it is ' the property which differentiates a living animal
or plant, or a living portion of organic tissue, from dead or
non-living matter,' which is to define life by itself. Bichat,
the physiologist, has a similar circular definition ; for,

UNITY OF THE LIVING INDIVIDUAL 199

according to him, it is ' the complexus of functions which
resist death.'

Somewhat better is Herbert Spencer's statement that life
is : ' the continuous adjustment of internal relations to
external relations.' This, however, merely describes certain
vital phenomena without any attempt to penetrate to the
reason of them, and is, therefore, incomplete both physio-
logically and philosophically.

Many similar vague descriptions of life might be quoted,
whose inadequacy is so evident as to lead to the assertion
that life is indefinable.1 That it is not so, however, we have
already seen.

1 Cf. Shipley, Life, ch. I.

DIVISION II. VEGETATIVE LIFE

We turn now to consider more particularly the various
grades of life. It goes without saying that we shall do this
from the philosophical point of view, not from that of Natural
Science. For the results arrived at by the latter, the reader
must be referred to books which deal professedly with
biology and kindred sciences.1 Our aim will therefore be to
discover, if possible, the natures of the three grades in
general, i.e. to make plain their generic character and their
specific differences.

1 e.g. Life, Sir A. E. Shipley, C.U.P. Biology, Geddes & Thompson.
Home University Library. Life, Geddes & Thompson, 2 vols.

200

CHAPTER V

THE NATURE OF VEGETATIVE LIFE

Opinions — Mechanism, Vitalism, Thomism — Reasons in Favour of
the Thomist View.

Beginning, then, with life at its lowest level, in the plants,
since this is the level at which living things exhibit differences
from other physico-chemical compounds, we are to ask
whether these differences are differences of kind or only of
degree, i.e. whether we are here dealing with a species of
material things — for plants are clearly material — which is
essentially different from that which comprises what are
generally called inorganic ones.

There are three opinions on this question. The first is that
of the Materialists, according to whom plants are merely
more complex physico-chemical compounds than are
inorganic bodies, but are not to be said to differ from them
in kind. This view is no new one, being found among the
Greeks ; Democritus, Leucippus, Empedocles and others all
maintaining that life is merely some form of matter in
motion.

Theories of this type were given a new vogue in modern
times by the speculations of Descartes, who thought that all
the actions of plants and animals could be accounted for
purely mechanically, and these views combined with the
growing prestige and success of experimental science led
eventually to the identification of life with its manifestations,
so that it was thought to be the mere sum of all vital pheno-
mena. Such was the view expressed by the Empiricists, as
Hume, and in recent times seems to be that which was held
by the eminent psychologist, Wilhelm Wundt.1 We may
notice that the mechanistic view of life is still regarded as
orthodox by biologists of the present day.

1 Cf. his Einleitung in die philosophic

202 MODERN THOMISTIC PHILOSOPHY

Another view has, however, been widely held which is
diametrically opposed to the preceding ; for according to
many authors the life-principle or vital forces are to be thought
of as being essentially immaterial, i.e. as in no way physico-
chemical, but some added unknown entity. The first to
make this view explicit was Stahl (i 660-1734), in reaction
against the mechanistic hypothesis of Descartes. He held
that bodily processes are guided both consciously and uncon-
sciously by the soul, and that it is because they are so guided
that living things differ from inanimate ones. This theory
with various modifications was the predominant one from
the end of the seventeenth century till the middle of the
nineteenth. Prominent among its adherents were anatomists
like Bichat, chemists like Liebig, or medical men such as the
members of the Montpellier school in the eighteenth century.
The vital principle was regarded as in some way a source of
bodily energy, and it was owing largely to the breakdown of
this notion due to the new discoveries (by Mayer and Helm-
holtz) of the sources of muscular energy, that the vitalistic
hypothesis came to be discredited in the middle of the nine-
teenth century ; though it is doubtful whether an even more
potent cause of this was not the acceptance of mechanical
explanations in science generally at this time. The whole
intellectual atmosphere was indeed poisonous to vitalism. It
is still not dead, though at present not popular among
scientists. Indeed it seems to be an hypothesis with which
science can have nothing to do, if indeed science does not
deal with ultimate causes ; and as Prof. J. S. Haldane points
out, it is one which is of no practical use in biology and
physiology.1

If we do not adopt vitalism it might seem that we
should be driven to a mechanical view of life. This, how-
ever, does not follow, since vitalism as put forward by the
biologists is necessarily a scientific theory, not a philosophical
one. In order that the vital principle may come within the
scope of a scientific theory, it is necessary that it should pro-
duce some results which can be subjected to scientific tests,
which will ideally be measuring tests, though in the present

1 J. S. Haldane, The Sciences and Philosophy, Lect. 4, esp. p. 74.

THE NATURE OF VEGETATIVE LIFE 203

state of the biological sciences this ideal cannot always be
attained. In any case, in order to be acceptable it must be
shown to produce observable effects which cannot be, and
appear never likely to be, accounted for by the observed
material elements. So it was thought to be the source of
physical energy, a notion which was soon disproved, and no
satisfactory material effect of the vital principle has since
been substituted for this ; while experience shows that the
progress of physical and chemical experiments constantly
accounts for more and more of the hitherto unexplained
phenomena on a physico-chemical basis. The abandonment,
therefore, of vitalism as a scientific theory only leads to the
conclusion that it was not a genuinely scientific one, and
does not even entail the adoption of mechanism for scientific
purposes, though unless some alternative to it is produced,
no doubt scientists would work on that basis, in the absence
of any other.

We, however, are not concerned to discover a theory
which is most suitable for the advancement of natural
science, but to point out what reason demands, if we wish to
avoid contradictions. This brings us, then, to the strictly
philosophical theory of the nature of life put forward by
S. Thomas. With reference to plants, this theory maintains
that these are not, in the last resort, the mere sum of the
chemical elements of which they are compounded, and the
forces of these elements ; secondly, that they possess an
essential unity ; and, lastly, that this unity and the vital
operations of the plants are due to a ' soul ' which is their
substantial form.

The first part of this statement clearly negatives a merely
materialistic and mechanistic conception of plant life. It
cannot be proved, according to the Thomists, in isolation
from the second part ; since their argument for it has always
been based on the fact of immanent action in plants, which,
as has been pointed out, can only be established when we
know that the subject of the action is an essential unity.
The nature of this argument marks the theory of a philo-
sophical as opposed to a scientific one, since it investigates
the ultimate nature of the thing in question, not those

-204 MODERN THOMISTIC PHILOSOPHY

attributes which are amenable to sensible observation and
experiment only. The Thomists argue, then, as follows :

Transeunt action differs in kind, or essentially, from
immanent action, since in the former there need be no
activity which is native to the thing which acts, the principle
of action will not be within it, but its action will be caused
by extrinsic influences acting upon it. So gunpowder will be
exploded or set in action by a blow from outside, but will
never blow up of itself if it be isolated. Moreover, it is clear
that the term of such action is not within the thing itself,
but in the launching of the bullet or other external effect ;
and such is its primary effect, not merely a secondary one.
In an immanent action, on the contrary, the initial source of
action is in the agent itself and is not introduced into it from
without. True, it may be stirred up or stimulated to act by
extrinsic influences, but the action though initiated by such
stimuli and using, in so far as it is expressed in physical
movement, etc., energy received from without, is yet itself
directed by, and derived from, the agent. The term of such
action also must be primarily in the same agent if the action
is to be truly immanent. This being so, we can see that these
actions have nothing in common beyond the generic charac-
ter of action, since the thing which acts immanently makes
itself pass from potency to act, while that which acts tran-
seuntly does not. If we now apply these considerations to
the life of plants, it becomes plain that this life is manifested
in actions which are, strictly speaking, immanent. In the
first place there can be no doubt that the essential vegetative
operations are produced by the plant and remain within the
organism, since they are the operations of nutrition, growth,
and generation. In nutrition the plant receives its nourish-
ment within itself and assimilates it to itself ; in growth it is
the plant which grows ; and in generation, though it is true
that the remote term of the operation of reproduction is a
new plant distinct from the old, yet the proximate term is
the reproductive cell which is evolved inside the plant from
the substance of the plant itself, and which remains a part
of it, at least for a time. In the second place we can see from
finality that plants are substantial unities, so that the

THE NATURE OF VEGETATIVE LIFE 205

apparent immanence of their actions which we have just
noticed is a real immanence. The test of substantial unity
is whether the being under consideration is such that all its
parts act primarily and essentially for the good of the whole
and only secondarily for their own benefit, for since action is
to be attributed to that which acts, where there is an essen-
tially unified action there will also be an essentially unified
agent. This is a consequence of the general principle that
a thing acts primarily and essentially for its own good and
only secondarily for some other thing, since the source of
every natural tendency is the inclination of the thing to that
which is suitable to its nature, its own good. Consequently,
if a thing were a collection of units accidentally joined
together it could not act as a whole, for the good of the
whole, primarily and essentially ; but each part would act
for its own good. So if we observe such action taking place,
we must conclude that the thing in question is an essen-
tial unity. Now this is precisely what we do observe in
the plants since the actions of their parts are primarily
directed to the preservation, building up and steady increase
of the plant as a whole ; to making good any damage it may
suffer, and finally to reproducing another plant of the same
specific type.

We may confirm these considerations by noticing what
takes place when life ceases, for during life the vital opera-
tions are directive, tending to a certain specified end, while
the purely material operations in living things are directed
by these things themselves. While a body lives, all its
chemical, physical, and mechanical powers are directed
towards the fulfilment of the purpose of the living body, but
when life ceases, all these powers tend to fulfil their own
purpose independently, with the result that the former
co-ordination ceases and disintegration sets in in the
body.

The vital principle, then, in bodies is the co-ordinating and
unifying principle, by which the living thing is specifically
constituted in its being and operation and distinguished
from inanimate ones. This is, as we have seen, precisely
what the Scholastics mean by the term substantial form, so

206 MODERN THOMISTIC PHILOSOPHY

that it is clear that the first principle of life is the substantial
form of the living thing.

It is plain from this that no living thing can be a collection
or colony of living beings, nor composed of a number of sub-
stances which remain actually and specifically distinct in it,
since its substantial form or first principle of life constitutes
it as a specifically distinct being. If, then, it had more than
one substantial form it would be constituted a being by one
of them, and again so constituted by the others, thus being
made over again what it was already, which is impossible.
Hence the substantial form or first principle of life in any
one living thing can be one only ; and it itself must be an
essential unity and not a ' colony.'

CHAPTER VI

THE TRANSMISSION OF VEGETATIVE LIFE

Reproductive Processes — Thomist View of Reproduction.

Before proceeding to deal with animal life, there is one
function which is common to both plants and animals, about
which it will be convenient to speak here in a little more
detail, viz. that of reproduction. All material living things
ensure the continuance of the life of their species by means
of generation or reproduction. There are two main modes by
which this is brought about : fission, i.e. a division ; and
conjugation, or joining together.

The first mode includes two reproductive processes. In
some cases a plant will develop a little bulge on its outer
surface, which grows gradually larger and eventually breaks
off from the parent plant. These are spores, which develop
into new plants. In other cases a part of the plant simply
divides off and forms a new plant of the same species. This
is called vegetative reproduction and is found very commonly
even among the highest plants. It also occurs in the animal
world, but does not reach very high up in the scale. It is
found among the hydroids ; and even animals as high in the
scale of development as sea-anemones will divide into two,
many worms also reproducing in this way. Such vegetative
reproduction by mere fission is evidently a very simple mode
of propagating the species. The name fission is often confined
to the second kind of reproduction just mentioned where the
parts are of equal size, as in the amoeba ; while that of gem-
mation is given to the process by which a small bud breaks
off from the parent as in the. yeast-cells. As we ascend the
scale of life the process of reproduction becomes more com-
plicated. First we have fission stimulated by conjugation,
i.e. by the passing of protoplasm from one organism to another,

207

208 MODERN THOMISTIC PHILOSOPHY

as in the case of paramcecium. A further stage is reached
when reproductive cells are formed in the body of the animal.
These are of two kinds, ova or eggs, and minute swimming
cells, called antherozoids in plants, and spermatozoa in
animals. Roughly speaking, where this is the case we find
in the plant or animal the two sexes — male and female — the
female producing the eggs, the male the antherozoids or
spermatozoa. These two, then, combine by the penetration
of the spermatozoon into the ovum. That this may happen
it is clear that the spermatozoon must be separated from the
male parent, and live a life of its own ; and the same is true
to a certain extent of the ovum. It is this fact which is of
importance from our point of view. S. Thomas and the
ancients thought that neither the male nor the female repro-
ductive elements were living, but that both were produced
from some superfluity in the nutriment of the plant or
animal, and not from previously living parts. They thought,
further, that the female element was merely passive, and the
sperm alone active ; the latter acting as the instrument of
the generator. These ideas are clearly untenable to-day :
for it is now certain : (i) that the ova and the spermatozoa
are true cells which are living before they are separated from
the organism ; (2) that the ova are not merely passive in the
process of generation, but active, though normally they
require to be first acted upon by the spermatozoa before
they can exercise their activity ; (3) that the fecundated
ovum (i.e. after penetration by the spermatozoon) begins at
once to exercise vegetative operations, i.e. to nourish itself
and grow ; (4) that the germinal cells can, even without
conjugation, evolve themselves into a new individual, at
least in some cases and for a time. The most common
instance of this is parthenogenesis (virgin-birth), when the
ovum which is not fecundated can, if placed in suitable con-
ditions, grow either naturally, as occurs in many plants and
among the bees, where the males are born in this way, and in
many other species ; or else growth may be induced by
artificial means, as has been done in the case of sea-urchins'
and frogs' eggs, among others. The first three facts require
that we should admit from the first moment of fecundation a

TRANSMISSION OF VEGETATIVE LIFE 209

principle of life in the ovum as well as in the spermatozoa,
and all four indicate that both male and female elements
have vital principles of their own from the start. Hence, we
have two living beings, the ovum and the spermatozoon,
and it is necessary to admit that at the moment of fecundation,
there must, in order that we may have true generation, be a
corruption of the previous forms or vital principles, and a
single new vital principle must be drawn from the poten-
tiality of matter : otherwise we should have the union of two
complete beings, which could not give a single complete
being.

The most difficult case is obviously that of man, since
here we cannot admit, as perhaps we might in other animals
and plants, that the vital principle is itself divisible. The
process seems to be as follows : at the moment when any part
of the human individual is separated from this individual,
this part, considered as properly a part of the human com-
pound, is corrupted, i.e. loses its previous form which was
the soul of the man or woman. This corruption must be, at
the same time, a generation. What is it that is generated ?
It may be a non-living body, as when a leg is amputated, or a
living one. In the case of the germinal cells it will be seen
from what has been said that it is a living one. The living
spermatozoon now penetrates the ovum, and gradually the
ovum changes its nature and becomes one with the sperma-
tozoon. This is .a second corruption and generation, the
corruption of the previous forms of the spermatozoon and
ovum, and the generation of the new form of the individual.
This form will certainly be a vital principle, but these con-
siderations afford no grounds for deciding whether it is
properly speaking a human soul, i.e. a rational one, or some
other form of life. The process is therefore much more
complicated than S. Thomas thought, but the essential
principles of his explanation by corruption and generation
are still applicable to it.

In the case of plants and animals their souls, forms, or
vital principles are universally recognised by Scholastics to
be drawn out of the potentiality of matter, under the
influence of the active principle of life in the parents. The

210 MODERN THOMISTIC PHILOSOPHY

reason of this statement is not far to seek, for we have seen
that all the essential operations of plants are dependent on
matter, and so their nature must also be of the material
order and dependent on matter. Hence their life will dis-
appear on the corruption of their bodies, and will also have
its beginning in dependence on matter. The production of
these forms, therefore, comes about in just the same way as
that of the forms of inanimate compounds as outlined earlier
in Cosmology. x What is true of the substantial forms of such
living things will a fortiori be true of those of their generative
elements and cells, so that the forms of the antherozoids,
spermatozoa and ova will all be drawn out of the potentiality
of matter, and these in turn will draw from matter the sub-
stantial forms or life-principles of the new plants or animals.

What is said here applies to plants and animals in
general, but it is evident that if — as we shall see later is the
case — man has a soul which is independent of matter or
spiritual, such a soul cannot be drawn out of the potentiality
of matter, so that in this, as in many other ways, he is an
exception to those laws which govern the animal world in
general. Nevertheless, since it is clear that the forms of the
human spermatozoa and ova are not human souls, since
they are corrupted when fecundation takes place, these can
be brought out of matter under the influence of the life-
principle of the parents, so that the first stages in human
reproduction will follow the same lines as those which govern
generation all through, in the lower animals and in plants.

Such generation, though belonging to the material order,
is nevertheless not a mere resultant of physical and chemical
forces, just as the life of plants and animals is something
which is not purely physico-chemical ; as Balfour says :
' though mechanical laws can account for rearrangements,
they cannot account for creation ; since, therefore, conscious-
ness is more than rearrangement, its causes must be more
than mechanical.'2

1 See pp. 135 fif.

2 A. J. Balfour, Theism and Humanism, p. 43.

DIVISION III. SENSITIVE LIFE

We can now take it as established that things possessed of
vegetative life, and therefore living things in general, differ
specifically or in kind from inanimate ones. The interest of
the study of plant life from the philosophical point of view
lay largely in the fact that since plants are the lowest forms
of living beings, it is among them that we must look for the
line of demarcation between the animate and inanimate
realms ; and we have seen that though they possess much in
common with inanimate substances, yet they have one
power which is never found in the latter, viz. that of imman-
ent action. We are now to go on to consider whether we can
assert that in the world of living beings there are similar
lines of demarcation which separate them into classes which
are different in kind one from another. If there are, no
doubt the first will be that which divides animals from
plants ; and we ask therefore whether these two classes of
things are in fact different in kind. Now the distinguishing
characteristic of animals is that they are capable of knowing
things other than themselves by means of their senses ; and
we shall be justified in concluding that this characteristic is a
specific one if we can show (a) that they can, in fact, gain
such knowledge, and (b) that plants never can.

211

CHAPTER VII

COGNIT/.ON

Nature of Cognition — S. Thomas' View — The Materialist and
Idealist Views — The Thomist View Further Explained.

What Do We Mean by Knowledge ?

Before we can discuss the question of the distinction of
plant and animal, we must have a clear idea of what is
meant by the word ' knowledge ' in general, and sensation or
sensitive knowledge in particular.

S. Thomas' view of the nature of knowledge, while based
on observation of the facts, is worked out in close connection
with his metaphysical system, or his general view of the
nature of reality.

In all the main questions which we have so far investigated,
we have seen that S. Thomas finds his solution in the applica-
tion of the distinction between potency and act. This is no
mere artifice, no ' abracadabra,' but something which is
forced upon him by the nature of the case ; as, for example,
' time ' becomes inexplicable without this distinction, as do
also the natures of material things. As we observe the
numerous instances in which this key unlocks the door, we
shall begin to feel sure that it is indeed a master key ; and
by the end of our enquiry we shall be quite certain of this.
The question as to the nature of knowledge is no exception
to our rule ; for if we consider what it is that occurs, at least
apparently, in knowledge, we shall say, no doubt, that it is
the union of the knowing subject with some object other than
itself. Now such union demands certain prerequisite condi-
tions, both on the part of the knowing subject and on that
of the object. From the point of view of the object, the first
necessity is that it should be something, i.e. something
definite and fixed, at least to some extent ; for it is impossible

212

COGNITION 213

to have knowledge of a thing which is in a state of flux, or
altogether undetermined. While we grasp it, it would have
changed, and we could never know it. We should continu-
ally have to say : ' I thought I knew ' ; we could never say :
' I know.' Our lives would be like those of Lewis Carroll's
Mad Gardener :

' He thought he saw a banker's clerk
Descending from a bus.
He looked again, and found it was
A hippopotamus.'

So we say that gold is yellow, heavy, opaque, etc. If we
remove all these, and every other determination from it, we
can say nothing about it, for we can have no knowledge of it.
In other words, the object can only be known by means of
its determinations, its constant attributes, its forms. The
underlying substance or potency or matter can only be spoken
of and known in terms of the act which is proportionate to it.
Thus only determinations, i.e. acts or forms, are intelligible.
From this it follows that since knowledge is a kind of union
between the knowing subject and the object of knowledge,
and the object being a determination or form, the subject
must in some way correspond with this form or act, for it
must be capable of receiving into itself the forms of things
other than itself. Further, it must receive these forms in a
peculiar way. If it simply becomes the things which it
knows, by the reception of their forms, as light becomes
coloured when it passes through a coloured glass, we should
not have what we mean by knowledge, since this implies the
perceived union of the subject with something other than
itself. Hence the knowing subject must receive the form of
things other than itself, not as its own form, but as they are
the forms of these other things, these known objects ; in
contradistinction from a nescient subject, which can only
have its own form, or if it receives those of others, receives
them, not as they are the forms of things other than itself ;
since in receiving them it makes them its own form. So a
stone lying in the sun's rays receives one of the sun's forms,
heat, and becomes hot ; but the heat once received is its
own, not the sun's. So a cannibal who eats his enemy does

214 MODERN THOMISTIC PHILOSOPHY

not become his enemy ; his enemy becomes him. The know-
ing subject which receives the forms of other things as such is
thereby made greater than before : it is enlarged. For form
is that which makes a thing what it is ; if, therefore, the
knowing subject receives the forms of other things which
remain the forms of other things after reception, it becomes
these other things in a certain way ; and if there are beings
who are capable of knowing all things, these are also capable
of becoming all things, and in so far as they do know, so is
their very being developed and widened.

Apart from this view of the relation of subject and object
in cognition, which is that of S. Thomas, there are two other
general ways of conceiving this relation, which, though in
some respects simpler and more obvious than his, yet in one
way or another fall short of giving a complete account of it.
On the face of it, it seems as if we must either say that the
cognitive faculty is perfected by the object which in some
way changes it intrinsically, so that the faculty is merely
passive with regard to the object, after the fashion of a
photographic film ; in which case cognition will not be a
vital or immanent action, which it certainly is : or else if
this last is to be maintained it seems that the object must be
related to the faculty merely extrinsically ; and the faculty
will be active only in the eliciting of its act, and will not,
properly speaking, know the object at all, since this will be
something extrinsic to its act. In other words, we seem
to be faced with the dilemma of saying either that know-
ledge is entirely immanent, when the object will not be
known, since it is outside thought (or sensation), which is
the position taken up by idealists : or else that it is not
immanent, but a transient action of the object which
impresses itself on the subject, the latter being quite passive,
and so not exercising any vital action, such as an act of
knowing must be, at all. This last is the view of the Materi-
alists, who wish to reduce cognition to a physical, as opposed
to a psychological, impression on the organism. In either
view, therefore, an essential element in our notion of know-
ledge is declared to be unattainable ; in the first, that the
subject can be united in knowledge with something other

COGNITION 215

than itself ; in the second, the vital character of the act of
knowledge.

Now the Thomistic view, in asserting that those things
which are capable of cognition differ from those that are not,
in having a capacity for receiving the form of something
other than themselves, resolves this dilemma ; for in so far
as it is the form which is received, it is clear that we are not
dealing with a merely material impression, as the Materialists
suppose, and in so far as this form is not that of the knowing
subject, but of the thing known, the act of knowledge will,
in a certain way, extend outside the subject ; which will not
be prevented by the prison walls of its own self from grasping
objects outside it. That such a process may be possible it is
necessary, as S. Thomas shows, that the subject should be to
some extent immaterial ; and this will be the very basis or
root of cognition.

After what has been said as to the nature of knowledge,
this further conclusion needs indeed but little elucidation,
since to receive the forms of other things in so far as they
are the forms of these things is clearly to receive them
immaterially, and only that which is itself immaterial, to
some extent, can do this. So long as the forms of the known
objects are restricted by the matter of these objects, they
remain individual and are incapable of being shared by any
other thing, for matter limits form as potency limits act.
The forms, therefore, to be shared by other things or united
to them must be dematerialised, and in such a state can
evidently only be received by a subject which is itself
immaterial to some extent. So a dog knowing a cat does not
know it in its material entity as a whole, its flesh and bones
as we might say, but knows certain characteristics or forms
of it, as its shape, smell, colour, etc. It is true that it does
not know such forms in general, but only as they characterise
this particular object, and therefore the process of demateri-
alisation is incomplete, but it could not know the object at
all if it had to receive it into itself in its physical entity as a
whole, it would merely absorb it into itself. Since it does not
do this, and yet is united to it, it is clear that it must be to
some extent immaterial like the forms which it receives,

216 MODERN THOMISTIC PHILOSOPHY

since to receive others as others is quite evidently not the
same as receiving them as oneself, nor yet the same as receiv-
ing them as a compound with oneself, the resultant being
some third thing differing from both recipient and the thing
received, e.g. a whitewashed wall. This last kind of recep-
tion is that by which a capacity or potency receives an act ;
so that if this be ruled out, the only kind of. reception which
remains is that by which an act receives a further act, by
which form receives form ; and this will be cognitive union.
Thus we see that the necessary basis of knowledge is that the
subject should be actual, formal, i.e. not merely potential or
material. If this be true, and it seems to be an inescapable
conclusion from the analysis of the act of knowing, it is
evident that the materialistic view of this process is peculiarly
superficial, for in conceiving of it as material they render it
impossible. Probably the thorough-going materialists, such
as the Behaviourists, would admit this conclusion ; but, of
course, in doing so they stultify themselves since neither this
conclusion nor any other thing can in this case be known.
The Idealist solution, though at first sight much more subtle
and profound, is, on examination, seen to be an incomplete
analysis of cognition ; for while they are right in insisting
that it must be a vital and immanent action, they cannot rid
themselves of the notion that such action must be contained
in the subject in a material and quantitative fashion ; and so
consider the idea, not as something which opens up on the
object, and by whose means we see it, but rather as if it were
a photograph of, or substitute for, the object enclosed within
the camera of our minds. Cognition, then, cannot be mere
reception of some form, a purely passive reception, since this
occurs in that imperfect reception of it which is distinct from
knowledge, as when the air or water receives warmth from
the sun. It always involves some efficient causality on the
part of the subject, which will be continuous so long as the
knowledge lasts. Hence the undoubted importance of
attention and concentration ; the subject must not only be
one which is in itself capable of knowing, but in order to
know actually must make the effort to know. The bee in
gathering honey does not flit aimlessly from flower to flower,

COGNITION 217

as the butterfly does, but sucks each one dry. It is impos-
sible to pour knowledge into a man as we pour water into
a jug. So, though the cognitive faculty is called passive,
inasmuch as it does not change its object, but is changed
and fertilised by it, yet it is indeed operative and active. So
Dr. Ross points out that, in Aristotle's view, sensation is
an alteration which is ' the advance of something towards
itself and towards actuality,'1 and he adds that ' it is only if
reception of form means awareness of form that it is a true
description of perception.' Such activity is a necessary con-
dition of cognition even in its simplest forms, since apart
from it the subject would remain involved in itself — as
indeed the Idealists think it does — and there would be no
distinction between it and the world outside.2 That such
' autonomy ' of the intelligence, along with its dependence
on, and heteronomy with regard to, the object, is an integral
part of the Thomistic view of this matter has been ably and
lucidly brought out by M. Maritain for, as he says, the
intelligence ' only knows the object by becoming it, and this
of itself and actively, in the final perfection of operative
activity.'3

Another consequence of great interest follows from this
position, namely, that this cognitive union is the closest of
all unions. For it is closer than that which joins form and
matter, since in the latter case the matter does not become
the form, but is intimately united with it to compose some
third thing, whereas in the former case the subject becomes
the form in a certain way, receiving it immaterially.4

1 Ross, Aristotle, p. 136.

2 Cf. Selbie, The Psychology of Religion (1924), p. 54.

3 Cf. Maritain, Reflexions sur l' intelligence (1924), p. 55.

4 For a full discussion of this point see ' Gredt. De Unione omnium
maxima inter subjectum cognoscens et objectum cognitum ' in Xenia
Thomistica, Vol. I, pp. 303-318.

CHAPTER VIII

THE PROCESS OF KNOWLEDGE

Necessary Conditions for Union of Subject and Object — Their
Assimilation Involves Change in Both — The Intentional
Species — Why they are Necessary — And Universally Necessary
— The Two Kinds of Species : Impressed and Expressed — Their
Nature and Mode of Production — Their Precise Function —
Are Expressed Species Present in Every Cognitive Act ?

In order to complete our notion of the nature of knowledge
it is necessary to see how knowledge, the peculiar kind of
union between subject and object which we have just been
considering, is brought about. What is the process employed
in knowing ; or, to use a metaphor, which must not be
understood too literally, what is the mechanism of
knowledge ?

Broadly speaking, two kinds of answer are possible, viz.
that the union is effected either by the action of the cognitive
faculty itself, or by that of something other than the cogni-
tive faculty, i.e. by the external object. The first view is
that taken by all the transcendental and objective Idealists,
as Kant, Fichte, Schelling, and Hegel, while the second is
held by all who maintain that our knowledge takes its rise
with things external to us, or, as we commonly say, by
Realists ; among whom are to be reckoned the Materialists.
The view of these last may be at once dismissed, since it
neglects an essential element of the problem, maintaining
that the object is present in the cognitive faculty in its
physical entity, whicl. i^ obviously untrue, since it is clear
that the object is in he knowing subject in a different way
from that in which it ex sts in nature. That the view of the
idealists solves the question of the union of the subject and
object is patent, since khe object is thought to be evolved
from the very fabric c* tne cognitive faculty, and thus, being

218

THE PROCESS OF KNOWLEDGE 219

the faculty, is evidently united to it. The very simplicity
of this solution, nevertheless, indicates that it is rather a
denial of the problem than an answer to it. It is, in fact,
contrary to the notion of cognition as being an expansion of
the knowing subject, by means of which it enlarges its bound-
aries to become other than itself ; this view making knowledge
to consist in the mere evolution of the knowing subject itself.
Our conception of the nature of this process of knowing will
evidently be determined by the view which we take of the
nature of the cognitive union, and we shall therefore try to
explain what this process must be if we accept that idea of
its nature which is set out above.

As we have already remarked, the cognitive faculty, con-
sidered simply in itself, is passive, and, consequently, if it is
to become active, it must be acted upon by the object. The
question therefore is as to the way in which the object acts
on the faculty and determines it.

In the first place it is clear that in order that the object
may be joined to the cognitive faculty, these two things must
be in some way assimilated to one another, since a thing
cannot be made one with another which is altogether different
from it. Animals of different species, such as dogs and cats, do
not interbreed ; and we are here, in speaking of a sense and
the object, dealing with two things which differ much more
radically from one another than do animals such as these.
If, then, they are to be united, either one or both of them
must undergo a change. That there is a change in the sense
organs is clear, and is universally admitted. For example,
in the sense of sight, the eye is affected by the light waves ;
in hearing, the ear is affected by the vibrations of the air,
and so on. Moreover, the nervous system connected with
any sense-organ is affected by the changes which occur in
that organ, and a ' stimulus ' is thereby carried to the brain.
This being so, it can hardly be doubted that a change occurs
also in the sense itself, since this must be affected by these
modifications of its instrument, the organ of sense. In the
abstract it might seem that such a change in the sense was
sufficient to assimilate it to the object, and that it is not
necessary to assert that the latter is also changed, but the

220 MODERN THOMISTIC PHILOSOPHY

Scholastics, and particularly the Thomists, have always
maintained that such a change in the object is essential in
order that it may be known. The object, according to them,
is not known as it is in itself outside the mind, but by means
of what they call an ' intentional species.' The object, of
course, as it exists outside the mind, remains unchanged, but
it produces a likeness or representation of itself, by whose
means it exists in a new way in the animal or man who knows,
and consequently as known it is changed. This likeness of the
object is the intentional species ;x of which the Scholastics
recognise two kinds, the impressed and the expressed
species ; the first being the form of the object which is
transferred to the cognitive faculty, making it actively to
know the object, while the second is, as it were, a sensible (in
the case of the imagination) or intellectual reproduction of
the object held up before the mind, in such a way that the
object is known by its means. It is to be noticed, and we
shall later have occasion to emphasise this, that in no case
is the species something which, being known first, leads to
knowledge of the subject, but always a pure means by, or in
which the object itself is known.

We are here concerned, however, with intentional species
in general, without going into this distinction between the
impressed and expressed species ; and it is with reference to
the species so generally considered that S. Thomas says that
it is ' the likeness of the very essence of the thing ; and is, in
a certain way, the very essence and nature of the thing with
regard to its intentional (i.e. mental) existence : not with

1 The reason why the means whereby the object is present in the
cognitive faculty are called intentional species is as follows. By species
generally is understood the definite complete nature of a class of things ;
e.g. the species ' man ' is the nature of rational animal which is found in
all men. Now, as we know, the nature of a thing is determined by its
form ; so that intentional species are sometimes also called intentional
forms. They are called intentional to distinguish them from those forms
which fix things in their physical entities : substantial and accidental
forms ; and to indicate that they are not something absolute, but essen-
tially relative, determining the knowing subject in his ' stretching out
towards ' (intendere) the object. The fact that they are called species or
forms, on the other hand, makes it clear that they are thought to be the
determining elements of the objects known, though inasmuch as they are
in the knowing subject, they are in a different state from that in which they
are when in the object itself ; as will shortly be explained.

THE PROCESS OF KNOWLEDGE 221

regard to its natural existence, as it exists in things.1 The
words ' in a certain way ' relate to the different states in
which this nature is found within, and outside, the mind ; to
its different modes of existence.

' Such a form,' as S. Thomas observes,2 ' can be considered
in two ways ; first, as it is in the knowing subject ; and,
secondly, with respect to the relation which it has to the
thing whose likeness it is. Considered in the first way it
makes the subject actually know, and considered in the
second, it determines this knowledge to be knowledge of
some determinate object.'

It is two-faced and two-voiced, with one it wakes up the
subject, and with the other it introduces it to the object.
Considered in the first way it must be assimilated to the
nature of the cognitive faculty, and so be in some way
immaterial ; while considered in the second way, it has the
nature of the known object, and is simply the intentional
reproduction or representation of it.

That the contention as to the necessity of intentional
species, in order that there may be knowledge, is justified, is
seen if we consider the ways in which union between subject
and object (which is the very essence of cognition) could be
brought about. In the first place they might be identical,
and if this is not so the union might be effected by the object
being communicated to the subject from without, either in
itself, i.e. immediately, or by some medium. These exhaust
all the possible modes of effecting the union.

The first supposition is in fact an impossible one, since it
would imply that the cognitive faculty was identical with all
things that it either does or can know. So Empedocles
thought that the ' sensitive soul is in a certain way com-
pounded of all sensible things ' ;3 an opinion which, as
S. Thomas points out, would lead to two unacceptable con-
sequences, namely, that the senses could themselves be
sensed, being composed of actual sensibles. and that they
could sense without exterior sensibles being present, since
they themselves would be actual sensibles. It follows, then,

1 Quodlibet, VIII, A. 4. * De Veritate, X, 4.

* S. Thomas in II de Anima, Lect. 10.

222 MODERN THOMISTIC PHILOSOPHY

that they are only potentially able to perceive the sense
objects ; and in order actually to perceive them they must be
actuated by these objects, i.e. informed by them, not identified
with them. This information cannot, however, be immediate,
both because the sensible objects acts primarily by a material
impression on the sense organ, and only by means of
this impression on the sense itself ; and also, since the sense
object is a finite entity, its form is limited to that entity,
and so cannot be also the form of another, viz. the sense.
If, then, the sense is not united to the sense object either by
identity or immediate information, it must, if it is to be
united to it at all, be so united by mediate information,
i.e. by the mediation of a form received from the sense
object ; a form which differs from that which informs the
sensible, not in its nature, but only in its mode of existence ;
being to a certain extent dematerialised, and so made
capable of informing an entity other than itself ; which form
is what we call the intentional species. Since, then, union
between subject and object is brought about in cognition,
this result can only be achieved by means of intentional
species ; which must therefore exist.

This conclusion holds good for finite knowledge of whatever
kind, though we have here spoken chiefly of sense-knowledge.
For it is clear that in the case of intellectual knowledge, since
the object of the intellect, as we shall see, is the whole of
being, it would be necessary, in order that the intellect
should be identified with every being, that it should actually
possess the forms of all beings or be infinite. Similarly, the
intellect cannot be immediately informed by the forms of its
objects, since, as we have seen, these forms, being those of
finite things, are limited to the things which they inform.
Hence intellectual knowledge must come about by means of
mediate forms, or intentional species.

This conception of the process of knowledge applies
universally to every form of cognition, and we cannot make
any exception even in those cases, such as sensations of
touch, where the object is in immediate contact with the
sense organ. In fact the species are not required in order to
transfer the object through some intermediate physical

THE PROCESS OF KNOWLEDGE 223

medium, but in order to render it capable of being known.
For this purpose a mere material presence is not sufficient,
otherwise knowledge would be indistinguishable from a
purely mechanical impression, and therefore in all cases this
material thing, the object, must be in some way raised to a
state in which it is to a certain extent immaterial, a function
which can only be performed by the intentional species.

As is implied in all that has so far been said, the species
are required for two purposes ; first, that the object may be
made present to the faculty ; and, secondly, that it may be
raised to a condition consonant with that of the faculty
itself, since like is known by like. It is clear that the inten-
tional species are required for the second purpose at least, in
all cases, since the cognitive faculty being a vital one, is more
or less immaterial, while the object of the senses is wholly
material.

So far we have spoken of the intentional species in globo,
but something must be added on the role of the two kinds of
species, impressed and expressed, which are recognised by
the Scholastics. Without the impressed species no know-
ledge of finite things is possible, since it is the function of
these to unite subject and object by assimilating the object
to the subject, dematerialising it to a certain extent. The
use of the expressed species, on the other hand, is altogether
different, for these, as we have said, are likenesses or repre-
sentations of the object, and are therefore only required
when the object itself is not present. From the point of
view of knowledge, the object is absent not only when it is
absent from the physical point of view, not being presented
to the faculty at that particular moment, as occurs in the
case of the imagination, and in intellectual cognition of
objects of which knowledge has been acquired in the past ;
but also when the object, though present physically, is yet
not proportionate to the faculty, as is the case in all intellec-
tual cognition, where the object in itself is an individual and
concrete nature, while the object as known is a universal
and abstract one. The expressed species thus terminates
cognition, not as if, being first known itself, it should lead to
knowledge of the object, but as a term in which the object is

224 MODERN THOMISTIC PHILOSOPHY

simultaneously known. Cognition must evidently, being an
action, have such a term ; so that where it is not already
given, as it is in the case of the knowledge of the external
senses, it must be produced ; or, in other words, the expressed
species must be formed. This expressed species is called by
the Scholastics the image or phantasm, in the case of the
imagination ; the mental word or formal concept, in the
case of the intellect.

Much ridicule has been poured on the notion of impressed
species on the supposition that these are some sort of
effluvia or material particles, thrown off by the objects,
which fly across to the sentient subject. Though this may
have been the opinion of Democritus, it certainly is not the
view which the Scholastics take of these species, since they
hold that the mode of existence which the species or forms
have in the object and sentient subject is different, being
physical in the one case and pyschical or intentional in the
other ; not physical in both, as would be the case if the
supposition as to their being effluvia were correct. Are we,
then, to suppose that the species are entirely spiritual and
not material at all ? This cannot be held either, since in this
case no cause could be assigned of their production, both the
object and the percipient being material things, and so
incapable of producing something purely spiritual. If, then,
they are neither wholly material nor wholly spiritual, they
must be something intermediate, and are to be called material
in so far as they belong to the material order, but not material
in the sense in which physical and chemical forces are. Their
nature, in fact, must exactly correspond with that of the
sentient organism which receives them, and this is itself
something belonging to the material world ; though its
forces, since it is living, are not purely chemical and physical
ones.

In order to obtain a thorough grasp of the Thomistic
theory of intentional species, it is important to understand
the way in which it envisages their production. In the first
place, it should be noted that what an agent communicates
is not its matter but its form, as S. Thomas explains,1 point-

1 II de Anima, Lect. 24.

THE PROCESS OF KNOWLEDGE 225

ing out that though every thing which is acted on receives
from the agent a form which is to some extent without
matter, yet there is a difference between the way in which a
merely physical subject receives forms, and that in which a
knowing or percipient subject does so. The physical thing
receives the form with the same material disposition to the
form as is present in the agent, so that it cannot be said to
receive the form wholly without matter, even though it does
not receive the very same matter as is in the agent. He
exemplifies this by the case of air warmed by the fire, which
in the process receives the same material disposition to the
form of heat which was present in the fire, even though it
does not receive the wood or coal. It is materially changed,
and not formally only. This holds good of the action of all
merely physical subjects of action, but in the case of per-
cipient or cognitive subjects it is not true, since these receive
the form from the agent or object, without receiving the same
material dispositions to that form as were present in the
object, and, in fact, they remain unchanged with regard to
their physical being after the reception of the form. Conse-
quently the similarity between the subject and object is one,
not of nature, but of representation. The species, there-
fore, are produced by the objects, but their mode of being in
the subject depends on the nature of that subject, which,
being a cognitive one, receives them without their material
dispositions. They are, as it were, filtered by the subject
which receives them ; so that their partially immaterial
character is accounted for. We can understand the reception
by the subject of these intentional forms more clearly if we
consider that every form makes its subject to be of a parti-
cular kind, as the form of heat (an accidental one) makes the
subject hot, and the form of life (a substantial one) makes
the subject living. Now these intentional forms make the
subject actually knowing ; leaving it, however, physically
unchanged ; and simply determining it to pass from the
capacity or potentiality for knowledge to the act of cognition.
Hence the intentional form does not make the subject
physically of a particular kind, but simply makes it an
actually knowing subject ; so that it gives it no other fresh

226 MODERN THOMISTIC PHILOSOPHY

being than that by which it is constituted as formally a
knowing subject. The species, then, though resembling
other forms in making the subject to be of a particular kind,
yet differ markedly from these others in not being the
source of the operations which follow on them ; since the
operation which follows on intentional species, viz. the act of
cognition, is generated by the cognitive faculty. This is clear,
since the impressed species simply determines the faculty to
know, while the expressed species follows on cognition, and
is that in which the subject formally has knowledge.

So Cajetan1 explains the difference between cognitive and
nescient things by pointing out that the latter receive their
forms by the operation of some extrinsic agent, which acts
efficiently on them ; while the former do not receive their
forms from the external object, which is known, but are
made formally or actually knowing by means of the exercise
of their own operation, when they are actuated or specified
by a certain object, i.e. when their attention is caught by it ;
so that the efficient principle which makes them actually
knowing is the cognitive faculty itself, and not something
external.

We can thus understand the statement which S. Thomas
often makes : ' The sense in act is the sensible in act, and
the intellect in act is the thing understood in act ' ; for the
form of the known object, the intentional species, does not
combine with the faculty to compose some third thing, as is
the case in nescient subjects, when matter and form combine,
but simply actuates, or calls out, the operation of sensing or
understanding. In this way the form of the object becomes
the form of faculty, which so informed or actuated, therefore
becomes the object in the psychic order, though, of course,
remaining unchanged as regards its own nature in the
physical order. Further, it is clear how the species con-
tributes to cognition, for if it be considered in relation to the
object by which it is produced, it must be said to be the
instrument which the object uses to determine the faculty,
so that both it and the object contribute to the production
of knowledge. Since, however, it is the active force by which

1 Comtn. in S. Theol., 1.14,1.

THE PROCESS OF KNOWLEDGE 227

the object produces its effect, it is correct to say that the
object is an immediate contributory principle of knowledge,
for the active force of a substance is to be attributed to the
substance itself, as Cajetan says : ' Accidentalis vis non sua,
sed substantia est virtus.' If, on the other hand, the species
be considered in relation to the cognitive faculty, we must,
as we have seen, say that it is the faculty which is the active
cause of cognition, though it is only so active under the
actuation and determination of the species, which can there-
fore be called, to this extent, an active principle ; inasmuch
as it, in union with the knowing subject, constitutes a single
principle of cognition.1

If it be true, as is said above, that the function of the ex-
pressed species is to be the term of the act of cognition when
the object is either not present or not proportionate to the
cognitive faculty, it is easy to see what answer must be given
to the question whether such species are present in every
cognitive act ; a question which has been hotly disputed
among Scholastics. The question may be put in other forms
besides the one just mentioned, for if it be maintained, as is
done by some recent Scholastics, that the expressed species
is only logically distinct from the act of knowledge, it is clear
that it will be present in all such acts, so that to ask whether
this distinction is real, or logical only, is a second form of the
question. Again, an action which is always directed towards
the production of a term is called a predicamental action,
while one which is not so directed, and produces nothing but
the reality of the action itself, is called a metaphysical one.
So the question can also be put in the form of asking whether
the cognitive act is a predicamental or metaphysical one,
since in the former case it will always be directed towards
the production of the expressed species. The Thomists, as
against Suarez, unanimously teach that no expressed species
is produced in the acts of external Sense knowledge ; and
this for several reasons. First, because such species would
be useless, since the object is itself sufficient to terminate the
act ; and, secondly, it would be positively harmful, since it

1 Cf. S. Thomas, De Veritate, Q. 8, A. 5 and 6 in corp. and A. 7 resp.,
ad 2um (of the last series).

228 MODERN THOMISTIC PHILOSOPHY

would prevent the sense from grasping its object immediately ^
so that we should have experience, not of the object, but of
the species. Thirdly, the view that the expressed species is
really identical with the cognitive act is untenable, since the
species is that in which the object is known ; whereas the
cognitive act cannot be said to be that in which the object is
known ; but only that by which we know it, without abandon-
ing the Thomistic theory completely, and adopting a purely
conceptualist one ; since the act of knowing must be some-
thing entirely our own or subjective. Hence we are not
obliged to posit an expressed species in all cognition on the
ground that it is identical with the cognitive act. Lastly, it
seems clear that cognition is not designed for the production of
a term, since, even when a term is produced, as in intellectual
knowledge, the cognition continues after its production, and
is, in fact, perfected and completed by the contemplation of
the term produced, whereas in a predicamental action, the
action ceases once the term has been produced. The fact,
then, that the perfection of cognition comes about after the
term has been produced, shows that this production is
achieved for the sake of cognition and not vice versa, as
would be the case if cognition were a predicamental action,
instead of being, as it is, a metaphysical one ; and so, a dis-
position or quality of the subject.

This doctrine brings out the true immanence of knowledge,
inasmuch as the act of knowledge is something perfect, and
complete in itself, and not designed to produce something
other than itself, while at the same time it gives no support
to Idealist theories of knowledge according to which we only
know our own mental acts ; since it maintains that the
object is known, either in itself, or in a representation which
is really distinct from the act of knowing. Cognition, conse-
quently, is rightly denned as metaphysical action, by means
of which possession is taken of a form immaterially, i.e. with-
out the potentiality of matter. So cognition, as such, has
nothing to say to matter, to potentiality, to imperfection ;
and consequently is what the Scholastics call ' a simply
simple perfection,' i.e. one which in itself involves no
imperfection.

CHAPTER IX

SENSE KNOWLEDGE

The Senses are Organic — Their Distinction and Number — Where
Sensation Takes Place — The Objects of the Senses — Immediate
and Mediate Sense Objects — Can we be said to Sense the
Externality of an Object ? — The Inversion of the Retinal
Image — Internal Sensibility — The Sensitive Appetite.

After this consideration of the nature and process of
knowledge in general, we can now pass to that of the know-
ledge of the senses, of sensation. In doing so we shall first
investigate the nature of the senses in general, and then the
different kinds of sense.

We ask, then, in the first place, whether the senses are
organic or inorganic faculties, i.e. whether they are depen-
dent on the organism or not.

That sensation is a vital action, by which the sentient sub-
ject knows corporeal objects, which act on the sense organs, is
hardly open to dispute ; and it follows that three things are
required for sensation : (i) an object, (2) an impression made
by that object, and (3) that the sense which is thus affected
should really know the object, i.e. sensation is a kind of
cognition.

By a sensitive faculty we mean a proximate and immediate
principle of cognition by means of which the sentient subject
is united to material things.

In asking whether such faculties are organic or not we mean
to enquire whether they are dependent, for their existence
and action, on the whole organic compound, on the material
organism itself ; and we presuppose that sensation cannot be
explained merely mechanically, since it is a kind of cognition,
which, as we have seen, in our discussion of cognition in
general, cannot be a merely mechanical process. Are we,
then, to adopt the opinion which is at the opposite extreme

229

230 MODERN THOMISTIC PHILOSOPHY

to this materialistic one and say that the senses depend
intrinsically only on the vital principle or soul ; a view
maintained, at least with regard to human sensations, by the
Cartesians.

This question is of considerable importance, since it deals
with the relations of soul and body, and if sensation be allowed
to be an act of the soul alone, then, first, we shall have to
prove in some other way, than by its intrinsic dependence on
the body, that the soul is its substantial form ; or else con-
cede that an animal is not an essential unity, but a duality,
composed of two complete and heterogeneous substances.
The opinion of the Cartesians was, in fact, due to their taking
this latter view of the nature of man. Moreover, whatever
we say about this question of essential union, it would be
difficult to deny that the sensitive soul is, of its own nature,
and consequently in the lower animals as well as in man,
spiritual and immortal. If, however, we establish that the
senses are organic it will naturally follow that the animal is
an essential unity, since it operates as a whole, and conse-
quently that its soul is its substantial form, and also that it
is not spiritual. Further, we shall have prepared the way
for showing that the intellectual soul in man is the form of
the body, even though it may be spiritual ; since in man the
principle of sensation and intelligence is the same.

Actually the proposition that the senses are organic is one
which is not likely to meet with much opposition at the
present day, when the tendency is to take a materialistic
rather than an immaterialist view of vital processes.; and
S. Thomas gives us a simple, but convincing, reason for
granting that i+ is true. For, as he points out,1 if the
operations of the senses are intrinsically dependent on the
organism the senses themselves must also be intrinsically
dependent. Now it is clear that sensation does depend
intrinsically on the organism, since experience shows : first,
that the objects of the senses are always singular and con-
crete things, which could only affect the sensitive faculty by
a physical impression on something material, viz. the organ
of sense ; secondly, that the sense itself is affected and

1 Summa Theologica, 1.77,5.

SENSE KNOWLEDGE 231

weakened by the physical forces of the object, as sight is by
too much light, or light of an unsuitable kind, touch by too
much pressure, and so on, and that it is sometimes destroyed
by the corruption of the organ of sense ; and, thirdly, that
the sense perceives all things as extended, i.e. material. For
all these reasons, then, we are justified in asserting that the
sense operations are intrinsically dependent on the matter
of the organism ; and consequently that the senses them-
selves are organic.

We can now turn to a more detailed consideration of the
particular senses. It is at once obvious that the sensations
of which we are aware are of very different kinds. So, e.g. the
sensation of seeing an object is quite different from that of
hearing a sound ; and consequently in trying to classify
sensations we shall soon pick out what are commonly called
the five senses of sight, hearing, smell, taste, and touch.
Common observation had always distinguished these five
senses, but from a philosophical point of view the division is
arrived at by considering the objects from which the sensa-
tions are derived, viz. colour, sound, odour, savour, and
tangible quality. It is clear that to say that the object of
touch is what can be sensed by touch is to say nothing ; and,
in fact, this sense has a very indefinite outline, and is really
a genus of sensation covering both sensations of pressure, or
resistance, as well as those of temperature — of heat and cold.
What are called nowadays ' organic sensations,' viz. those
connected with internal feeling of the organism, as sensations
in the stomach, bowels, etc., as well as muscular sensations,
and so on, all come under this head. Sensations of touch,
moreover, are generally present along with the sensations of
the other four senses, particularly in tasting and smelling,
though they are also present to some extent, generally with-
out our being aware of it, in seeing and hearing.

Nevertheless, since in the last-named sensations we do not
know, by pure sensation, that the objects of sight and hear-
ing are acting causally on our organs, but regard them as
being things not in contact with our bodies, these two senses
are often named by the Scholastics the superior senses, while
those senses in whose action we are aware of causal action of

232 MODERN THOMISTIC PHILOSOPHY

the objects on the organism, in the sensation itself, are called
the inferior ones, viz. smell, taste, and touch.

Some remarks may be made about particular aspects of
the sensations of these inferior senses. With regard to the
sense of touch, touch-sensations include, as we said, those of
heat and cold. There are spots on the skin, known as heat
and cold spots, and also areas covering a system of nerve-
endings, at which sensations of heat and cold are aroused on
contact with points or surfaces. Pain sensations are also
included under the sensations of touch ; but, of course, such
sensations are not to be confused with feelings of pain, which
belong to the affections or emotions. With regard to the
sense of taste, there seem to be only four or five savours
properly so-called : sweet, sour, bitter, salt, and alkaline.
The variety of savours which we usually suppose ourselves
to recognise are a combination of taste and smell. Odours,
lastly, are almost impossible to classify, owing to their
variety and composite character.

Each of the sense organs is connected with areas in the
brain by means of the nervous system, of which the auditory,
visual, and olfactory areas have been most definitely located.

In view of this fact many modern psychologists consider
that sensation takes place in these sensory areas, i.e. that we
actually sense, not in the sense organs, but in the brain.
This opinion seems to have been too hastily arrived at ; for
it is based on the fact, or supposed fact, that if the sensory
area in the brain is destroyed, the corresponding sensation
does not take place. This fact would only show that the
brain plays an essential part in sensation ; and does not
warrant the conclusion that it is the brain alone which
senses. On the other hand, we have positive reasons for
adhering to the opinion that sensation takes place in the
sense-organs, and is thence carried by way of the nervous
system to the brain, so that we, as subjects, become fully
conscious of it, only on the completion of this process. This
view is in accord with the strong testimony of experience, in
so far as we always localise our sensations in a particular
part of the body : e.g. in the leg or arm, and the fact that
a man may ' feel ' sensations in an amputated limb only

SENSE KNOWLEDGE 233

shows how strong is habitual imagination, which, when the
nerved, before connected with that limb, are affected, still
persists in localising the sensation in the absent limb ; not
that when the limb is present the man really had no sensation
in it. The testimony of common experience, then, ought not
to be reckoned erroneous, unless there be some certain reason
which renders it untenable. Such a reason was thought to
be the fact that impressions of light and sound could be
engendered by direct excitation of the visual and auditory
centres ; but it should be noticed that it does not seem poss-
ible to do this in subjects which have never possessed the
sense in question ; and, moreover, the impressions so pro-
duced are not of any determinate object, but indefinite
ones of illumination or noise, etc., in which, again, imagina-
tion would have a part to play. The opinion we are oppos-
ing seems to rest on an inveterate prejudice that the
organism is really a mere mechanism, like a photographic
camera, so that the organs and nerves could only be mere
media to transmit a physico-chemical impulse to a purely
material receptacle, and so could not be said to receive the
impressions themselves. If, however, we reject this view as
being a merely a priori one, as it is, and founding ourselves on
experience, maintain that the organism acts as a vital whole,
there seems to be no reason for abandoning the doctrine that
sensation takes place, i.e. the object is sensed primarily, in
the organs on the body's surface, and is completed, and made
fully conscious, when their impressions affect the sensory
areas in the brain ; and so the general sensitivity, and the
whole sensitive subject.

The Objects of the Senses.

The Scholastics distinguish two kinds of sense objects,
essential and accidental ones. The first class is again divided
into proper and common sense objects. By an essential
sense object they mean one which is in fact presented to,
and grasped by, the sense or senses in question, as distin-
guished from an accidental object which is not in fact grasped
by a sense, but being known by some other faculty, an*
accompanying the essential sense object, is known by the

234 MODERN THOMISTIC PHILOSOPHY

subject along with it. Thus bodily substance is an accidental
sense object ; for, though it is not known by any of the
senses — it cannot be seen, or heard, or touched, and so on —
but only by the intellect ; yet, since it goes along with what
is sensed in itself or essentially, viz. bodily accidents, it is
said to be accidentally sensible. The class of essential
sensibles called proper are those which are the immediate
objects of any sense, which specify it, and so are grasped
only by that sense and no other, while common sense
objects are those which are mediate objects of any sense,
and are often grasped by more than one sense.

Such mediate sensibles are, however, of two kinds : those
which are known in themselves through some medium, and
those which are not known in themselves, but in some
representation or image of themselves. To make clear what
is meant by this we might use the example of the telescope.
In the usual form of telescope the star is seen directly, and in
itself, though only by the medium of the instrument ;
whereas in the reflecting telescope, what is seen is an image
or reflection of the star, not the star itself, the medium of
seeing this image being the instrument ; and that of seeing
the star its reflection in the mirror of the telescope. The first
class of immediate sensibles, viz. those which are mediately
sensed in themselves, are quantity and things connected
with it, viz. motion, rest, shape, and position. These are
presented to the sense by means of something else, e.g.
colour, but nevertheless they are presented as they are in
themselves. Shape cannot be seen without colour, but never-
theless the shape of a coloured object is seen, is grasped by
the sense of sight.

The second class of mediate sensibles are very different from
these, for what is grasped by the sense here is not any sense
object, as it is in itself, but as it is in some image or reflection
of itself. This reflection which represents the object as it is
in itself, more or less accurately, is to be found in all sense
perceptions, since there is always one essential sense object
which is immediately sensed, and is within the organ of sense,
in immediate contact with the nerve endings, as e.g. the
retinal image, or rather the extended coloured surface which

SENSE KNOWLEDGE 235

is in immediate contact with the retina ; and another
mediate essential sense object, viz. the object from which
this extended coloured surface is transmitted, i.e. the ex-
ternal object. This last is known only by the mediation of
the internal object.

Simple sensation does not distinguish between the object
as it is outside the subject, and the object as it is within it.
Both are known by it, but confusedly, the internal object not
being known as internal, nor the external as external. This
is clear, since we do not see an object as being in our eye, nor
hear a sound as the vibration of that part of the air which is
in immediate contact with the basilar membrane of the ear,
though scientific investigation shows that these internal
objects are present, and that it is only by their means that
we see or hear the external ones. Consequently the external
object is not known to be external by means of sensation
alone ; it is not an essential sensible, but only an accidental
one. We conclude that it is external by repeated observa-
tions and comparison of different sense experiences, and so
may be said to perceive its externality, though we cannot sense
that it is external. The external object, then, considered from
different points of view, can be said to be either an essential
sensible, or not an essential sensible, but an accidental one.
In itself, simply as coloured, round, etc., it is an essential
sensible, though a mediate one known in its intra-organic
representation ; but in so far as it is external it is not an
essential sensible at all. Consequently, as it is, if considered
absolutely in itself, without relation to the internal sense
impressions which it produces, or even considered precisely
as the source of the whole complex of such impressions, the
external object is an accidental sense object which comes to
be known gradually by putting together and comparing a
large number of sense experiences. In this process imagina-
tion and, in the case of man, intellect play a large part ; and
thus the way is laid open to numerous mistakes and illusions.1

From what we have said it will be clear that what any sense

1 The theory here sketched with regard to mediate sensibles is derived
from Fr. Jos. Gredt, O.S.B. See his De Cognitione Sensuum Exlernorum,
ed^ 2a Romae, 1924. This essay can also be usefully consulted for the
analysis of the objects of each of the senses in particular.

-236 MODERN THOMISTIC PHILOSOPHY

perceives immediately, and essentially, is the proper sense
object which is internal to the organ of the sense in question.
Thus the sight, e.g. senses the coloration of the ether which
is in immediate contact with the retina : it does not sense
essentially, and in itself, the object from which this im-
pression is derived, nor yet the retinal image produced by
the ' internal ' object. This explains why it is that though
the retinal image is inverted the object is not seen as
inverted, a fact which is generally explained by saying that
custom enables us to ' rectify ' the inversion of the retinal
image, interpreting it, by the imagination, as direct. But if
what is seen is not the_ physical (or photo-chemical)
impression on the retina, which is certainly inverted,
but the interior object which represents the external
one, this object will represent not the position of the rays
of light as they are about to fall on the retina, which are
already refracted, but the position from which the rays come,
and so their direction ; so that the eye will see, as coming
from above, what does indeed come from above, and from
below, what comes from below. This explanation will only
hold good if the sensation of sight takes place in the eye ;
whereas if it be held that the sensation takes place in the
brain this difficulty with regard to the inverted image seems
almost insoluble, since the brain can only register what is
given it, viz. the inverted image ; and cannot perceive from
what direction the light-rays come to fall on the retina, in
which case the deliverances of the senses of touch and sight
ought to be discordant, which is not the case. This affords,
then, a confirmation of the view that sensation takes place
in the sense organs and not in the brain.

Internal Sensibility.

The Scholastics usually partition the functions which are
performed by the internal sensibility among four ' internal
senses ' ; the common sense, imagination, estimative faculty
and memory ; though Suarez considers these four to be but
different functions of one sense.

The functions of the common sense would be those of
sensitive consciousness, by which man and the animals

SENSE KNOWLEDGE 237

would be conscious of their sensations, and that of discrimina-
tion and comparison between various sensations, e.g of
sight and touch, by which the subject is at the moment
affected.

Though traditionally the common sense has been con-
sidered by the Scholastics to be a separate faculty with a
special organ, it does not seem clear that Aristotle thought
it to be other than the general sensitivity.1 In fact, this
view, as Cardinal Mercier points out,2 is consonant with the
teaching of S. Thomas, and avoids the considerable difficul-
ties which arise if we regard the common sense as a distinct
faculty. Since the subject is itself a unity it will be able to
unify and compare its own sensations, by means of the sen-
sitivity which is distributed through the whole organism, and
especially through the nervous system and brain. Another
function which is exercised by the internal sensibility is that
of imagining. We know as a fact of our own experience that
sense perceptions of objects are often followed by our making
representations of them to ourselves, picturing them, and
forming images of them. This is the work of the imagination
which, by means of the formation of such pictures or images,
thereby enables the animal to retain the knowledge of
sensible objects, to know them when absent, and to reproduce
and associate them.

The third function of the internal sensibility is what
S. Thomas called the ' estimative force ' or power, a function
which is included under what now goes by the rather vague
name of ' instinct.' By its means an animal is able to
appreciate the beneficial or noxious character of the objects
of sense, and so try to get them, or avoid them. This power
arises from natural predispositions which are doubtless
educated by experience. The animal being by nature of a
certain kind finds some things useful to it and some harmful,
so that its very nature moves it to acquire the first and reject
the second. No really satisfactory explanation is, however,
forthcoming to show how it is that a quite inexperienced
animal is able to make such discriminations, as, e.g., to avoid

1 Cf. Ross, Aristotle, p. 140.

2 Mercier, Psychologie, Tom. I, paragraphs 100 flf.

238 MODERN THOMISTIC PHILOSOPHY

eating poisonous or harmful herbs. It seems certain that any
satisfactory explanation will have to allow that the animal
has certain innate natural tendencies to definite ends. If
such tendencies be ruled out, as they must be by any
mechanistic account of animal behaviour, the fact of
instinctive discrimination becomes inexplicable.1

The last function of the internal sensibility is sensitive
memory by means of which the animal recognises past
experiences as past ; the memory, thus differing from the
imagination, which merely reproduces them without putting
them in their setting as things experienced in the past. Such
recognition of past experiences is clear in ourselves, when we
recognise a face or a place which we have seen before, and is
not to be denied to the lower animals, who also recognise
persons and places from which they have been separated,
sometimes for a long time.

The Sensitive Appetite.

To complete our consideration of the activities of sensitive
nature we must add something with regard to its conative
capacities, or, as the Scholastics call it, ' sensitive appetite.'
Though the word ' appetite ' is used by the Scholastics to
signify any natural tendency which may be found in any
thing, covering such tendencies as that of heavy bodies to
move towards one another ; in this connection its significa-
tion is narrower and, excluding such innate or natural ten-
dencies as those just mentioned, is confined to tendencies
which follow on cognition. The tendencies which are brought
into play by cognition may be purely natural ones, the instinc-
tive tendencies of the animal ; or intelligence may combine
with instinct, so that the resulting action is spontaneous, and
not dictated merely by the nature of the subject : and, in
the case of man, it is at least theoretically possible that he
should desire what he knows by his intellect to be good,
quite apart from any impulse of his nature driving him to
do so.

This notion of purposive tendencies in man, and a fortiori

1 For a full discussion of instinct see McDougall, Outline of Psychology.
Esp. Ch. IV.

SENSE KNOWLEDGE 239

in the lower animals, is altogether repudiated and excluded
by modern psychologists of the materialistic and Behaviour-
istic schools, because it is not observable by the methods of
natural science, which can know nothing of final causes, of
the ' why ' of an action. The success of both biologists and
psychologists in their attempt to bring vital phenomena
within the bounds imposed by itself on physical science has
been, however, very incomplete ; so that in both sciences
there are many authorities who wish to retain the notion of
purpose when dealing with animal or human behaviour, and
even to make it central, and the ruling principle of such
behaviour ; as does McDougall, and those associated with
him in the Hormic school.

It is, in fact, extraordinarily difficult to deny the fact of
purpose in human behaviour, and even those psychologists
who do not allow its existence devote all their energies to
a definite purpose : the exclusion of purpose. A detailed
examination of the behaviour of animals, in order to deter-
mine whether their actions can be said to be purposive,
would require a volume ; and, what is more important, is
outside the scope of a philosophical investigation ; but both
common and scientific observation of their actions shows
that it is at least much the simplest explanation of them, and
in fact the only one, at present in the field, which is reconcil-
able with all the known facts. From a strictly philosophical
point of view, moreover, it is certain that where we have
cognition we must also have appetition or conation ; so that
on the supposition that the animals have the former, they
must also have the latter. The reason of this statement is
that every action must have a definite efficient principle
and be directed towards some definite object or end. For if
there were no definite efficient principle of action there
could be no action, and if the action had no definite direction
the agent would not do one thing rather than another, and
so would not act at all. The actions, moreover, of things are
governed by their natures or forms, i.e. they will act in
accordance with their natures. Now the forms which are
found in things are, as we have seen, of two kinds, their
innate physical forms, and those which they acquire through

240 MODERN THOMISTIC PHILOSOPHY

cognition ; and each of these will direct their actions towards
a definite object or end, so that in both cases there will be
an inclination or tendency which accompanies the possession
of these forms. In the case of physical forms we shall have a
uniform, constant, and determined tendency towards a given
end ; and in the case of forms acquired by cognition a ten-
dency towards, or away from, an end, according as this is
known as suitable or unsuitable to the agent in question.

We see, then, that if we acknowledge that animals have
sense cognition we are also obliged to grant that they have a
conative tendency which follows on it, and is determined by
it, i.e. that they have a sense appetite. Whether, in fact, they
have such cognition is the question which must now be
discussed.

CHAPTER X

THE NATURE OF THE LIFE-PRINCIPLE IN ANIMALS

What We Mean by ' Animal ' — Have they Sensation ? — Opinions :
Descartes, Loeb — The Thomist View — Is Sensation Peculiar to
Animals ? — The Life -principle in Animals Essentially Sensitive,
and their Substantial Form : so One Only — Belonging to the
Material Order, yet Specifically Distinct from that of Plants —
Summary.

As a result of our discussion of cognition we can now see that
sensation is a cognitive action, whose formal object is the
individual material thing which is presented to the sense,
and that cognitive action itself is a metaphysical one, by
which immaterial possession is taken of a form ; the form in
the case of sensation being, however, that of an individual
material thing, and so conveniently called a material form,
in contrast to those which are altogether denuded of matter,
either owing to their nature, as spiritual beings would be, or
through the operation of mind which takes away all materi-
ality, and consequently all individuality from them.

If we are to ask whether animals are capable of sensation,
and if so whether they differ from the plants in this respect,
we must have a clear idea of what we mean by an animal as
distinguished from a plant. Though everyone has a vague
notion of what constitutes an animal, it would often be
found, on examination, to be that an animal is a living being
which has senses, as opposed to a plant, which has none.
Such a notion, if it were employed here, would evidently lead
us in a vicious circle, for this is precisely the question we are
enquiring into : whether animals do indeed possess this
peculiar power which is not shared by beings lower in the
vital scale. It is obvious that this preliminary notion which
we may have of an animal cannot be its essential definition —
its real definition — since if we return an affirmative answer

241

242 MODERN THOMISTIC PHILOSPOHY

to this question it will be equivalent to saying that the
specific difference of animal nature is sensibility, so that we
must be content, at this stage, with a nominal and descrip-
tive definition which may leave a certain amount of doubt as
to whether some particular organisms are to be considered as
animals or plants. The difficulty is paralleled by that which
we experience when we ask whether rationality is the pre-
rogative of man ; for here again we must take such outwaid
characteristics as taillessness, erect walk, articulation of
limbs, brain-structure, and so on, to indicate what we mean
by man, and so find it difficult to decide whether certain
fossil remains are human or not. We must notice that two
questions are included in the one stated above, viz. (i)
whether animals are capable of sensation, i.e. whether any
of those beings which we agree to call animals are capable of
it, and here the difficulty just mentioned does not arise, and
(2) whether all animals, and they alone, are capable of it,
where the lack of precision in our descriptive definition of
' animal ' is bound to result in a certain amount of doubtful-
ness and obscurity. We can say, for certain, that capacity
for sensation constitutes a specific difference or difference in
kind between those beings which have it and those which do
not, though we may find it difficult to determine precisely
where the line of demarcation is to be drawn.

Let us first see what sort of nominal, or descriptive
definition we can give of ' animal.' From a physico-chemical
point of view, animals may be said to be distinguished from
green plants by the tendency of the processes of energy-
transformation which go on in them. The tendency of the
green plant is to accumulate energy in the form of high
potential compounds, such as carbo-hydrates, proteid, fat and
oil, while in the animal body the tendency is to break down
these compounds into water, carbonic acid, urea and other
nitrogenous substances. Thus the metabolic action in the
animal is destructive, in the plant constructive.

A more obvious, as well as a more essential, characteristic*
which is to be observed in animals, as contrasted with green
plants, is mobility, and mobility which is, at least in appear-
ance, purposive. Not only is the mobility of animals much

LIFE-PRINCIPLE IN ANIMALS 243

more extensive than that of plants, but the typical animal
moves as a whole, while the typical plant only moves its
parts, such as leaves, roots or tendrils, and these merely by
reflex motions responding to some external stimulus. The
variety of animal movements is also much greater than that
of the plant. This capacity for movement is due to the
structure of the animal as contrasted with the plant, for the
former possesses a sensori-motor system which the latter
does not. This system is the skeleton and muscles whereby the
animal is enabled to move from place to place, to seize its
food, and so on, and to masticate it, as well as the peripheral
sensory and motor nerves, and the central nervous system
and brain. No doubt the plain man would say of a creature
that was observed to move itself from place to place that it
was an animal and not a plant ; and though this charac-
teristic, by itself, is not for us a sufficient indication of the
nature of an organism, it occupies, no doubt, an important
place in the characteristic behaviour of the typical animal.
As animal life progresses the sensori-motor system becomes
more developed and the animal grows more and more mobile.
According to these indications, then, it will be sufficient for
our present purpose to describe an animal as a living being
whose characteristic metabolic tendency is analytic, and
which is mobile, its mobility being due to the possession of a
sensori-motor system.

We can now ask whether those beings which possess a
combination of these characteristics are capable of sensation,
while those which do not possess it, are not. We remarked
that the capacity for sensation must constitute a specific
difference, and the truth of this statement appears if we
consider that sensation implies a degree of immateriality
in its possessor which is not found in an insensitive
being.

Such a surplus of immateriality is a positive addition to
the being of a thing, and so is an element of being, found in it
over and above that which is found in other entities. Evid-
ently nothing more than additional being can be required to
constitute specific difference, since there is nothing more
than being, so that where we find a positive addition of being,

244 MODERN THOMISTIC PHILOSOPHY

as in this case, we can affirm that we are in the presence of a
specific difference.

Our first question, whether any animals, using the word
animal in the sense indicated above, are capable of sensation,
is one to which common sense readily gives an affirmative
answer ; nevertheless, a negative one has often been given by
philosophers. It must, of course, be denied that animals
sense, by the materialists and those who deny that there is
any distinction, except that of the degree of its complexity,
between organic and inorganic matter. Their view on this
point is clearly but a corollary of their general position, and
we have already seen that it is impossible to maintain that
living things are a mere compound of matter and its forces.

There are, however, others who while not denying the dis-
tinction between animate and inanimate things, nevertheless,
will not allow that the animals sense. Of these the first is
Descartes, who divided beings into two classes, those which
are constituted by geometrical extension, and those which
are endowed with thought. Since he held that the animals
are not capable of thought, as a consequence he had to
include them in his first class, and say that they are purely
material constructions, inanimate and insensible. So he
says : ' The animals act naturally by springs, like a watch.'
He imagined that the more rarefied parts of the blood
ascended to the brain, and there, in the ventricles, became
what he called ' the animal spirits ' ; a kind of fluid contained
in them, whose flow was regulated by valves in the nerves,
which he thought of as fine tubes. On the stimulation of the
surface of the body, threads in the nerves were pulled by it
opening the valves, and allowing the animal spirits to flow
along them, thus causing contraction, etc., of the muscles,
motion, and the other phenomena of what we call life.
Though this theory, with the growth of physiological know-
ledge, had to be abandoned altogether, the underlying notion
that the motions of animals are to be explained merely
mechanically has survived, and has been embodied in theories
such as that of Loeb. This is known as the theory of
' tropisms ' ; which in its generalised form ascribes all the
motions of animals to physico-chemical responses or reactions

LIFE-PRINCIPLE IN ANIMALS 245

to external stimuli, such as light. So, for example, the
motions of a caterpillar which moves up a plant and eats the
green shoots at the top are explained by saying that, if at
the beginning of the movement, the body of the caterpillar
is at an angle to the direction of the light rays (in this case
the sun's rays), one side of its body will be more illuminated
than the other. This will cause the muscles on that side to
contract, and so the caterpillar will be turned round towards
the rays, and when its body is in line with their direction,
both sides of it will be equally stimulated, and contracting
equally, will cause it to move towards the light. This posi-
tion will clearly be one of stable equilibrium, since on any
divergence from it the unequal stimulation of the sides of its
body will cause it to resume it. Such an organism is said to
be positively heliotropic, or positively phototropic. Move-
ments away from a source of light are explained in a similar
way. Though, in fact, the hypothesis was only successful in
explaining some parts of the movements of some of the
lowest organisms, it was hoped that with increased know-
ledge it might be made to cover all movements of all organ-
isms ; a pious hope whose realisation is becoming continually
less probable, as new facts become known which cannot be
forced within the limits of the theory.1 Though, then, it
may be true that tropism plays a part in directing the
motions of animals, it cannot be considered to be an all-
sufficient explanation of them. According to Professor
J. S. Haldane, the mechanistic theory of life is now ' bank-
rupt,' and physiologists have lost interest in it ;2 but
whatever be the prevailing opinion of scientists with regard
to it, the following considerations are sufficient to show it to
be untrue in its application to the animals. For, in the first
place, 'the variety of the motions of animals shows that they
do not move merely in response to physico-chemical stimuli,
since they change their motions and cease from action even
though the stimuli remain constant. Further, they do not
always respond in the same way to the same stimuli ; and

1 Cf. McDougall, Outline of Psychology, pp. 62 ff. Johnstone, The
Philosophy of Biology, pp. 148 ff.

2 J. S. Haldane, The Sciences and Philosophy, p. 57, and the whole of
Lect. 3.

246 MODERN THOMISTIC PHILOSOPHY

very different stimuli often produce the same response.
Moreover, they adapt themselves to the situation in which
they are placed in a way which mechanisms cannot do, as
Professor Haldane shows with respect to breathing in a pro-
gressively rarefied atmosphere.1 Add to this, that if we
grant, as we can hardly refuse to do in the face of our own
experience, that we have sensible cognition, we cannot deny
it to the animals, since they display signs of emotion similar
to those which we observe in ourselves, exhibiting in various
ways marks of pleasure, affection, anger, fear, and so on. It
is also difficult to deny that they desire and go in search of
food, drink, and other bodily gratifications if we allow that
men do, since their mode of behaviour is precisely similar to
our own. No one can refuse to admit that many animals
have all the sense-organs which we ourselves possess, and all
of them at least some of these organs. If, then, we admit
that we have sense cognition by means of these organs, we
can hardly deny such cognition to the other animals,
especially in view of their behaviour and use of these organs.
All these considerations, at any rate if taken together, ought
to be sufficient to convince us that the animals are indeed
capable of sense-knowledge, and are not to be considered as
mere automata or machines. Are we, however, to regard
this capacity as the peculiar prerogative of animals, or
should it be extended to all living organisms ? Those who
think that it should are chiefly influenced by the fact that
we find no absolutely sharp line of demarcation either in
structure or behaviour between the lowest forms of animal
life and the highest forms of what are recognised as plants.
Thus it is stated that ' some lower organisms, the Peridinians
and the Algal spores, exhibit all the characters which we
utilise in separating animals from plants.'2 Apart from the
fact that this statement seems somewhat exaggerated, since
it is acknowledged that they possess but the rudiments of
a sensori-motor system, if it be regarded as such at all, and
other animal characteristics, if at all, only in a very elemen-
tary form ; it is surely a fallacious method of argument.
What is shown by the facts is merely that there are some

1 Haldane, op. cit., p. 94. 2 Johnstone, op. cit., p. 201.

LIFE-PRINCIPLE IN ANIMALS 247

organisms about which we cannot be certain whether they
are to be reckoned as plants or animals ; not, as is assumed,
that we must attribute to some plants, and then, by an added
assumption, to all plants, the essential characteristics which
are found in acknowledged animals. From the point of view
of philosophy it is of no consequence to decide what particular
organisms are to be reckoned as plants and what as animals,
the only question is whether some organisms must be held
to be capable of cognition, while others cannot be said to be
capable of it : for this, if it is the case, will establish the fact
that there is a specific difference among organisms. No
doubt the gradual fading, as it were, of the animal world into
the vegetable, makes us suspect that plants differ only in
degree, and not in kind, from the animals ; but we ought to
base our theories on facts, not our facts on theories. We
ought to say that since we see clear indications of sensation
in almost all the organisms we class as animal, and no such
indications in almost all those we class as vegetable, it is
present in the one class and not in the other ; and not that
since we think it may be present in a few examples of plant
life, it must be present in all, even though observation lends
no support to such a view. Probably the chief ground for
making such an assertion is an unacknowledged prejudice, or
belief, that in fact all living things have been evolved from
simple protoplasm and therefore life must be essentially the
same whether it be that of a man or an acorn. Such a falla-
cious a priori way of arguing might be excusable in a philo-
sopher during the decadence of Scholasticism ; but is much
less so in the scientist in an age of positivism and enlighten-
ment. Further, it is not by any means clear that the facts
which are supposed to lend their support to this theory
really do so. It is true that in what we may call ' boundary-
forms ' we may find, on what is reckoned as the animal side,
some energy-transformations which are of the same kind as
those typical of plants, viz. synthetic ones, while analytic
transformations are found among organisms reckoned as
vegetables ; yet the main tendency in the first is analytic,
and in the second synthetic. Again, though motility is
found in some plants, as we have noticed, yet it is so

248 MODERN THOMISTIC PHILOSOPHY

undirected and random, so lacking in any appearance of
spontaneity or purpose, that it looks much more like a tropism
than a sensitive reaction to felt stimuli, whereas the motions
of even the unicellular animalcule, such as Paramcecium,
exhibit fairly clear signs of conscious and spontaneous action.
So, on coming in contact with a solid object, it usually
reverses its motion and backs away from it, then turning
slightly swims towards it again, and lastly remains quiescent;
all without any change in the external stimuli ; so that the
changes in its movements must be ascribed to something
within the animalcule, viz. its consciousness or sensitivity.
So it does not seem possible to explain all its movements in
terms of reflexes or tropisms,1 as apparently can be done in
the case of Algal Zoospores. If all this is even approximately
true, it seems that the nature of these organisms is too
obscure to justify us in using our view of it as a basis for
asserting that all plant and animal life is of the same kind,
in face of the clear evidences of sensitivity which are mani-
fested by the majority of animals, and the absence of any
such evidences in the majority of plants.

We can conclude, then, with a fair degree of confidence,
that animals are possessed of sensitive life, which is their
own peculiar prerogative, so that cognition being found in
the animal world and not in the vegetable, these two differ
specifically, or in kind.

Two corollaries follow from this : first, that the animals
are animated by a principle of life which is sensitive, since
there must be a source of their sensitive operations which is
of the same kind as these ; and, secondly, that this life-
principle is their substantial form, since, their specific
difference being sensitivity, that which makes them sensitive
beings will be that which constitutes their nature specifically:
that is to say, their substantial form ; and it is clear that it
is their sensitive life-principle which makes them sensitive
beings, and is therefore their substantial form.

It is hardly necessary to emphasise again, what has been

1 H. S. Jennings, The Behaviour of the Lower Organisms, pp. 23 fif., who
concludes, from his observations, that ' the behaviour of Amoeba is
directly adaptive,' and that its ' behaviour is not purely reflex.'

LIFE-PRINCIPLE IN ANIMALS 249

said so often already, that substantial form can be one only ;
but applying this truth to the case in question, we see that
the animals cannot have two life-principles, one vegetative
and the other sensitive, but only one, which is formally
sensitive and virtually vegetative, i.e. one which can cause
those effects which would proceed from a vegetative one
were it present. Further, since it is formally sensitive, it is
of its nature occupied only with material objects and
material operations ; in other words, its operations are
essentially dependent on matter, and it itself is not spiritual,
but belongs to the material order ; for we are bound to judge
of the nature of a thing from the consideration of its essential
operations. If, then, it is dependent on matter both for its
operation and its very being, it will be generated from
matter, and, on the corruption of the compound of which
it is the form, will cease to be actually ; and so is not
immortal.

Such, then, are the general conclusions which we can come
to as to the nature of animals. Just as even the lowliest of
living things in the realm of plants are superior to, and
specifically distinct from, all inanimate things, being capable
of immanent action, and so having an actuality and
immateriality which is not found in the inorganic realm ; so
also the animals are superior to, and differ in kind from, the
plants ; being possessed of that immateriality which is
implied by cognition ; and so of a positive perfection over
and above those found in the lower realm. At the same time,
their life is still altogether dependent on matter ; and they
cannot be called spiritual, but must be reckoned as belonging
to the material order. We are now to ascend one step
further in the scale of living beings, and consider those
which seem to bridge the gap, as it were, between the
material and the spiritual, viz. men.

Before doing so, it may be well to pause, and look back
over our account of the life of plant and animal ; and to
synthetise our notions of the life-principle in these realms,
since the Thomistic idea of the ' souls ' of plants and animals
has been so often misconceived. We are unable to agree
either with the materialistic and mechanistic view of life,

250 MODERN THOMISTIC PHILOSOPHY

which represents it as simply the sum total of the physico-
chemical forces of which the body is made up, or with that
of the vitalists, such as Stahl, who imagined that there was
in the living body some energy-producing force, or forces,
over and above, and independent of, the physico-chemical
ones which are present in it. The ' soul,' in S. Thomas'
view, is not a thing or entity on its own account, but the
directing, co-ordinating, unifying principle of the whole
organism, whereby this organism acts immanently and as a
whole. The action of this principle in no way affects the
total energy of the organism, but merely directs it in a
particular way. Just as a workman with a pile of bricks
expends the same amount of physical energy whether he
piles them in a disorderly heap, or builds a house with them,
so the energy of an organic system remains the same whether
the physical forces in it act independently, and at random,
or are directed in a definite fashion, and co-ordinated by
this vital principle. Further, though this ' soul ' belongs to
the material order, as contrasted with the spiritual one ;
being dependent for its very existence on the matter which
it informs, it is, nevertheless, not in itself endowed with the
properties of matter, not being in itself spatially extended,
though it acts in space ; and not being a source of physico-
chemical energy, though it directs it.

DIVISION IV. INTELLECTUAL LIFE

We are now to investigate the third and highest grade
of life, namely, human life. The most striking difference
between man and the other animals is, no doubt, the pos-
session by the former of intellectual powers ; so that our
primary business will be to enquire into the nature of these
powers ; first, with regard to their generic nature : to
determine whether they are organic or not ; secondly, with
regard to their specific nature, which is the question concern-
ing the object of the intellect ; and, lastly, to ask how the
intellect comes to know its objects ; the question of the pro-
cess of intellectual knowledge, or of the origin of ideas.

In treating of these questions here, in the philosophy of
nature, we shall use the same methods as those employed in
dealing with the ones which we have already discussed ; that
is to say, direct methods of observation, both of other men,
and more especially, since we ourselves are men, of our own
mental processes, by introspection. The question whether
the results of such observations are valid, or whether we are
led astray by deceptive appearances, is one which is outside
the limits of our present enquiry ; since it can only be
answered, if at all, by means of a reflective analysis of our
knowledge ; and so is dealt with in Epistemology, whose aim
is to investigate the nature of our knowledge by means of
reflection. Thus questions as to the nature of universal
concepts, and so on, are left over to a later stage. This being
understood, we can now proceed to ask what the nature of
intellectual life appears to be.

251

CHAPTER XI

THE NATURE OF THE INTELLECT

Views as to its Immateriality — S. Thomas' Primary Reason for
Holding it to be So — Its Objects : Common Formal Object,
and Proper Formal Object — Further Reasons for Regarding
the Intellect as Immaterial — The Question of Its Activity —
Our Knowledge of Individuals.

We have seen that the root of cognition is immateriality, so
that a thing which is wholly and purely material can have
no knowledge ; and since it is undisputed that the intellect is
a cognitive faculty, it follows that it must be to some extent
immaterial. What, then, is the extent of its immateriality ?
Is it like the senses, which are organic, being dependent on
the organism both for their existence and their action, or, if
not, is it entirely independent of the organism ? To be so it
would have to be independent of it both subjectively and
objectively, that is to say, it would have to be capable of
existing independently of the organism, and also able to
acquire its knowledge of objects without its aid.

The question whether it can do this last, or not, can only
be answered when it is known what these objects are, a
subject which is to be discussed later, so that here we are
only concerned to discover whether it is subjectively indepen-
dent of the organism or not. If this were the case, it would
neither contain matter as a part of itself, nor be dependent
on it for its existence and action ; but having an existence
of its own, and not as an element of a compound which
receives existence only as a whole, would be strictly speaking
immaterial or spiritual.

It is obvious that materialism must deny any immateri-
ality to the intellect, and, a fortiori, that it is subjectively
independent of the organism : a denial which is expressed
plainly, though crudely, in the assertion that ' the brain

252

THE NATURE OF THE INTELLECT 253

secretes thought as the liver secretes bile.' A more subtle
form of the same notion is to be found in the view of the
Behaviourists that thought actually consists of minute move-
ments of the larynx in forming sub-vocal speech. This
theory as to the nature of thought was, of course, devised to
bring it within the general scheme as to the character of all
vital action, viz. that it is essentially a physico chemical
reaction to stimuli of the same kind. Since we have already
tried to show that vital action cannot be of this sort, we
must omit any special criticism of this theory of thought,
and resist the temptation to point out its inconsistencies.
The English Empiricists, as Hume and the Associationists,
carrying to its logical conclusion the movement begun by
Locke, considered that intellectual thought is a combination
of particular sense-images, and so implies no more spiritu-
ality in its possession than sensation does.

Those philosophers who have been in the main stream of
philosophic thought since philosophy first emerged from its
sources, beginning with Socrates, Plato, and Aristotle, or
even earlier thinkers, have always consistently maintained the
essentially immaterial character of the intellect. This tenet is
common to those whose views in other respects differ widely :
as S. Thomas, Descartes, Leibniz, Kant, Hegel, and their
successors, as well as the modern representatives of this
tradition, as Bradley, Croce, or Bergson. This conviction,
so constant among philosophers, if not easily arrived at, yet
is one which grows gradually in strength as each aspect of
our experience successively confirms it. That reality is
essentially immaterial, and that the human mind, as the
nearest approach to absolute reality of which we have
immediate experience, is so also, are assertions which
become increasingly clear and certain as philosophic reflec-
tion continues. Some of the main roads by which we are
led to this conviction must now be mapped out ; and it will
first be well to trace that one which S. Thomas seems to have
regarded as leading most plainly and directly to this con-
clusion.1

1 Summa Theologica, 1.75,2 ; Q. disp. de Anima, A. 14 ; Comm. in de
Anima, Lib. Ill, Lect. 7.

254 MODERN THOMISTIC PHILOSOPHY

This argument is derived from the unlimited scope of
intellectual operations. It should be clear from all that has
been said as to the nature of knowledge that it is a kind of
union between its subject and object, whereby the knowing
subject becomes, in a certain way, the things which it knows,
while retaining its own nature. It must therefore be capable
of becoming any of these, but not be actually any of them,
since, if it were, it is clear that it could not become them.
Thus, that the sense of sight may know various colours it
must be capable of receiving or becoming all of them, but
cannot be any of them. As a man looking through blue
glasses sees everything blue, so the sense of sight, if it were
itself of any determinate colour, could not know a variety
of colours. If we now apply this principle to the intellect, we
observe that there is no corporeal nature which is incapable
of being known by it ; for, of whatever sort it is, we certainly
can know it as a thing or a being of a definite kind ; and it
therefore follows, from our principle, that the nature of the
intellect cannot be that of any one of the bodies which it can
know. Since, then, these are all the bodies there are, its nature
cannot be corporeal or bodily at all, but must be incorporeal
or spiritual. In saying that the intellect can know the nature
of any body, since it can always know it as a being or thing
of a determinate kind, we do not mean to imply that it can
necessarily grasp that ultimate specific difference whereby it
is, in the last resort, differentiated from all other bodies ;
but that it can grasp it as a thing which is at least super-
ficially or accidentally differentiated from all others. More-
over, since, as we have seen, it can know the essential
difference between inorganic and organic bodies ; and, again,
within the latter class, the essential differences between plant
and animal; and, as we shall see shortly, between
animal and man ; it can grasp the determinate nature
of all these bodies, and consequently, cannot be either
inorganic or organic body : either brute matter, plant,
animal, or man. These classes, however, cover all bodies ;
so that it cannot be any body. Notice, further : it is said
that it can know all bodies, not that it actually does so ; for
since its knowledge is derived from experience, and it has no

THE NATURE OF THE INTELLECT 255

intuition of the natures of things, the process of acquiring
knowledge of these is a long and arduous one ; but it can,
nevertheless, absolutely speaking, penetrate beneath the
superficial appearances to know what is essential to them, as,
e.g., that they are animals or plants. It has been objected
that the principle : ' that which knows any nature cannot
have that nature intrinsically and physically in itself ' cannot
be maintained at the same time as the proposition that the
intellect can know being, since, in this case, the intellect
would not have the nature of being intrinsically and phys-
ically in itself, and so would not be being, i.e. would be
nothing, which is absurd. Such an objection shows that the
point of S. Thomas' argument has been missed, since the
nature of being is not a determinate nature which excludes
others, but, on the contrary, an indeterminate one which
includes all. The whole point of the argument is that the
possession of a particular determinate corporeal nature by the
intellect would render it unable to know things as of a
different nature to its own ; as the sight knows all things as
coloured, never as odoriferous or resonant — its own nature
preventing it from knowing these other attributes — and
knows only a certain very limited range of colours, the
visible spectrum, all others being excluded from the range of
its knowledge owing to the fact that the organ on which it is
essentially dependent possesses a determinate bodily nature.

This argument, then, gives us a solid ground for thinking
that the intellect is a strictly incorporeal and spiritual
faculty, and, moreover, that it cannot act by means of any
bodily organ, since, if it did it could only know that deter-
minate class of bodies which have affinity with this organ,
and not all bodies, just as the sight can know only a deter-
minate class of colours.

Our conclusion that the intellect is thus incorporeal
will be strengthened after an examination of its objects,
which will at the same time tell us what its specific nature is,
since faculties are specified by their objects,1 and to this we
now pass.

By ' object ' in this context we mean the formal object,2

1 Cf. Part II, Ch. Ill, Q. 2, p. 194. 2 Cf. p. 195.

256 MODERN THOMISTIC PHILOSOPHY

and if we wish to discover the nature of the human intellect,
as distinguished from any other, we shall have to find out
what its proper, as distinct from its common, formal object
is ; for the common formal object of the intellect is that
which the intellect, as such, and not some particular kind of
intellect, formally grasps ; while the proper formal object of
the human intellect is that which is formally known by it
alone. These two are also sometimes known as the adequate
and proportionate objects of the human intellect. If, then,
we ask what is the adequate or common object of the human
intellect, as intellect, we see it must be that object outside of,
and apart from, which nothing can be known, and which
includes all the particular intelligible objects. This object
must be being, for, in the first place, nothing is intelligible
unless it is being of some kind ; for what is not being is
nothing, and so not knowable ; since, to say I know nothing
is equivalent to saying I do not know. Secondly, the only
object which includes all particular objects of the intellect is
being in general ; for every addition to being limits it ; and
so; by such addition, being in general is transformed into a
particular kind of being. So, for instance, spiritual being,
human being, and corporeal being, are classes formed by the
addition of some quality to being in general. From this it
follows that since the intellect knows, or can know, things
which are included in all such classes ; all its objects will
not be included in any one of them ; some being found in
one class and some in another. These classes of beings, more-
over, agree in the notion of being, and in nothing else. Hence
the objects of the intellect also, included in these classes,
agree in the notion of being only ; which notion, therefore,
includes all intelligible objects. So every notion must
ultimately be resolved into the primary notion of being.1
If, e.g., we were to ask : What is man ? the answer would be
rational animal. What, then, is an animal ? We answer ;
sensitive living substance ; and what is substance ? a thing
or being to whose nature is due existence in itself. Similarly,
with all other notions, analysis always leads us eventually to
the notion of being. In the same way every judgement has as

1 Cf. S. Thomas, De Veritate, 1,1.

THE NATURE OF THE INTELLECT 257

its formal element the word ' is/ whereby identity of being
between the subject and predicate is affirmed ; and every
argument assigns from the premisses the reason of being of
the conclusion, so that in the three operations of the mind
nothing is intelligible except as it is resolved into the notion
of being. It is thus absolutely clear that if the adequate
formal object of the intellect were not being, the intellect
would not have an adequate formal object at all ; since
nothing is intelligible except in so far as it is being ; and all
those things which are intelligible agree in this common
formal notion of being.

We can also look at this question from a purely meta-
physical point of view, and observe that since the root of
cognition is immateriality, a thing is intelligible in so far as
it is immaterial. Now it is clear that the more immaterial a
thing is, the more actual it is ; since actuality is opposed to
potentiality, which includes materiality, so that lack of
materiality implies greater actuality. Greater actuality, in
its turn, implies more perfection, i.e. more positive being, and
it follows that a thing is more perfect, more actual, more
immaterial, more intelligible, in proportion as it is more
positively ' being.'

The statement that the adequate object of the intellect is
' being as such ' is not, of course, to be taken to mean that
the intellect does not know anything but ' being as such,' but
that it bears on things precisely as they are beings ; and, as
a consequence, knows also the differences and determinations
of being : just as the sight which bears on things as they
are coloured, knows also the differences of colour.1

We have now to ask what is the proper formal object of the
human intellect ; that object, namely, which is naturally
known by this particular kind of intellect, an intellect which
is found in intimate union with a bodily organism. The
answer which S. Thomas gives to this question is that this
object is the natures of sensible things in so far as they are
universalised, or abstracted from individuating conditions.
By the word ' natures ' we understand all natures whether
substantial or accidental ; but this statement is not to be

1 Cf. Summa Theol., 1.5,2,0 ; and 1.79,7,0.

258 MODERN THOM1STIC PHILOSOPHY

thought to mean that the intellect immediately, specifically,
and perfectly understands the natures of material things ; it
comes to the knowledge of them gradually, at first perceiving
its object under the general forms of being, substance, etc.
Nor do we mean to assert that the intellect knows' nothing
but corporeal things, but that it perceives these natures first,
and because of its own natural constitution, perceiving other
things indirectly, and by means of this proper object. This
idea is opposed to the notions of all those who grant man some
intuitive knowledge, whether by way of what are called
innate ideas, as did Plato and Descartes, or by an immediate
intuition of God, as did the Ontologists. We can approach
the question either a posteriori or a priori — using these
expressions in the Scholastic sense — for we may consider
either the way in which the intellect understands, as we
experience it actually at work, and so arrive at a knowledge
of its proper objects ; or we may consider the nature of the
intellect in itself, and deduce what must be its object.

If we adopt the first way, we see that there are three classes
of things which are known by the intellect : (i) sensible
singular things, (2) supersensible things, and (3) the natures of
sensible things. Now experience shows that purely super-
sensible things cannot be the primary object of the intellect,
since we always come to know them by way of sensible
things. The fact that we cannot express our thoughts of
spiritual entities except by means of words and phrases
derived from our knowledge of material ones, shows this
also. So the names, God, angel, spirit, are derived from
roots meaning to invoke, send, and breathe, respectively,
and this fact is true in all languages. Nor can singular
things be the primary object of the human intellect, for we
always understand first that a thing is a being, and after-
wards that it is this or that being ; for example, we cannot
understand the individual man unless we have first under-
stood what human nature is. Hence it must be the natures
of sensible things which the intellect understands first, and of
its very nature.1

If, again, we consider the nature of the intellect itself, we

1 Cf. Summa Theol., 1.84,3,6,7 ; 85,3 ; 87,1-4 ; 88.

THE NATURE OF THE INTELLECT 259

arrive at the same conclusion, since the object of the intellect
must be proportionate to it ; for, in knowing, it receives and
unites itself to the known object, which therefore must be
assimilated or made proportionate to it. Now the intellect
is an immaterial form joined to matter, and it follows that
the known object must be of the same kind, viz. the
dematerialised nature of material things.1

The process of cognition shows also that this is so ; since,
when dealing with material things, the intellect abstracts
from individuating conditions, and leaving them on one side,
grasps the natures of the things, a fact which would be
inexplicable if its objects were purely material, as the Empiri-
cists maintain. On the other hand, while dealing with
immaterial or supersensible things, though it understands
them, it does so by reconverting them into the sensible, by
way of the imagination ; which could not be explained on
the hypothesis that its proper object is the purely super-
sensible, since in this case we should not understand spiritual
things after the manner of material ones, as we do, but
material ones as spiritual.

Intellectual knowledge, then, consists in the reception by
the intellect of the forms or essences abstracted from
material things. We see that this is so, apart from the con-
sideration that the intellect is a spiritual faculty united to a
material body ; and we can therefore use this result to
strengthen our conviction that it is indeed spiritual ; for it
is clear that if intellectual operations are immaterial, the
intellect must also be immaterial. There can be no doubt
that it is impossible for an organic, or material, faculty to
know any object without its individuating conditions, since
such a faculty depends in its action on an extended organ, so
that its action and the result of its action cannot be indepen-
dent of extension ; i.e. both of them are affected by a deter-
mined quantity. Thus, an organic faculty will only know
things which have such quantity, or concrete beings with
their individuating conditions. The intellect, on the con-
trary, has as its object, as we have seen, natures abstracted
from their individuating conditions, and it therefore cannot

1 Cf. Summa Theol., 1.12,4 ; 1.55,2 ; 1.84,7.

260 MODERN THOMISTIC PHILOSOPHY

be an organic faculty, but must be immaterial. Further, its
way of grasping these unextended objects is itself unext ended
or immaterial ; since it grasps the whole of its objects, and
all their parts, simultaneously, in contradistinction to an
extended faculty which grasps its object partially, and the
parts separately. So the intellect sees the nature of a thing
as a whole, whereas the sense sees, e.g., particular patches of
colour.

Again, one of the most striking characteristics of intellectual
action is the power of reflection, by which the intellect, as a
whole, considers itself as a whole, reflecting on its own being
and nature. Such a process is clearly beyond the powers of
an extended or material faculty, which cannot reflect wholly
on itself ; since, if it has parts outside parts of its very
nature, these parts cannot all be together without destroying
its nature. So a piece of paper cannot be completely folded
on itself, so that the whole of it covers the whole of it ; but
only so that one part covers another.1 The intellect, then,
is immaterial.

The cumulative force of all these considerations is very
great ; for from whatever point of view we regard the
intellect and its operations, we find ourselves led to the con-
clusion which we previously arrived at, from the widest
view of its nature (when we considered it as being unrestricted
in its range ; and so being, in a certain way, all things), viz.
that it is spiritual or immaterial.

If, then, we grant that it is so, it might seem natural to
conclude that it is essentially active, since a spiritual thing
is, as such, not hampered by material restrictions ; and
should be able to act without being, as it were, set in motion
by anything material. Nevertheless, all that has been said
so far as to the nature of intellectual knowledge suggests
that the intellect receives quite passively the dematerialised
forms of material things, having them imprinted, as it were,
upon it ; and not stretching out to grasp its object. Which
of these, then, is the true view of the intellect ? Is it active
or passive ? This question cannot be answered by a simple
affirmation that it is active and a denial that it is passive, or

1 Cf. S. Thomas, II Contra Gentiles, c. 66

THE NATURE OF THE INTELLECT 261

vice versa ; though such solutions have been attempted.
Thus, the Transcendentalists, who consider the principle of
immanence — that we can know only our own thoughts — as
axiomatic, deny the passivity of the intellect altogether ; as
do also the Cartesians, in consequence of their belief that the
mind is always actually thinking ; and this view is, generally
speaking, held to by all the advocates of innate ideas, who
think that the intellect is complete in itself, through the
ideas which are naturally inborn in it. On the other hand,
some Scholastics speak as if the intellect were wholly passive,
and not active at all, a point of view which is suggested by
the phrase ' tabula rasa,' the blank sheet of paper : and
which may, without unfairness, probably be attributed to
Locke, who, as Mr. Morris says : ' rejected the view that the
mind is active as being evidently inadmissible.'1

Though S. Thomas certainly recognises a certain passivity
in the intellect, such passivity is not in any way that of
inanimate things, such as that of a sheet of paper, nor is it
even of the same kind as the passivity of vital operations in
general, such as nutrition, where the nutriment is simply
received and absorbed. For knowledge is, as we have
seen, an immanent action whereby the subject becomes,
in a certain way, the object, and not vice versa ; and
is, moreover, one which enables it to receive the object,
in accordance with its own nature, but without changing
the object. If, then, the intellect is called passive, this is
only in relation to the object inasmuch as it is actuated by it,
not in the sense that it is itself devoid of activity. Conse-
quently, when S. Thomas says that the intellect is a passive
power,2 he is careful to explain that it is only passive in
relation to the object or species which actuates it, because it
stands to this in the relation of potency to act. It is there-
fore perfected by the reception of the species, and becomes
actively understanding. So if we consider the intellect in
relation to the act of understanding we shall say that it is
active, since it produces this act. What was said as to the

1 Cf. C. R. Morris, Locke, Berkeley, Hume, p. 26. (Clarendon Press,

I93i)

a Cf. Summa Theol., 1.79,2.

262 MODERN THOMISTIC PHILOSOPHY

activity of cognition in general,1 finds its application here ;
since, though the intellect in no sense makes the reality, but
has to be actuated by it (here is its passivity), yet, at the
same time, it actively apprehends it, and by its own action
is simultaneously conscious of itself. So ' the intellect in
act and the thing understood in act are one and the same,'
being unified in the identity of one and the same act.

The intellect which actually understands, in this way, is
called by the Scholastics the passive intellect, or the
intellectus possibilis (since it can become all things) ; in
conformity with their general rule as to the way in which
the faculties should be discriminated, viz. with reference to
their objects ; and this intellect is, as we have seen, in
potency with respect to the objects which actuate it.

That such passivity as this must be ascribed to the intellect,
if we wish to maintain that it is a faculty which discovers,
and does not create, its object, is undeniable, when we con-
sider that since the intellect in act and the intelligible in act
are one, an intellect which was not potential to its objects
would be those objects actually, and so actually universal
being ; since the object of the intellect is, as we have seen,
universal being. Intelligence of this kind is evidently not to
be found among finite beings which come to know a limited
number of objects gradually, and so are potential or passive
with respect to them. To deny this would be to identify the
human intellect with the divine, making it the intelligible
forms of all things simultaneously and actually, knowing
itself, and so all things, perfectly and at once ; a claim so
incredibly arrogant as to be intolerable, apart from its
obvious falsity in the light of experience.

A corollary as to our knowledge of singular things follows
from the Thomistic teaching on the proper object of the
human intellect ; for if this object be the natures of material
things, which are universal, it is clear that the intellect is not
primarily and essentially directed to the material things' as
singular, but only as universal. If, then, we know singular
things at all, as we certainly do, since we judge and reason
about them, and distinguish them from the universal, such

1 Cf. pp. 216 f.

THE NATURE OF THE INTELLECT 263

knowledge can only be indirect and secondary, and obtained
by comparing their universal nature with the concrete image
which we have of them as pictured in the imagination.
Moreover, since the source of singularity or individuality is
matter, and matter is not intelligible in itself, for the root
of knowledge is immateriality, it is impossible to maintain
that the individual qua individual is intelligible in itself, and
directly. It can only become so in so far as the universal
form is seen to belong to this particular concrete imaged
object. Suarez, in holding the contradictory view, that the
intellect knows singular things directly, recognises that it is
opposed to that of S. Thomas and all the Thomists ; but
seems to have been led to adopt it for fear of falling into the
opinion held by Cajetan that we know singulars confusedly
only, and not distinctly, i.e. as distinct one from another.
This consequence, however, in no way follows from the
Thomistic position, and is indeed excluded by it ; and if
the view of Cajetan is an exaggeration in the direction of
intellectualism, that of Suarez undoubtedly tends to confuse
sensible and intellectual knowledge ; which is, at least, an
equally dangerous deviation in the direction of empiricism.

We have now a general notion of the nature of the intellect
which we have seen to be an immaterial power by which
man knows abstract universal natures primarily, and singu-
lar things secondarily ; in order to do which his intellect
has to be acted on by the objects, and so is said to be passive,
though considered from other points of view it is active.

From this general view of its nature it is natural to pass
to an enquiry into its way of working.

CHAPTER XII

THE ORIGIN OF IDEAS

The Empiricists — Innate Ideas — The Transcendentalists and Hegel
— The Difficulty of the Question — The Thomist Solution — The
Active Intellect — Its Necessity and Function — Summary of the
Intellectual Process.

The question ' how do we know ? ' naturally follows the dis-
cussion of the question ' what do we know ? ' ; and is
generally called by modern writers the problem of the
origin of ideas.

As our purpose is to explain the Thomistic view of mental
action, it will be unnecessary to subject to detailed criticism
the many divergent opinions which, particularly in recent
times, have been put forward on this subject. At the same
time it is useful to enumerate them shortly, since they throw
light on the real nature and difficulty of this question. These
views, generally speaking, are based on conclusions pre-
viously reached by their exponents on the relation between
body and mind, and the nature of their union. Thus, those
who deny the immateriality of the mind, making it something
bodily, will necessarily say that ideas arise entirely from the
senses and sensible things, while those who, at the opposite
extreme, regard the mind as wholly spiritual, and an acci-
dental adjunct only of the body, naturally conclude that
ideas originate independently of material objects and the
senses ; while finally, if it be maintained that both mind
and body are essential elements of human nature, the origin
of ideas will be attributed to the senses and intellect in
conjunction.

Thus we find three general classes of opinion :
i. That of the Empiricists, according to whom sensible
experience is the adequate cause, not merely of sensible

264

THE ORIGIN OF IDEAS 265

knowledge, but also of intellectual. The movement which
eventually resulted in the distinct formulation of this view
was begun by John Locke, who recognised two processes in
the acquisition of ideas, — sensation and reflection. He thus
maintained, in a fashion, the distinction between the senses
and the intellect. But it is to be observed, that since he
accorded to sensation the acquisition of simple ideas which
represent the primary qualities of bodies, such as solidity,
extension, etc., which ideas, according to him, really resemble
these qualities, while by reflection we only come to know
the internal operations of our own minds ; and, further,
that by putting together the simple ideas, already acquired
by sensation, we form compound ones, he, in fact, equiv-
alently asserts that reflection adds nothing new to the
fabric of science, and the whole weight of the production of
ideas rests on sensation. It does not seem as if Locke
realised all the implications of his own doctrine, but they
were quickly brought out by Condillac, in France ; and by
Hume, the two Mills, and Bain, in our own country. These
all got rid of the power of reflection as being useless, and
substituted for it the alleged laws of the association of ideas,
so that all ideas are but transformed sensations. From this
theory their doctrine came to be known as Associationism.1
2. The second class of opinion maintains that ideas essen-
tially originate independently of sensation. This view is
found, in an undiluted form, in the doctrine of innate ideas
professed by Plato, Descartes, Rosmini, and others. Plato
emphasised the distinction between opinion and science, of
which the first only is derivable from sense experience.
Science, then, must come to the mind independently of such
experience, so that the ideas which constitute it will be native
to the intellect, which is supposed to have known them in a
previous existence. Knowledge, therefore, in this view,
would be reminiscence ; though perhaps this phrase is not
to be taken too literally. According to Descartes, it is
essential to the soul to think. Now thought is impossible
without ideas, so that the soul must from the beginning

1 For a short account of the details of this theory cf. e.g. McDougall,
Outline of Psychology, pp. 237 ff. Stout, Manual of Psychology, pp. 117 ff.

266 MODERN THOMISTIC PHILOSOPHY

possess at least some congenital or innate ideas, though Des-
cartes did not deny altogether the possibility of acquiring
ideas. Such acquired ideas fall, in his view, into two classes ;
viz. : (a) those which are, properly speaking, acquired by
way of the senses and which he calls ' adventitious ' ; and
(b) those which are evolved by the mind itself, through the
association of sensible images, which he calls ' fictitious '
ideas. Rosmini, lastly, held that the idea of being in general
is innate, for he considered that it is impossible to think until
this idea is present.

This general class of opinion is also represented, in a modi-
fied form, by the Transcendental Idealists, who consider
that intelligible objects altogether transcend sense experi-
ence, so that the origin of our intellectual ideas must be
sought in an analysis of thought alone. It is put forward in
various forms by Kant, Fichte, Schelling, and Hegel. In his
first period, Kant accepted the theory of innate ideas derived
from Leibniz and Wolff ; but later, under the pressure of
Empiricist and Sceptical objections, abandoned it, and felt
obliged to recognise that there is, in our thinking, a universal
and necessary element, as well as the fact that it is, at least
partially, derived from the external world. The necessary
element, which is formal, comes from our own minds ; the
material element, from without. The formal elements he
calls ' categories,' of which the intellect possesses twelve,
into which all the objects of our knowledge are fitted. From
this it appears that we do not know external things as they
are in themselves, but as they are moulded by these forms or
categories ; and there is, therefore, no guarantee that our
intellectual knowledge will correspond with external reality.
Fichte and Schelling carried the ideas of Kant to their logical
conclusion, by abolishing the ' thing-in-itself,' and with it
the individual ; leaving nothing but mind-in-general, or the
Absolute. The development of this line of thought is com-
pleted by Hegel, who taught that the absolute and universal
principle of cognition is the Idea of Being in its most abstract
form, that is, ' Pure Thought.' In the first moment the Idea
of Pure Being is pure indetermination, for determination
implies an opposite, and in the beginning there can be no

THE ORIGIN OF IDEAS 267

opposite. Now pure indetermination is pure not-being, and
therefore Pure-Being is Pure Not-Being ; so that the Idea
and Reality of Being is itself its contradictory, and the
reconciliation of contradictories. Thus the Idea of Being
contains that of Not-Being, which is therefore deduced from
it. Moreover, Being which is not-Being, and not-Being
which is Being is Becoming, which is neither Being nor not-
Being. So that the third Idea of Becoming is deduced from
the first two. This process can be continued indefinitely till
all the Ideas are deduced, and it is this which Hegel attempts
to do in his Logic. The origin of our ideas, then, in his view,
is to be found in this first Idea of Pure Being ; and our whole
knowledge is merely the development of this Idea, by means
of the Dialectic method.

We may notice, in passing, that when it is said : ' in the
beginning there can be no opposite,' this is equivalent to
saying : ' in the beginning nothing can be an opposite,' and,
in this case, there is an opposite of Being, viz. nothing.
Being therefore can be determined, not it is true by anything
external, nor yet as a genus or species, since it is transcendent,
but in its positive entity as opposed to Not-Being, and conse-
quently none of the conclusions follow. They can only hold
good if the phrase ' pure indetermination ' be taken equivo-
cally, signifying the entire lack of determination of Being to
genus and species, in the first place ; and an absolute void
without determination of any sort, in the second.1

The foregoing theories bring out clearly the difficulty of
this question of the origin of ideas, for, on the one hand,
those who hold that all knowledge is sense knowledge can
urge that if this be not true it is impossible to explain the
fact that all our actions, even the most abstract, are only
intelligible in terms of sense and sensible images ; while, on
the other hand, those who think that ideas originate indepen-
dently of sensation have strong grounds for asserting
that the opposing theory cannot be true, inasmuch as the
objects of the intellect, which are universal and necessary,

1 For a full explanation of Hegel's theory vide Stace, The Philosophy
of Hegel, esp. pp. 90 ff. ; and, for its criticism, Garigou-Lagrange, De
Revelatione, Vol. I, pp. 244-272, esp. p. 271.

268 MODERN THOMISTIC PHILOSOPHY

and the objects of sense, which are singular and contingent,
are of different kinds, so that one cannot be derived from the
other. Thus we seem to be on the horns of a dilemma : unless
we accept Empiricism we cannot explain the facts of experi-
ence ; and if we do accept it, we cannot account for the
necessary and universal character of our ideas.

3. The theory of S. Thomas resolves this apparent contra-
diction by combining both the elements of the situation
in a higher synthesis, and is indicated by the phrase : ' Know-
ledge begins in the senses and is perfected in the intellect.'
According to this view we are not in possession of ready-made
ideas ; nor are they infused into us by God, or any separated
Form ; nor do we gain them by intuition of God and the
Divine Ideas ; while, on the other hand, the senses are not
the proper cause of the ideas of the intellect ; and the mind
therefore has to acquire them. As we saw, it is at first
potential to knowledge, not actually knowing, and so is
passive ; but, in order that it may be in possession of its
ideas, it needs to be actuated and determined. Are we, then,
to say that it actuates and determines itself, or that it is
actuated by something other than itself ? Both suppositions
seem impossible, for a thing cannot actuate itself, since to do
so it would already have to possess that perfection which it is
supposed to bestow on itself, nothing being able to give what
it does not possess : nor yet can it be actuated by something
other than itself, for the only thing other than the intellect
which is present in this situation is the material objects of
the senses which, being material, are not proportionate to
the immaterial intellect, and so cannot perfect or actuate it.
In this impasse, if we re-examine the statement just made, we
see that though there can be no possible doubt that the
intellect cannot actuate itself, since the hypothesis that it
did so would involve a contradiction, yet the same is not
true of the assertion that the only elements in the situation
are the intellect and the material objects, for no contradiction
is involved in the supposition that there is some active agent
which concurs in the process of understanding, by demateri-
alising the objects of sense, and so bringing them to a state
in which they are fit to be perfections, or actuations, of the

THE ORIGIN OF IDEAS 269

immaterial intellect. We are, therefore, driven by the logic
of the facts to assert the existence of such an active agent,
as the only means of extricating ourselves from an impossible
situation. What is the nature of this agent ? Absolutely
speaking, it might be something extrinsic both to us and the
material objects. The whole of our experience of the process
of knowledge, as well as the requirement that we should be
sure of its truth, renders, however, such a supposition
untenable. For the whole intellectual process exhibits itself
as a gradual one, by which we come into possession of know-
ledge of things, slowly and with much effort, passing pro-
gressively from confused notions to distinct ones, and from
the widest ideas, such as that of being, to specific ones, such
as that of man. It is easy to see, that if ideas were implanted
in our minds by some agent outside ourselves, this laborious
process becomes inexplicable, for we should pass in a flash
from nescience to full knowledge, as soon as the ideas were
imparted to us. Moreover, if the ideas are given to us in
this extrinsic fashion, how could we know that they corres-
pond to the reality ? Evidently, this would only be possible
if we knew what the reality was, independently of them, in
which case they become quite useless. If, on the other hand,
we do not know their correspondence with reality we cannot
have any assurance of their truth, and so are left a prey to
Scepticism.

If, then, we dismiss the hypothesis of an external agent
which implants the ideas in us, and further observe, what is
also clear, that the material objects themselves cannot be
the formative cause of our ideas, for the very reason that
they are material, the only conceivable cause of them will be
some agent within us. In other words, the mind of man
must possess some active power by which he is enabled to
dematerialise the objects, and make them fit objects of the
intellect. It is precisely the existence of such a power which
S. Thomas asserts, since v/ithout it we can give no satisfac-
tory account of the origin of our ideas. As it must evidently
be an intellectual power he calls it the ' active intellect ' or
' intellectus agens.'1

1 For a summary of this argument cf. Cajetan Comm. in 1.79,3.

270 MODERN THOMISTIC PHILOSOPHY

The function, then, of this mental power is to demateri-
alise the objects, as offered by the imagination, in such a
way as to make them able to be dealt with by the intellect
which is to understand them. It will, therefore, abstract the
formal element in them, leaving aside the material elements,
and seize the universal, neglecting those characters which
make the objects individuals. These objects are those
offered by the imagination, as we have just said, so that the
imagination has a necessary part to play in the intellectual
process, by offering the material on which the mind is to
work. This necessary condition of human knowledge —
necessary, because man is partly material, partly spiritual —
has very obvious dangers, since it is quite easy for us to
mistake the imagined picture of a thing for its real nature.
Such an error will always be made when the conclusions of
one science are imported bodily, and as they stand, into
another, as, for example, if a man were to argue from the
determinism which physical science recognises in nature to
the impossibility of freedom in human life. The image,
then, presented to the intellect needs to be changed and
made abstract, or as S. Thomas often says, ' illuminated ' ;
the active intellect being a sort of mental X-ray which
pierces through the flesh or matter of the image to reveal its
internal nature. But just as such rays do not perceive the
internal structure themselves, but only reveal it, so the active
intellect does not itself know the universal form or nature
which it reveals in the image, this being the function of the
passive intellect, of which we have already spoken at length.

To complete this account of the way in which ideas originate
we must recall what was said earlier.1 Since, in intellectual
knowledge, the object itself is not cognitively present to the
mind, the intellect has to form for itself a representation of
it to be the term of cognition, i.e. it forms an expressed
species of the object, a formal concept, or ' mental word ' or
expression of what it has already understood by means of
the impressed species. This concept, then, is not the thing
which is understood ; what we know is not our own ideas, but
the object, in and along with these ideas.

1 Cf. Part II, Ch. viii.

THE ORIGIN OF IDEAS 271

So the whole process of intellectual cognition may be sum-
marised as follows : though it is not to be supposed that
the elements which we find, by analysis, in the act have a
temporal sequence, or work on one another like the wheels
of a watch. The intelligible object is in the intellect in a two-
fold fashion, first, as impressed and the principle of know-
ledge, secondly, as expressed and its term. Now the im-
pressed object is an habitual representation, which is called
the intelligible species, and is abstracted from the images in
the imagination by the active intellect whose instruments
these images are.1 This impressed form of the object is the
principle which determines the passive intellect and co-
operates with it efficiently in the act of understanding, and
so makes the intellect, when acting, one with the object.
Lastly, the expressed species is the actual representation of
this object, in which the passive intellect, now in act, as it
were, says, or expresses, the object to itself, and actually
assimilates it to itself. This mental word or concept is not
the act of understanding itself, but the intrinsic term of this
act, giving satisfaction and completion to it, just as in the
process of generation or reproduction satisfaction and com-
pletion is found in the conception and birth of offspring.

1 John of S. Thomas, Phil. Nat., P. Ill, Q. 10, A. 2.

CHAPTER XIII

THE INTELLECTUAL APPETITE \ THE WILL

Its Existence — Nature — What Necessity is — Freedom of the Will —
History of the Problem — Summary of Opinions — Arguments in
Favour of Liberty — The Limits of Liberty — Views on the Nature
of Liberty — The Answer to Indeterminism — The Answer to
Psychological Determinism — Summary of results arrived at.

In the preceding chapters we have dealt with the nature and
work of the mind in knowing. Another aspect of intellectual
life must now be investigated in order to complete our view
of its activities, viz. its volitional aspect, for it is universally
recognised that it exhibits itself not only in cognition, but
also in conation. No doubt is possible with respect to the
fact that some conative activity, or striving in general, is to
be found in man, for experience speaks too plainly. Moreover,
we have already noticed that action must be in some deter-
minate direction, or towards some end, otherwise it would
have no direction, and so would not exist. It follows, then,
that to every species of activity will be attached a certain
striving to attain the end to which it is directed, though in
the case of inanimate agents, or those without knowledge or
consciousness, we cannot call such striving ' willing,' in any
proper sense. In things which know the end to which their
actions are directed we shall first begin to have desire for it,
for in their knowing of it, they will perceive it as something
which is either suitable, or unsuitable, to them. Desire, or
appetite, will therefore accompany, or rather follow, all
kinds of cognitive action, whether sensible or intellectual ;
so that if we grant the existence of an intellectual power in
man we shall be unable to deny him an intellectual appetite,
or will, also. As was pointed out, in dealing with the
faculties in general, such a power is not to be supposed to be
a thing in its own right, but is merely the means which a man

272

THE INTELLECTUAL APPETITE 273

uses in striving to attain a desired end, just as the intellect
is the means he uses to unite the object to himself in cogni-
tion. Hence it is not the intellect which knows, properly
speaking, but the man , by its means ; and not the will which
desires, but man, by means of it.

The Nature of the Will.

What, then, is the nature of this intellectual appetite ?
Clearly it is distinguished from the blind direction to parti-
cular ends which characterises the actions of inanimate
things, and also that conscious desire of sensible objects
which is to be observed in the actions of animals, since it
follows neither on the intrinsic tendency of man's nature as
a material being, nor on knowledge which is purely sensible ;
though it is true that he has tendencies which follow on both
of these. We observe that such tendencies in beings other
than man are characterised by necessity ; for a stone
necessarily falls to the ground, and a hungry animal neces-
sarily desires suitable food. This suggests that the same
may be the case with the will. Even though it follows on
intellectual knowledge, not on sense perception, it may
necessarily desire what it thus knows.

Before discussing the thorny question whether the will is
necessitated, it will be useful to notice some points both
about the will, and about necessity, in order to have a
clearer idea of each of them.

In the first place, the will, being the appetite which follows
the intellect, will have as its objects those things which are
the objects of the intellect ; now, however, regarded as
things which are desirable, or good, and not merely know-
able. Since the object of the intellect is being as such, that
of the will will be being in general, regarded as desirable, or
suitable, and this we call the good in general. Similarly, the
object proportionate and proper to the human will is the
good in material things, just as the human intellect is directed
to the being of material things.

With regard to the acts of the will there is clearly a dis-
tinction between those which proceed immediately from the
will itself, such as a particular desire or wish, as was that

274 MODERN THOMISTIC PHILOSOPHY

of Browning when he says : ' Oh, to be in England, now that
April's there ' ; and those which proceed from some other
faculty, though under the influence and direction of the will,
as are, for example, acts of walking and speaking. The
first class are called elicited, and the second sanctioned acts.

Necessity.

Secondly, with regard to necessity, we notice that it may
arise either from an intrinsic, or an extrinsic, cause ; and an
intrinsic cause, being the nature of the thing, such necessity
is called natural necessity ; whereby a thing is obliged to act,
if it acts at all, in accordance with its nature. There are two
extrinsic causes from either of which necessity may arise,
viz. efficient and final causes. If some external agent forces
a thing to act in a certain way, such necessity is called com-
pelling necessity ; while if the thing is obliged to act in a
particular way in order to attain a given end, we have what
is known as hypothetical necessity, since it must so act on
the hypothesis that it wishes to gain this end.

If we now apply these notions to the will, we see that
though the will can be bound both by natural and hypo-
thetical necessity, it cannot be under the dominion of com-
pelling necessity. The reason for the last part of this state-
ment is, that since compelling necessity, by definition, acts
on the will from without, it cannot affect the initiation, but
only the execution of an act of the will, since the former pro-
ceeds from within. Such necessity, then, does not affect the
act at its source, but at most prevents the will from setting
in motion the faculty on which force is exerted. Thus com-
pulsion may prevent a man from walking, but not from willing
to walk ; so that external force, or ' violence,' as S. Thomas
calls it, cannot dominate the will's elicited acts, but only its
sanctioned ones. But if such compulsion as this is impossible,
the will is, nevertheless, necessitated from within, because
whenever it is desirous of some object, it cannot help also
desiring the means which are necessary for its attainment ;
as a man who wishes to be in some place, at a distance, must
also wish to be transported over the distance, and so desire
some means of transport. In this way the will is hypo-

THE INTELLECTUAL APPETITE 275

thetically necessitated. But it is also naturally necessitated,
for it has its own definite nature, and must, therefore, of
necessity, tend towards that nature's end, and obey that
nature's laws. The end to which the will is thus naturally,
and so necessarily, directed is good in general, so that it is
bound to wish for complete goodness, or that which is
suitable to man in every respect, perfecting him in every way
and so giving him complete happiness. To suppose it could
will otherwise than this is evidently an hypothesis which is
contradictory in itself, since then it would will something
which does not suit it, and so, is not desirable, and cannot
be willed.

The will as nature is, no doubt, influenced by the life-
history of the human race, and by inherited tendencies ;
though it should be noticed that such tendencies cannot
alter the very nature, or essence, of the will in itself, since
to do this would be to destroy it altogether ; but can only
modify its actions. Moreover, they cannot modify it to the
extent of never allowing it to act in accordance with its
nature, since this, again, would be equivalent to destroying
that nature.

Though the will be necessitated in the ways we have
mentioned, yet such necessity cannot reach to determining
it to exercise the act of willing either what is entirely good
for the whole man, or thosemeans which are necessarily con-
nected with some willed end ; since the intellect may not
put these before the will ; in which case it will not exercise
the act of desiring them. If, however, they are put before it,
it must desire them of necessity.

Freedom of the Will.

We see, then, that our wills are necessitated, at least to
some extent ; and this leads us to ask whether such necessi-
tation extends to all our volitions, a question which has
given rise to interminable disputes. Dr. Johnson cut short
this discussion in characteristic fashion, by saying : ' All
theory is against freedom of the will, all experience for it.'

Whether this summary of the state of the case is true we
shall soon see, but it is not difficult to understand why this

276 MODERN THOMISTIC PHILOSOPHY

question has so continually engaged the attention of philo-
sophers, for it is one which has a very definite bearing on our
everyday life ; and, in particular, it seems very difficult, if
not impossible, to attach any meaning to the word ' morality,'
if human liberty be denied. How can a man be said to act
rightly or wrongly, to do good or evil, if he is incapable of
acting in any other way, or of refraining from action ? Can
we say that a machine which works accurately is virtuous, or
one which does not, vicious, and so worthy of punishment or
reward ? So, it has always been felt, that unless liberty can
be defended, morality and the essential dignity of man would
be destroyed.

These may, perhaps, be thought to be but sentimental
considerations ; and we ought, then, to view the subject
impartially" in itself, and not merely in the consequences
which a denial of freedom would entail.

Whether freewill exist or not, there can be little doubt
that we conceive of it as a ' power of choice ' ;x and since no
choice is possible with regard to that which presents itself
to us as an end absolutely speaking, it must be a power of
choice of means which are adapted to attain the end in view.
Now such liberty, or immunity from necessity, may be con-
sidered either as it affects action itself, or as it affects the
object of action. So we can conceive of two cases : first, if
the will is not determined to action, rather than the absence
of action, or vice versa — such a state being called by the
Scholastics liberty of exercise, or contradiction — and,
secondly, if the will can desire one or other object of action
indifferently, a state known as liberty of specification — or if
the objects are contraries, of contrariety. An example of
the first is that of a man who is free to walk or not to walk ;
of the second, of one who is free to walk to one place or
another.

History of the Problem.

Such are the preliminary notions which are necessary if we
are to deal with this problem with any lucidity ; for to state
a question clearly is often to go a long way in providing the

1 Ci. Summa Theol., I, 83, a. 4.

THE INTELLECTUAL APPETITE 277

solution of it. That it has not been found easy to make such
a statement will be seen if we glance at the attempts which
philosophers have made to deal with it. The first to treat it
professedly was Socrates, who pointed out that man desires
only the good, from which he concluded that if he wills
what is evil, this must arise from ignorance. Such evil
desires will therefore not be truly voluntary, so that in a
sense he is not free, being determined by knowledge. Though
Plato, by saying that only true science is invincible, while
opinion is a kind of ignorance which leaves the will free to
follow it or not, modifies the Socratic doctrine considerably,
this consideration does not really come to grips with the
problem, but only makes it less difficult to continue to
believe in freedom.

Aristotle, though ' he did not examine the problem very
thoroughly,'1 is, nevertheless, a decided opponent of both
the Socratic and Platonic point of view, since, as he points
out, a man must be held morally responsible for his opinions,
' for what appears good to him,' since he is responsible for
his moral state ; for if he is not, virtue is no more voluntary
than vice.2 So he cannot agree with the saying of Socrates,
' No man is willingly bad ' ; even if his badness be attributed
to his having an opinion, and not science, with regard to the
point in question.

Though none of these theories go very deep into the
question, yet they were of great importance as pointing out
that the centre of the problem is to be found in the nature
of the judgements which precede choice ; and in this way.
contributing to an exact statement of the problem.

The Christian Doctors, generally speaking, assumed the
existence of freewill in man, but as they tried to investigate
its nature they gradually led up to a clear understanding of
the meaning of the question : ' Is man endowed with free-
will ? ' which is formally put by S. Thomas Aquinas.3 The
preoccupation of S. Augustine, and many of these thinkers,

1 Cf. Ross, Aristotle, p. 201.

2 Cf. Ethica Nic, Bk. Ill, Ch. V, 11^3-1115*3.

3 Summa Theol., I, Q. 83, a. 1. For the history of the problem in the
preceding centuries cf. Lottin, La theorie du libre arbitre depuis S. Anselme
jusqu'a S. Thomas D'Aquln. (Publications de la Revue Thomiste.)

278 MODERN THOMISTIC PHILOSOPHY

was rather with the difficulty of reconciling freewill with
grace, and Divine prescience, than with the strictly philo-
sophical question as to the nature and existence of liberty.

Passing to modern times, we are faced in the seventeenth
century with an intellectualist determinism, or denial of free-
dom, whose first representative is Spinoza. Applying to
philosophy the methods of mathematics, which takes no
account of efficient and final causes, he consequently
eliminates these from philosophy, and holds that the same
necessity rules in the realm of being as in that of quantity,
and that all things exist by reason of the mathematical
necessity of the Divine nature, no choice being possible to
God. The seventeenth century also gave birth to another
form of determinism, that of Leibniz, which is known as
Psychological Determinism. In his view, the last practical
judgement, which ends a deliberation, is indifferent in the
sense that it is contingent, i.e. that the contrary, or at least
the contradictory, judgement is possible, inasmuch as it
does not imply a contradiction ; but not in the sense that a
man, in such-and-such circumstances, and being mentally
disposed in a particular way, could form the contrary or
contradictory judgement. To admit this would be, in Leib-
niz's opinion, to deny the principle of sufficient reason.
Hence this last practical judgement is not, as Spinoza would
have it, necessary as a conclusion of geometry is, but is neces-
sary with a moral necessity.

This intellectualism and determinism was followed by a
voluntarist, and indeterminist, reaction initiated by Kant,
who, in the realm of Ethics, to which metaphysics is to be
subordinate, introduced the supremacy of the will over
reason ; an idea which was carried much further by subse-
quent thinkers.

Summary of Opinions.

Thus we see that two extreme opinions confront one
another : absolute determinism, which holds that the will is
always necessitated by something extrinsic to itself, and
absolute indeterminism, which considers that it is entirely
autonomous, its determination not arising from determinate

THE INTELLECTUAL APPETITE 279

rational judgements, but incalculably, from its own hidden
depths. The reasons, in obedience to which it appears to
act, are thus not the true determining causes of its actions,
but only ' excuses,' put forward to make it appear rational ;
the real determination coming entirely from the will itself.
Such a view as this last, even in a modified form, seems, how-
ever, to destroy that liberty which it is intended to safeguard ;
since, if the reason is not guiding and dominant we shall
really be acting on blind impulse, either by instinct, or under
the influence of urges which are perhaps inherited from our
ancestors, and, at any rate, are not under our own individual
control ; since the only thing we can even profess to control
is what is known to us, i.e. our rational judgements. More-
over, if our analysis of the nature of will is correct, it is essen-
tially a rational appetite ; dependent, therefore, on reason,
and, through it, on the senses ; the reason itself being
dependent on these. So everything which influences the
reason will also influence the will as, e.g., suggestion, training,
circumstances and so on. This view is entirely consonant
with our experience of free acts, since we do, in fact, deter-
mine such actions in accordance with the motives which are
put before us. It agrees also with our conception of freedom
of the will ; for we call a man obstinate or pig-headed, rather
than strong-willed, who sticks to a course of action which is
clearly shown to be unreasonable ; while the strong-willed
man is one who does not falter in carrying out a resolution,
formed after due deliberation, but who is ' open to reason,'
as we say. Such a man will modify his action if good reason
for doing so be shown him.

It would be desirable, though it is not possible in a short
summary such as this, to review the development of the
intellectualist and anti-intellectualist points of view, up to
the time when they meet in an identification of liberty and
necessity ; the first maintaining that whatever is right, is ;
and the second that whatever is, is right.1

But, perhaps, enough has been said to suggest that both
eliminate freedom, intellectualism denying it outright ; and

1 Cf. Garigou-Lagrange, Dieu, 5e ed„ pp. 595-601. Sorley, Moral
Values and the Idea of God, pp. 394-423. (C.U.P., 1924.)

280 MODERN THOMISTIC PHILOSOPHY

anti-intellectualism by implication, since it is not we, by the
use of reason, but the facts, the push of nature, the ' elan
vital,' or what not, which are the masters of the situation.

Arguments in Favour of Liberty.

Let us then pass on to see what positive grounds there
may be for asserting that we have the power of choice, being
necessitated, neither by some external force of circumstance,
nor yet by some internal force, whether of nature, making us
subject to natural necessity, or of motive, necessitating us
psychologically.

We have already seen that the will cannot be subject to
compulsion ; and it only remains to enquire whether it is
necessitated from within.1 At this stage, with the object of
making clear the Thomistic argument for liberty, we shall take
it for granted that the will is, as we have already asserted it to
be, the rational appetite, thus subordinated to the intelligence :
' Voluntas consequitur intellectum.'2 We shall have occasion
later to discuss this more fully. Proceeding on this basis,
then, S. Thomas following the lead given by Plato and
Aristotle looks for the source of liberty, or immunity from
necessity, in that faculty which guides and directs the will,
viz. the reason. Liberty will indeed be impossible if the
judgement of the reason which immediately precedes the
definite act of willing is determined of itself, without the
intervention of the will ; whereas, if, at this moment, it is of
itself indifferent or contingent, it will leave the will free to
follow it or not. Obviously, that judgement which is, in fact,
acted upon must be a determinate one ; but, as we shall see,
this determination comes to it, not from the reason as such
but from the will, or rather the whole man.

Freedom, then, must be conceded to us in the degree in
which the judgement which precedes and guides our choice
is, considered in itself, indifferent ; for, in this case, since it
is in essence indifferent, its final determination, removing
this indifference, will come to it, not from itself, but from
something else ; otherwise it would give itself a perfection, a

1 Cf. Summa Theol., 1.19,3 ; 59,3 ; 83,1 ; De Malo, Q. 6, A. 1.

2 Summa Theol., 1.19,1.

THE INTELLECTUAL APPETITE 281

determination, which it did not itself possess. That this
judgement, so considered, is indeed indifferent, is seen if we
consider that man, being in possession of the idea of good in
general, i.e. of that which perfects him, is able to compare
the particular goods presented for his acceptance with this
general idea. So the state of affairs, just before the moment
of coming to a decision, is as if he said to himself : ' What I
desire, since it is that which perfects me, is good, total good ;
whereas this object which is put before me, e.g. a sum of
money, is good and not good, according to the aspect in
which I consider it ; and consequently I am not bound to
desire it, but I desire it from one point of view, though not
from another.' This form of reasoning (which no doubt is
rarely, if ever, explicit) represents truly the state of mind of a
man immediately before his determinate decision and shows
that the foundation of liberty is in the intellect, which knows
the nature of good, and whose judgement is, consequently,
indifferent when confronted with any object, or any act,
which is not devoid of all evil or imperfection. This judge-
ment, being in itself undetermined, cannot therefore determine
the will ; and, if it be true that what guides the will is the
intellect, it remains undetermined by anything outside itself,
and so has mastery over its own act, or is free. Clearly, this
derivation of the freedom of the will from the indifference of
the intellect only holds good for those who admit that the
intelligence is of a different nature to the senses. The
Empiricist, who reduces all ideas to sensible images, and so
denies the possibility of forming a universal judgement,
containing under itself many particulars, must also neces-
sarily deny liberty to man. As S. Thomas says : ' Pro tanto
necesse est quod homo sit liberi arbitrii ex hoc ipso quod
rationalis est.'1 He is guided, not by natural law, as a
stone is in falling, nor by instinct, like the animals, but, in
virtue of the universal range of his intellect, he can compare
the particular good presented, with universal good, so that
he is not determined by the object but by himself. Thus,
we see that the immediate source of liberty is the universality
of the will, resting on the universality of the intellect in

1 Cf. Summa Theol., 1,83,1.

282 MODERN THOMISTIC PHILOSOPHY

action, which is a consequence of its universal nature, of its
spirituality. So that, in the last resort, it is the fact that
man is a spiritual being which causes him to be a free
one.

Before we turn to the consideration of the way in which
man so determines himself, we may mention some other
reasons which confirm our conclusion that he does so. In
the first place, it is clear that to deny freedom is to run
counter to an absolutely universal opinion, for even those
who, in their speculations, deny it, nevertheless always leave
these behind when they go out into the world, and behave as
if they were free. The idea of moral responsibility is universal
also, but how can a man be held morally responsible, and
worthy of praise or blame, who, in fact, is bound to follow a
certain course of action, who is a prisoner in chains which
bind his very soul ?

What purpose, again, could advice serve if we were unable
to revise a judgement we had formed, and so act in a different
way to that which we at first intended ? Moreover, by
introspection we see that we do indeed ' make up our minds,'
as we say, how to act ; at the very moment of action we
can change our decision, and even while action is in progress
we can cease from acting, or even begin to act in a contrary
way.

The Limits of Liberty.

If, then, we have such freedom, what are its limits ?
First, in order to have freedom at all, we must have liberty,
both from compulsion by an extrinsic cause, and from
necessity or determination arising from our intrinsic nature,
since actions which proceed from our nature as men are not
under our power. What nature bids us will we cannot but
will, whereas it is essential to a free act that we should have
power over it. Such unloosing of bonds as this is evidently a
minimum requirement for freedom, but, in fact, it is not
enough, if we are really to have mastery over our acts. We
must here introduce a distinction which we shall find useful
more than once, that between active and passive indifference.
By active indifference we mean the power to produce or not to

THE INTELLECTUAL APPETITE 283

produce certain acts, while by passive indifference we mean
merely the capacity for receiving various determinations.
Bearing this in mind, we see at once that freedom implies
active, and not merely passive indifference, for a passive
capacity cannot exert mastery, being potentially at least,
under the dominion of that which determines it. Active in-
difference must then be added to the minimum requirement
for freedom. Nor is this all, for we have seen that the object
towards which the will is directed must be such as does not
determine its action, and the subject which wills must be such
that it can will or not will an object. So, again, in our
minimum requirement we must include both objective and
subjective indifference, of which the first will, of course, be
present if the object is not wholly desirable, but contains
good and bad elements, and the second, where the subject
has the power of choice.

Such being the minimum of indifference which is required
if there is to be freedom at all, we may naturally ask also
what is the maximum of liberty which is possible. It appears
from the analysis we have made of freedom that there can
be no liberty of specification except with regard to particular
goods which have not, at the moment of willing, an evidently
necessary condition with the acquisition of total good, since
it is clear that total good, or entire happiness, must be pre-
ferred to all else ; there being no aspect of it which can
appear displeasing to us. Hence when it is presented to us,
if we will at all, we must will this, and cannot will anything
else ; so that here we retain liberty of exercise1 only. Even
this liberty is very limited, for though it is true we can judge
that it is better, at any given moment, not to consider our
complete happiness, or to consider it, yet, at the same time,
we cannot will anything whatsoever without virtually
desiring to be happy. Thus, on the one hand, there must be
active indifference in the will in order that there may be
liberty at all ; but, on the other, liberty of specification is by
no means always to be found in free acts, often we have
liberty of exercise only. Such freedom as this, however, is
sufficient to ensure that the will should be free, and never

1 Vide p. 276.

284 MODERN THOMISTIC PHILOSOPHY

disappears entirely, except in the case of intuitive knowledge
of absolute good.

Within these limits, then, we may take it as established
that we have freedom, in so far as we are not determined
either by our own nature or by the object itself, since the
final judgement of a deliberation is, considered in itself,
indifferent, inasmuch as it presents the object to the will as
partially desirable and partially undesirable.

Views on the Nature of Liberty.

Is anything more than this indeterminate judgement
required in order that we may actually choose ? This
question brings us to the discussion of the views which are
taken as to the nature of liberty. These are, in fact, of two
opposing kinds, for, on the one hand, we have those who say
that human liberty consists in this, that since the final
practical judgement relates to a partial good the will is in no
way necessitated by it, and so, where the intellect judges
that two objects are equally good, or even that one is less
good than the other, the will can, without further direction
by the intellect, choose either of the two equally good
objects ; or even, in the other case, that which is judged to
be less good. This view of liberty, known as liberty of
indifference or equilibrium, has been held by many eminent
Catholic thinkers, notably by the Molinists and Suarez, as
well as by Scotus. On the other hand, in resolute opposition
to this opinion, that, in the last resort, the election made by
the will is not dependent on the motives put before it by the
reason, we find the adherents of Psychological Determinism
who say that it is impossible to explain how an absolutely
undetermined cause, such as the will is, in the Molinist view,
can produce a determination. As Leibniz himself says :
They ' (i.e. the Molinists) ' were asked not only how it
would be possible to know to what an absolutely undeter-
mined cause would determine itself, but also how it would be
possible that there should not finally emerge from it a deter-
mination of which there would be no cause.'1 Nevertheless,
Leibniz, and his followers, maintain that human action is

1 Leibniz, Essays on Theodicy, I, Sect. 48.

THE INTELLECTUAL APPETITE 285

still free, inasmuch as it deals with objects which are in
themselves contingent, so that it is possible to conceive with-
out contradiction of a man acting in a way different to that
in which he does, in fact, act ; though, at the same time, he
cannot, at any given moment, choose to act in either one or
other of two contrary ways, since he is predetermined to
act in one only by ' an infinity of great and small internal
and external movements, which for the most part pass
unnoticed.'1 The conception of liberty presented thus by
Leibniz is that of a purely theoretical liberty : in fact, all the
actions of our lives from the cradle to the grave could not be
otherwise than they are, being predetermined in the states
which immediately precede them, and so follow necessarily
from them ; though they are not themselves necessary
events, but contingent ones. That this is Leibniz's meaning
is seen from the fact that in dealing with divine foreknow-
ledge he is able to dispense both with the ' scienta media ' of
the Molinists, and the divine decrees of the Thomists, and
maintain that God foreknows free acts, solely in the causes
which will produce them. They must, then, be pre-
determined in these causes.

If we now turn to the opinion of the Thomists on this
question, we find them in partial agreement and partial dis-
agreement with both parties ; for they agree with the Molin-
ists that freedom is destroyed if the will, at the moment of
choice, is determined either to act, or not to act, by causes
outside its control, whether these be rational considerations
or internal dispositions ; while they agree with Leibniz that
it is impossible that the will, faced by two equal goods
should choose one rather than the other, unless some new
motive intervenes. They maintain, therefore, that nothing
is willed unless it is first known as suitable to the subject,
that an uncaused determination of the will is impossible ;
and along with this, that the last practical judgement of
the reason is not determined in itself, so that the will must
intervene in order to determine it. Thus they wish to
uphold, as against Scotus, the principle of intellectualism,
the subordination of the will to the reason ; and, as against

1 Ibid., Sect. 46.

286 MODERN THOMISTIC PHILOSOPHY

Leibniz, the determination of the reason by the will. They
think, moreover, that adherence to both these propositions
is forced upon us by the analysis of the act of choice, and not
by any consideration of expediency.

Nevertheless, at first sight, it seems as if this position were
an impossible one. Thus Suarez contends that these two
propositions are mutually incompatible, since the act of the
will which determines the practico-practical judgement must
itself be determined by another judgement, in virtue of our
principle : ' Nil volitum nisi precognitum ut conveniens,' and
one which is determined in itself, since we cannot have an
infinite series of these subordinated acts of the will and the
intellect. Thus, since we maintain liberty to be a fact, we
must abandon our assertion that the will follows the lead
of the intellect always, and assent to his theory of liberty of
equilibrium. So he does not hesitate to write : ' Si voluntas
in omnibus sequatur ductum intellectUs destruitur libertas.'1

He therefore considers that if we cling to the principle of
intellectualism, we are driven to determinism, while if we
allow that the will itself determines the judgement of the
intellect, we must accept the theory of liberty which he
favours, and abandon intellectualism. The Leibnizians would
agree with this view that there is no middle road between the
indeterminism of the liberty of equilibrium and their own
psychological determinism.

The Answer to Indeterminism. Liberty of Equilibrium
Excluded.
Eminently logical though this verdict appears to be, the
answer to it will be found in the very principles of intellec-
tualism itself, of which the first, viz. that all the acts of the
will are formally determined, or specified, by the intellect,
seems almost too clear to need justification. For how can
the will, which is of its essence not cognitive, know any good
and so be attracted to it, unless the good is first put before it
by a faculty which does know. The will cannot judge what
is practically preferable, since it has no knowledge at all, of
itself : it must depend on the intellect for knowledge of the

1 Cf. Suarez, Dis-putationes Metaphysicce, Disp. XIX, Sec. 6.

THE INTELLECTUAL APPETITE 287

characteristics of the objects presented, and for judgement
that one is practically preferable to another. This judgement
cannot be given in favour of the less good of two objects, nor
yet for one, or other, of two which the intellect judges to be
equally good. If, then, it must be given for the better, it is
the intellect which formally determines or specifies the will
which, as has been well said, is like a blind man who uses the
eyes of a paralytic in order that he himself may walk,1 as he
might do by pushing him in a Bath-chair. Though we may
use such a simile as this, it is worth while reiterating the
warning, already given, against succumbing to the tendency
to which we are so prone — the tendency to substantialise, or
even personify, our faculties. For the truth of the matter is
that man by his intellect moves himself to will, and by his
will moves himself to understand. Unless this essential
unity of the subject be always borne in mind, we cannot
hope to understand the interplay of the faculties. The will,
then, being non-cognitive or blind cannot see for itself which
of two actions is better, but must have its object put, as it
were, into its mouth, when it will find it desirable and be
attracted to it. But, it will be urged, this is plain deter-
minism, for, in this case, it is not the will itself which chooses,
but its choice is already determined for it by the intellect,
independently of it. If it were true that the intellect comes
to its determination independently of the will, the conclusion
would certainly follow ; but it is not true, for we are here
dealing with a judgement concerning what is desirable, here
and now, for a particular man, not what is theoretically
desirable in the abstract ; and it follows that no decision
can be come to as to this, without taking into account the
whole concrete state of the man by whom the particular
object is to be desired. So S. Thomas, and the Thomists,
constantly assert that this practico-practical judgement,
unlike speculative ones, derives its truth, not from con-
formity with the thing, but from conformity with the sane
or healthy appetite. Now man is a being whose will is, of its
very nature, directed towards the plenitude of goodness,
towards absolute good, and so no extraneous influence,

1 Sertillanges, S. Thomas d'Aquin, Vol. II, p. 231.

288 MODERN THOMISTIC PHILOSOPHY

whether of reason, passion, or habit can force it to desire
any particular good. These influences will incline it in one
direction rather than another, but can never necessitate it.
Thus the very constitution of human nature dictates that
the intellect should specify, and formally determine, the will,
since this latter is blind ; and that the will itself should
determine the judgement of the intellect with respect to what
it desires here and now ; the intellect by itself being able to
judge only in the abstract, and so to form an interdeter-
minate judgement ; so that the man can only say : ' This
in the abstract appears preferable ' ; not, ' This is to be
desired by me here and now,' which can only be settled by
the will which desires.

We are not, however, at the end of our difficulties, for if
the intellect must determine the act of the will and the act
of the will must determine the judgement of the intellect, we
seem to be involved in a vicious circle. This is not so,
nevertheless, for it is one and the same act of the will which
determines the practical judgement, and is itself determined
by it, though in different respects. This all happens instan-
taneously, so that it is not the will which first determines
the intellect, and then the intellect the will, nor vice versa.
There is no priority of time of one determination to the other,
but both occur simultaneously. It is a case of the mutual
causality so often spoken of by Aristotle, and the axiom :
' causes which are causes of one another belong to different
genera of causality,' finds its application here. So we have
seen, in Cosmology, that matter determines form by limiting
it and making it individual, while at the same time form
determines matter, limiting it and making it specific. Simi-
larly, the soul moves and determines the body, giving
direction to its actions ; and the body, at the same time,
moves the soul, determining, by its physical constitution,
i.e. here and now in the concrete, how these actions are to be
carried out. In the same way, mental ability is required in
order to learn, and learning increases mental ability. This
mutual anteriority of two causes to one another is to be
found wherever there is life, and indeed, wherever there is
movement, as by running an engine it becomes less stiff, and

THE INTELLECTUAL APPETITE 289

by becoming less stiff it is helped to run. Here, then, at the
point when the last practico-practical judgement is about to
be made, the will applies the intellect to judge determinately
what is to be done, and receives thereby from this determinate
judgement, so instantaneously formed, the guidance and
determination of the intellect in choosing that this is to be
done. This may perhaps be compared to the action of the
driver of a motor car, who switches on his headlights in
order to see where to steer the car, and in doing so his motion
receives formal determination from the light which he him-
self has caused. Thus the last judgement is not merely and
wholly intellectual, but contains a large admixture of
volition ; for if of the two partial goods proposed in the
deliberation which thus ends, the will chooses one ; it only
does so, and puts an end to the deliberation, when one or
other of these goods sufficiently appeals to it, and suits its
taste, for it to be satisfied with it. The goodness of the
object is judged in relation to the appetite which it attracts.
We thus avoid altogether the vicious circle in which we
seemed to be involved, and with it the theory of liberty of
equilibrium ; for we can and indeed must affirm, that just
as an artist cannot work unless he first determines his
action by the idea of the work to be executed, so the will
cannot act unless it first be determined by the intellect, so
that in all its actions it follows the lead of the intellect, and
therefore the liberty of equilibrium is at once excluded. And,
similarly, just as the artist's idea does not exercise its deter-
mining effect on his action, unless he actually, by acting,
uses it as directive in his action, so the determination of the
intellect is only effective in making the will dependent on it,
if the will itself, by its own action, enters into this relation
of dependence on the intellect. The same act of volition
which thus follows the judgement, in a certain sense also
precedes it, there being relative priority, from different
points of view, of the acts of the intellect and will, with
temporal simultaneity.

290 MODERN THOMISTIC PHILOSOPHY

The Answer to Psychological Determinism. The Theory of
Leibniz Excluded.
It still seems, nevertheless, that if the will determines the
judgement in this way, putting an end to the deliberation,
it must do so because it is itself in a certain determinate
state, and so could not choose otherwise : in such a way that
a man placed twice in precisely the same circumstances,
which include both exterior ones and interior dispositions,
could not, in one case, decide to act, and in the other not to
act. If he did so, it appears, his action would be without
sufficient reason, unmotived, irrational and so not human.
We have only extricated ourselves from liberty of equili-
brium to fall into the clutches of psychological determinism.
In what has been said, in setting out the principles of
intellectualism, the solution of this difficulty is already to be
found, for though it is certain that the will must have a
sufficient reason for determining the intellect, such sufficient
reason cannot absolutely and infallibly determine it. This
is clear from the very nature of the will which is completely
satisfied by, and, of its nature, tends towards nothing less
than the acquisition of total good. Consequently, no partial
good can have an invincible attraction for it ; and no
amount of interior or exterior impulses, so long as they are
finite, can do so. They will incline it, perhaps with great
force, to act or not to act, but can never necessitate it to do
one or the other. The motive, then, which is finally accepted
by the will, and which determines it, is relatively sufficient,
i.e. in relation to the will itself at that particular moment,
but it is not absolutely sufficient ; seeing that the range of
the will is universal, as wide as being itself. When the choice
is about to be made the will, of its own power, deterfnines
the judgement, which thereby determines the act of the will.
The acceptance, or not, of any particular motive depends,
then, on the gratuitous motion of the will, and this in turn on
the state of the will at that moment. The motive in itself
is powerless to force itself upon the will, and demand that it
be accepted, and the intellect, which can judge in the
abstract that such-and-such an action is advisable or not, is

THE INTELLECTUAL APPETITE 291

powerless to decide whether it is that one which is acceptable
to the will in the concrete, and here and now. This applies
in all free acts, acts which are rational, being determined by
the reason, but free, since, unless the weight of the will's
own power comes to supplement their force, they have not,
of themselves, the power to attract it invincibly. This is
clearly seen in relation to the act of faith, where the reasons
for making it are cogent ; but it depends on the will itself,
here and now, whether it will accept them, and make them
its own reasons. ' Qualis unusquisque est talis finis apparet ei, '
says Aristotle,1 ' it is because we are persons of a certain
kind that we put before ourselves such-and-such an end ' ;
and, at any moment, we are persons of a certain kind by the
self-determinations of the past, and by the non-necessitated
acceptance of a self-determination here and now. It is not
necessitated, since it does not satisfy our desires wholly, but
partially only, so that it is in our power to accept it, or turn
aside ; and thus, if we accept it, we determine ourselves,
and are our own masters ; which is to be free. It is in this
very continuous self-determination of the unified self that
freedom essentially consists ; the man, as a whole, ruling
himself by reason and will, determines his own course of
conduct, and is captain of his soul.2 To be dragged from
such dominion over himself by circumstances, passion, or
error is, so far forth, to forfeit this dominion ; and for this
reason, just as none would allow that vacillation and a
wavering purpose is essential to liberty, so the Thomists
have always maintained that freedom to sin is no integral
part of freedom, but only a sign of it. Just as illness is a
sign of life, or a limp possible only to one who can walk, so
also a man could not sin unless he were free. A healthy
animal, however, is more alive than a sick one, and a sinless
man who masters himself, by a sane reason and a healthy
will, is more free than one who does not ; but allows himself
to be dominated by impulses not so controlled.

It follows also from our principles that a man who not
only did not sin, but who was incapable of sinning, would be

1 Ethica Nicomachea, Bk. Ill, Ch. V, 111^23.

2 Cf. Sorley, Moral Values and the Idea of God. Ch. XVII, esp. pp. 436 S.

2Q2 MODERN THOMISTIC PHILOSOPHY

free in the highest degree ; for we have seen that the end
and object of the will is true good, while liberty is the power
to choose means which are in accordance with this end. It
will, therefore, clearly be most perfect where there is no
power of choosing means which are discordant with the
attainment of true good, i.e. where there is no power of
sinning. This, the theologians tell us, is the state of those
who have immediate knowledge of Good itself, which is God.
It belongs to the perfection of liberty, as S. Thomas points
out,1 to be able to choose among different things which lead
to the desired end ; but to its imperfection to be able to
choose those which lead away from it. Where, then, there is
no power of sinning there is none of choosing any means
which will lead away from the acquisition of true good, and
thus the imperfection of liberty is eliminated ; its perfection,
or the power of choosing among the means which will lead to
it, being maintained. For just as when we wish to go from
place to place, we may suitably choose to travel by train, by
car, on foot, or by some other means, similarly, in seeking
goodness itself we should be wholly free in choosing among
the means of acquiring it, even if we were quite incapable of
choosing anything which diverted us from it.

For freedom of use does not imply freedom to misuse ; and
is indeed greater in proportion as the chance of misuse
diminishes. So a barber who was incapable of making a slip
— if we can conceive such a marvel — would use his razor
much more freely than one who was not ; and, in fact, with
perfect freedom.

These considerations are sufficient to show .us that the
power to sin is no necessary part of freedom ; its presence
in us is a sign, but still more, a defect of liberty. Thus Von
Hugel, who so constantly and emphatically affirmed this
truth says : 'To be able to do, to be, evil is a defect, a restric-
tion of liberty. . . . We should feel humbled, not only by
our actual sins, but already by the fact that we can commit
such things.'2

1 Summa Theologica, I, Q. 62, a. 8, ad 3.

2 Von Hugel, Selected Letters, p. 317. Cf. Essays and Addresses (Second
Series), p. 203.

THE INTELLECTUAL APPETITE 293

S. Augustine finely sets out this doctrine when, to the
assertion of Julian that man could not be capable of his
proper good, unless he were capable also of evil, he replies :
' Say rather that man's nature was first made capable of
good and evil, not that it could not become capable of good
only ... so that if he had not sinned when he could sin, he
would have come to that blessedness where he could not sin.
For each is a great good, though one is less, the other
greater. For it is less to be able not to sin, greater not to be
able to sin.'1

Just as a man now is free, though unable to will anything
except in so far as it appears to be good, so he would be
wholly free if he could not will anything except in so far as it
was in truth good. It is for this reason that S. Augustine
also says : ' Multo liberius erit arbitrium quod omnino non
poterit servire peccato.'2

There is one last point to which reference must be made
before we close this consideration of liberty. We have said
that the will in choosing has a sufficient motive, but one
that does not infallibly determine it. But is not this to assert
a contradiction, for how can the will be determined, and yet
not infallibly determined ? It seems that this is both to be
determined and not to be determined. Now we have already
seen that in order to account for movement and multiplicity
we were bound to assert the existence of a not-being, which,
in a certain sense, is, viz. potency ;3 so here, the fact of the
relation between universal good and particular goods forces
us to assert the existence of a determination which does not
actually determine us, but is only able to do so. For it is
precisely on these particular goods that the will bears, and
since there is indetermination in its object, there must be
also indetermination in the will. So S. Thomas' teaching
on liberty joins up with the great central thesis of his philo-
sophy, the division of finite being into potency and act.
This division is demanded by the facts of multiplicity and of
movement, and both the will of man, and its objects, must

1 Opus Imperfectum contra Julianum, Liber V, LVIII. (Opera Omnia,
ed. Cong. S. Mauri, Tom. X, 939 F.)

2 Enchiridion Fidei, c. 105.

8 Cf. Cosmology, ' Discussions on Motion and Individuality.'

294 MODERN THOMISTIC PHILOSOPHY

share in this indetermination of finite being. This is a
doctrine which has its roots deep down in the teaching of
Plato and Aristotle ; and which is found at every stage of
S. Thomas' presentation of the ' philosophic/, perennis.'

It will be useful to summarise the results arrived at in
this chapter :

i. Man is free, since the judgement presented by the reason
for his acceptance is never absolutely determined in itself,
owing to the disproportion which exists between total good,
the adequate object of desire, and the partial goods which
are made known to us by the judgement.

2. Nevertheless, all the actions of his will are formally
determined by the judgement, so that the theory of liberty
of indifference, or equilibrium, is excluded : the judgement
which determines the will owing its determination to the act
of the will itself.

3. This strange fact is due to the unity of man's conscious
life ; for that is desirable to a particular man which suits
his particular state here and now. This can never be decided
by the intellect, judging, as it were, in the abstract, but only
by the concrete desire of the will.

4. This concrete self-determination of man is not a neces-
sary consequent of his antecedent states, which, though
affecting him, cannot infallibly determine him to choose one
of two partial goods in preference to the other, since such
goods are both equally incapable of satisfying his unlimited
yearnings for absolute good. Thus psychological deter-
minism is excluded by the domination of the will in action,
over the intellect in judging. So man, by his will, is master
of his judgement, and, under the guidance of judgement,
so mastered, is master of himself.

Psychological determinism neglects the unity of the self,
forgetting that a motive only becomes a motive for me here
and now, if I desire it to be so, if I adopt and accept it.
Indeterminism, on the other hand, makes the will, an
incalculable force which interferes with the guidance of
reason, and turns it from its normal course without reason.
Such irrational willing could not be freedom, but merely the
emergence of some blind impulse, an impulse which is not

THE INTELLECTUAL APPETITE 295

under the man's control. In neither of these ways can man
be his own master, but only by the control of the will by the
intellect, and of the intellect by the will, of the whole man by
himself.

The more such freedom is developed the more will conflict
and strain be eliminated ; and, if its development were
fully achieved, a man would be in possession of the un-
fettered exercise of a good will, whereby, without deviation,
he would uniformly desire only his true good : to serve
which is to rule.1

1 For the whole of this subject the following may be consulted :
Garigou-Lagrange, Dieu, Son existence et sa nature, 2e partie, Ch. IV.
Sertulanges, S. Thomas d'Aquin, Tom. II, Livre VI, Gh. I— III. Cf. also
Sorley, op. cit., Sect. 17. Ward, The Realm of Ends, Lectures 13 and 14.

CHAPTER XIV

THE NATURE OF THE INTELLECTUAL SOUL IN MAN

Its Substantiality — Its Spirituality — It is the Substantial Form —
Simple — And One Only — Differing Specifically from that of
Other Animals — Reasons for this View.

In the three preceding chapters we have seen something of
the way in which the mind of man works ; and we now pass
on to enquire what information we can gather, from our
conclusions as to its working, with regard to its nature.
What sort of thing is this mind, or intellectual soul ?

The phrase ' mind or intellectual soul ' by its very
ambiguity at once suggests a question as to the nature of
the intellectual principle in us, viz. is it merely a mental
power, or is it something substantial ? — for mind may mean
either mental powers, or a substantial principle of such
powers. Our first question, then, is whether there is a sub-
stantial principle of our intellectual powers. The idea that
there is not some principle which is capable of producing
thoughts and retaining them, but which does not itself
require to be produced or retained by any other principle —
in a word, that there is not a substantial principle of intellec-
tual operations — would hardly occur to common sense.
Nevertheless, many philosophers have held that there is in
us no substantial mind, but only a series of mental acts.
Such a view must necessarily be taken by those who deny
altogether the possibility of affirming the existence of any
substance, as do the Phenomenalists, e.g. Hume and Taine.
In accordance with this view, the Associationist Psychology
was developed, to give some sort of account of our processes
of thinking, and, if possible, some plausibility to the idea of
thoughts without a thinker. Though Associationism finds
little, if any, acceptance among modern psychologists, the

296

INTELLECTUAL SOUL IN MAN 297

phenomenalist point of view is still prevalent. The denial
of the substantiality of the human mind is not confined to
the Phenomenalists, for in Monist theories, such as those
of Spinoza and Hegel, though the substantiality of mind is
not, in a sense, denied, nevertheless, the mind which they
recognise is either the Divine mind, in the case of Spinoza,
or the Absolute, in the case of Hegel. Human minds are but
an aspect or phase of these.1 Consequently, such philo-
sophies in no sense allow the substantiality of the individual
mind of man.

The main stream of philosophic thought has, on the other
hand, always considered that common sense is, on the whole,
right ; and so has recognised that psychic phenomena, such
as thoughts and volitions, need some substantial subject,
which, owing to its capacity for supporting itself, is enabled
to support them also. In the Platonic tradition this subject
is called the soul.

This view of the matter is surely true, for how can we con-
ceive of thoughts, volitions, etc., which have no subject to
support them, since they are actions, and an action sus-
pended in the void is quite inadmissible. Just as it is
impossible to have motion without something which moves,
so also it is impossible to have thought without a thinker, or
willing without a subject who wills. Moreover, consciousness
tells us, not only of the presence of thoughts and volitions,
but also that it is I who think, feel, will, and so on. Hence
this ' I ' remains permanent beneath the changing pheno-
mena. If I, the man, am but a series of phenomena, with the
passing of the phenomena, I should also pass away. But
consciousness tells me that I endure. Thus, to say : ' I think,
feel, will,' etc., is to testify that there is not merely a multi-
tude of thoughts, volitions, etc., but that there is a single
principle of them all. Further, such statements, expressing,
as they do, a most clear conviction of consciousness, show
that these phenomena cannot be attributed to any particular
organ, or part of us, to the exclusion of the rest, but must be
attributed to us as a whole, i.e. to some substantial principle
in us.

1 Cf . Stace, The Philosophy of Hegel, pp. 439 ff.

298 MODERN THOMISTIC PHILOSOPHY

It might, perhaps, be suggested that the support which
such phenomena necessarily require is merely the material
organism. This, however, cannot be true, since the organism
is not in itself a unity, but is composed of a multitude of
diverse parts ; and, moreover, it is not fixed and permanent,
but constantly changing, so that after a time it is entirely
renewed. It follows, then, that the substantial principle
must be something distinct from the body considered in
isolation, or that the soul of man must be substantial,
unifying the body.

We may add that if the soul were nothing but a succession
of phenomena, memory, the conviction of the continuity of
the Ego, and the feeling of responsibility become inexplicable.
No reason could then be assigned why any thought, feeling,
or desire, should be connected with any other.1

If, then, we recognise, with common sense, that there is
in man a substantial principle of psychic acts, or a soul
which is substantial ; we shall naturally wish to discover
something concerning its nature. Such an enquiry can
evidently be carried out only by philosophy ; it is one
which is beyond the scope of experimental science, the inner
nature of a substance not being amenable to experiment.
Hence, experimental psychology rightly excludes such con-
cepts as the simplicity or spirituality of the soul. Such
exclusion should not, however, lead to denying these or other
attributes to the conscious subject, in fact such a denial
would be as much beyond the sphere of natural science as an
affirmation of them would be.

If man is indeed in possession of intellect and will, as we
have maintained, it follows at once that the substantial
principle of these powers must also be intellectual, since they
derive from it. Further, we have seen that this intellectual
power in man is an immaterial one, though dependent on
matter — i.e. on the body and the senses — in order to act ;
in other words, it is one which is extrinsically dependent on
matter, though not intrinsically, and subjectively in its own
nature. The same, then, must also be true of the source of

1 So Ward, Psychological Principles, pp. 34-41, and McDougall, Outline
of Psychology, pp. 39 ff., affirm that we are obliged to recognise a ' conscious
subject ' as ' an indispensable hypothesis.'

INTELLECTUAL SOUL IN MAN 299

intellectual power, viz. the soul, which will, therefore, also
be spiritual in this sense.

The principle of life in man, which we call the soul, must
necessarily be of the nature of form, that which makes a
thing what it is, since it is in virtue of the soul that man is a
living intellectual being ; and since it is substantial, it will
be his substantial form. Like all other substantial forms, it
will not have quantitative parts of itself ; and we have seen
reason to believe that the souls of the higher animals, among
whom no doubt man must be reckoned, have no quantitative
parts, even owing to their union with the body, and so are
indivisible. We should conclude, then, that the human soul
is quantitatively simple from our previous considerations,
but we have now learned, in addition to these, the fact that
it is spiritual, and so must be unextended ; extension being
an attribute of the body, not of the spirit ; and consequently
from this point of view also, we are led to affirm that the
human soul is simple. But even if the intellectual soul be
thus in itself spiritual and simple, it might be maintained,
it seems, that there is more than one life-principle, or soul,
in man. A little reflection will shew that this is impossible,
for not only would this destroy the essential unity of the
individual, since each life-principle must be a substantial
form, so that any such principle, after the first, must
form an accidental union with the already constituted com-
pound ; but also it is clear that vegetative, sensitive and
intellectual life mutually help or hinder one another,
which could only be the case if they all proceed from
one and the same principle. So sensitive and vegetative
life are conditions sine qua non of intellectual life, and
they, in turn, are guided and preserved by means of the
intellect. We observe also that an intensity of action in
any one of the three spheres results in diminution of activity
in the others ; thus intense action of the senses, or vital
organs, hinders mental operations. In the reverse order,
intense mental activity leads to insensibility, generally
partial, but in exceptional cases, complete ; as in the self-
hypnotism practised by the fakirs.1

1 An account of some instances of such self-hypnotism is given by
Dr. William Brown in Philosophy (1931), pp. 215 ff.

3oo MODERN THOMISTIC PHILOSOPHY

So far we have considered the nature of the soul, in itself
and intrinsically, and we have seen that it is substantial,
spiritual, simple, and not accompanied by other life-
principles in a single individual. We must now ask what is its
relation to the life-principles in other animals. Is it of the
same kind as these, or does it differ specifically from them,
in such a way that we can assert that no animal, other than
man, has an intellectual soul ? We shall be obliged to
recognise a specific distinction if we find that in the life of
man we have a positive addition of perfection, or actuality,
and not merely a development, or increase, of powers which
are possessed by animals lower in the scale than man. It is
clear enough that the possession of intrinsic independence
of matter, as contrasted with intrinsic dependence on it,
will constitute a distinction of this kind, if it be established ;
since here we should have a positive addition of immateri-
ality, or of actuality ; for what is of itself dependent on
matter cannot develop into something which it is not, i.e.
something independent of matter ; so adding to itself a
positive perfection or actuality, for which it has no capacity,
and which is, indeed, excluded by its very nature.

We have already seen the evidences of such independence
in man in his capacity for forming universal and so
immaterial concepts, in his freedom, and in the unlimited
range and scope of his intellect. To these we may add
further signs, such as his capacity for progress, and his
power of speech.

His freedom, as we saw, is rooted in his capacity for com-
paring the particular goods proposed for his acceptance with
universal good, and in the last resort in his spirituality, as is
also the distinctive way in which his mind works in the
formation of universal concepts. Capacity for progress,
which man possesses, is but a consequence of this, for it is
obtained by means of reflection, envisaging the end to be
aimed at in general, and then comparing the various means
which might be used to gain it. Consequently, it is a sign of
the universality or immateriality of that mind which is the
source of progress. The power of speech again is an indica-
tion of the immateriality of the mind of the speaker ; for

INTELLECTUAL SOUL 1^ MAN 301

speech is articulated sound, composed of arbitrary symbols
which are designed to express concepts. Speech, therefore,
implies that the speaker has concepts to express, and indicates
the existence of thought, even though it may sometimes, as
has been suggested, serve to conceal thoughts.

Do we, in fact, find any evidence of the existence of these
indications of intellectuality and immateriality in other
animals than man ?

This, no doubt, is a disputable question ; and to answer
it fully would require a minute observation and examination
of the actions of all animals. Clearly, such an enquiry is
far too extensive to be undertaken here, if indeed it can be
undertaken at all. Nevertheless, if we look at the matter
impartially, uninfluenced by any presupposition, either in
favour of, or against, the evolutionary hypothesis, we shall
see that there are a number of converging probabilities which
all point to the conclusion that animals, other than man,
have not that immateriality which we are obliged to ascribe
to human beings.

In spite of the keen and wide observation of animal actions
in recent years, no definite evidence of freedom has been
discovered in them. Though it is true that when confronted
with particular material obstacles to action they may modify
their action to some extent, yet there is no indication that
this arises from any abstract consideration of the problem,
but can be wholly accounted for by a power of combining
sense images.

It is not in dispute that, normally, each class of animal
has its own determinate way of acting which never varies ;
' every swallow,' as S. Thomas says, ' building its nest in the
same way.' Each species has its own definite mode of
breeding, nesting, and feeding, from which it deviates little,
if at all. There is thus : ' no evidence that it ever does, or
makes anything according to a plan of its own.'1 It shows
none of the signs of freedom.

Similarly, no progress is observable among animals, such
change as there is, not being initiated by themselves, but

1 Cf. Ivy Mackenzie, Aristotelian Society's Proceedings (1927),
pp. 275 f.

302 MODERN THOMISTIC PHILOSOPHY

coming about from nature and circumstance, not of their
own intention. No doubt they can learn, but only within
very narrow limits, in so far as they associate particular
sensations with particular acts. Nowadays, this fact is
explained by the theory of conditioned reflexes ; but what-
ever explanation be accepted, the fact of their lack of initi-
ative and progress is certain.

Do animals speak ? Certainly they communicate their
emotions to one another by cries and sounds of various
kinds, but there is no shred of evidence that they have any
conventional system of articulate sounds ; in fact, since
here, again, we find stereotyped sounds which differ in each
species we are justified in concluding that their ' speech ' is
fixed for them by nature, and not by themselves. Talking
animals are a figment of the imagination of romantic story-
tellers and are only to be found in fairy tales, not in nature.
The absence of conventional speech has the advantage that
they cannot lie, as man can.

From every point of view, then, we may conclude that it
is as certain as such a thing can be that animals have not a
mind and soul of the same immaterial kind as man has.

If this be so we once more find ourselves in the presence of
two grades of life which are distinguished by an essential, a
specific difference, and not merely a difference of degree. As
living things differ from inanimate ones, as animals from
plants, so also do men differ from the other animals. No
evidence is forthcoming that animals are possessed of an
abstractive universalising faculty such as the human intel-
lect is ; but the progress of investigation shows them, even
more clearly than common observation had done, as confined
to particular objects of knowledge, and very limited in their
modes of action even with regard to these. That the higher
animals, at least, have a kind of intelligence, no one would
deny ; but it does not appear to be of the kind which sees
the meaning in things, but merely that which is able to
observe that certain objects are desirable and useful to them
here and now. Human beings, perceiving the meaning of
objects, are not tied to the concrete, the particular, the
material, and so in them there is a definite increment of

INTELLECTUAL SOUL IN MAN 303

immateriality, actuality or perfection over and above that
found in the other animals.1

The intellectual soul of man is not, however, divorced
from his material organism, but is evidently intimately
connected with it ; which brings us to the question of the
nature of this connection.

1 Prof. Julian Huxley, though a decided opponent of the ideas here
advocated, goes so far as to assert that ' there is no evidence at present
that even the highest animals possess ideas, or even images.' (Essays of a
Biologist, Essay II : ' Biology and Sociology,' p. 97, 1923 edition.) He
quotes in support of this view Thorndike, Animal Intelligence, New York,
191 1, and Washburn, The Animal Mind, New York, 1913.

CHAPTER XV

THE UNION OF SOUL AND BODY IN MAN

Views on the Question — Monism — Psycho-physical Parallelism —

Accidental and Essential Union — Reasons for the Thomist View

The Mode of the Union — How the Soul is Present to the Body.

The question of the union of soul and body is, no doubt,
a very perplexing one, for if there is such union we must
assert that the material and the immaterial, the qualitative
and the quantitative, the necessary and the free are one.

In the few pages at our disposal we can give no adequate
account of all the theories on this subject which have been
advanced ; but it is necessary and possible to see what are
their general types.

In the first place, we may cut the knot by denying that
there is any union, inasmuch as there are not two entities or
entitative principles to unite but one only. This one may
be either the body alone, or the soul alone ; the first being
the solution of materialistic monism, which alleges that mind
is either a form of matter, or an appearance of matter, while
the second is the view of idealistic monism, according to
which matter, and body, is an illusion. In the materialistic
theory, mind or soul is something we construct owing to our
ignorance of the workings of material forces, and so is an
illusion like the dryads, river-gods, and other spiritual forces
which were supposed, by primitive peoples, to direct the
operations of nature, operations which we now know to be
the result of material forces only. Idealistic monism, on the
contrary, holds mind to be the only reality, and what we call
matter but a projection or shadow of mind.

In both these theories the problem disappears ; but
neither accords with common sense, since no one would
naturally suppose, either that thought and consciousness

304

UNION OF SOUL AND BODY IN MAN 305

are simply some kind of bodily secretion, nor yet that he had
no body at all. If it be recognised, then, that there are, in
fact, two realities in man, body and soul, it may still be
denied that they are united, in which case they continue in
company, side by side, but without affecting one another.
How this unfailing concomitance is to be explained it is
difficult to say, but it seems that it would have to be attri-
buted to some kind of Pre-established Harmony.

These seem to exhaust all the possible ways of solving the
problem of union by denying that body and soul are united.
If, then, we allow that they are united, their union may be
either essential, if they form one nature, or accidental, if
they merely act on one another, while remaining in them-
selves distinct. This last type of view seems very natural
to us, and has in fact been widely held, both by ordinary
men and by philosophers, such as Plato. It is somewhat
difficult to see how such diverse things as mind and matter
could, in fact, act on one another ; but the chief objection to
this theory is that it breaks up the essential unity of the self,
so destroying human nature altogether. If consciousness
tells us anything about ourselves, it is surely this, that we
are unities ; not a soul which is imprisoned in, or hovering
about, a body with which it is not connected by nature ; or,
rather, to which it is by nature opposed. Neither body nor
soul can be said to be the individual man, so that if they do
not form one nature together, the man himself disappears.
This difficulty is expressed in William de Morgan's
epigrammatic lines :

' John has a soul.' Upon the whole
The tombstone lies which says ' Hie jacet.'
But if John really has a soul,
What in the world is John who has it ?

It seems, then, that we are bound to assert that soul and
body together form one nature ; that the union between
them is an essential one. This is the view expressed by S.
Thomas and constantly adhered to by the Thomists, in spite
of the fact that the Platonic view, according to which the
soul finds only a temporary home, or prison, in the body is

306 MODERN THOMISTIC PHILOSOPHY

clearly more easily reconcilable with the Christian doctrines
of immortality and resurrection.

Scotus, who followed the Platonic and Augustinian tradi-
tion, thought that there are in man two substantial forms,
that of the body, the form of corporeality, which makes it a
specifically human body, and gives it existence as such ; and
the soul-form, which is a substance in its own right ; while
at the same time he maintained that the union of the soul
and body is an essential one. If by substantial form we
mean that act by which a thing is constituted in its specific
nature and distinguished from others, it seems impossible to
see how essential unity can, in this hypothesis, be maintained;
for if the body is constituted as a body by the form of cor-
poreality, it cannot be given its nature by the soul since it
already has it ; consequently, the soul cannot be its sub-
stantial form, but must be an accidental one, and the union
will be accidental. If, on the other hand, we do not mean by
substantial form that which gives specific substantial nature
to a thing, then we must acknowledge either that the body
never has such a nature, or that it receives it from something
other than the form of corporeality, which consequently will
be unable to do more than add something to a body already
constituted as a substance ; in which case it is clearly an
accidental form, and the union is once more an accidental
one. We are, in fact, back again in our old dispute about the
plurality of forms, about which enough has already been said.

It is not our business, however, to discuss the Scotist
opinion, but to explain that which the Thomists hold. The
latter, both on the grounds of observation and introspection,
as well as on account of the logic of their system, feel obliged
to assert that the body has no form of its own, but is immedi-
ately informed by the soul, which is, therefore, not a com-
plete substance, but the actual element in the composite
human substance. This position, it may be noticed, is not
unaccompanied by difficulty ; since, according to the
fundamental principles of Thomism, it is impossible to have
numerical differentiation of any specific form except by the
reception of this form in matter. Hence, it seems that when
union with the body ceases at death, the soul will either not

UNION OF SOUL AND BODY IN MAN 307

survive at all, or if it does, will be merged into a universal
soul, losing its individuality. S. Thomas was unable to
accept either of these consequences, whether as a philosopher
or theologian, and he points out that the relation of form
and matter being a transcendental one,1 which arises from
the very nature of the related terms, so long as either of them
remains in being, it will retain its relationship to the other.2
If, then, the soul survives death, it will not cease to be
individual, but will retain, as part of its very being, that
essential relationship to the body which it had before its
severance from it.

In order to establish the strictly essential character of the
union of body and soul, the Thomists point, in the first place,
to the observed actions of human beings ; and they notice
that some of them are, in their origin, common to both soul
and body. Such are anger, fear, and, in general, the emotions,
as well as all sensation, since, as we have seen, this is organic,
and so only possible as proceeding from body and soul in
conjunction. Now, though it is true that two principles of
action might produce a single resultant action, as the motion
of a wagon might be the single result of the pull of two or
more horses, yet it is impossible that one and the same action
should issue from more than one source of action, since the
action of a thing is the consequence of its powers and so of
its form ; so the two essentially distinct principles of action,
two forms, must produce actions which are also distinct,
though they may combine in a common effect. Hence a
single common operation cannot proceed from two essen-
tially distinct principles, and emotion and sensation, being
such operations, their principle, the human being, must also
be essentially one.

Further, similar considerations to those which led us to
conclude that animals are essential unities will be applicable
to the case of man. For here, again, we find that all the
operations of mind, and of the several organs of the body,
tend to the preservation and well-being of the organism, or
individual, as a whole ; the parts of the body, under the

1 Cf. S. Thomas, Contra Gentiles, II, c. 81.
* Cf. Vol. II, General Metaphysics.

308 MODERN THOMISTIC PHILOSOPHY

influence of life, adjusting their actions in such a way that
the normal functioning of the organism as a whole may not
be impaired. If, then, both bodily and mental actions
naturally tend to the well-being of the whole man, rather
than to that of any particular part ; not to their own good,
but to the good of the whole, we are justified in concluding
that this is due to the fact that man himself, body and soul,
is a single nature, an essential unity. For the natural
tendencies of a thing are but the expression of its nature, so
that the end to which a thing tends must correspond to the
principle of its operations, which is its nature. If, therefore,
various operations all tend constantly to a single end, this
must be because it is their nature to do so, which nature
must thus be common to them all, and so a single remote
principle of them all.

We may here mention very briefly some further considera-
tions which strengthen our conclusion. In the first place,
we attribute all our actions, whether of mind or body, to
one and the same self ; and say : ' / think, love, hear, see,
feel, grow,' and so on. Consciousness, therefore, bears
testimony to the fact that soul and body form a single nature.
Again, we fear death, the dissolution of the union of body
and soul, a fact which finds no ready explanation if soul and
body are joined only accidentally, or not joined at all, as
Psycho-physical Parallelism suggests. According to these
theories, it seems that we should ' dread the grave as little
as our bed ' ; but we do not, and if our thesis is correct,
ought not to do so.

The modern alternative to our theory is that of parallelism,
which denies the causal influence of mind on body, and vice
versa. Both these denials are faced by grave difficulties, for
if body does not act on mind, how are we to account for
sensation, which is certainly mental ? On the parallelist
theory, it must arise from some mental cause, and no such
cause is discoverable, either in my own previous mental
states — for which among them can cause me to have sensa-
tion, e.g., of some sudden sound ? — nor in the action of any
other mind. Again, if mind does not act on body, we must
deny the influence of thought and volition on our bodily

UNION OF SOUL AND BODY IN MAN 309

movements, such as walking, which seems fantastic ; and
all handicrafts, and artificially constructed articles must
be attributed simply to bodily motions without any inter-
vention of thought or intention.1

It will be seen that though, from one point of view, the
Thomist theory of the union of mind and body may be called
an interaction theory, in so far as each exerts causal influence
on the other ; nevertheless, since they are said to be united
in a single nature, such causality is not to be understood as
that of two complete beings, of different kinds, on one
another ; as would be, for example, the action of a pure
spirit on a material object. Soul and body are so interwoven
that there is something of the body in the nature of the soul,
and something of the soul in the organisation of the body.
Human nature is something greater than either soul or body,
and embraces them both. This idea is emphasised, and
worked out, in the view which the Thomists hold as to the
mode of their union, for they consider that the soul is, of its
nature and without any intermediary, the substantial form
of the body.

It is clear that it must be the body's substantial form, and
not an accidental one, if the two are to form one nature, this
being the very meaning of substantial, or essential, union as
opposed to accidental. Moreover, it is by the soul that man
is made a living, sentient and intellectual being ; and so, by
it, he is constituted in his specific nature and distinguished
from others, to do which is the office of substantial form.
Again, it is the principle of being, which also is due to sub-
stantial form ; for in living things to live is to be, and since
the soul is the principle of life, it is also that of being. It is
also the principle of action, for human actions are vital ones,
and the soul, as the life-principle, is, therefore, their source ;
and so the substantial form in man.

Neither can there be, in addition to the soul, some sub-
stantial form which informs the body, as such ; and which
is subsumed under the form which is the soul, for we have

1 Space does not allow of a full discussion of these theories, but the
reader may be referred to Broad, The Mind and its Place in Nature, pp.
113-117 ; McDougall, Modern Materialism, Ch. Ill ; Hobson, The Domain
of Natural Science, pp. 67, 355 f. ; Driesch, Mind and Body.

310 MODERN THOMISTIC PHILOSOPHY

seen that it is impossible to retain essential unity if there is
more than one substantial form1 since the first form would
constitute the body as a substance, so that it could not be
made so by the soul, which, therefore, could add to it no
substantial, or essential, perfection, but only an accidental
one ; and so would be joined to it accidentally. The same
consideration also applies to the view, recently put forward,
that the chemical elements in the body retain their own
specific natures, and so their own substantial forms, even
when they are parts of man's body. If this were so, a man
would be a mere conglomeration of material elements, all
essentially distinct, but, in some unexplained way, under the
influence of the soul. There can be no question of there being
such a thing as human nature in this case ; nor, since the
chemical elements must, a pari, be also considered as essen-
tially composite, of any specific chemical nature ; but all
those differences in kind which we thought we found in the
world of nature will be done away with. So true is it that
unless we preserve essential unity we cannot have essential
diversity : the many are impossible without the one. Again,
we are at the very heart of the Thomistic view of the universe,
which refuses to reject the many for the one, or the one for
the many ; but, in the successive increments of actuality
which it observes to be added to the potentiality of matter
in the ascending scale of material things, clings firmly to
variety in unity, specific variety in the unity of being, and
individual variety in the unity of species. The only alterna-
tive to this view they consider to be some form of Monism ;
all things being either some undifferentiated matter, or all
some undifferentiated form or act. It is because they reject
with all possible emphasis, on the basis both of experience
and consciousness, such views as these, that they insist so
untiringly on the unity of form in the individual.

If, then, we admit that the soul is the one substantial form
of the body, giving their specific nature, as human, to all its
parts, we see at once the mode of its presence to the body ;
since it must be clearly be present to the whole body, making
it human, and to each part of it. The whole of it must thus

1 Cf. Cosmology, Ch. X, Q. i, pp. 129 fi.

UNION OF SOUL AND BODY IN MAN 311

be present in the whole body, and in each and every one of
its parts — in contradistinction to the way in which one
extended thing is present in another, e.g. when a bottle is
filled with beer, the whole of the beer is in the whole bottle,
but not in each part of it. It does not follow that all the
soul's powers are exercised in each part of the body. In
fact it is obvious that this is not the case, for the soul cannot
exercise the whole of its power in every part of the body,
as the legs cannot be used for seeing, or the eyes for hearing ;
while no part of the body, nor the whole of it, is fitted to be
the instrument of intellectual operations, of thinking and
willing.

Such essential presence is, evidently, not circumscriptive,
a mode of location which belongs only to bodies ; nor yet
definitive by means of operation, since the union of soul and
body is essential, but definitive by means of information ;x
so that the soul is tied, by its very nature, to the place which
the body occupies, and cannot, at the same time, be also in
another place.

1 Cf. Cosmology, Ch. VI, Sect. I, esp. pp. 81 f.

CHAPTER XVI

THE ORIGIN AND DESTINY OF THE HUMAN SOUL

Origin — Not by Generation or Emanation, but by Creation — The
Transmigration of Souls — The Thomist View of the Succession
of Forms in the Individual — Immortality — Opinions — Reasons
for Thomist View — The Metaphysical Argument.

The soul, then, is spiritual and simple, and yet, at the same
time, it has an essential relation to the body, forming one
nature with it. What light do these conclusions throw on
its origin and destiny ?

First, with regard to its origin, we observe that the soul is
a form, and a special kind of form, viz. a spiritual one :
which is independent of matter in its nature ; so that this
nature cannot have been derived from matter. In the case
of the forms of other animals, where this special considera-
tion did not apply, we saw that it was not necessary to postu-
late any other cause of them than the vital powers of the
parents ; so that their generation belongs entirely to the
material order ; but, in the case of man, this cannot be so,
since that which is generated is a being which, as far as its
form is concerned, is a spiritual one. The cause, then, of a
human being must be at least as spiritual as this being
itself. Such a cause might be either the child's parents, or
God. As for the parents, they are doubtless, in any event,
the cause of the child's coming to be, for even if they do not
generate the soul, they do produce the body which is essen-
tially related to it ; and since the term or result of any
generative process is neither matter nor form in disjunction
from one another, but the compound of the two, that agent
will properly be said to generate the compound which is
the cause of uniting a new form with matter. This is pre-
cisely what the parents do, since by forming a body which is

312

THE HUMAN SOUL 313

fitted to receive, and actually requires a human soul to
inform it, they cause the union of matter and form to come
about. It is not necessary, therefore, in order to maintain,
as we certainly must, that parents generate their own child,
to say that they produce its soul from their own sub-
stance. In fact, if we were to suppose that they did so, we
should, if we grant that the soul is immaterial, find ourselves
in an impossible position. It seems quite clear that it could
not be produced by their purely physical or bodily powers,
since it has a nature of a higher order than these. Nor yet
could it be produced by their souls or spiritual powers, since
the souls of the parents are indivisible. Since they have no
parts, the souls of the children could not be parts of them,
or divided off from them by emanation. Thus, the spiritu-
ality of the human soul debars us from saying that it is
produced by the parents. It appears, then, that its
production must be due to some other spiritual cause.
We might conceive such a cause bringing the soul into
being either by emanation from itself, or by way of
creation ; i.e. making it to be, without drawing it out
of itself, or of any other pre-existing being. The emana-
tionist hypothesis cannot be entertained for the reason
just given, viz. that spiritual beings are indivisible, and
so cannot separate anything from their own substance
by way of emanation. It might be suggested that an infinite
being of this kind could, without such separation or in other
words, with the entirety of its being, be itself the spiritual
principle of all men. This idea, apart from the fact that it is
clearly pantheistic, is excluded by the other aspect of the
human soul, the fact that it is the form of the individual
man, and so limited and finite, as the correlative of a finite
body. Consequently, it could not also be an infinite spirit.
No other hypothesis, therefore, remains, with regard to the
origin of the human soul, than the creationist one. We shall
see later that such an act of creation, the absolute beginning
and production of some being, cannot be effected by any
finite cause ; and, if this be true, we must conclude that
human souls are created by an infinite spiritual being. Such
an infinite being is commonly called God. The Scholastics

314 MODERN THOMISTIC PHILOSOPHY

are thus in general agreement in asserting that the human
soul comes into existence by means of creation by God.

Even if this be accepted, we should wish to know when this
' infusion ' of the soul into the body, this coming into it
' from without,' of which Aristotle speaks,1 takes place.

The doctrine that the soul is the form of the body, so having
an essential relation to this individual body, and to this only ;
excludes two notions as to the way in which it comes to be
in it, viz. by metempsychosis, and by passing into it after a
previous existence. The first view, the theory of the trans-
migration of souls, has been, in the past, very widely
accepted ; and even to-day is held by many, as by the
Theosophists and the Hindus. Plato took over the idea
from Pythagoras, who may himself have derived it from
Orphism. It maintains that one soul may pass through
many bodies, both of animals and men.2 If, however, it be
true that soul and bodv really form one nature, standing to
one another in the relation of potentiality to act, it will be
impossible for a soul, or act, which is thus essentially related
to one body, to become essentially related to another,
without parting with something essential to it, and so, at
least breaking its actual continuity. In fact, it cannot so
change essentially, being a simple nature or form, and must
therefore continue to be related to one body, and one only.
The doctrine of transmigration is, therefore, compatible
with Platonism, where the union of the soul and body is
looked on as accidental, but not with Aristoteleanism, in
which the body derives its nature from the soul, giving to it,
in turn, individuality. Such a relationship as this can,
evidently, not be destroyed so long as the soul continues in
existence. The supposition that the soul exists before the
body is also seen to be gratuitous and bizarre, if their
relationship is such as S. Thomas holds it to be ; for the
soul's natural being is in the body, and if it existed before its

1 De Generatione Animalium, II. 3 ; 736b28. Aeiirerai 34 rbv vovv ixbvov
Ovpadev iireiaiivaL kclI Oelov elvai ixbvov.

2 Cf. Taylor, Plato : The Man and his Work, p. 308 ; Stace, Critical
History of Greek Philosophy , p. 217. See also the interesting account of the
history of the doctrine, and of the light-hearted way in which it was
treated by Plotinus, in Dean Inge's Philosophy of Plotinus, Vol. II, pp. 29-
36.

THE HUMAN SOUL 315

union with the body it would do so in a state of frustration,
unable to fulfil its natural function ; and without any
spiritual or intellectual activity, such as it would have if it
continues to exist after separation from the body, since it
would not naturally have acquired any knowledge in the
pre-existing state. Under these conditions it seems almost
impossible to attach any definite meaning to the question :
did the soul exist before the body P1

S. Thomas, as is fairly generally known, held a view of a
contrary kind, viz. that what, by a process of evolution,
becomes the human body existed, prior to its becoming so,
in the two lower orders of life, the vegetative and the sensi-
tive. Beginning its life with a vegetative form or soul, as
organisation increases and advances far enough to make the
foetus capable of sensitive activity, a corruption and a
generation taking place, the body receives a sensitive, and
with further development an intellectual, or human, soul.2
He thus admits specific evolution, or development, within
the individual, under the influence of a higher power, i.e.
human life, or the souls of the parents ; these in turn, as he
points out,3 being, like all the activities and powers of nature,
subordinated, as instruments, to the power of God. The
principle which leads to this view is that matter must be
proportionate to its form, and so, in this case, the body must
be sufficiently organised to be a fitting correlative of the
intellectual soul, before it is informed by it. Whatever may
be thought of the truth of this view,4 it no doubt harmonises
well with the modern way of envisaging the development of
life through the ages ; though embryology seems to show
that sensitivity is present in the human foetus very early, if
not from the start.

Whether we accept this view, or hold that the soul is
infused at the moment of conception, our conclusion that

1 Cf. S. Thomas, Contra Gentiles, Lib. II, Chaps. 83 and 84.

2 Summa Theol., I, Cj. 118, a 2, ad 2.

3 Contra Gentiles, II, Ch. 89.

4 For a discussion of it from a philosophical point of view cf. Hugon,
Cursus Philosophies Thomistica, Vol. Ill, pp. 199 ff. Its theological
aspect is dealt with in the Diet, de Theologie Catholique , art. " ame," Vol. I,
Cols. 1306 ff., and Vol. VII, Col. 846. Cf. also Mercier, Psychologie, Vol. II,
PP- 339-34°-

316 MODERN THOMISTIC PHILOSOPHY

the parents really generate their children, will not be
affected, since the earlier life-principles will be but forms
whose raison d'etre is to lead up to, and prepare for the
coming of, the human soul. Thus in either view the parents
prepare the body, and make it proportionate to this soul.

We can, then, take it as proved that the human soul
originates by means of creation, and is not produced by any
kind of conception of it by the parents, whether spiritual or
physical ; and, further, that it does not exist before union
with the body ; though the supposition that it does so does
not seem to be absolutely impossible. Moreover, it does not
pass from body to body, since it is the form of this particular
body. What, then, becomes of it when it is separated from
the body at death ? Does it cease to exist altogether ? So
we find ourselves brought naturally to the question of the
immortality of the human soul, a question which, like that
of liberty, and for a similar reason, has always been in the
forefront in philosophical discussions : for it is vital to us,
and not merely a matter of curiosity, to give an answer to it.

We shall, therefore, not attempt to give an account of
the history of this question of survival, as this is impractic-
able in a short space ; but it is necessary to glance at some
of the principal answers to the questions : can and will the
soul survive death ?

First, there are, of course, those who deny the possibility
of survival altogether, inasmuch as they think that life is
essentially of the material order, and simply disappears when
the organism ceases to function normally.1 Few, perhaps,
adopt an attitude quite so intransigent as this, but rather
say that it is more probable that life altogether disappears
at death. These profess to hold this only as an opinion, but
actually they hold it so tenaciously that it is, for them, rather
certain than probable.2 If, on the other hand, it is allowed
that there is some survival after death, we find no agreement

1 So one of the materialists picturesquely asserted that it is as im-
possible for the soul to exist without the body as it would be for the flame
of a candle to exist without the candle.

2 Cf. E. S. P. Haynes, The Belief in Personal Immortality. In spite of
his profession of open-mindedness, it seems clear the author regarded the
belief as an illusion.

THE HUMAN SOUL 317

as to its nature ; and in particular there is a great difference
of opinion on the question whether such survival is a per-
sonal or impersonal one. It may, perhaps, be said roughly
that those who do not adhere to the Platonic and Christian
tradition, as Spinoza, hold the latter view, while Christian
philosophers adhere to the former. It is further supposed by
some that those, who in life devote themselves to material
and temporal interests, will cease to be when these interests
cease, while those who live the higher life of the spirit will
survive. ' We are what we love and care about.'1

The Thomistic doctrine is very definite, for it regards the
soul of every human person as being of its nature indestruc-
tible, so that survival does not depend on its own activities
during life ; and, moreover, since it is also by nature a finite
form, it must survive as such ; and so, not as absorbed into
the divinity, or in any collective fashion.

In support of their contention, modern Thomists use
arguments of many different kinds ; which may perhaps be
grouped under two heads, moral and metaphysical. Such
is the general agreement of mankind as to the fact of sur-
vival, a belief which is found at all times and in all races ;
the necessity for the rigorous enforcement of the moral law,
or the supremacy of the good and the true over evil and
irrationality.

This last argument must take the form that the purpose
of the moral life is unattainable if death extinguishes life
entirely. If, then, we recognise the absolute claim of
morality, so that we feel certain that, whatever fails, right
must endure and prevail, we shall be forced to recognise
survival after death as the necessary condition for the fulfil-
ment of this claim. No one who perceives at all clearly the
fundamental notions of Thomism will be in any doubt as to
the conclusions a Thomist must come to as to the perman-
ence and absolute claim of moral good ; for, as we have seen
all along, the intellect is, in their view, of its nature directed
to nothing less than being as such, the entire range of
reality ; and the will satisfied with nothing less than infinite
good. Such good is permanent if anything is, and being

1 Inge, The Philosophy of Plotinus, Vol. II, p. 25.

318 MODERN THOMISTIC PHILOSOPHY

infinite, unattainable under the finite conditions of this life.
Again, it is central in the philosophy of S. Thomas to judge
of the nature of a thing from the end to which it tends, or, in
S. Thomas' phrase, by its ' natural desires.' Such desires
cannot be fruitless, incapable of satisfaction, for if they were
the nature which, as a nature, tends towards their fulfilment,
would clearly be tending to nothing and so not towards their
fulfilment. It would therefore be and not be that nature.
Desire, moreover, follows and is proportionate to knowledge,
so that since man by his intellect grasps universal and per-
petual being, and so, of his nature, desires it,1 such perpetual
existence must be attainable by him.2 Such arguments as
these, no doubt, need much fuller development than we are
able to give them here if they are to strike the mind with
their full force ; but even in this skeleton form it can be
seen that they are not lightly to be dismissed.3

Let us now turn to the argument which is par excellence
the metaphysical argument for the immortality of the soul.

We must first consider the ways in which anything can be
corrupted or destroyed. This may come about owing either
to some extrinsic or some intrinsic cause of corruption. It
comes from intrinsic corruption when there are in the thing
warring elements which seek to oust one another from it, or,
at least, dissociable elements. Examples of the first are to
be found in gasses which remain stable only under the
influence of some external force, or pressure ; of the second
in all chemical compounds. Another type of intrinsic cor-
ruption is that which occurs as a consequence of something
on which there is dependence being corrupted ; as the sight
fails when the eye is injured, or a picture is destroyed if the
canvas rots. Now neither of these modes of corruption can
affect the human soul ; for since it has no parts, whether
quantitative, since it is not extended ; or essential, since it is
form only and not a compound of form and matter, it is

1 On this question of natural desire Fr. O'Mahoney's book, The Desire
of God in the Philosophy of St. Thomas Aquinas, may be consulted with
much profit.

2 Cf. Contra Gentiles, L. II, Chaps. 55, 59 ; Summa Theologica, 1.76,6.

8 For a lucid and full exposition of the first argument cf. Taylor, The
Faith of a Moralist, Series I, Lect. 7, pp. 281 ff.

THE HUMAN SOUL 319

obvious it cannot have any contrary or dissociable elements
within it, and so is immune from the first kind of corruption.
It is, in fact, impossible to suppose that the unifying prin-
ciple should not be itself a unity. This indeed applies to
all forms, which are all of them acts, and not a compound of
act and potency, and yet we have seen that some of these
are divisible with the division of the matter which they
inform. This second kind of corruption and division cannot,
however, affect the human soul, for as we saw again, it does
not depend on the matter which it informs for its existence,
but being in itself immaterial or spiritual, exists in its own
right and independently. A material thing is corrupted
when its form is separated from matter, but an immaterial
thing cannot suffer this fate, since it is form, and form cannot
be separated from itself. Thus, we see that neither in itself
does the soul carry any seeds of death or corruption, being
simple life ; nor yet can it be destroyed by the corruption
of the body on which it never depends for existence.

But even if it is thus in itself intrinsically incorruptible,
may it not be annihilated by the cause which gave it being ?
The introduction of this question shows that no finally
satisfactory solution of our problem can be arrived at without
acknowledging the existence of such a cause of being, viz.
God. Not only does it seem that immortality without God
would not be desirable ; but also, that unless the soul is
dependent for its being on a source which is altogether per-
fect and infinite, immortality could not be secure. The finite
cause and power which brought it — if by an impossible sup-
position it could create — into being might fail to preserve
it, whether through malice, caprice, or lack of power. To
attribute to God, on the other hand, the purpose of annihi-
ating the souls He had created, is an impossible supposition.
Though it is true He has the power to annihilate, as to create;
nevertheless, the exercise of this power is excluded by His
essential perfection and wisdom ; since it is incredible that
all-wise and all-knowing Being should deprive His creatures
of the nature which He has given them. This is precisely what
He would do if He were to annihilate intellectual natures,
since they are essentially not subject to corruption, but have,

320 MODERN THOMISTIC PHILOSOPHY

in virtue of their nature, perpetual being. Such a suggestion
must be particularly repugnant to those who are so attached
to the inviolability of natural law that they are unwilling
to allow that God can even suspend its operation. To
deprive a soul of immortality after endowing it with an im-
mortal nature would be an inconsistency even more flagrant
than would be the endowment of material things with a
nature which necessitates their coming together, in accord-
ance with the law of gravitation, and then preventing them
ever coming together in this way.

In the Summa Contra Gentiles,1 S. Thomas gathered
together a great array of arguments which all tend to prove
the truth of personal immortality for man, and we may con-
clude this short indication of some of them, by reminding
ourselves that what properly speaking perfects a man is
itself incorruptible, viz. the knowledge of eternal truths,
and the free but undeviating practice of virtue, which
certainly is not material. The incorruptible cannot perfect
the corruptible, or the immaterial what is essentially
material ; but a perfection must be proportionate to that
which it perfects, an act to the capacity for that act. We
cannot, then, suppose that man belongs essentially to the
temporal order with its change and corruption, but his nature
finds its true perfection in a life eternal and incorruptible,
where intellect and will find their full development, ever
satisfied and never satiated.

1 Lib. II, cc. 55, 79.

CHAPTER XVII

THE ORIGIN OF LIFE

The Origin of Life on Earth — Opinions — Spontaneous Generation —
Two Forms of the Theory — Their Possibility.

Having now investigated the three great divisions of animate
nature, we are in a position to survey it as a whole. We have
seen, in connection with each of them, that these three
species of living things are composed of individuals who, in
every case, act with an intrinsic tendency towards the
preservation and well-being of the living individual as a
whole, such actions originating with the life-principle
within them. Further, it has been established that through
the whole range the individual living thing is an essential
unity, and that, as between the three grades of living things,
there exist specific or essential differences. Thus we see
that the Aristotelean definition of the soul or life-principle
which we mentioned at the start — the soul is the first act of
a physical organic body — is fully justified.

If these results as to the world of animate nature be taken
as established, we still have left two questions which relate
to it considered as a whole : first, how did life originate ?
and, secondly, what are the relations between its different
manifestations ?

The first question, which is to be discussed in this chapter,
is concerned primarily with the origin of life on this planet ;
and though, from the point of view of biological science, life,
if it is allowed to be of a different nature to non-living matter,
may have to be accepted as an ultimate datum, as to the
origin of which no significant question can be asked ;x yet,

1 As is asserted by Dr. Johnstone, The Philosophy of Biology, pp. 340 f.
He says : ' The problem of the origin of life, an it is usually stated, is only
a pseudo-problem ; we may as usefully discuss the origin of the second
law of thermodynamics ! If life is not only energy but also the direction

321

322 MODERN THOMISTIC PHILOSOPHY

from the point of view of philosophy, this is not so, since it
cannot be supposed that life, as we observe it, is ultimate in
the order of being. In the same way, a physicist does not
enquire how natural laws, such as that of entropy, i.e. the
second law of thermodynamics, came into being, since these
laws (indicating the natures of things which obey them) are
taken as ultimate ; but the same is not true of the philo-
sopher who must try to discover why nature is governed by
such laws, in other words, to penetrate behind the laws to an
understanding of the natures themselves which obey them ;
so that he can properly ask what the origin of these laws is.

If, then, we ask how life originated on this earth, there are
four possible answers : (i) that it did not begin, but was
eternally present ; (2) that it came to this planet from some
other part of the universe where it was eternally present ;
(3) that it arose by spontaneous generation from inanimate
matter ; (4) that it arose by creation.

As to the first view, this is clearly impossible since we know
that the earth is itself not eternal, but had a beginning.
Moreover — and this consideration disposes of the second
view also — by asserting its eternity we do not answer the
question as to its origin, for even if it were supposed to be
eternal it would, since it is not self-sufficing and necessary,
but dependent and contingent, still require a source from
which it eternally proceeded, so that we are no nearer to a
solution of the problem of its origin.

The second view encounters, moreover, another insuper-
able objection, inasmuch as the assertion that it came to
earth from some other part of the universe does not solve
the question of its origin, but only puts it one stage further
back. It is interesting, however, to notice that this view
has been held by many eminent men. It seems to have first
been put forward by de Month vault in 182 1, and was
developed thirty years later by Count Keyserling, who held
that life, like the world, is eternal, but from time to time

and co-ordination of energies ; if it is a tendency of the same order, but
of a different direction, from the tendency of inorganic processes, all that
biology can usefully do is to inquire into the manner in which this tendency
is manifested in material things and energy-transformations. But the
tendency itself is something elemental.'

THE ORIGIN OF LIFE 323

changes its habitat. He thought that it passes through the
universe in the form of living germs. Some thought these
germs were brought to us in cosmic dust or comets, while
others, as Count de Salles-Guyon, Lord Kelvin, and Helm-
holtz supposed them to have come in meteorites. Since,
however, the germs must come not only from the planets,
but from the stars, they must be supposed to be incom-
bustible, and even if it were conceded that this marvellous
property might be possessed by some very minute germs,
yet the minutest germs are destroyed by ultra-violet rays.
The theory is therefore unacceptable from every point of
view. 1

Turning to the third hypothesis, we find that it had a
longer and more honourable history. It was, in fact, the
universal belief of men of science till the first part of the
seventeenth century. Aristotle held that the more imperfect
animals, such as parasites, were spontaneously generated by
warmth, without the intervention of any living thing. This
view was also held by S. Thomas.2

The first doubts seem to have been raised by Francesco
Redi (1626-1697), who showed by experiment that no living
organisms appeared in the flesh of a dead animal if it were
carefully protected from the entry of living germs from
without ; but he was not so successful in the case of parasites,
whose origin was not established till the nineteenth century.
The chief of the experimenters of this time was Louis Pas-
teur, who showed that all putrefaction and many kinds of
fermentation are due to the presence of microscopic living
organisms ; while Tyndall showed that absolute sterilisation
of infusions could be attained by intermittent applications
of heat. These discoveries led to the general acceptance of
the law of biogenesis, which does not, as is sometimes sup-
posed, assert that every living thing does, or still less must,
originate from another living thing, but only that there is no
known instance of living organisms arising from non-living
matter. Whether under conditions widely different from

1 Cf. Perrier, The Earth before History, pp. 61 ff.

1 Cf. Aristotle, Met., 1032a 27 ; S. Thomas. Comm. in Met. (ed. Cathala),
1400, 1401 ; Summa Theol., I, 105, 1, ad 1 ; I, 71, 1, ad 1 ; I, 72, ad 5.

324 MODERN THOMISTIC PHILOSOPHY

those which come under our observation, this could happen,
must necessarily be, from the scientific point of view, a
matter of simple speculation, since the only scientific
method of deciding the question, that of observation and
experiment, is clearly not available. Consequently, any
dogmatic assertion that under such conditions life did, in
fact, arise from non-living matter must be considered to be
unscientific.1 Many attempts, however, have been made to
find some positive justification of it ; of which the most
famous, or perhaps notorious, is that of Haeckel, who pro-
duced some of the ocean slime as the primordial living sub-
stance, to which Huxley, who at first accepted it as genuine
protoplasm, gave the name of Bathybius Haeckeli : i.e.
Haeckel's Low-life. Huxley later identified it as being only
a mineral precipitate of gelatinous appearance, which arises
when distilled alcohol is poured into sea-water containing
organic matter in suspension, and so essentially a non-living
substance.2 Haeckel, however, persisted in his defence of it ;
and an attempt has been recently made to rehabilitate it.
Nevertheless, it is true to say that the production of the
living from the non-living, or abiogenesis, as at present
occurring, finds no definite positive support in modern
scientific investigation. This, of course, leaves the question
of the possibility of such an occurrence an open one ; and a
decision with regard to it can only come, if at all, from the
side of philosophy. Now, with regard to this possibility,
two hypotheses present themselves for discussion : first,
that life was originally produced by a fortuitous combination
and disposition of inorganic matter, or that such matter was
combined and arranged and life produced under the influence
of some cause of another order ; of what S. Thomas calls an
analogous cause, which is in itself superior to the effects
which it produces.

It may be stated at once that most modern scientists3
incline to accept the first hypothesis as a result of their

1 As, for example, that of Perrier : ' What we are unable to achieve
was done spontaneously in the beginning.' The Earth before History, p. 66.

2 Cf. Perrier, op. cit., p. 59.

3 Cf. Philosophy (1932), art. by Prof. J. Johnstone, p. 293. Cf. also
Jeans, Mysterious Universe, pp. 6 ff.

THE ORIGIN OF LIFE 325

general physical conceptions. Though they admit that the
coming of life by such a chance combination of atoms is a
highly improbable event, in the sense that the chances
against its occurrence are enormous, yet they do not regard
it as inconceivable.1 In this belief they take for granted that
life is not essentially different from inorganic matter ; as is
shown by such assertions as that it is ' just as conceivable
as would be the " spontaneous " segregation of, say, a litre
volume of gas into two regions, one of which had a much
greater density than the other one.'2 Evidently, no new
nature would appear in such a segregation, and if ' spon-
taneous generation ' is just as conceivable as this, it will be
so only if no new nature appears in such generation, or if
animate and inanimate matter are of the same kind. As,
then, we are unable to accept this presupposition, neither
can we accept the conclusion that spontaneous generation,
due to a chance combination of atoms, is conceivable,
though improbable. According to the view which we have
been led by our consideration of living things to accept,
these possess, in addition to the properties of inanimate ones,
various perfections which the latter do not possess at all,
such as the acts of nutrition, growth, and reproduction. It
is here not a question of mere difference of properties, but of
a positive addition to them, so that the living thing possesses
the properties of non-living ones, and in addition, certain
active characteristics which are entirely its own. If, then,
life arose ' spontaneously ' in this sense, i.e. by chance and
without any additional principle, from purely inorganic
matter, such positive activities, such increases of perfection,
would have to be held to have arisen from nothing ; since
matter itself does not possess them, and no cause other
than brute matter is, in this hypothesis, postulated.

An even more fundamental reason for disallowing the
possibility of life originating solely from a random combina-
tion of inert bodies is to be found in a consideration of the
finality of living things. These are essentially one, having
one form only, which form tends to a single end, the good of
the individual as a whole, and of the species. That the

1 Cf. Johnstone, art. cit. 2 Ibid., loc. cit.

326 MODERN THOMISTIC PHILOSOPHY

multiple tendencies, then, of a number of inanimate bodies
should produce this single unified tendency of the living
thing, in the absence of any directive power to unify and
co-ordinate them, is strictly speaking inconceivable. The
unconditioned union of things which are essentially different
is impossible, for being by nature many they cannot also be
by nature one, unless they are brought into this unity by
some unifying and directive principle. Such a principle
would not be present in the hypothesis we are considering,
since it allows of no principle but the unco-ordinated and
divergent forces of inanimate elements. This doctrine as to
the impossibility of the unconditional union of the many is
common to Platonism and Aristoteleanism, and, indeed, to
the whole tradition of the ' philosophia perennis.' We shall
have occasion to consider it again at a later stage.

It will be seen that the reasons we have just advanced do
not militate against the possibility of life having arisen from
inanimate matter under the direction and influence of some
power higher than that of matter itself, by whose means life
is brought from a state of potentiality to one of actuality.
It was in this way that S. Thomas conceived of some forms
of life being spontaneously generated from inanimate matter
under the directive and unifying action of God ; and the
same conception may perhaps be found in the theory of
Emergent Evolution, which has had a certain vogue in
recent times. Its exponents, however, do not seem to speak
with any great consistency.1

As to the probability of such emergence of life being a
fact, the evidence at present appears to be inadequate for
the formation of any definite conclusion, but it does not
seem that a Thomist is obliged to bang, bolt, and bar the
door on its possibility.2 If it is not thought probable we
shall, of course, adopt the only remaining hypothesis to
explain the origin of life, viz. that it was in the first instance
created by God. Even if this be so, we may still be in doubt

1 Cf. McDougall, Modem Materialism and Emergent Evolution, pp. 152
ff. ; Lloyd Morgan, Emergent Evolution ; Lloyd Morgan, Essay on Biology,
pp. in ff. in Evolution in the Light of Modern Knowledge.

*• With regard to its probability cf. McDougall, op. cit., Ch. V. Its
possibility is discussed in Revue Thomiste, 1923, pp. 298 ff., 305 ff.

THE ORIGIN OF LIFE 327

as to the origin of the different species of living things. Are
we to attribute their existence to a series of creative acts, or is
there reason to think that they have been developed, and
progressively differentiated from one another, by a purely
natural process ; so that all of them are to be thought of as
being descended from some one primitive form of life ?

This is the question of evolution or transformism, the dis-
cussion of which in the next chapter will conclude our survey
of the world of animate nature.

CHAPTER XVIII

TRANSFORMISM

Preliminary Remarks — Sketch of Evolutionary Theories — Lamarck —
Darwin — The Materialist Theory — Reasons which Exclude It —
Consideration of Evolutionary Theories in General.

Probably no scientific theory has aroused such widespread
and heated controversy as that which is popularly known as
the theory of evolution. This was due, not to its scientific
content, but to its philosophical and religious bearings, since
it seemed to imply an entire absence of purpose in nature ;
and, what appeared more objectionable both to the man in
the street and the upholders of orthodox religion, that man
was merely an intelligent kind of ape. This suggestion was
not merely unflattering, but seemed to be clearly contrary
to the account of man's origin given in the Bible, on both of
which accounts it was at first vigorously repudiated.

The controversy has now died down to a great extent,
largely because prolonged investigation has shown what are
the true implications of the theory, as well as bringing to
light the serious, and perhaps insurmountable, difficulties
which attach to the suggested explanations of the method
by which evolution has proceeded. Theological opposition,
in England at any rate, has practically ceased, owing to the
abandonment by the Protestant churches of belief in the
Biblical account of creation, and their acceptance in its
place of the infallible decisions of the biologists. It is curious
to notice that both sides appeal to authority for the settle-
ment of this question. In its early stages the theologians
attempted to silence the Darwinians by the authority of
Genesis, while at present the evolutionists try to silence the
doubter by the authority of scientific opinion. This fact
suggests the reflection that the truth or falsity of this theory
may not indeed be very plain to reason, if our guides urge us

328

TRANSFORMISM 329

to accept or reject it on faith. These attempts at bullying
failed, as they were bound to do, since those who were
bludgeoned with the Bible were at least doubtful as to its
infallibility, and those who are now threatened with ' scien-
tific opinion ' and the views of ' every educated man ' are
equally doubtful as to the infallibility of science. The
method of authoritative imposition of beliefs, though
invaluable if the competence of the authority be admitted,
is, consequently, not one of universal application, being
limited to the circle of ' true believers.' If we are, then, as
philosophic method demands, to consider this question
solely by the aid of natural reason, no fulminations of
scientists accusing us of heresy, or of ignorance and stupidity,
if we find ourselves unconvinced of the truth of their dogmas,
can carry any weight with us ; unless on other grounds we
have already admitted the infallibility of scientific opinion.
In its proper sphere, and when it can be had, authoritative
decision is an invaluable method of settling troublesome
questions ; but this sphere is that of faith, not of reason. As
S. Thomas says : ' Locus ab auctoritate quce fundatur super
ratione humana est infirmissimus.'1

We can therefore approach this question with an open
mind, and see what reason can tell us as to the possibility of
transformism. If it is found to be possible, the question of
its probability is one which must be decided in the light of
available evidence, a discussion of which belongs rather to
natural science than to philosophy.

There is probably no one who has not at least a vague
idea of what the word evolution, as applied to living things,
means ; but in ordinary language it is confined to one par-
ticular transformation of a species, that which is naturally of
most interest to ourselves, the transformation of some ape-
like creature into man. This popular use of the word is,
however, far from expressing the scientific idea ; and though
fortunately we are not obliged to consider all its scientific
applications, we must get some more precise notion of it
than this narrow and inexact one.

The word ' evolution ' is itself not a strikingly happy one,

1 Summa Theol., I, Q. I, a. 8, ad 2.

330 MODERN THOMISTIC PHILOSPOHY

as applied to the transformation of living species, since many
things unroll without being transformed, as carpets and
snakes, while the transformation which is asserted in most
modern evolutionary theories can hardly be called an unroll-
ing. It has, however, been commonly adopted in England,
and applied not only to the realm of living things, as in
Biology and Psychology, but also to the development of the
material universe in Cosmogony, and to its minutest con-
stituents in Physics and Chemistry. Whether it is, in fact,
applicable to any of these spheres except Biology, in a sense
which is properly speaking analogical to that which it con-
veys in this science, is very doubtful, and has possibly led to
confusion of ideas ; but this is a question which lies outside
the boundaries of our present discussion.

The term Transformism, which is in general use on the
continent of Europe, is much more exact, and indicates the
transformation of living things into new species.

The idea of such transformism, or gradual development of
living things from pre-existing forms, is not a modern one,
but at least as old as the fifth century B.C. It occurred to
the earliest Greek thinkers, and even the Darwinian method
of evolution by survival of the fittest was suggested by
Empedocles (495-435 B.C.). Aristotle, who was, of course,
eminent among the Greeks for his biological observations,
made the idea more precise ; but his theory of transformism
consistently with his general fundamental principles was, in
contrast with those of his predecessors, a decidedly teleologi-
cal one. Rejecting the idea of the survival of the fittest, he
maintains that nature successively adapts organs to their
function, and this in the order of their necessity, those
essential to life coming first, to be followed by those which
are of service in the full functioning of the nature of parti-
cular species. Thus those animals which have eyes have
them in order that they may exercise the powers of their
nature. What determines the evolution of the animal is
their nature, which strives to produce a certain result, so
that ' the process of evolution is for the sake of the nature
evolved, and not this nature for the sake of the process.'1

1 Cf. Aristotle, De partibus animalium, 640s 18.

TRANSFORMISM 331

S. Augustine is generally thought to have been favourable
to a view of evolution in some form, and in spite of doubts
raised as to the precise meaning of his theory, it can hardly be
denied that he entertained the idea of new species arising
in virtue of the powers bestowed on matter at the creation.

It is not easy to determine S. Thomas' precise view on
this question, but he did not allow that material elements
have in themselves, or essentially, the power of producing
all animals, though they could do so under the influence of
an analogous cause.1

Though Cajetan supported a form of evolutionary theory,
in later times, and under the influence of Suarez, it was
generally abandoned among theologians, and the doctrine
of special creation was left without a rival. According to
this view, all existing species had been created at the begin-
ning in their present forms ; so that as Linnaeus says : ' tot
nunc species sunt, quot ab initio creavit infinitum ens.' In
order to square this view with the apparent appearance of
new species, some had recourse to a series of special creations,
thus dropping the ' ab initio ' ; or else maintained that the
so-called new species were not properly species at all, but
merely racial variations of already existing species. It was not
until the nineteenth century that evolutionary theories again
became prominent, and eventually were generally accepted.

The modem history of the problem really begins with
Lamarck, the most important forerunner of Darwin, whose
theory of evolution was first outlined in 1802, and fully
developed in his Philosophic Zoologique in 1809.

Four laws constitute the skeleton, so to speak, of his
system. These are : (1) the law of growth, (2) of functional
reaction, (3) of use and disuse, and (4) of use — inheritance.

The first asserts that the size of the living being is increased
by the activities of this body itself up to some limit imposed
by its own nature ; the second that new organs arise in
response to some new felt need ; the third that organs
develop proportionately to their use, and atrophy in so far as

1 Cf. Summa Theol., I, Q. 71 ; 1.69,2 ; 1.73, a.i, ad 3. The opinions of
S. Augustine and S. Thomas have recently been discussed by Dr. Messenger
in his Evolution and Theology, Part I, Chaps. VIII-X, and Ch. XIII.

332 MODERN THOMISTIC PHILOSOPHY

they are not used ; while the fourth maintains that charac-
teristics acquired by an individual organism in the course of
its life are transmitted to this individual's descendents.

The last two laws are particularly interesting, since the
third asserts that bodily structure depends on function, and
the last the heritability of acquired characters, a doctrine
which is still the subject of acute controversy. All four laws,
it should be noticed, embody a teleological conception of
evolution, and so, to this extent, are in line with the Aris-
totelean ideas on this subject.

In the period immediately preceding the publication of
Darwin's work the transmutation theory was shelved or
rejected, so that the appearance of The Origin of Species in
1859, followed by that of The Descent of Man in 1871, had a
startling and sensational effect. The reason of this was not
merely, and not chiefly, that transformism had fallen into
disrepute, so that Darwin's ideas had a certain freshness and
novelty, but essentially to the fact that he was the first to
give it such a basis as seemed to establish it firmly as a fact.
It was not his theory, but his facts which revolutionised
scientific opinion. The vast accumulation of facts which his
laborious researches, in the five years in which he was
travelling in the Beagle, and the twenty succeeding years,
had enabled him to collect, made a profound impression on
biologists ; and the sensation caused among the general
public by his theory, and especially by his account of man's
origin, is largely attributable to its antiteleological, and
apparently anti-religious, tendency, due to his attributing
transformism to Natural Selection, which works blindly and
automatically. Prof. Hobson asserts that ' after Darwin's
work it (i.e. the fact of organic evolution) was no longer a
speculative hypothesis, but a well-attested deduction from
observation. As regards the position of Natural Selection
as the chief factor in Evolution, it is not possible to speak so
positively : on this matter the opinions of Biologists have
been, and still are, much divided.'1 This statement probably
represents the state of scientific opinion at the present day
fairly accurately.

1 E. W. Hobson, The Domain of Natural Science, pp. 437 fif.

TRANSFORMISM 333

From what has been said the reader will have gathered
that there are three main elements in Darwin's theory. The
first the establishment by observation of the fact that new
species have originated from older ones, the new being
descended from some of the individuals of the older species.
The second element is the attributing of this emergence of
new species primarily and principally to Natural Selection,
which works by causing those individuals, which happen to
vary slightly from the norm of their species, to be more, or
less, capable of surviving than normal members of the
species would be, according as the possession of such vari-
ations puts them in an advantageous or disadvantageous
position in the struggle for life. So, for example, we might
suppose that those giraffes which have the longest necks
would more easily be able to reach the higher branches of
trees, and so could procure food more easily than the shorter-
necked ones ; and thus, if food was scarce, only the long-
necked ones would survive, the others dying of starvation.
The same sort of process would occur in animals which
possessed superior weapons of defence or offence. Thus
nature herself would gradually eliminate the less fit, but
blindly, and without any purpose. This brings us to the
last element of the theory, which is perhaps the most
important from the philosophical point of view^ viz. its anti-
teleological tendency ; since it accounts for what appears to
be a purposive adaptation of the various species to their
environment by a process which eliminates purpose altogether.
Thus the peculiarities which appear to have been designed
in order that the individual may survive owe their origin to
chance, and their continuance to the less easy elimination of
the individuals possessing them ; and not to any striving
on the part of the individual itself. Since they have come
about by chance they cannot be purposive, either in their
inception or their continuance. As Huxley says : ' Darwin
gave the death blow to teleology by showing that apparently
purposive structures could arise by means of a non-purposive
mechanism.'

In this way it was thought that Biology was brought into
line with Physics, from which purpose had already been

334 MODERN THOMISTIC PHILOSOPHY

excluded. As Tennyson says in In Memoriam, alluding to
the mechanistic view of Physics :

' The stars ' she whispers ' blindly run ' ;

and now it appeared that living things, animals and man
also ' blindly run,' driven on by the whips of uncontrollable
forces to an inexorable doom.

It has been necessary to give this account of the theories
of Lamarck and Darwin in order to bring into prominence
those characteristics of modern evolutionary theories which
are of importance from a philosophical point of view. But
it would not be to our purpose, even if it were possible, to
trace the history of these theories to the present day ; since
the modern theories, though showing many marked variations
from those of Darwin and Lamarck, from which they are
descended, have yet not changed their species, but remain
true to the general principles which governed the parent
theories. Thus interest has chiefly centred since Darwin's
time on the discussion as to the relative importance of
Natural Selection and the inheritance of acquired characters
as the causes of mutations, the first being stressed by the
neo-Darwinians, and the second by the neo-Lamarckians ;
and, speaking generally, we have two theories or groups of
theories, one of the Lamarckian and teleological, the other
of the Darwinian or antiteleological type. The most
important modification introduced into evolutionary theories
of recent years is the assigning of the transformation of
species by some scientists rather to sudden large mutations
than to the slow accumulation of small ones, as was postu-
lated by Darwin's original theory.1 This modification was
due to the investigations and discoveries of Mendel, de Vries,
Batesori, and others, which threw doubt on the truth of the
hypothesis that transformation of species was produced by
an accumulation of small variations. This doubt was
increased by the researches of Johannsen, Agar, and Jennings,
which seemed to show that the small variations postulated
by the Darwinian theory were not inheritable ; and thus

1 Cf. E. W. Hobson, The Domain of Natural Science, pp. 449 £f. ;
Dampier-Whetham, A History of Science, pp. 247 ff.

TRANSFORMISM 335

there arose a tendency altogether to discredit Natural
Selection, as the instrument of evolution.1

Thus, while some biologists continue to maintain the
sufficiency of Natural Selection as an explanation of trans-
formism, many others incline to regard use and disuse and
purposive striving as its chief causes, while others again are
not prepared to commit themselves to any opinion as to its
cause. So Bateson said : ' In dim outline evolution is
evident enough. From the facts it is a conclusion which
inevitably follows. But that particular and essential bit of
the theory of evolution which is concerned with the origin
and nature of species remains utterly mysterious.'2

From all this one thing is very plain, viz. that there is not
that unanimity with regard to the theory of evolution which
is often asserted, so that a controversialist who demands its
acceptance because it is the opinion of all educated men is
not only irrational, as we have seen, but also disingenuous.
In fact, it is only the materialists or ' rationalists ' who
adopt this unreasonable method of forcing their opinions
down the throats of others ; and it will be convenient to
examine this extreme form of evolutionism before passing
on to see what light, if any, Thomistic principles can throw
on the theory of transformism in general.

The professed Materialists, then, recognising no other
reality than matter, assert that all species of living things
have arisen from inorganic matter ; the first forms of life
coming about by spontaneous generation, and later ones
being differentiated from the primitive forms by a process of
blind determined law ; without any internal teleological
tendency, or any intervention of the first cause, which by
hypothesis does not exist. The chief advantage of this
theory, from the philosophical point of view, is that it gives
a complete unity to all our knowledge of the world, every-
thing being wholly and essentially material, though if
thought and knowledge be, as the theory demands, but
secretions of the brain, the advantage is more apparent than

1 Cf. Evolution in the Light of Modern Knowledge, pp. 224 ff.

2 William Bateson, Naturalist. Memoir by Beatrice Bateson, p. 395,
quoted by Dampier-Whetham, op. cit., p. 353.

336 MODERN THOMISTIC PHILOSOPHY

real. For this reason and because the theory, when thus
plainly stated, seems self-condemned, we find that its
adherents are not very anxious to set it down in black and
white, but are inclined to hedge and to amuse themselves by
ridiculing the ' Fundamentalists ' ; instead of establishing
their own position. We should observe, however, that the
slightest departure from this materialist scheme breaks the
unity of the conception, and readmits those realities which
the materialists are bent on excluding, viz. immaterial or
spiritual ones.

The theory was put forward in an uncompromising form
by Haeckel in the last century ; and is adhered to, at the
present day, by Biological Materialists, such as Sir Arthur
Keith, and J. B. S. Haldane ; while Bertrand Russell has, as
it seems very reluctantly, made an act of infra-natural faith
in the same view.

Since, from their own point of view, the opinions of such
people are merely physical states induced by their own bodily
conditions, no doubt they would be content to be dealt with
rather by medical than philosophic methods. Nevertheless,
as we do not concede their premises, it is worth while to see,
for our own satisfaction, whether such an attitude as theirs
is compatible with reason.

It is, of course, obvious that since this theory denies that
there is any purpose, or teleology, in the evolutionary process,
it denies also the principle of finality, according to which
every agent acts for an end. Can this denial be rationally
sustained ? We can see the answer to this question by con-
sidering the consequences which follow from the denial of
finality.

First of all, it is clear that any agent, when in act, is acting
in a fixed way : it is performing this act and no other. Its
act, therefore, has a definite direction and achieves a definite
result. All this is allowed by the materialists who maintain,
in fact, that biologically useful characters achieve by their
use the survival of their owner. If they do this, they do it
because they are a certain definite kind of character, e.g. a
longer as compared with a shorter neck in a giraffe. Now,
it is asserted that though the particular actions by whose

TRANSFORMISM 337

means the process is carried on have a definite direction and
tendency, yet the process as a whole has no purpose. It is
clear, however, that the evolutionary process is not some-
thing distinct from the actions of the evolving things, but is
merely the resultant of all these actions, and it is impossible
to see how if all its components have one definite tendency
the process itself should have none. But, it will be said, the
Materialists do not maintain that it has no tendency, and, in
fact, affirm that it causes the fittest to survive ; what they
do maintain is that it has no purpose, no conscious tendency,
no plan. Let us then consider what it is that makes an
inanimate thing act in a determined way and consequently,
without knowing it, tend to a definite end. Surely it is
because it has a definite and determined nature : just as the
eye sees and does not hear or smell, because of its particular
structure. It is easy to see, then, that any being which has a
determinate nature must act in a determinate way, such
direction of its action being due to the fact that its nature is
of a particular kind. Now, this theory of evolution has as its
object the explanation of the way in which all things come
by their determinate nature, and it cannot, therefore, assume
a determinate nature as a starting point. It must, therefore,
start with an indeterminate being, a thing with no definite
nature at all ; a thing, then, which is either simply nothing,
or at best a' pure capacity or potentiality for everything. If
it is nothing we are left with the assertion that from nothing
everything comes ; which is simply unintelligible, and
obviously not an explanation. If it is a pure capacity for
everything, having no determination of its own, from what
does it derive the determination which starts the evolutionary
process ? Evidently not from itself ; and consequently from
something else, which has a determinate nature and action
of its own, i.e. from something which determines itself, and
so acts with purpose and intention. Such a being as this is,
however, absolutely excluded by the materialist hypothesis,
inasmuch as it denies finality of purpose altogether, and
moreover is, as we saw, obliged to start with the altogether
indeterminate. By denying finality, then, it is driven to
hold that the first being is not even a pure capacity for all

338 MODERN THOMISTIC PHILOSOPHY

things, but strictly nothing ; and is essentially irrational
and unintelligible.

The Scholastics, by means of their highly polished tech-
nical language, can express this argument very clearly and
concisely. So they say that every agent must act for an
end, at least in the order of execution, for otherwise it would
not do one thing rather than another. This intention of the
agent to gain a certain end, may be conscious, as in man, or
unconscious, as in inanimate bodies. But even if unconscious
it is still purposive since otherwise its tendency in a definite
direction would be without reason of being. For this deter-
minate direction must be in the agent, and if it is not present
in it by conscious purpose, so that the agent actively directs
itself to the end, it must be passively directed to it. Such
passive direction, however, presupposes active direction
which imparts it, and in the last resort, active self-determin-
ing, or conscious, direction. So there is conscious or uncon-
scious purpose in the action of every agent, and the maxim :
' potentia dicitur ad actum ' is universally true. The whole
raison d'etre of any capacity, and so of any agent, is in its
power of producing the effect, and so in its tendency towards
that effect, that act or perfection.1

To deny such finality, therefore, as the materialist evolu-
tionists do, is to deny the reason of being of the determinate
direction of the agents, or to assert that something is which
has no reason to be. This is obviously not to explain it ;
and is, moreover, an assertion that something can and does
come from nothing.2

The same conclusion is arrived at if we look at this process
from the point of view of efficient causality, for few would
be found to deny that life is a positive addition to matter
without life, sentience to matter which is living but not
sentient, intelligence or reason to being which is devoid of
these. Now, according to this theory, matter destitute of
life, of its own power produces it, living matter destitute of
sentience, brings it forth, and sentient life having no intel-

1 Cf. S. Thomas, Summa Theol., IaIIaeF Q. i, a. 2.

2 Cf. Garigou-Lagrange, De Revelatione, Vol. I, pp. 255 ff., 259 f., and
the same author's La Realisme du Principe de Finalite, Ch. II.

TRANSFORMISM 339

lect, evolves this from itself. In each case the greater being
produced by the less, something is caused by nothing.

Further, no reason can be assigned in this theory why
evolution, the first modification, and the perfection of the
evolutionary process should be at all rather than not be ;
while at the same time it is asserted that they are. Thus
evolution can have no reason of being either in something
other than itself, there being no cause apart from it, nor yet
in itself, for it is a movement or transit from indetermination
to determination, from potency to act, which cannot come
about of itself, since indetermination neither is, nor contains
in itself, determination. It has, and can have, therefore,
no reason of being according to this view.

As Professor A. E. Taylor points out, evolution, if it is to
be thinkable at all, must presuppose both environment and
the environed interacting on one another : ' When there is
change, there is reason for change . . . and the reason for a
change can only be found in something not involved in that
change. It follows that if there is such a thing as a process
of change with a definite and discoverable law which embraces
the whole of physical reality, the whole of physical reality
must have a non-physical environment.'1

Now, it is precisely this environment which is denied in
the theory we are considering, which is thus strictly speaking
unthinkable.

We are forced to the same conclusion when we consider
the first modification which inaugurates the evolutionary
process. It is ascribed in the theory to chance ; and this
phrase might mean either that chance is the cause and
reason of its appearance, or that we do not know what factor
in nature actually was responsible for it. No doubt, it is the
second sense which is intended, since chance cannot be con-
ceived as a thing or reason which could of itself produce a
positive effect. But the second sense does not avoid the
difficulty, since the unknown element in the situation,
whether internal to the being which produces the modifica-
tion, or external to it, would in its turn have to be accounted

1 A. E. Taylor, Evolution in the Light of Modern Knowledge, Ch. XII,
pp. 449 ff. Cf. Lossky, art. ' The Limits of Evolution ' in the Journal of
Philosophical Studies, October 1927.

Z

340 MODERN THOMISTIC PHILOSOPHY

for. Here a^ain, it cannot be accounted for by ' chance,'
using chance in the first of the senses given above, and so
once more this must be accounted for by a further unknown
factor in the physical situation. Now we cannot go on for
ever finding the reason of one unknown factor in a preceding
one, not because we should get tired of so doing, as has been
suggested, but because each unknown factor essentially
depends on another, so that all of them must in the last resort
depend either on some determinate and knowable character
in the physical situation and not on chance, or else depend
on something outside the series altogether. For if the
material world, which in the end produces the modified
being, had no determinate nature at all it would be useless
to look upon it as the source of the determinate modihcation ;
and if it had a determinate nature, the fact that it had it
could not be accounted for by means of something internal
to itself, but must be sought outside it. By the theory,
however, we are prohibited from going outside the physical
world, since it maintains there is nothing else than that
world. Hence, we must accept the origin of the first modifica-
tion as being unaccountable, inexplicable, and unintelligible ;
and as all the subsequent modifications depend on the first,
the whole process becomes entirely unintelligible.

Lastly, the theory that evolution is a process of accumula-
tion of modifications, offers no explanation of the fact of such
accumulation in the same direction, and does not attempt to
do so. It is not, however, only unexplained, but in fact
inexplicable, on the theory, for what has to be accounted for
is a series of modifications which all tend in the same specific
and determinate direction. Now it is clear that the first
modification cannot account for others in the same specific
direction, since these are posterior to, and an addition to,
itself ; and at the same time it is denied that there is any
other determination present at the start, except this first
modification. Consequently, there is nothing at all which
can account for the accumulation of modifications of a
definite kind, which remains therefore inexplicable and
unintelligible.

In a word, to start with something altogether undifferen-

TRANSFORMISM 341

tiated, indeterminate, and homogeneous, is to start with
nothing : and from nothing, nothing comes. This is what a
theory of materialistic evolution does and must do, since to
start with a determinate and differentiated being would be
to confess that evolution was unable to explain this being,
and this determination, and was therefore bankrupt. Evolu-
tion is incapable of explaining the whole universe, as the
materialists claim it can, but at best is only capable of
explaining the development of parts of it.

In conclusion, then, we must shortly consider its ability
to do this.

First, we must notice the distinction which is drawn
between natural and systematic species. From a strictly
metaphysical point of view, a natural species will be one
which differs from other things by an essential difference, or
a collection of individuals having the same essential proper-
ties, though differing as regards accidental ones. In accor-
dance with this definition we shall say that man forms a
natural species, inasmuch as he has a spiritual soul or form,
whereby he is essentially differentiated, or made different in
kind, from all other animals. We have further seen reason
to conclude that the same holds good of the lower animals as
distinct from plants. Further than this it seems impossible
to go with any certainty from the metaphysical point of
view.

If, however, looking at the world in this way, we may not
be able to distinguish more than three natural species, yet
it seems not unreasonable, regarding the matter in the con-
crete, to say that a natural species, in a general and wider
sense, is a collection of living individuals which preserve the
same powers and the same type, by means of generation one
from another.

To natural species, taken in either of these senses, is
opposed systematic species, which is a collection of indivi-
duals belonging to the same natural species, which have
certain accidental characteristics in common, which charac-
teristics are not found in the other members of the same
natural species.

There is, clearly, no reason, from a philosophical point of

342 MODERN THOMISTIC PHILOSOPHY

view, for refusing to admit the transformation of such
systematic species, since there would be no change of nature,
but merely one of accidental attributes. Whether it is
to be admitted, or not, depends therefore on the
weight of the observed evidence for, or against, its
occurrence.

Considering, then, natural species in the strict sense, do
our principles allow us to say that they could be transformed?
There seems to be nothing in them to render it impossible
for we should only have a striking example of substantial
change. If we admit its possibility, however, we can only
do so if it is allowed that the proper substantial form of the
inferior living thing is drawn out of matter, when suitably
disposed for the reception of such a form, while that of man,
being spiritual, can only come from without. This last
proviso evidently breaks the unity of the evolutionary
scheme ; and so robs it of its chief aesthetic charm, viz. its
unification of the whole material world as proceeding from
one germ or source. But it is to be observed that it is already
deprived of this attraction if we admit that an absolutely
homogeneous and indeterminate entity — a polite name for
nothing — cannot be the source of all that is. By this admis-
sion a dualism of the material world and its non-physical
environment is introduced. Since reason absolutely demands
that there should be a break in continuity here, the second
break owing to the entrance of the spiritual soul, loses its
importance. Neither of them is, however, acceptable to
what is called ' the scientific mind ' ; and scientists have
generally found the theory, according to which man's body
is derived from other forms of life while his soul is not so
derived, as objectionable as a downright denial of evolution
as a whole.

Lastly, if natural species, in the strict sense of the expres-
sion, could be transformed, it follows, a fortiori, that natural
species, in the wider sense, could be. In saying this, how-
ever, we do not affirm that they have been ; for indeed the
scientific evidence of the transformation of such natural
species, as of reptiles into birds, seems to be by no means
conclusive. The question of fact in this regard is, therefore,

TRANSFORMISM 343

one which belongs properly to physical science to
decide.1

A conclusion of this indefinite kind has seemed unsatis-
factory to many Scholastic philosophers, and consequently
they have attempted to argue that species differ in nature,
and that, therefore, there can be no transit from one to
another. Both these propositions, however, are open to
objection, since there seems to be no test by which we can
determine the difference of essence as between, say, two
animals ; and, further, the impossibility of transit from one
essence to another is not proved. As Guibert says : ' To
say that living species have not a common origin because
they differ in their essence, would be to argue from the
unknown. It would be better to say, if the species have a
common origin, perhaps the differences between them are
not essential. However difficult the problem of the origin
of species may be, it is without doubt more accessible than
that of distinction of essences.'2

What philosophy can tell us, then, about evolution is
first, that purely materialistic evolution of the type put for-
ward by Haeckel is impossible ; and, secondly, that any
theory of evolution which sets out to give an account of the
way in which the animate world has come to be in its present
state, and aims at making such an account satisfactory from
the philosophical point of viev,, i.e. as giving an ultimate
explanation of the whole matter, must take account both of
teleology and purpose, and of the action of the first cause.
On the other hand, an evolutionary theory might be regarded
as a purely scientific one, a working scheme which covers
the facts known at a particular time ; and from this point
of view, if it did not find teleology and the action of the first
cause useful for such a scheme, it might, and indeed ought,
to omit them. In doing so, however, it could not exclude
them from reality, but only from the picture it makes of the
world for its own practical purposes. Few Darwinians have,

1 The evidence for and against the transformation of natural species
is summarised by Monaco, Prcelectiones Metaphysics Specialis, Pars II,
De Viventibus seu Psychologia, pp. 215-239.

2 J. Guibert, Les Origines, translated by G. S. Whitmarsh as In the
Beginning, p. 152.

344 MODERN THOMISTIC PHILOSOPHY

in fact, been content with this modest programme, but
finding, or at least considering that they had found, that these
concepts were unnecessary in the construction of a simple
all-inclusive and homogeneous scheme of the action and
development of living organisms, they have jumped to the
conclusion that they had no place in life as lived, instead of
concluding that they had no place in life as conceived in a
particular scientific picture. The world of life, as lived, is
fuller and more solid than the picture which biological science
is able to paint of it ; for the reason that biology, of its very
nature, can take account only of its proximate causes, and
not of its ultimate nature and ground. When these are also
considered we see that it must be set against a background
of life underived and self-sufficing, a background which is
unchanging and eternal.

Conclusion.

This reflection leads us on to consider what ultimate
truths reason can extract from the material provided by
observation of the physical world, a subject which is dis-
cussed in Metaphysics ; the last great branch or genus of the
philosophical sciences ; and it is to this science of meta-
physics that we are now to direct our attention.

Before doing so, it may be convenient to glance down the
ladder of being which we have been ascending, and notice
its principal steps ; which are all concerned, in different
ways, with the problem of multiplicity and unity, of the
many and the one, of potency and act.

Thus, we saw that the endeavours made both by mechan-
ism and dynamism to reduce the material world to a simple
unity were unsuccessful ; and that we must recognise in it a
double multiplicity, that of nature, and that of the indivi-
dual. We saw that the material world is composed of a large
number of bodies which differ essentially ; the element
which thus specifically differentiates them from others
being the same as that which causes them to be essential
unities in themselves, viz. their form or act. Many of them,
however, are not simple unities, but combine, with unity of

TRANSFORMISM 345

nature, great heterogeneity of accident or quality ; and thus
have a certain organisation ; and may be called organic.
The individual, on the other hand, considered merely as an
individual, is a simple unity, but a negative one, inasmuch as
its unity consists in its distinction from all other individuals ;
which distinction is due to the material element in it. Here,
then, matter is the source of unity, though a unity of a
negative kind.

With reference to the next step in the ladder, that of
quantitative being, we found that the abstract continuum is
composed of parts which are not actual in it, but potential
only, though the physical continuum is actually multiple.
These considerations found an application in the two special
forms of the continuum which we call space and time.
Passing to the next step we found again a multiplicity in
unity. The more complicated forms of inanimate things
having already exhibited a certain material organisation, as
soon as we enter the world of living things we observe a
formal organisation whereby living things move themselves,
one part moving another. These things, then, are, in a
fuller sense, organisms. This organisation does not, how-
ever, interfere with their natural or essential unity. At the
same time, there is not unity of nature, of form or act, all
through the animate world ; but we saw reason to dis-
tinguish at least three natures among living things, those of
plants, of animals, and of man. As we rise thus in the scale
of being, we find unity becoming more prominent, and
multiplicity of nature less so. There is more of act and less
of potency, and, moreover, the forms of the two higher
grades of life, the animal and human, possess in their unity
the perfections of the lower ; man thus, by means of his
spiritual soul, being a sort of epitome of the whole material
creation. A further unification is introduced into the world
of living things by means of knowledge, the knower and the
known being joined in the closest of all unions, so that the
soul is ' in a certain way ' all things. The soul of man,
moreover, being spiritual, introduces us into a world which
is immaterial ; and as, in a sense, the more complex material
substances lead us up to the organisms found in the world of

346 MODERN THOMISTIC PHILOSOPHY

life, so man, being formally spiritual, leads us up to that of
immaterial being. He is thus a denizen of two worlds, the
material and the immaterial ; the second of which is con-
sidered in the science which deals with being as such, viz.
Metaphysics, the explanation of which is to form the subject
of our second volume.

END OF VOLUME I

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