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No apology would seem to be required for an attempt 
to examine the historical development of Berkeley s 
philosophy as a whole. In this book I have tried 
to throw light on the evolution of Berkeley s 
thought by a careful study of his works in their 
chronological sequence and by detailed reference 
to his relations with his predecessors and con 
temporaries. I have naturally devoted most 
attention to what is central in Berkeley s philo 
sophy his metaphysics and theory of knowledge, 
but I have not neglected the other problems that 
were touched by his wide-roving mind. 

Every student of Berkeley owes a debt of enduring 
gratitude to the careful and loving work of Campbell 
Fraser. In addition to his indispensable commen 
taries and memoirs, I have sought help from every 
source that seemed likely to afford it. In general, 
however, I have found Berkeley to be his own best 


This book contains the substance of the Shaw 
Fellowship Lectures which I had the privilege 
of delivering in the University of Edinburgh in 


August, 1923. 




I. Philosophical and Religious Environment 
II. The Commonplace Book 
in. The Influence of Locke 
iv. The Influence of Cartesianism 
v. Mathematics in the Commonplace Book 



I. The Possibility of Knowledge 
ii. Knowledge and its Objects - 
vin. The Existence of Things 
X IV - The Existence of Spirits _^ .. 
^ v. Causation - 
vi. Motion, Space and Time 
vii. Siris : the Closing Phase 

V. MATHEMATICS - - - - - 










246 \]V\ 



319 U 







THE early eighteenth century, with all its wealth of 
versatility, possessed no one who touched its life at 
more points than Berkeley. But though he was 
intimately connected with almost every department 
of the life and thought of his time, it is for his philo 
sophy that he is, and deserves to be, chiefly remem 
bered. His reputation does not, however, rest 
equally on every part of his philosophy. The three 
great philosophical problems with which the 
eighteenth century concerned itself were those of 
knowledge, morality and religion. Berkeley tra 
versed the whole of this field of contemporary 
speculation, and to the study of all its problems he 
made worthy contributions ; but his philosophical 
significance depends almost wholly upon his treat 
ment of the problem of knowledge. 

In spite of Berkeley s originality of thought and 
unconventionality of life he remains the entirely 
typical English philosopher. English philosophers 
in general, and its five greatest representatives in 
particular, display three well-marked characteristics. 
A survey of the work of Bacon, Hobbes, Locke, 

P.P. A 


Berkeley and Hume shows that (1) their interest in 
philosophy is predominantly practical, (2) their in 
quiries are prevailingly epistemological in character, 
and (3) the general method they adopt is psychological 
and inductive. These three features are more or 
less characteristic of English philosophy as a whole. 
But they are specially prominent in Berkeley. 

(1) Berkeley entirely agrees with Bacon that 
" knowledge is power," and that its end is " the 
improvement of man s estate." This does not, of 
course, mean that he minimises the importance of 
the theoretical interest. In his view, the conduct 
of the understanding does not yield in importance 
to the conduct of life ; and, indeed, he has a great 
deal more to say about knowledge than about 
practice. But the value of knowledge does not end 
in itself ; it is value for something, power to produce 
something. He never allows us to forget that all 
his writings are dominated by a double practical 
aim. " The new principle " will, in the first place, 
" abridge the labour of study," and render the natural 
sciences and mathematics more compendious and 
useful ; and, in the second place, by making manifest 
the nearness and omnipresence of God, it will exercise 
a profound influence for good in the world. This 
twofold purpose animates every page of Berkeley s 
work ; " the whole," he says, is " directed to 
practice." 1 

But Berkeley s practical spirit went further 
than this. And here also he is typical of English 
philosophy. For it is characteristic of the philo- 

1 Works, i. 92. (All references are to the Oxford Edition of 
Berkeley s works in 4 vols. 1901.) 


sophy of England, more than that of any other 
country, that its chief representatives have been 
not academic savants but men of affairs. Not to 
mention others, all the great men already named 
took a prominent and honourable place in the public 
life of their time. Now 5 though for many years 
Berkeley was connected with Trinity College, 
Dublin, his life was not that of a University teacher. 
Associating with the wits of a brilliant London, 
denouncing free-thinking in the Guardian, acting as 
chaplain to an embassy, exploring Sicily to discover 
the cause of its volcanoes, writing an Essay towards 
preventing the ruin of Great Britain, inspiring London, 
in an age when an enthusiast was considered either 
a knave or a fool, with the romantic missionary 
project of a college in Bermuda, sailing to America 
in a " hired ship of 250 tons," farming and preaching 
and waiting in Rhode Island for the fulfilment of 
Walpole s promise of Government assistance for his 
college, and in the evening of his days as Bishop of 
Cloyne caring for his people s souls, healing their 
bodies with tar-water, and castigating their idleness 
in the Querist such, in some of the aspects of his 
varied life, was George Berkeley. Through all the 
vicissitudes of this eventful life his practical interests 
were supreme. 

(2) Berkeley also agrees with the prevailing 
tendency of English thought in basing his philosophy 
directly on experience, and in attending specially 
to psychological and epistemological questions of 
the relation between the mind and the world of 
nature. With regard to the problem to be solved 
and the point of departure he is at one with Locke. 


Both start with experience, and both follow " the 
new way of ideas." .Along that way, however, 
Berkeley went a step further than Locke ; and it is, 
in one respect, his chief historical significance that 
he formed a link in the chain of reasoning which 
terminated in Hume s scepticism. /Berkeley accepts 
Locke s doctrine that the object of thought is an idea, 
but, denying that this idea is a copy of an external 
thing, he maintains that, as we cannot know material 
reality either by way of ideas or by perception of its 
effects, so-called material substances and material 
causes are simply non-existent. Instead of material 
substance and material cause Berkeley posits spiri 
tual substance and spiritual cause ; and thus his 
universe consists of spirits, substantive^and causal, 
and ideas, inert, unitary and dependent^ Hume has 
only a single step to take to reach his sceptical 
conclusion. The same arguments, he insists, can 
be advanced against Berkeley s spiritual substance 
and spiritual cause as Berkeley had brought against 
Locke s material substance and material cause : if 
spiritual substance be simply an indefinable " some 
thing," we have no more ground for maintaining its 
existence than Locke has for his material " some 

Now, from one standpoint, this is Berkeley s place 
in the history of English philosophy. But it is not 
a complete account of his philosophical significance. 
It is a great mistake to say, as Green does, that 
Berkeley is " merely Locke purged." For the most 
suggestive part of Berkeley s doctrine is not his 
criticism of Locke, but his positive theory of spirit. 
And that doctrine cannot really be overthrown by 


the same arguments as proved fatal to Locke s 
material substance, for Berkeley insists that we can 
know spirit though we do not perceive it as an 
idea, we have a notion of it, and know it to be active. 
Now, his insistence on the reality of mind or spirit 
is of the first importance. Locke, indeed, had not 
denied the existence of mind, but he did not fully 
realise its indispensability for knowledge. And 
Berkeley was, in fact, the first modern philosopher 
to discover the importance of the thinking subject 
in knowledge. Whereas previous philosophy had, 
in general, been content to regard mind as dependent 
for its knowledge on the external world, Berkeley 
made a veritable Copernican change, and insisted 
that the so-called external world depends for its 
existence on the mind. Thus mind or spirit becomes 
the most important thing in the world. /Reality is 
primarily spiritual, and the existence of the physical 
universe is mind-dependent.. 

But Berkeley was in advance of the process of 
thought, and it was left to Kant, after the depths 
of scepticism had been sounded by Hume, to rein 
state the self in a more secure position than it 
occupied in Berkeley s system. For Berkeley had 
allowed two great lacunae to remain in his doctrine. 
He left side by side two kinds of knowledge, (1) 
knowledge of ideas, and (2) knowledge of spirits by 
way of notions ; and until Siris he made no attempt 
to bring these two kinds of knowledge into any 
system. But in that work he points out the neces 
sary interconnection of perceptions and conceptions ; 
and, in terms that remind us of Kant, insists that as 
understanding alone cannot perceive, so sense alone 


cannot know, for all real knowledge requires the 
concurrence of both ways of knowing. But this 
view was never worked out. The other great defect 
in his theory is his failure to give any account of 
relations. He does, indeed, once or twice mention 
relations as involving mental activity, but such 
suggestions do not amount to a serious attempt to 
deal with the problem. Berkeley explicitly holds 
that things can be known apart from their relations, 
and, though he insists on the uniformity of experience 
and the systematic and harmonious nature of the 
world, he maintains that no necessary connection 
subsists between the particulars which constitute 
the physical order. 

To psychology Berkeley made contributions which 
were of the first importance for the development of 
that science. Mill, in a burst of generous enthusiasm, 
attributes to him " three first rate philosophical 
discoveries, each sufficient to have constituted a 
revolution in psychology, and which by their com 
bination have determined the whole course of 
subsequent philosophical speculation ; discoveries, 
too, which were not, like the achievements of many 
other distinguished thinkers, merely refutations of 
error, but were this and much more also ; being all 
of them entitled to a permanent place among 
positive truths." 1 The three doctrines on which 
Mill bestows such praise are the theory of visual 
perception, the contention that we reason always on 
a particular, and the theory that reality consists of 
groups of sensations. How far these doctrines have 
the right to be called " positive truths " we shall see 

1 Dissertations and Discussions, iv. 155. 


later ; but there can at least be no doubt of the 
importance of their influence on the development 
of psychology. If we trace the growth of psychology, 
we shall find, as Ward has pointed out, 1 that it was 
first unduly objective and then improperly sub 
jective. A mature psychology will hold in due 
balance both the objective and subjective aspects ; 
its fundamental conception will be experience, in 
which subject and object are correlated. Now, while 
Berkeley properly belongs to the second period, he 
has done much to pave the way towards an adequate 
psychology of experience. Aristotle, whom Ward 
takes as the representative of the first period, 
developed his psychology from a standpoint re 
sembling that of the modern biologist, and it was 
characteristic of his work to contemplate psychical 
facts from without, rather than introspectively 
from within. Advancing on these lines, Aristotle 
was unable to give any adequate account of the 
unity of consciousness as the central feature of all 
psychical acts. In Descartes and Locke psychology 
assumed a more subjective tinge. They did not, 
however, remain true to the introspective method 
which they professed. They introduced meta 
physical distinctions, and vitiated their psychology 
by a dualism of mind and matter. Now, Berkeley 
denied the existence of that dualism, and, by his 
insistence on the importance of the subject within 
experience, anticipated the day when psychology 
would strike the proper balance between the sub 
jective and objective elements within the unity of 
experience as a whole. To adapt a Kantian dis- 

1 " On the Definition of Psychology," Br. Jl. Psych, i. 4. 


tinction, while Descartes subject in knowledge 
performs only regulative functions, Berkeley s subject 
is constitutive of experience. Berkeley s significance 
really lies in his suggestion that both external and 
internal fall within the subject s individual experi 
ence. But the importance of this suggestion (for it 
is nothing more than a suggestion) was overlooked 
by Berkeley s successors ; and it has remained for 
Ward and others in our own day to re-learn and 
re-teach the lesson. 

(3) Berkeley did not distinguish between philo 
sophy and psychology. He believed that the only 
method of dealing with the facts of experience is 
what we should now call the psychological. And 
here also his procedure is typical of English philo 
sophy in general. It is characteristic of English 
thought to assume that philosophy consists mainly 
in an analytical examination of mental processes. 1 
We may say either that English philosophy confuses 
psychology and philosophy, or, if we prefer, that its 
philosophical method is exclusively psychological. 
English philosophy attempts to satisfy the wonder 
in which philosophy arises by analysing conscious 
experience into its constituent elements. It seeks 
to apply to conscious experience (what it calls 
" inner experience ") the same methods of observa 
tion and experiment, examination and analysis, 
division and classification, as have proved useful in 
the natural sciences, the sciences of " outer experi 
ence." This treatment of experience gives us, on 
the one hand, the body of natural science, and on 
the other, mental science or philosophy. The 

1 This refers, of course, to the traditional English method. 


psychological method in philosophy involves an j 
examination of the contents of the mind, regarded 
as particular facts ; and on the results of its observa 
tion it constructs a system of generalised propositions 
which form the body of philosophy. 

This method Berkeley inherited from Locke, and 
in his earlier work it and it alone is employed., _ In 
the New Theory of Vision -and Pnnci/^s^JihejcyQ^y 
method wliicTTTie uses is introspection upon conscious 
experience. The person who introspects is regarded 
as somehow standing apart from his experience : 
his experience is for him a series of isolated presen 
tations, presentative of nothing outside themselves, 
and having no essential relation to other presenta 

But Berkeley soon came to doubt the validity and 
universal applicability of the traditional psycho 
logical method. One or two entries in the Com 
monplace Book show that even in those early days 
he had a presentiment of the inadequacy of the 
method, and the impossibility of explaining by it 
the mind and its operations. Tlie. complete analysis 
of conscious experience which the method professes 
to supply leaves out of account the self for which 
that experience is. Introspection Hiannv^yg only 

series of particular ideas : it reveals no permanent 
and identical self. Now Berkeley believed that the 
existence of the self is essential to the constitution 
of experience, and the psychological method is there 
fore inadequate in so Jar as it is unable to give any 
account of the self. 

In his later work he gradually recognised the 
deficiencies of the standpoint and method with which 


he started. Any knowledge we get by this method 
must be supplemented and corrected with reference 
to a new way of knowing, viz. knowledge by way of 
notions. We have nqtions_of the self, of relations, 
and of mental operations, none of which are revealed 
to us by a psychological analysis, and to none of 
which have we any right if we proceed solely by the 
psychological method. In Berkeley s middle period 
knowledge of ideas and knowledge of notions were 
allowed to remain side by side as two isolated and 
distinct kinds of cognition, each fitted for obtaining 
awareness of its appropriate objects, and no attempt 
was made to show the relation of these kinds of 
knowledge. But in the latest stage of his philo 
sophical development he realised, as we have already 
, mentioned, that we cannot have in isolation know 
ledge of particulars and knowledge of universals, 
and that all knowledge requires the concurrence of 
both the universal and the particular. Sensation 
gives merely the raw material of knowledge, which 
needs to be understood and interpreted before 
becoming knowledge ; and the understanding by 
itself is empty and can give no knowledge apart 
from the filling of sense. All this, of course, proves 
the inadequacy of the psychological method. But 
though Berkeley certainly did see that it is inade 
quate, he does not seem to have understood precisely 
why it is inadequate. It is unsatisfactory as a 
philosophical method because it takes very little 
account of a group of problems which it is one of 
the principal tasks of philosophy to examine, the 
problem of the relation of the self to its experience, 
the problem of the relation of inner experience to 


outer experience, and the problem of the relation 
of the finite self to the Infinite. All these problems 
are touched by Berkeley, but in no case did he face 
thoroughly the difficulties which they involve. And 
his philosophical weakness may be said to be due, 
in a word, to his failure to work out the implications 
of personality. The world is, for him, dependent 
for its character and existence on persons ; yet he 
deliberately avoids any fundamental discussion of 
the meaning of personality. 




IT is the merest commonplace to say that every 
thinker owes much to his predecessors and contem 
poraries. His thought is consciously influenced by 
philosophers, scientists and moralists ; and, in 
addition, it bears upon it the stamp of that subtler 
but none the less potent force, the social environ 
ment in which he lives. Berkeley is perhaps the 
freshest and most original thinker in the history of 
British philosophy ; yet, more than any other, he 
was influenced both by his immediate philosophical 
predecessors and by the social surroundings in which 
he was placed. He was aware of his debt, though 
not, perhaps, of the full extent of it. "I must 
acknowledge myself beholding to the philosophers 
who have gone before me," 1 he reminds himself in 
the Commonplace Book ; but at the same time he 
compares these predecessors to adventurers, " who, 
tho they attained not the desired port, they by 
their wrecks have made known the rocks and sands, 
whereby the passage of aftercomers is made more 

1 Commonplace Book, i. 38. 


secure and easy." l But Berkeley s indebtedness 
was not merely of this negative kind. He did not 
use other philosophers merely as beacons to enable 
him to keep clear of the errors on which their thought 
had been wrecked. This metaphor is entirely 
inadequate. In reality, other philosophers formed 
his spiritual meat and drink, and it was because he 
assimilated so well the nourishment they provided 
that he was able to reach the philosophical stature 
to which he actually grew. 

In Berkeley s case it is possible, with greater 
certainty than is usual, to discover the material 
which his receptive mind acquired from his pre 
decessors and contemporaries, and, in general, to 
trace the outlines of the main formative influences 
which played upon his mind. When his first book 
appeared, he was still very young. He was only 
twenty-four when the New Theory of Vision was 
published, and the Principles was given to the world 
in the following year. In these works he makes no 
effort to conceal the sources from which the New 
Principle was derived. One of his great aims, he 
tells us, is to " remove the mist or veil of words " 
by which philosophy is obscured, and he has no wish 
to hide the origins of his own thought or mask the 
workings of his own mind. His own consciousness 
of his relations of attraction and repulsion to other 
philosophers renders the determination by us of the 
extent and nature of those relations, if not an easy 
task, at least a practicable one. A Locke, a Kant, 
or a Hobbes, who does not produce his work till near 
the evening of his days, finds it impossible to say 
1 Ibid, i. 38. 


which among the myriad influences to which he has 
been exposed have really been vital in the formation 
of his mind. And it is often equally impossible for 
the historian to disentangle the various threads 
which have been woven so closely into the texture 
of the particular philosophy. But Berkeley s en 
during philosophical work was nearly all done when 
he was a very young man, and while the impressions 
of his student-days were still fresh and vivid. It is 
thus possible for us to trace, from his own writings, 
the influence of his social and philosophical environ 
ment on the development of his thought. 

What we have to do, then, is to study the evolution 
of Berkeley s philosophy, and, as no study of evolu 
tion is complete without some investigation of 
environment, it is necessary to sketch in outline the 
nature of the environment of mental and moral 
forces with which Berkeley was surrounded during 
his student-days at Trinity College, Dublin. 

In his College days or earlier Berkeley encountered 
the two great influences which affected the whole 
course of his life and work. The one aim which he 
kept persistently before him through all the vicissi 
tudes of a varied life was the refutation of deists and 
free-thinkers. Now, in the formation of this purpose 
and in the preparation for carrying it out, he was 
affected by two main influences or sets of influences, 
one religious, the other philosophical. He was 
influenced not only by the new experimental philo 
sophy of mind and nature introduced by Newton 
j and Locke, but also by the great religious contro- 
i versy, which lasted over half-a-century, between 
^orthodoxy and deism. 


When Berkeley went to Dublin, the great deist 
controversy, in which he was destined to play a 
not unimportant part, was just beginning. In 1696 
the flame was fairly lit by John Toland with his 
anonymous book, Christianity not Mysterious. The 
publication immediately became notorious, and a 
second edition bearing Toland s name was issued 
in the same year. In the spring of 1697 Toland 
went to Ireland, his native country, and discovered 
that intense excitement had already been caused 
by his book. He did everything to encourage it. 
In tavern and coffee-house he never wearied of airing 
his views and repeating his main arguments. His 
skill in debate won many to his side, and Authority 
considered it necessary to institute a vigorous 
campaign against him. 1 Everything possible was 
done to crush his views. State, Church, and Uni 
versity were all arrayed against him. Dr. Peter 
Browne, 2 at that time Provost of Trinity, published 
a violent attack on his views, 3 in which he endea 
voured to excite a popular outcry against him. 4 
The Church was not behind in lending its voice to 
the general condemnation, and from every pulpit, 
by Archbishop and curate, Toland and his views were 
denounced. 5 The affair was even taken up by the 

1 Cf . Lechler : Geschichte des Englischen Deismus, p. 1 95. 

2 Peter Browne, with whom Berkeley subsequently had a con 
troversy, was the author of The Procedure and Limits of Human 
Understanding, and The Divine Analogy. 

3 A Letter in Answer to a Book Entitled Christianity Not 
Mysterious, 1697. 

4 Molyneux, the friend of Locke, criticised Browne on this 
score. (Locke s Works, viii. 428.) 

5 " A sermon against his errors was as much expected as if it 
had been prescribed in the rubric ; and an Irish peer gave it as 


Irish Parliament, a special commission was appointed 
to deal with it, and eventually a resolution was 
passed by the whole House declaring the book to 
be antagonistic to the Christian religion and the 
Established Church, and decreeing that it should be 
publicly burnt by the common hangman, and the 
author arrested by the Serjeant at Arms. Toland 
fled. But the controversy which he had popularised 
was not so easily got rid of, and when Berkeley 
entered Trinity College in 1700 free-thinking was 
still a subject of the keenest debate. From the 
beginning Berkeley took the greatest interest in the 
controversy, and definitely ranged himself on the side 
of the orthodox. 1 

Berkeley s Dublin environment was also respon 
sible for leading him in the direction in which the 
work was to be done that would secure for him a 
permanent reputation. If his work had consisted 
simply in the refutation of the deists, he would now 
be as much ignored as they are. His reputation 
rests on his philosophy pure and simple, and the 
general character of his philosophy was determined 
by his early studies at Trinity College. The College 
in which he lived had changed greatly since Swift s 
student-days. Swift took his degree in 1685, after 
wrestling contemptuously with the " Logics " of 
Burgersdicius, Keckermannus and Smiglecius and 
the " Manuals " of Baronius and Scheiblerus. But 

a reason why he had ceased to attend church that once he heard 
something there about his saviour Jesus Christ, but now all the 
discourse was about one John Toland." (Hunt, Religious 
Thought in England, ii. 244. ) 

1 For a detailed account of Berkeley s attitude to the deists 
vide infra, chapter vii. 


by Berkeley s time these tomes had been discarded 
from the curriculum, and very little attention was 
paid to the subtleties of the Schools. Trinity 
College had given a welcome to Locke s Essay, 
published in 1690, and Newton s Principia, published 
in 1687 ; and all interest was now concentrated on 
the new philosophy initiated by them. Thus, when 
Berkeley became a student in 1700, Locke and 
Newton were the great intellectual forces in his 
environment. Berkeley became greatly interested 
in both thinkers, and in 1706 he was the leading 
member of a society which met weekly for the 
discussion of their views. 

This society, which was founded on January 10, 
1705/6, consisted originally of eight persons only ; 
and there is some reason to suppose that Berkeley 
was president and Samuel Molyneux (son of Locke s 
friend) secretary. 1 Though the statutes of this 

1 The reasons for this conjecture are as follows. Berkeley, we 
know, was far ahead of his fellow-students (Life and Letters of 
Berkeley, p. 23), and it is therefore a priori natural to suppose 
that he was the first president of the society. Further, the 
statutes, which deal mainly with elaborate rules of procedure, 
are written out in full in his book, but not in his handwriting. 
They are written, no doubt by the secretary, in the president s 
book for his guidance in directing the discussions. Again, the 
date of the foundation of the society is January 10, 1705/6, and 
there is in existence a manuscript of Berkeley s the Description 
of the Cave of Dunmore bearing the same date, which was almost 
certainly read by Berkeley at the first meeting of the society 
(See Hermathena, vol. xi. p. 181.) And it seems probable that 
the inaugural paper would be read by the president. 

That Samuel Molyneux was secretary is suggested by the fact 
that the manuscript just referred to and the manuscript of 
Berkeley s essay Of Infinites (which was apparently read to the 
same society) were discovered among the Molyneux papers in 
the library of Trinity College, Dublin, and both bear an endorse 
ment in the writing of Samuel Molyneux (Hermathena, xi. 181) 

B.P. B 


society, which are preserved in Berkeley s Common 
place Book, are rather elaborate, yet, oddly enough, 
the object of the society is not stated. It was clearly 
to be very comprehensive, members being entitled 
to " propose to the assembly their inventions, new 
thoughts, or observations in any of the sciences." x 
The constitution provides for a museum, with one 
of the members as " Keeper of the Rarities " ; and 
it is clear from some entries which immediately 
follow the statutes in Berkeley s Commonplace Book 
that Locke was the subject of much discussion. 
Directly after these entries follows another list of 
statutes, a short one this time, which is dated 
December 7, 1706. These statutes may refer to a 
new society, but it is more probable that they merely 
correct or amplify the constitution of the original 
society. The object of the society is now denned. 
It is " to discourse on some part of the new philo 
sophy." 2 

In this society, accordingly, Berkeley discussed 
with his friends the New Philosophy of Locke and 
Newton ; and in connection with these discussions, 
he wrote his Commonplace Book. 


The Commonplace Book is in itself of unique philo 
sophical interest, and is, in addition, of the utmost 
value for the light it throws on the genesis, evolution, 

Now it was one of the statutes of the society " that the secretary 
have the charge of all papers belonging to the society." (Life 
and Letters, p. 24.) 

1 Life and Letters of Berkeley, p. 25. 2 Ibid. p. 26. 


and affiliation of Berkeley s thought. Begun early 
in 1706, the book contains a full and suggestive series 
of notes of what he was reading and thinking and 
planning during the earliest years of his philoso 
phical development. In its vivid, disjointed, and 
staccato jottings it reveals a mind pregnant with a 
great discovery. More important still, it displays 
the sources from which that great discovery was 
nourished prior to being brought forth in the New 
Theory of Vision and Principles, and enables us to 
discern the emotions which, in Berkeley s mind, 
accompanied the birth of the New Principle. The 
notebook was intended for the eye of its writer alone, 
and it contains the freest possible expression of his 
attitude towards the philosophers and mathe 
maticians from whom he was still learning. Its 
casual and unstudied utterances throw a brilliant 
light on the origin and progress of his thought. 

The earliest philosophical remarks in the book 
are the queries interposed between the statutes of 
January 1705/6 and December 1706. These have 
reference, without exception, to particular points 
of Locke s doctrine. Several isolated questions refer 
to matters which Berkeley was later to raise, though 
they have little connection with the fundamentals 
of his own theory ; but more interesting than these 
are the important queries which indicate that 
already Berkeley s mind was tending in the direction 
of the New Principle. Suggestive, for instance, is 
the very first entry, " Query. Whether number be 
in the objects without the mind ? Locke, b. 2, c. 8, 
s. 9." * Berkeley s conviction of the mind-dependent 

1 Life and Letters of Berkeley, p. 25. 


reality of the world was already dawning ; and that 
he was thus early inclining to the emphasis on sense 
which is so marked a feature of his earlier thought is 
evident from the tentative and awkwardly expressed 
statement, "Things belonging, to reflection are for __ 
the most part expressed by forms borrowed from 
.things sensible.." * But such suggestions as these 
are merely prolegomena to the New Principle : the 
New Principle itself has not yet been revealed to 
Berkeley s ardent mind. 

The revelation takes place in the most striking 
way in the next group of entries. As we read the 
phrases they contain, it needs no effort of imagina 
tion to reconstruct the stages of the development of 
the New Idea. No harsh Socratic maieutic was 
needed to bring it to the birth ; it came to light easily 
and almost imperceptibly, and as we scan the 
sentences in which Berkeley indicated the process, 
it is easy to sympathise with his joy and surprise as 
he gazes at the child of his mind" The obvious 
tho amazing truth." 

The whole process of evolution takes place in a 
single page, and that the first page of the Common 
place Book proper. 2 Berkeley is considering the 
problem of time and eternity, and after one or two 

1 Ibid. p. 26. 

2 My account of the development of Berkeley s early thought 
as revealed in the Commonplace Book is based on the supposition 
that the order in which Berkeley actually made the entries is 
not that which is adopted by Campbell Fraser in the Oxford 
edition, but is as follows. 

I. The Statutes of January 1705/6, the queries, and the 
Statutes of December 1706. (Though these are all in 
the manuscript of the " Commonplace Book," they are 
not printed by Fraser in the Commonplace Book, but 


remarks of no particular importance, he makes the 
significant statement, " Time is the train of ideas 
succeeding each other." 1 Next he says, " Duration 
not distinguished from existence." Time, he means, 

are inserted by him in his Life and Letters of Berkeley, 
pp. 23-27.) 
II. Commonplace Book, pp. 58-89. 

III. Commonplace Book, pp. 7-58. 

IV. Commonplace Book, pp. 89-92. (These references are to 

the " Commonplace Book " as printed by Fraser in the 
1901 edition of the Works.) 

It is necessary now to give reasons for adopting this order. 

The essential question relates to the order of the two sections 
numbered above II. and III. And it may at the outset be 
pointed out that section I. coheres closely with section II., and is 
to be regarded as prefatory to it. Section I., which was extracted 
from its proper place in the " Commonplace Book " by Campbell 
Fraser for biographical purposes when he published the 1871 
edition of the Works, and was apparently overlooked altogether 
when he brought out the edition of 1901, stands written in the 
manuscript volume which we call the " Commonplace Book " 
between the quotation from Clov (?) and the sentence "One 
eternity greater than another of the same kind." The quota 
tion from Clov (?) ends one page. Then follow three blank pages. 
Then we have the statutes of January 1705/6, and the other 
items which constitute what I have called section I. The 
sentence " One eternity greater than another of the same kind " 
runs on immediately after the last of the statutes of December 
1706. It is clear, then, that the statutes and queries are con 
nected with section II., and are disconnected from section III., 
from which they are separated by the three blank pages. That 
is, section I. is connected with II., but not with III. It is, as 
we have said, prefatory to II. 

Having now made clear the close connection of I. with II. 
(which nobody doubts), we proceed to the crux of the question, 
viz. the transposition of sections II. and III. 

The order in which the Commonplace Book is printed by Camp 
bell Fraser is that of the manuscript volume. The only altera 
tions which Fraser made in editing the manuscript were (a) the 
excision of section I. (to which we have already alluded), (b) the 
omission of a few repetitions, and (c) the addition on p. 92 of a 
few remarks taken from another manuscript of Berkeley. Apart 
from these intentional interferences with the text of the manu- 
1 Commonplace Book, i. 58. 


exists only so long as it endures. The existence of 
time is its duration and nothing else ; hence, in 
general (this seems to be his argument), existence is 
identical with duration. But the difficulty arises 

script, and some errors in deciphering Berkeley s handwriting, 
the Commonplace Book printed by Campbell Fraser is identical 
with the manuscript volume. 

Now, as Lorenz was the first to point out (Archivfiir Geschichte 
der Philosophic, xviii. 554), the manuscript volume consists of 
two notebooks, bound together. Evidence of the former bindings 
remains, and there is a slight difference in the texture and quality 
of the paper. One notebook comprises pp. 7-58 down to and 
including the qxiotation from Clov (?), i.e. what we have called 
section III. For convenience we will call this notebook A. The 
other contains the statutes and queries followed by pp. 58-92, 
i.e. what we have called sections I., II. and IV. Let us call this 
notebook B. 

It was suggested by Lorenz that these notebooks had 
accidentally been bound together in the wrong order. This 
supposition I have adopted. To substantiate it, it is necessary 
to show that notebook A must be later than notebook B. 

(1) A contains the date August 28th, 1708. B contains the 
dates January 10, 1705/6, and December 7, 1706. There is no 
doubt as to these dates, consequently A must be later than B. 
This is absolutely conclusive. (There is an entry on p. 84 which 
might be taken to suggest that it had been written before April 1 6, 
1705. It refers to " Mr. Newton," and as Newton was knighted 
on April 16, 1705, the entry, Fraser suggests, would seem to 
indicate that it was written before that date. This is not, of 
course, conclusive. It is quite possible that Berkeley simply 
wrote " Mr. Newton " inadvertently. If Fraser s supposition be 
true, it still further confirms our contention that B is earlier 
than A, though it gives rise to difficulties of its own in connection 
with the statutes, which would then, though preceding the 
Newton entry in the manuscript, be subsequent to it in time. And 
this, I think, is a further objection to Fraser s suggestion.) 

(2) That B was written as early as 1706, and therefore before 
A, is confirmed by the discovery made by Prof. S. P. Johnston 
of an essay by Berkeley entitled " Of Infinites." On external 
and internal evidence Prof. Johnston assigns this essay to the 
period 1706-7 (Hermathena, vol. xi. pp. 181-2), and a comparison 
of it with the Commonplace Book shows that it was certainly 
written at the same time as pp. 83-88. 

(3) Berkeley tells us (Works, ii. 19) that one of his earliest 


that, if this be so, we seem to be deprived of any 
objective measure of existence. In pain time is 
longer than it is in pleasure. Because its duration 
is longer, its existence is longer. The conclusion 

enquiries was about time. Now the only group of entries in the 
Commonplace Boole concerning time is that on pp. 58f. This 
would be " one of his earliest enquiries " only if B is prior to A. 

(4) But by far the most convincing confirmatory evidence of 
the priority of B is that supplied by a consideration of the sub 
jects dealt with in the two parts. There are, for instance, two 
or three fairly certain references from A to B. On p. 12 we have 
the following : " Motion on 2nd thoughts seems to be a simple 
idea." Now, motion has not been mentioned previous to this 
in A. In B, on the other hand, motion is mentioned in such a 
way as to imply that it is a complex idea. That is, we have 
Berkeley s first thought in B, and his second thought in A. 
Again, in B we frequently find dogmatic and unguarded state 
ments which are carefully qualified in A. For instance, he states 
in B, absolutely and without qualification, that in perception the 
mind is essentially passive (p. 83). But in A he qualifies this by 
adding, " There is somewhat active in most perceptions " (p. 37). 
Lastly (and this seems to be an irrefragable example), in B he 
defines " bodies " as " combinations of powers," obviously a 
technical definition of his own (p. 64). But in A he reminds 
himself " not to mention the combinations of powers " (p. 50). 
Now, the phrase "combinations of powers" has not previously 
been mentioned in A. The reference is clearly to the passage in B. 

(5) Finally, if we take the Commonplace Book printed in the 
Oxford edition, it is impossible to trace any development in 
Berkeley s thought. On the very first page of A, in the second 
entry, we have a reference in detail to the structure of the Intro 
duction to the Principles, and Berkeley speaks in a most familiar 
way of the application of the Principle to various difficulties. 
The first few pages of A show, in fact, that he had already reached 
the stage of drafting the Principles, and was even paying atten 
tion to the phrasing of important passages. In A the references 
are all to the Principles. On the other hand, B contains almost 
the whole of the argument of the New Theory of Vision, which 
was certainly developed before the Principles. And the general 
style and atmosphere of A are more mature than B. Most 
important of all, on the supposition that B precedes A in time, it 
is possible to discern a real continuity of argument and progress 
of thought. This is shown in the brief exposition of the argument 
of the Commonplace Book which I have given in the text, and need 


would seem to follow that the measure of time, and 
consequently the measure of existence, differs from 
individual to individual, and in the same individual 
from moment to moment. This consequence is, 
in part, admitted by Berkeley. " The same TO vvv" 
he says, " not common to all intelligences." There 
is no objective or universal measure of time, and the 
conclusion must be drawn, " Time a sensation ; 

not be repeated here. The reality of this continuity grows on 
the mind the more frequently one reads the Commonplace Book ; 
and no one who reads it over several times, first in one order and 
then in the other, can avoid the conclusion that Berkeley wrote 
B before A. 

For all these reasons, then, we maintain that the order in 
which Berkeley actually made his jottings is that which we have 
adopted. The essential question, let us repeat, concerns our 
transposition of sections II. and III., and this we have proved to 
be justified. 

A word or two will suffice for the unimportant question why 
pages 89-92 are postponed to notebook A, though they really 
occur at the end of B. In the manuscript there is a hiatus where 
on p. 89 in the Oxford edition a line is drawn. That is, the 
portion of p. 89 after the line does not follow on uninterruptedly 
the part of p. 89 before the line. We thus have this initial reason 
for separating p. 89 ff. from the rest of B. Now, pp. 89-92 
.consist of (a) nineteen carefully stated and numbered axiomatic 
statements of the salient points of Berkeley s New Principle, 
followed by (b) a few jottings of the usual kind. Now, it may be 
suggested that what Berkeley did was this. He began by writing 
notebook B from the beginning to p. 89. He then left a few 
pages blank at the end of the notebook, in order to state there 
the positive results of his thought. At the same time he started 
a new book (A) for the purpose of continuing his jottings and 
queries. Finally, when A was completely filled (it is filled from 
the first page to the last), he returned to the pages at the end of 
B, some of which still remained blank, and wrote the page or 
two of jottings which form the end of the Commonplace Book. 
But it should be remembered that this is merely conjecture. 
And, in any case, nothing of importance in connection with the 
development of Berkeley s thought depends upon it. On the 
other hand, what is of vital importance, i.e. the transposition of 
II. and III., we take to be definitely established. 


therefore onely in ye mind." This conclusion is 
obviously of the first importance in the development 
of Berkeley s philosophy. Time, he has been forced 
to state, has no existence in itself or in an external 
world of things. It is simply a sensation or series 
of sensations, and is thus entirely dependent on the 
mind. But much more than this is implied. Berke 
ley has already declared that duration and existence 
are identical, and the tremendous conclusion follows 
that all existence is mind-dependent. Time is a 
sensation, or, as he else where Bays, "U perception . . . 
tempus est perci pi ; and existence itself is simply a 
perception or series of perceptions . . . esseestpercipi. 
That is the first part of Berkeley s New Principle. 

In the next few entries Berkeley confirms and 
extends " this amazing truth." Extension, he 
declares, is a sensation, " therefore not without the 

*^infl " AT1fl fra"**^ "" mfl -Y paWtfiftH +.r> affirm 

" Primary ideas proved not to exist m matter ; after 
the same manner that secondary ones are proved 
not to exist therein." Primary , ideas, equally with 
secondary ones (which Locke and others had proved 
to be dependent on perception), are mind-dependent. 
Hence the great conclusion is confirmed that the 
whole world depends on thought. " World without 
thoughlf IB" nee quid, nee quantum, nee quale, etc." 
The world owes its dftterTninq^existence to the fact 
that it is an object of thought or perception. In 
being perceived it exists. Hence the source of 
existence must t)e in that on which existence 
depends, and that is consciousness. Consciousness, 
then, is the only real existence, for the things which 
owe their being to it have a merely derivative 


existence. And the conclusion follows that Nothing 
properly but Persons, i.e. conscious things, do exist." 
Existence, then, is of two kinds : in its primary 
sense it means " perceiving," in a secondary sense 
it means " being perceived." We may accordingly 
state the universal and comprehensive truth esse est 
aut percipere aut percipi. 

This is, in essence, the kernel of Berkeley -s theory 
of knowledge and existence. The evolution and 
it is a real evolution is complete in the first page 
of the Commonplace Book. 

But no sooner had Berkeley reached this conclusion 
(and indeed before he reached it), than difficulties 
came crowding into his mind. Nothing, I think, in 
the whole course of Berkeley s work leaves such an 
impression of freshness, vitality, and vigour, as the 
early pages of the Commonplace Book. His mind 
was literally open to the world, problems of all kinds 
impinged upon it from every direction, and, now that 
he had discovered his New Principle, it was essential 
that all these problems should be considered with 
reference to it, and in the light which it had to give. 

These problems fall naturally into three classes : 
they are either religious, psychological, or mathe 
matical. As an example of the way in which 
problems literally overwhelm him, it may be of 
interest simply to enumerate some of the points 
which he mentions and considers in the first two pages 
of the Commonplace Book. (1) Religious. Immor 
tality, the wisdom of God, the fall of Adam, the 
knowability of the soul, and the proofs of the being 
of God. (2) Psychological. The nature of primary 
and secondary qualities, the question whether a 


blind man made to see would know motion at first 
sight, the nature of colour, the relation of visual and 
tactual qualities, and the query of Molyneux whether 
a born-blind man made to see would know a cube 
or sphere at first sight. (3) Mathematical. The 
infinite divisibility of time and space, the nature of 
motion, and the question whether the incommen 
surability of the side and diagonal of the square is 
compatible with the New Principle. Most of these 
special difficulties, many of them of the first import 
ance in themselves and with reference to his theory, 
were dealt with in detail by him subsequently : the 
impressive thing about their appearance here is just 
the fact that they do appear. Berkeley s instinct 
for the important elements was not at fault ; for as 
early as this he descried the obstacles and hazards 
in the way of the exposition of the Philosophy of the 
New Principle. 

In the rest of the Commonplace Book the New 
Principle is turned over and over in Berkeley s mind, 
scrutinised from every possible point of view, 
examined in the light of all the reading he could 
bring to bear upon it, and defended against the 
attacks of imaginary critics. In these pages there 
is naturally much repetition, for the same difficulties 
recur again and again. But the repetition is, like 
Kant s, never entirely negligible. The same funda 
mental ideas are advanced in slightly different 
settings, for they have been suggested in slightly 
different ways. 

The development of what is commonly known as 
the Berkeleian theory is in essentials completed, as 
we have seen, in the first few lines of the Common- 


place Book, and it is unnecessary to trace in any 
great detail the progress of Berkeley s thought in 
the remaining pages. The precise way in which he 
dealt with the various difficulties which confronted 
the New Principle will be treated subsequently. In 
the meantime it will be sufficient to indicate, in the 
briefest outline, the order in which the various 
problems seem to have become prominent in his 

The general problem which first occupies him is 
the nature of extension. He has already concluded 
that extension is simply a collection of ideas ; but 
this conclusion, he soon realises, teems with im 
portant and difficult problems. What, for example, 
is the relation of visible extension to tangible exten 
sion ? and the relation of either or both to reality ? 
Again, since the existence of extension consists in 
being perceived, what becomes of it when it is not 
being perceived ? Has extension any permanence ? 
And further, what is the relation of the extension 
that I perceive to the extension that you perceive ? 
Has extension any self -identity ? Lastly, if exten 
sion consists of discrete ideas, particular perceptions, 
what do we mean by speaking of its continuity ? 
(pp. 60-63). 

These problems of permanence, identity and con 
tinuity are next considered in relation to persons. 
The existence, permanence, and the like of the 
external world, Berkeley believes, depend on the 
perception of persons ; and it is therefore obviously 
important to examine the grounds on which we 
ascribe existence to persons. If the existence of 
persons consists in perceiving, what becomes of them 


when they are not actually perceiving ? Does it 
follow that " men die, or are in a state of annihilation, 
oft in a day ? " Or, if we say that identity of per 
sonality consists in the will, and that the will is 
continuously active, what is the relation of the 
finite will to the will of God ? Is its existence 
swallowed up in God as the ultimate power of per 
ception and action, or does it enjoy a distinct and 
particular permanence and reality ? (pp. 64-72). 

The next main group of problems is concerned with 
the perception of distance and magnitude. Questions 
relating to perception have, as we have seen, already 
been raised by Berkeley, but he does not become 
preoccupied with them till p. 72. On that page he 
states in successive entries the two fundamental points 
in his theory of vision, viz. that there is no necessary 
connection between optic angles and extension, and 
that distance is not immediately perceived by sight. 
The relation, he goes on to point out, between visual 
signs and the distance or magnitude they suggest is, 
though constant association leads us to imagine it 
to be necessary, really only an arbitrary one. We 
never immediately perceive distance or magnitude. 
They can only be inferred by us, for they are 
suggested to us by the signs which, in our experience, 
uniformly accompany them 1 (pp. 72-82). 

In the next few pages Berkeley s mind is, in spite 
of many distractions, occupied in the main with 

1 It is noticeable that in dealing with these points, soon to be 
expounded in the New Theory of Vision, Berkeley is distinctly 
more sure of himself than when discussing the problems which 
we have mentioned in the previous two paragraphs. There he 
is, for the most part, still asking questions. Here, on the other 
hand, he makes assertions. 


mathematics. The mathematical doctrine of the 
nature of infinitesimals was perhaps the most difficult 
obstacle with which his theory had to contend, and 
it is clear that he read widely in contemporary mathe 
matics with a view to the discovery of a means of 
overcoming the difficulty. The pages in which he 
deals with mathematics are the most unsatisfactory 
in the whole Commonplace Book. He saw clearly 
that, if extension consists of minima sensibilia, then 
of course infinite divisibility is impossible, and the 
recently discovered and generally accepted mathe 
matical doctrine of infinitesimals must be branded a 
fiction. Not only so, but it would have to be asserted 
that the bisection of a line is possible only when it 
consists of an even number of minima sensibilia, and 
the time-honoured theorem that the side and diagonal 
of a square are incommensurable would have to be 
denied. Berkeley accordingly devotes much time 
to a discussion of these and kindred difficulties 
(pp. 83-89, 7-14). 

In the rest of the book no one group of problems 
occupies his attention for any length of time. It is 
noteworthy, however, that psychological questions 
are almost excluded, no doubt because by this time 
the New Theory of Vision was already in manu 
script ; and Berkeley s attention is devoted to re 
thinking, in all its aspects and implications, the 
New Principle which he was preparing to publish 
to the world in the Principles. He was thinking a 
good deal about the relation of the New Principle to 
religion and morality, he was working out a concep 
tion of will and soul that he intended to expound in 
a subsequent volume of the Principles, he was dili- 


gently drafting important paragraphs for the Intro 
duction to the Principles, and he was reading and 
re-reading Locke, Newton, Descartes, Malebranche, 
Hobbes, Spinoza and others, in order to see what 
criticisms could be brought against his theory from 
their standpoints (pp. 15-58). 

We have now indicated, as far as it is possible to 
do so with brevity, the origin of Berkeley s philo 
sophy, and the general order in which he considered 
the problems to which it gave rise. So far, we have 
not said anything in detail of his relation to other 
thinkers, and of the extent to which he was influ 
enced by them. And we now proceed to state, in 
some detail, the points at which his thought seems 
to have been influenced by other philosophers. In 
doing this our method will be strictly historical. We 
will not go beyond the data supplied by the Common 
place Book, and one or two slight contemporary 
writings ; and, as our method is historical, dis 
cussion and criticism of the various theories will be 
postponed to subsequent chapters. Here we are 
concerned simply to state seriatim the various points 
of relation and lines of influence. 

In the Commonplace Book we find three main 
sources of Berkeley s philosophy, or perhaps it would 
be better to say, three main lines of influence on the 
development of his thought. These were (1) Locke, 
(2) the Cartesians, especially Malebranche, and (3) 
Newton and other contemporary mathematicians. 
Of these Locke is by far the most important. It 
might, indeed, be proper to claim that he is the only 
real source of Berkeley s philosophy, and to regard 
the others as contributing only formative influences. 


From Locke only did he really derive anything of the 
first importance. The original impulse and direction 
of his philosophy came from Locke, and from Locke 
also the great Gemeingut of ideas which makes the 
continuity between them as remarkable as their 

In the following three sections of this chapter, we 
shall examine the influence of (1) Locke, (2) the 
Cartesians, and (3) contemporary mathematicians 
on the development of Berkeley s thought, especially 
as it is revealed in the Commonplace Book. 


That the mind of Locke exercised an almost 
magisterial influence on Berkeley is indisputable. 
But Berkeley was by no means willing to take every 
thing on trust from his master. His admiration was 
tempered by criticism. Thus, his relation to Locke 
is one both of attraction and repulsion. This double 
attitude is manifest at almost every point at which 
Berkeley came into contact with Locke. 

To speak first of the method of philosophy. At 
first Berkeley here followed Locke implicitly. Locke s 
method is empirical and psychological. He makes 
an inventory of the actual contents of human experi 
ence, and holds that, as our knowledge is wholly 
derived from experience, philosophy must consist 
simply in an analysis of that experience. 

Locke himself describes his method and aim very 
clearly in the Second Letter to Stillingfleet. " If I 
have done anything new," he says, " it has been to 
describe to others, more particularly than has been 


done before, what it is that their minds do when they 
perform the action that they call knowing." The 
a priori methods of scholasticism had been dis 
credited in natural science ; and it seemed probable 
that the methods of observation and analysis which 
had proved so fruitful in physical enquiries would, 
if applied to " inner experience " as their subject- 
matter, lead to equally successful results. Thus 
" inner experience " as well as " outer experience " 
is matter for scientific treatment. In the latter case 
the enquiry gives rise to the various special sciences ; 
in the former to mental science or philosophy. 
Observation as directed upon inner experience is 
introspection, the chief method of philosophy, which 
Locke denned as the process of " looking into the 
mind to see how it works." 

Berkeley s method is at first, like Locke s, entirely 
introspective. His objection to Locke is not that 
he used the method of introspection, but that he did 
not use it enough. Locke, like other philosophers, 
had been misled by words, and ha_d_been_cqntent to 
take words a.t their face-value without trying to 
verify their real meaning. Let Locke and his 
followers, Berkeley urges, examine their own experi 
ence, and they will find that the abstract ideas which 
they posit have no real existence corresponding to 
the words which name them. Hence, as the panacea 
for incorrect thinking Berkeley advocates intro 
spection, or, as he sometimes terms it, using a 
scholastic word, introversion. " Consult, ransack 
your understanding," he says. 1 And he is as good 
as his injunction. For most of the jottings in 

1 i, 27. 
B,P, C 


the Commonplace Book are the result of his own 
application of the introspective method to his 
own experience. 

Hence for Berkeley the only real philosophy is 
empirical. "Mem.," he says, " much to recommend 
and approve of experimental philosophy." 1 The 
New Theory of Vision is wholly psychological, and 
in the Principles he claims that his results are based 
entirely on his analysis of his own experience : in 
>. both cases he advises the reader to confirm the 
doctrines expounded by examining his experience. 2 
We should base our jghilosogh^^in^sts^n our 
o^n.Qbservatipji^fjour ; own ;_ experience. There is 
nothing more requisite than an attentive perception 
of what passes in my own understanding." 3 In 
philosophy it is vain, he declares, to postulate any 
thing which we do not find in our analysis of our 
own experience. 

But though Berkeley thus follows Locke s metho 
dology, he goes further than his master. He goes 
further by going back to investigate the foundations 
of science and the roots of knowledge. 4 He believes 
that philosophers like Locke have occupied a vast 
tract of country, but they have not been sufficiently 
careful to establish their base and organise their lines 
of communication. They have not possessed their 
possessions. Thus the territory that they discovered 
needs re-discovery and development. Or, to vary 
the metaphor, the ground which they tilled exten- 

1 i. 18. 

2 Cf. Introduction to the Principles, 13, Principles, 8, 10, 
22, 24, 25, 27, 45. 

3 Introduction to the Principles, 22. 4 i- 25. 


sively, and whose produce they thought they had 
exhausted, can be made to yield still richer and more 
abundant fruit by the application of intensive 
methods of cultivation. 

Berkeley believes in the need of a critical regress 
on current methods and assumptions. Locke, indeed, 
had criticised the scholastic presuppositions which 
were still implied in much of the philosophy of the 
day ; and, in particular, had destroyed the hoary 
doctrine of innate ideas. But his criticism had not, 
Berkeley maintains, been sufficiently radical, and 
thus many of the old errors were still suffered to 
persist. The notable instance of an error which 
had not only not been removed by Locke, but which 
he actually took pains to reinforce with new argu 
ments of his own was the doctrine of abstract, id^as 
Locke s acceptance and confirmation of that doctrine 
is, in Berkeley s view, his greatest mistake, and one 
which seriously affects the value of the critical 
method. And in Berkeley s eyes his own great 
methodological reform consists in driving back the 
critical regress which had been started by Locke 
beyond the point reached by him ; and in 
showing that any conception of abstract ideas 
formed according to the currently accepted 
theories must be avoided by a true philosophical 


But in spite of this important difference, a differ 
ence which greatly affects the results and ultimate 
orientation of the two systems, Berkeley agrees with 
Locke that the great philosophical method is that 
of observation and introspection. Berkeley is, in 
i fact, a more consistent Locke. All our philosophical 


conclusions must be based, he insists, on our examina 
tion of experience. 

Up to a certain point, Berkeley also follows Locke 
in his view of the result of this examination of 
experience. At first his inventory of the contents 
of the mind is very similar to Locke s. With Locke 
he agrees, at least at first, that " all knowledge [is] 
onely about ideas." 1 Now for Locke " idea " 
means, in the oft-quoted definition, " whatsoever, is 
the object of the understanding when a man thinks," 
In this definition "thinking" covers both sense- 
perception and reflection. Ideas of sensation are 
produced by external objects, ideas of reflection by 
the operations of the mind ; but both ideas of sensa 
tion and ideas of reflection may be called the objects 
of the mind. This in outline is Locke s theory of 

Now, a good deal of misunderstanding of Locke s 
view has arisen from not keeping carefully in mind 
a point which, it must be admitted, Locke did not 
make sufficiently clear ; and, if we are to understand 
Berkeley s relation to him, his theory must be 
explained with some care. 

For Locke,jmidpa nf sensation is one produced bv 

_ |" I *S - 

external object on the senses. But an idea of 
reflection is producedby~the operation of the mind 
on what Locke calls " internal sense." In each case 
the preposition " of " indicates the source from which 
the idea comes. On the other hand, when Locke 
speaks of an idea of blue, " blue " refers to the 
object which gives rise to the idea. An idea of blue 
may be either an idea of sensation or an idea of 

1 Commonplace Book, i. 21. Cf, Locke s Essay, iv. i. 1. 


reflection, according as it is produced by direct 
stimulation by an external object, or by the repre 
sentative operation of the mind. Locke calls the 
idea. jfche_Qhiect_of J^e_jmdnd J^ Jie_ . aJsQ_c^lls. the 
external thing the object of the mind... On his view, 
if we analyse any process of perception, we really 
have three elements, (i) the external thing, (ii) the 
idea which results from the perception of the external 
thing by the mind, and (iii) the mind for which the 
idea becomes an object. The idea thus occupies 
an interme^a^jp^itmn_^tween Jjie_jmnd_and the 
thing. " It^s^ evident the mind knows not things 
immediately, but only bv the intervention of the 
I ideas it has of them." x 

To formulate in exact and precise terms Locke s 
conception of the relation of the idea to the mind 
on the one hand, and to the thing on the other, is 
exceedingly difficult, if not impossible. But it is 
possible to say what he did not mean. (1) The 
relation between mind and idea is not that of 
substance and attribute, nor of phenomenon and 
noumenon, nor of appearance and reality. All these 
statements of the relation involve metaphysical 
theories foreign to Locke. The best statement of 
the relation, and one sanctioned by Locke, regards 

, . _ / 

the idea as the copy of the thing. But only some 
ideas (those of primary qualities) are copies of 
things, (2) The difficulty of stating the relation of 
the idea and the mind is equally great. Locke 
constantly speaks of ideas as " in the_min(L_ But 
it ia. a mistake to say that, for Locke, ideas are 
" states of CQns.fiiQu.snessJl.or " mental affections." 

1 Essay, iv. iv. 3. 


He does not dream of saying that we know only our 
own states of consciousness. Nor is an idea a 
" mental affection." Malebranche had raised the 
question of the relation of a mental modification or 
affection to an idea. In the Essay Locke does not 
touch the problem at all, and in his criticism of 
Malebranche l he does not seem to see that there is 
a problem. To say that the idea is "mental" 
would suggest an opposition which was absent from 
Locke s mind between " mental " and " non-mental." 
In so far as an idea is said to be in the mind, it would 
seem to be mental ; but as the object of the under 
standing, that which is perceived, it would seem to 
be non-mental, though on a different level from the 
physical object. But Locke does not seem to have 
asked himself whether an idea is mental or non- 
mental. He was content simply to say that it is 
thfi_i>bject of the understanding. Thus the funda 
mental fact, and that in which Locke is mainly 
interested, is that in the widest sense the idea is 
(i) the copy of the thing, and (ii) the object of the 

Berkeley at first, in his zeal " to simplify and 
abridge the labour of study," thought of denying 
the existence of both minds and things. Only ideas 
would be left. Of different kinds, and in various 
combinations, they alone would constitute the whole 
of experience. But though Berkeley actually sug 
gests the banishment of both minds and external 
things, he insists upon it only in the case of external 

1 An Examination of Father Malebranche s Opinion of Seeing 
All Things in God. 


He had what seemed to him excellent reasons for 
denying the existence of external things, and indeed 
his criticism of Locke left him no option. Locke s 
account of the " original " of knowledge, Berkeley 
maintains, is untenable. His view of the relation 
of idea and thing as that of copy and thing copied 
is impossible, because if the mind is confined to 
knowledge of its own ideas, " it can compare nothing 
but-its-own ideas." l In order to test the truth of 
its own ideas, the mind ought to be able to compare 
them with the things which they copy. But this 
is impossible, (a) because the idea caa.Lfi.likfijaathing 
but another idea, 2 and (6) because. t_he__min.d, on 
LQcke s view, is incapable of knowing things without 
the medium of ideas. 3 Further, jince external 
material things cannot be known directly, it will be 
necessary to show that they perform some useful 
practical function, if we are to be justified in retaining 
them even as postulates. But Locke s own account*" . 
of material substance shows how incapable material 
things are of undertaking the task he has assigned 
to them, for, as in his view matter is wholly passive, | 
it is unable actively to produce ideas in us. Berkeley^ 
accordingly thinks that, since Locke s external 
things have been shown to be theoretically unknow 
able and practically useless, we are justified in 
applying Occam s Razor, and retaining ideas, only. 
He has no objection to calling ideas " things," though 
"_ thing " is wider than " idea," provided we do not 
import into the termJlJthing " any.nQMorj_Ql.iaate- 
rial existence, 4 And he protests against the use 
of the phrase, "idea of something," on the ground 
1 i. 90. 2 i. 56. 3 i. 63. 4 i. 50. 


that it implies the false suggestion that the idea 
and the thing are different. 1 For Berkeley the_ 
idea is the thing perceived, and the thing perceived 
is the idea, " By idea I mean any sensible or 
imaginable, thing." a The problem of the relation 
of idea and thing thus becomes non-existent, for 
iey._are identical . 
Not so the question of the mind s relation to its 
ideas. That is a real problem. Berkeley speaks, 
as Locke had done, of ideas being " in the mind," 
and once or twice even suggests that the mind is 
nothing but these constituent ideas. He very soon 
abandoned that theory, but there is some justifica 
tion for the view that in the Commonplace Book an 
idea is regarded as some kind of mental modification. 
Yet in the Commonplace Book we also have the 
reiterated assertion that the idea is the object of the 
mind. 3 " The house itself, the church itself, is an 
idea, i.e. an object immediate object of thought." 4 
To Berkeley s treatment of this problem we must 
return later. In the meantime it is sufficient to 
note that the important thing for Berkeley is that 
the .universe consists solely of minds and ideas. 

His study of Locke s and Descartes theory of 
primary and secondary qualities also helped to lead 
him to this conclusion. Locke, largely following 
Descartes, had developed the distinction between 
/" primary and secondary qualities. Primary qualities 
are extension, solidity, figure, number, motion and 
rest. All others are secondary. Primary or real 
qualities actually belong to the thing, whether it 
is perceived or not ; but secondary or imputed 

1 i. 35. 2 i. 47. 3 i. 51. * i. 9. 

v r 


qualities rkwrmt inVmm in th^ihlhing but depend for 
^nce on our perception of them. Only 
in the case of primary qualities 7s the idea like the 
flginal. ^Their patterns do really exist in the .._ 

Bodies themselves." 7 But with secondary qualities^ 
" there is nothing like our ideas existing in the bodies 
themselves." J Ideas of secondary 

entirely dependent on the mind which perceives 
them. Now Berkeley points out that Locke s argu 
ments for the mind-dependent existence s ^secondary 
qualities may be applied also to primary-qualities. 2 
He holds that Locke has failed to make out a case 
for the different treatment of primary and secondary 
qualities, and maintains that ideas of primary 
qualities must be reduced to the same level as ideas 
of secondary qualities. Both alike are entirely 
dependent on being perceived ; and the .only_xeality 
is mind and its ideas. 

But Berkeley insists that this is reality. He 
admits, indeed, that at first sight his argument 
against .the independent existence of primary qualities 
seems to deprive us of reality. The reality of ex 
tension, figure, solidity and so on seems to have 
vanished. But this is only in seeming. Berkeley 
maintains that his theory conserves reality, and he 
is inclined to think that it is the only one that does. 3 

Berkeley s theory of reality, like his theory of 
knowledge, is very closely connected with Locke s 
doctrine, and, if we would understand its significance, 
we must examine how Berkeley developed it by 
criticism of Locke. 

Locke s doctrine of reality follows directly from 

1 Essay, n. viii. 15. 2 i. 59. 3 i. 23. 


his theory of knowledge. For Locke the only 
objects of knowledge are ideas ; and ideas, distin 
guished according to their source, may be classified^ 
as we have already pointed out, as ideas of sensatior 
or ideas of reflection. But there is another distinc 
tion drawn by Locke, to which, though it is of greal 
importance, we have not yet paid attention. That 
is the distinction between simple ideas and complex 
ideas. Simple ideas are the ultimate unanalysable 
elements of all knowledge, and in its apprehension 
of them the mind is wholly passive and receptive 
On the other hand, in complex ideas, which resul 
from the union or composition of several simple ideas 
the active operation of the mind is displayed 
Regarding simple ideas as the material and founda 
tion of all knowledge, the mind combines, by deter 
minate processes, certain of them which are regular!} 
found together in our experience into aggregates 01 
compounds ; and to each of the complex ideas thus 
formed we assign a name, and come to regard it as 
representing one thing. 

Now, this would be impossible, said Locke, unless 
some " substance " existed to account for the 
coherence of simple ideas. Without some support 
or substratum simple ideas would fall apart ; and, 
if nothing but simple ideas existed, knowledge would 
not be possible, for knowledge depends on the 
practicability of combining and compounding them. 
Thus reality depends on substance : substance is 
the support or substratum of real things, and without 
this substratum permanence and self-identity, the 
two ultimate characteristics of reality, would not 
be possible. 


What, then, is substance, which apparently dis 
charges an indispensable function in the universe ? 
Locke admitted that he could give no account of it. 
We no more know what the substratum or support 
of things is than the Indian philosopher did who 
declared that the world is supported by an elephant, 
the elephant by a tortoise, and the tortoise by he 
knew not what. Substance, then, is an obscure 
idea of somewhat we know not what. 1 

At first Berkeley seems simply to have taken over 
this conception from Locke. Thus in one of his 
early entries he claims that he has demonstrative 
knowledge of the existence of bodies, meaning by 
" bodies " " combinations of powers in an unknown 
substratum." 2 But from such a conception of an 
unknown support of qualities or powers he very 
soon emancipated himself. 

Against the view he brings the very natural 
argument that, as we can in no way know the support 
or substratum, and as it performs no indispensable 
function, it is quite unnecessary to The| 
reason why no account can be given of this substra- 1 
turn is not that it is obscure, as Locke supposed, but I 
thn.t it is non-existent. And Berkeley suggests thatf^ 
all we mean by the substance of a thing is " the 
collection of concrete ideas inc1n(fef| in thft*- thinp-." 
In this sense, Berkeley allows, we may still speak 
of the substance of a thing. But substance in 
general^ or the abstract idea of substance, is nothing 
but a philosophical fiction. 

( ranted, then, that Locke s substance is an im 
possibility, what gives permanence and reality to 

1 Essay, n. xxiii. 2. 2 i. 64. 3 i. 20. 


things ? At first Berkeley was inclined to assume 
the existence of certain mysterious powers to per 
form this function. 1 But he soon recognised that 
such powers, of which we can give no account, are 
in no better case than Locke s substance, and if 
Locke s substance be abandoned, these obscure 
powers cannot be retained. 

The conclusion to which Berkeley is finally driven 
is that the reality of things rests on no substance or 
set of powers, but depends on being perceived. This 
is what Berkeley regards as his great discovery 
esse est percipi. That this conviction dawned on 
him very early in his philosophical development has 
already been pointed out ; but it is interesting to 
notice that this, which is usually regarded as the 
most original element in his whole philosophy, had 
already been suggested by Locke. " When ideas 
are in our minds," said Locke, " we consider them 
as being actually there, . . . which is that they exist 
or have existence." 2 For Locke the esse of ideas 
is percipi. Now, Berkeley held, as we have seen, 
that things are simply collections of ideas, and there 
fore, adopting Locke s view of the esse of ideas and 
applying it universally, he reaches the conclusion 
that the esse of all collections of ideas, i.e. all things, 
is percipi. The general principle may, therefore, be 
stated as esse est percipi. 

But this definition, Berkeley sees, is not sufficiently 
comprehensive. It is true only of one of the two 
classes into which Locke divided things. Locke 
drew a distinction sharp on the whole between 
active things and passive things. Passive things 

1 i. 60, 61, 64. 2 Essay, 11. vii. 7. 


are those which are not self-subsistent, but depend 
on something outside themselves, while active things 
are self-supporting and substantial. It should not 
be overlooked that this distinction, which is of the 
utmost importance in Berkeley s philosophy, is 
simply taken over by him from Locke. 1 Berkeley, 
of course, translates it into his own terminology, and 
holds that while passive things depend on being 
perceived, the existence of active things (or persons) 
consists not in being perceived but in perceiving. 
Thus the complete definition of existence is as 
follows : " Existence is percipi or percipere." 2 

Hence the pivot of Berkeley s whole doctrine of 
reality is the mind. Active things exist as percipient, 
i.e^. a,H mind a ; and passive things exist as objects of 
perception, i.e. as dependent on the mind. All 
reality, then, is connected with the mind, and it is 
obviously of the greatest importance for Berkeley s 
theory of reality to know exactly what the mind is . 

1 At the risk of labouring the obvious, I should like to repeat 
that the features of Berkeley s theory which excited most atten 
tion in his own day on account of their apparently paradoxical 
character were immediately derived from suggestions made by 
Locke, though never elaborated by him. 

2 Under percipere Berkeley here means to include volitions 
and other active operations of the mind. In the margin of the 
Commonplace Book, opposite the entry quoted above, and with 
reference to the word Percipere, he adds a note, " or velle, i.e. 
agere." He hesitates a good deal whether to affirm that the 
mind is active in perception. On the whole, he seems to incline 
to the view that (a) in sense -perception the mind is passive and 
receptive, while (6) in imagination (which he sometimes includes 
under percipere) the mind is active. But he also maintains, 
without vacillation, that it is really volition that constitutes the 
activity of the mind ; and, as he believes that volition is impos 
sible apart from perception, the activity of volitional experience 
confers a certain degree of activity on percipient experience. 
(Cf. Commonplace Book, i. 34, 37, 47, 52, 83.) 


In his investigation of the meaning of the mind, he 
again has recourse to a consideration of Locke s 
theory. , x 

To the question What is the mind ? Locke had 
given two distinct answers, both of which occupied 
Berkeley s attention. 

(1) The mind is, on Locke s view, apart from 
experience, a piece of white paper whose blanks have 
yet to be filled. It is a tabula rasa on which ideas 
must be impressed ab extra. In perception the mind 
is thus purely passive ; it depends for its knowledge 
wholly on what it receives from the external world, 
and it can exercise no active function at all. 1 Locke 
disagrees with the Cartesian view that because it is 
the essence of the mind to think therefore the mind 
always thinks. " Every drowsy nod shakes their doc 
trine, who teach that the soul is always thinking." 2 
Berkeley criticises Locke, 3 and returns to the 
Cartesian theory, for he sees clearly Locke s incon 
sistency. If the mind is purely passive, how does 
it come by complex ideas ? Can the piece of white 
paper make marks upon itself ? Complex ideas are 
the result of the voluntary operation of the mind in 
dealing with simple ideas impressed upon it in 
perception. But a mind which voluntarily operates 
cannot be passive. 

(2) On the other hand, Locke holds also that the 

1 In the fourth edition of the Essay, Locke, perceiving the 
inconsistency into which he was led by this doctrine, introduced 
a paragraph or two pointing out that in certain cases the mind 
might exercise active functions. (Essay, n. xii. 1.) 

2 Es.say, n. i. 13. 

3 " Locke seems to be mistaken when he says thought is not 
essential to the mind " (i. 34). 


mind is a complex spiritual substance. 1 When he 
speaks of the activity of the mind, he is usually 
thinking of this theory. He holds that the same 
arguments as lead to the belief in material substance 
justify our belief in spiritual substance, for only those 
whose thoughts are immersed in matter find it 
more difficult to conceive spiritual than material 

This theory also influenced Berkeley. He had 
denied the existence of retrial auhfltffliP ^ main 
taining tb*+- *-*""g is nodiing hut a collection of 
sensible qualities ; and he was inclined to think that 
consistency required him to deny the existence also 
of spiritual substance, and affirm that the mind is 
only an aggregate of ideas. In the Commonplace 
Book he actually suggests this, and thus anticipates 
Hume in reducing his theory to consistency. 
" Mind," he says, " is a congeries of perceptions. 
Take away perceptions and you take away the mind. 
Put the perceptions and you put the mind." He 
means to deny, as Hume afterwards did, that there 
is any entity apart from ideas, and asserts roundly 
that the understanding is simply perceptions and 
the will nothing but volitions. Self, soul, under 
standing, will, are merely names for collections of 
ideas or volitions. Apart from these ideas and 
volitions, which wholly constitute them, they have 
no existence. 3 

1 Locke left the question open whether spiritual substance is 
really spiritual or simply very finely material. The latter inter 
pretation of the spiritual was well known in the Schools, and 
Locke admits the possibility that spiritual substance may really 
be very fine material substance. This was anathema to Berkeley. 

2 i. 27, 28. 3 i. 27, 31, 38, 41, 51, 53, 56, 69. 


Though Berkeley reiterates this view and is 
apparently satisfied with its theoretical consistency, 
certain practical considerations made it impossible 
for him to rest in it. Is it quite certain, he asks, that 
the understanding is nothing over and above its 
perceptions ? Still more, " what must one think of 
the will and passions ? " * Is the will, as Hume was 
later to say, nothing but the passions ? Berkeley s 
moral and religious interest prevented his believing 
this. The will must be distinct from, and superior 
to, the passions. The understanding is more than 
the ideas. Both understanding and will are active 
and may be identified with one another and with 
spirit. But Berkeley prefers to regard under 
standing and will as at least verbally distinct. " The 
concrete of the will and understanding I might call 
mind." 2 Mind as an entity must exist. 

Berkeley was led to the same conclusion by the 
consideration of the problem of the unity of experi 
ence. If there is no matter, but only sensible 
qualities, and if there is no mind, but only fleeting 
ideas, how can mind have any unity ? I cannot 
even speak of my ideas, because I do not exist apart 
from the succession of ideas. An experience of this 
sort would be utter chaos. " What mean you," 
Berkeley asks, " by my perceptions, my volitions ? " 3 
Berkeley sees that it is necessary to postulate the 
existence of a personal self to guarantee the unity of 
experience. But he deliberately avoided giving any 
account of the meaning of personality. " Mem.," 
he says, " carefully to omit defining of person, or 
making much mention of it." 4 

M. 28, ^i. 41. 3 i. 45. Italics mine. i. 41. 


Still another point impressed upon Berkeley the 
necessity of a permanent mind or self. As we have 
seen, ideas are passive, " impotent things." Hence 
an active mind is necessary to bring them into 
complexes and manipulate them. A collection of 
ideas by itself will always remain passive. Thus 
the active mind or spirit must be more than any idea 
or congeries of ideas. 

But the problem of identity and permanence must 
be probed further. Granted that there are minds, 
and that existence means simply perceiving and being 
perceived, what account can we give of the perma 
nence and identity of ideas or things and of minds 
or persons ? Neither persons nor things have 
identity, if identity means durational continuity. 
Berkeley is at first inclined to give up the permanence 
both of things and persons, and he is thus forced 
to seek some other ground for their identity. With 
regard to things, he points out that their existence 
is often interrupted by " divers beginnings and 
endings." x Ideas are particular perishing existents. 
Nor do persons have an uninterrupted existence. 2 
The mind does not exist in sleep. 3 The mind exists 
only so long as it is actually perceiving, and things 
exist only when they are being perceived. But 
Berkeley s efforts to find any adequate ground for 
the identity of persons and things, after maki^or this 
admission, proved fruitless ; and he was thereto, 
compelled to retrace his steps and attempt to 
establish the permanence both of things and persons. 
In dealing with persons, he simply reaffirmed, 
against Locke, the Cartesian view that the mind 

1 i. 72. 2 i. 71. 3 i. 34. 


always thinks. Even in sleep the mind is active 
and thus the mind as thinking substance is permai 
nent and self -identical . Mind is essentially percipient i 
and hence permanently existent. 

But the permanence of things cannot be so easily 
preserved. It will not do to say that things an 
always perceived by finite minds, because that carj 
be experimentally disproved . Berkeley first attempts 
to maintain the permanence of things by an inter 
esting variety of the Cartesian cogito ergo sun. 
argument. According to this argument, I cannol 
doubt my own existence, because the very doubt 
the thought, proves that a thinker exists. N 
Berkeley believes that things exist whenever the} 
are perceived or imagined or thought of. Hence 
the very question whether a thing exists proves thai 
it does. As mentioned, it exists. 1 But Berkeley 
soon saw that this explanation is untenable. In the 
first place, the existence of an object merely thought 
differs from the existence of an object directly 
perceived. In the second place, what happens tc 
the thing when it is neither perceived nor imagined, 
nor thought on nor referred to in any way ? It must 
simply vanish. But Berkeley could not rest in this 
conclusion. It is necessary, in order to account foi 
our practical social and moral relations to our fellow- . 
men, that things should exist even when they are,! 

jt being perceived or referred to in any way. The 
permanence of things cannot, therefore, depend on 
our finite minds. It is based on the fact that they 
exist as powers, or potentially, in the mind of God. 5 
But this is not an actual existence. 3 Berkeley is 
M. 61. 3 i. 71. 


thus forced to distinguish two kinds of existence, a 
permanent potential existence in the mind of God, 
and an actual intermittent existence only when things 
are being actually perceived by finite beings. This 
intermittent existence owes what unity it has to the 
fact that its potential permanence is guaranteed by 

Even here Berkeley was influenced by Locke. It 
is true that God in Berkeley s system is much more 
important than in Locke s, but the function which 
Berkeley makes God perform is suggested by Locke. 
When pressed, Locke is unable to explain how we 
come to have ideas. In the last resort, he thinks, 
God is responsible for the regularity and uniformity 
of our experience. " I see or perceive or have ideas 
when it pleases God that I should, but in a way that 
: I cannot comprehend." In imagination I can bring 
ideas before my own mind by my own volition, but 
not in perception. The regularity of my perceptual 
experience depends partly on God, and partly on 
the material supports of ideas. As Berkeley elimi 
nates material substance, God is left to sustain the 
whole burden of securing the permanence and 
identity of things and the regularity of perceptual 
f experience. Berkeley agrees with Locke that while 
perceptual experience must ultimately be referred 
to God as its ground, we are the causes both of our 
| imaginative and volitional experience. 

Berkeley believes, as we have seen, that minds 

are necessary for the constitution of experience. 

iBut so far we have not yet considered how minds 

Imay be known. Minds for Berkeley are sharply 

Idistinguished from ideas, and therefore we can have 


no perceptual or imaginative knowledge of minds 
How then do we know minds ? On this problem 
also Berkeley s efforts to reach a solution show th< 
influence of Locke. Locke maintained that know 
ledge of the mind is possible. If we regard the mine 
as a tabula rasa, then the knowledge we have of 11 
is intuitive. On the other hand, if we take the mine 
to be a spiritual substance, then we can have of ii 
precisely the same sort of knowledge as of any othei 
complex idea. Mind, as a spiritual substance, know* 
itself, as a spiritual substance. Thus a complex ide* 
knows itself. The difficulty of this view is obvious 
A complex idea, like the simple ideas of which ii 
is compounded, is passive. How then is it abl< 
actively to compound itself ? It must be active 
to bring together the complex of ideas whicl 
constitute it. But in its nature it is passive. 

In the Commonplace Book Berkeley tried to makt 
use of both of Locke s explanations, but he felt tha 
neither of these views was really satisfactory. Botl 
of them are inconsistent with his doctrine that al 
our knowledge is derived from the senses. Ez 
hypothesi, intuitive knowledge is neither sense 
knowledge itself, nor derived from sense -knowledge), 
It is a unique and peculiar sort of knowledge, o:i 
which we can give no account. For Berkeley r 
was a scandalous exception to his doctrine, and on<: 
which he was anxious to remove. On the othe: 
hand, the view that an idea of the self is possible 
conflicts equally with Berkeley s theory that al 
knowledge is perceptual. Berkeley s introspection 
revealed to him only aggregates of ideas in perpetual 
flux. Introspection does not enable us to form ai 


idea of the mind as an entity distinct from the series 
of fleeting perceptions. It is impossible to perceive 
the mind. Must we then conclude that the mind is 
utterly unknowable ? 

Hume, arguing in precisely the same way as 
Berkeley, that no idea of the mind is possible, took 
the further steps of affirming that the self is therefore 
unknowable, and that because it is unknowable it 
is non-existent. We have seen that Berkeley was 
unable to rest in the sceptical denial of the perma- 
nence of the self. Equally did he avoid scepticism 
with regard to the knowability of the self. He saw 
the need of revising his doctrine that all knowledge 
is knowledge of ideas. Nor was he willing to take 
;refuge in intuition. When the entities of which it 
was necessary to postulate an intuitive knowledge 
were only one or two, e.g. the self and God, such 
[(important exceptions to the general doctrine that 
ill knowledge is sense-perception might perhaps be 
allowed. But as soon as it became clear to Berkeley 
j*;hat it would be necessary to admit an intuitive 
smowledge of whole classes of things, e.g. volitions 
i ind other mental operations, he realised that it would 
i)e essential to modify his early theory of knowledge. 1 
Knowledge, be believed, is perceptual ; but it cannot 
mil be perceptual. There must be another kind of 
Knowledge of such things as selves, volitions, mental 
iterations, and relations. Now Berkeley refused to 
ye content with the obscurum per obscurius of 
f erring such knowledge to intuition. What kind 
f knowledge is it, then, that we have of such objects? 
n the Commonplace Book Berkeley has no answer 
1 i. 24. 


to this question, though he is convinced that (a) we 
can have no idea of them, and (b) we can know them 

Of what nature this non-ideal knowledge would 
be Berkeley does not make clear. But he suggests 
that it would be by way of " pure intellect," for 
in such knowledge the mind is active and 
thoughts called "the interior operations of themind." 1 
And Berkeley once or twice speaks of the mind 
" considering " things, in distinction from perceiving 
or imagining them. Such entries as these, vague 
as they are, suggest that even in the days of the 
Commonplace Book he was engaged on the problem 
of the nature of what he afterwards came to cal 
" notions." With this notional knowledge of selves 
mental operations, and moral conceptions he intended 
to deal in Part II. of the Principles. 2 

So far, we have been dealing with the implications 
of what Locke called the complex idea of substance 
But substance was not the only kind of complex idea 
mentioned by Locke. He assumed the existence o 
two other types of complex idea, which he callec, 
respectively modes and relations. Now, modes anc 
relations stand on a very different footing fron 
substances. Substance is not only self -subsisting 
it also serves as the support of all qualities. Bu 
modes and relations cannot subsist of themselves 
Modes depend upon substances, or are attributes o 

ii. 81. 

2 It is quite certain that, when the Commonplace Book wa 
written, Berkeley believed that this non-ideal knowledge is th 
only kind of acquaintance we can have with the self, the wil 
and mental operations in general. Of these, he repeatedly state;: 
we can have no idea. (Cf. Commonplace Book, i. 35, 36, 49.) 


substances ; and relations, depending on the com 
parison of one idea with another, have no existence 
apart from the ideas which they join, or on which 
they terminate. Hence modes and relations can 
never be independent. They cannot exist by them 
selves : they exist only as dependent upon substances. 

On the whole, Berkeley paid very little attention 
to Locke s doctrine of modes and relations, but even 
here certain lines of influence may be traced. 

With regard to. modes Berkeley differs in an im 
portant respect from Locke. For Locke all modes 
are complex ideas, which the mind has made " by 
combining several simple ideas into one compound 
one." l With this definition Berkeley refuses to 
agree, for in his view a complex idea is not a com 
pound, not one idea, but simply an aggregate of 
several simple ideas, and, though we may express 
this aggregate by a single word, no idea corresponds 
to it. Again, Berkeley holds, modes cannot depend 
upon, or be affections of, material substance, for it 
is non-existent. He agrees with Locke that modes 
are not self -subsisting : " they are not so much 
existences as manners of the existence of persons." a 
He thus substitutes spirit for material substance as 
the support of modes. He takes little notice of 
Locke s distinction between simple and mixed modes. 
The distinction depends on whether the simple 
constituents are of similar or different sorts. If the 
mode is simply the repetition of the same simple 
idea, as a score, for instance, is a repetition of unity, 
then the mode is simple ; but if the simple ideas 
[Compounded to make the complex one are of different 

1 Essay, n. xii. 1. 2 i. 59. 


sorts, e.g. as beauty involves different ideas of colour, 
shape, and so on, the mode is mixed. In the Common 
place Book he uses Locke s terminology, but for him 
the distinction is strictly unmeaning. If a complex 
idea is merely a bare aggregate (and this, as we have 
seen, is the only meaning Berkeley is willing to assign 
to it), it does not matter whether that aggregate is a 
collection of similar or different ideas. 

Of relations, the second of Locke s types of complex 
ideas which we are at present considering, Berkeley 
has little to say. He agrees with Locke, as we have 
seen, that relations exist ; but he holds that we can 
have no idea of them. We can use relations, talk 
about them, and express them in language by 
particles. They have a meaning, and that is all 
we can say of them. 

In connection with one particular type of relation, 
however, Berkeley paid a good deal of attention to 
Locke s theory. The relation in question is the 
causal relation. Locke had confused his treatment 
of the problem by introducing an artificial distinction 
between the relation of cause and effect and the mode 
of power. But Berkeley has no artificial schema 
to support, and he holds that the problems of power 
and causality are essentially the same. In the 
Commonplace Book, we may remind ourselves, his 
world consists of (i) God, (ii) finite selves, and (iii) 
ideas. He first states that no idea can be a cause, 
for all ideas are passive. So far ho agrees with 
Locke, 1 who maintained that God and spirits mani 
fest active power, while things (i.e. Berkeley s ideas) 
are passive powers. Idea-things for Berkeley as for 

1 Locke is not quite positive on this point. (Cf. Essay, u. xxi. 2.) 


Locke are susceptible but not productive of change. 
Thus, for Berkeley as for Locke only God and selves 
are active ; and they alone can strictly be called 
causes. 1 At one time Berkeley thought of allowing 
causality to idea-things, while carefully distinguish 
ing this physical causality from spiritual or true 
causality. 2 But later on he deemed it better to 
restrict causality to spiritual causes alone, and to 
term idea- things " occasions." An idea-thing may 
be the occasion of an action or thought, but it cannot 
really be the cause. 3 

The problem next arises how to apportion causality 
between the self and God. In the Commonplace 
Book Berkeley vacillates, at one time tending to the 
extreme theory of Malebranche that God is the sole 
cause, at another to the common-sense belief that 
finite selves exercise a real causality. On the whole, 
his view in the Commonplace Book is that God is the 
ultimate cause of all things, but the proximate cause 
only of immediate perceptions. Finite selves are the 
proximate causes of imaginative and volitional 

So far, in considering Berkeley s relation to Locke, 
we have not adverted to the aspect of Locke s theory 
which, more than any other, led Berkeley to devote 
himself to the task of refuting him. This was 
Locke s scepticism. 

That Berkeley was hostile to the deists has already 
been pointed out. Now, the deists themselves 
regarded Locke as the father of their scepticism, and 
though Locke went out of his way to disclaim the 

1 There is, however, another side to Locke s view. 2 i. 55. 
3 i. 55. 


paternity, Berkeley seems to have been inclined to 
impute it to him. At any rate, he felt it necessary, 
in his practical efforts to stamp out " atheism," to 
aim straight at what he considered the sceptical 
tendencies of Locke s theory of knowledge ; and his 
arguments to prove Locke a sceptic are quite 
ingenious. He shows that, on Locke s own theory, 
he cannot possibly escape absolute scepticism. 

Locke divided knowledge into three kinds which 
he called respectively intuitive, demonstrative, and 
sensitive. He believed that only in intuition and 
demonstration is certainty possible, for only there do 
we have " real,. knowledge. Of all the kinds of 
knowledge intuition is, Locke affirms, the most 
certain. By it we perceive the agreement or dis 
agreement of two ideas immediately, without any 
process of reasoning or inference ; e.g. " that white 
is not black, that a circle is not a triangle, that three 
are more than two and equal to one and two." l 
Demonstrative knowledge, on the other hand, is not 
immediate ; it is always mediated by other ideas, 
and depends on processes of reasoning which we call 
proofs. Demonstrative knowledge depends for its 
certainty on the possibility of proving relations 
between abstract ideas. 

All other so-called knowledge, Locke maintained, 
is not really knowledge at all, but only opinion. For 
all knowledge not based on intuition and demon 
stration is, in the last resort, sensitive knowledge, 
and thus can give no certainty. For in mere sense- 
perception we are confined within the limits of our 
own ideas, and can never reach reality. 

1 Essay, iv. ii. 1 


For the purposes of criticism Berkeley accepts 
this classification of knowledge ; and argues that, 
as it can be shown that the first two kinds of know 
ledge do not give certainty, and as Locke himself 
admits that the third does not, he cannot escape 
absolute scepticism. 

Berkeley reminds us that demonstrative know 
ledge for Locke depends on proving relations of 
agreement and disagreement by means of abstract 
ideas.. Now, Berkeley has already shown that such 
a conception of abstract ideas as is cherished by 
Locke is self -contradictory, and it therefore follows, 
he holds, that the vaunted certainty of his demon 
strative knowledge will vanish. 

Thus, as Locke himself admits that sensitive 
knowledge supplies no certainty, and as demon 
strative knowledge (at least on Locke s view of it) 
has been shown to be impossible, it follows that 
only intuition remains to save him from utter 

But intuitive knowledge, Berkeley maintains, is 
only a broken reed ; and so far is it from being able 
of itself to bear our weight that unless we can bring 
support to it from other quarters we are not justified 
in ascribing any certainty at all to it. We often 
think we have an intuitive certainty of what is 
either unreal or non-existent. Again, what seems 
intuitively true to one man may seem intuitively 
false to another, and, if our only standard of certainty 
is intuition, it will be impossible to decide which of 
these conflicting intuitions really gives truth. Thus, 
here also, Berkeley urges, Locke is necessarily 
involved in scepticism. 


Berkeley s own theory of knowledge is, of course, 
largely modelled on Locke s ; but he believes that 
the changes which he has introduced enable him 
to escape the force of the criticisms which he has 
just brought against Locke. Intuitive knowledge 
he wisely avoids as much as possible, for he sees that 
the criticisms he has used against Locke s theory 
are valid against any theory of intuition. Therefore 
he sets no store by it. 1 But he believes that certainty 
is possible on the theories of sensitive and demon 
strative knowledge which he developed. 

He claims, in the first place, that knowledge in 
sense-perception is not mere opinion, as Locke held, 
but gives absolute certainty. " Certainly," he says, 
" I cannot err in matter of simple perception." 2 
" We must with the mob place certainty in the 
senses." 3 " Certainty, real certainty, is of sensible 
ideas." And though Berkeley came later to 
modify his belief that error is impossible in sensitive 
knowledge, he never resiled from the conviction 
that, in general, the senses provide us with certain 
knowledge ; and he always regarded it as a great 
part of his work to have vindicated the senses from 
the aspersions cast upon them by Locke and others. 

And certain knowledge is possible also in demon 
stration. But by demonstration Berkeley does not 
mean, as Locke did, reasoning by means of inter 
vening abstract ideas ; he means reasoning by means 
of words or signs. " Demonstration," he says, " can 
be only verbal." 4 In the Commonplace Book 
Berkeley has simply adopted the extreme nominalism 

1 Yet he occasionally uses intuition rashly. (Cf. i. 24, 26.) 

2 i. 39. 3 i. 44. * i. 50. Italics mine. 


of Hobbes. The possibility of reasoning depends on 
the demonstration of words. In reasoning about 
particular things we take one particular to stand for 
or represent other particulars of the same kind, and 
to designate the whole class of particulars we use 
one word. We pay no attention to the differences 
the particulars : they bear jme iname^ and 

it is on the name that we reason. In the Common 
place Book Berkeley simply substitutes words for 
Locke s abstract ideas. And the reason he gives 
for the demonstrability of words or signs is precisely 
that which Locke finds to be responsible for the 
possibility of demonstrating relations of abstract 
ideas, i.e. that they are made by us. 1 Berkeley 
changes Locke s conceptualism into a nominalism. 
But this was a passing phase which was under eclipse 
by the time he wrote the Principles. 

Berkeley s general conclusion in the Commonplace 
Book is that his theory of knowledge is free from the 
sceptical tendencies which Stillingfleet and others 
had discerned in Locke ; and that, in spite of its 
paradoxical appearance, it is the only theory of 
knowledge perfectly consistent with common sense. 

Before passing from our investigation of Berkeley s 
relation to Locke, we may note (the point is inter 
esting and may be important) that his criticisms 
of Locke, on several fundamental points, are very 
similar to those of the latter s little-known critic, 
John Sergeant. It would be very rash to say that 
Berkeley adopted them from Sergeant. There can 
be little doubt that he arrived at them independently. 
But it is well to bear in mind that, as is shown by a 

1 i. 44. 


reference in the Commonplace Boole, 1 he was ac 
quainted with Sergeant s Solid Philosophy, and 
further, not only were many of his most telling criti 
cisms of Locke anticipated in that book, but his own 
conception of a mind-dependent universe was very 
clearly foreshadowed by its author. 

Though Sergeant was a writer of some merit, he 
is now almost unknown, and as his Solid Philosophy 
is extremely rare, I shall point out with some care 
the respects in which his criticism of Locke forestalls 
Berkeley, and the suggestions which he makes 
towards the philosophical doctrine which Berkeley 
afterwards expounded. 

Sergeant s book 2 is a criticism of Locke s " way 
of ideas." In it he makes it his aim, he tells us, " to 
disintricate truth," which Locke had allowed to 
become sadly entangled with words and fancies ; 
and thus to establish " solidly," in opposition to 
Locke s ideism and scepticism, our real knowledge 
of the real world. It is rather interesting to notice 
in passing that just as our contemporary realists 
seem all to be tending towards phenomenalism, so 
this " solidist " anticipates the idealism of Berkeley. 
But in the meantime I wish to draw attention, not 
to his anticipation of Berkeley s positive work, but 
to his criticism of Locke. 

Sergeant interprets Locke s " ideas," precisely as 
Berkeley does, to mean merely copies or images of 
things ; and he argues, on the same lines as Berkeley 

M. 54. 

2 Solid Philosophy Asserted, against the Fancies of the Ideists : 
or, the Method to Science Farther Illustrated. With Reflections on 
Mr. Locke s Essay concerning Human Understanding. London, 


adopted, that if our knowledge starts with ideas, we 
must be forever confined within the circle of our 
own ideas. If, that is, our knowledge begins in 
ideas which are denned as similitudes, resemblances, 
pictures, then our knowledge must terminate in 
ideas. " That only is known," says Sergeant, 
" which I have in my knowledge, or in my under 
standing ; for to know what I have not in my 
knowledge is a contradiction : therefore, if I have 
only the idea, and not the thing, in my knowledge 
or understanding, I can only know the idea and 
not the thing ; and, by consequence, I know nothing 
without me, or nothing in nature." 1 

Sergeant goes on to show that if ideas are the 
copies of things, and if truth consists in the agree 
ment of the copy and the thing, then we must know 
both the copy and the thing. But we have already 
seen that we know only the copy. Hence Locke s 
account of truth falls to the ground. Sergeant, 
then, deserves credit for his acumen in exposing the 
fallacy of the doctrine of representative perception. 
" We cannot possibly know at all the things them 
selves by the ideas, unless we know certainly those 
ideas are right resemblances of them. But we can 
never know (by the principles of the Ideists), that 
their ideas are right resemblances of the things ; 
therefore we cannot possibly know at all the things 
by their ideas." 2 Of this thesis Sergeant proceeds 
to give a syllogistic proof. " The minor is proved 
thus ; we cannot know any idea to be a right re 
semblance of a thing, (nor, indeed, that anything 
whatever resembles another rightly,) unless they be 

1 Op. cit. p. 30. Cf. p. 20. 2 Op. cit. p. 31. 


both of them in our comparing power, that is, in 
our understanding or reason, and there viewed and 
compared together, that we may see whether the 
one does rightly resemble the other, or no. But this 
necessitates that the thing itself, as well as the idea, 
must be in the understanding, which is directly 
contrary to their principles ; therefore, by the 
principles of the Ideists, we cannot possibly know 
that their ideas are right resemblances of the thing." 1 

Sergeant also argues that Locke s theory involves 
a regress ad infinitum. " Again, since Mr. Locke 
affirms that we know nothing, either by direct or 
reflex knowledges, but by having ideas of it ; it must 
follow, that when by a reflex act I know my first 
idea got by a direct impression, I must have an idea 
of that direct idea, and another idea, when I know 
that reflex one, of it ; and still another of that ; and 
so still on. ..." 2 What seems to impress Sergeant 
most is the impossibility of an idea of an idea, in 
the sense of an image, a similitude of a similitude. In 
this, in itself, there is in reality no difficulty, and his 
argument is of little value. He is on surer ground 
when he points out that in the regress of ideas we 
reach no end : if, that is, we cannot know a thing 
directly and immediately, but only by means of an 
intervening idea, then we need another idea to 
intervene and relate the mind to the original inter 
vening idea. This regress in infinitum is the direct 
result of the initial assumption of Locke, viz. that we 
cannot have immediate knowledge of particular things. 

Another of Berkeley s criticisms of Locke which is 
anticipated by Sergeant concerns abstract ideas. 

1 Op. cit. pp. 31-32. Cf. p. 342. 2 Op. cit. p. 20. 


Like Berkeley, he argues that abstract general ideas 
are self-contradictory, because idea for Locke means 
Tniage^or likeness, and an abatradi-iiniversal image 
or likeness is a contradiction in terms. ^Images, 
like tiie thingsjof^which they are copies, are always 
particjjlajcl If then we have an idea or likeness of 
universality, or generality, what is it like ? It must 
either be like the thing, or must be like nothing, and 
so is no idea or likeness at all. But it cannot be 
like the thing in any respect, because in the thing 
there is nothing that is general or universal ; but all 
that there is particular and determined ; which is 
quite unlike, nay, opposite to universality or 
generality." * 

Sergeant then states sharply the dilemma with 
which Locke and his supporters are confronted. 
" Philosophy," he presumes, " is the knowledge of 
things ; but if I have nothing but the ideas of things 
in my mind, I can have knowledge of nothing but 
of those ideas. Wherefore, either those ideas are 
the things themselves, ... or else they are not the 
things, and then we do not know the things at all." 2 
Now, the latter alternative can be shown to lead, as 
Sergeant points out, to absolute scepticism. He 
confirms this, at length, by his criticism of Locke s 
view of the intervention of ideas between the mind 
and the thing ; and concludes, " Wherefore Mr. 
Locke in pursuance of his own principles should 
not have said that the mind does not know things 
immediately, but by means of the ideas ; but that 
it does not know them at all, neither mediately nor 
immediately." 3 

1 Op. cit. Preface, 24, * Op. cit, p, 30. * Op. cit. p. 341, 
JJ,P, E 


Thus our general conclusion from the dilemma is 
that if knowledge is to be saved, the former alter 1 
native must be accepted. And it can be proved, 
Sergeant believes, that the " ideal theory " of Locke 
logically results in the adoption of the former 
alternative, i.e. that the ideas are the things them 
selves. It is necessary for the " ideal theory," he 
argues, to identify " idea " and " thing." " Being 
thus at a loss to explicate intervention or to 
know what it, or the idea or representative serves 
for, we will reflect next upon the word know 
which Mr. Locke applies (tho not so immediately, 
yet) indifferently, to the thing and to the idea. Now, 
if this be so, and that to be known agrees to them 
both ; then, as the idea is in the mind when it is 
known, so the thing, when known, should be in the 
mind too, which is our very position, thought by the 
ideists so paradoxical, and yet here forcibly admitted 
by themselves." * 

All this is, of course, very closely akin to the process 
of argument by which Berkeley reaches the New 
Principle, and more than once Sergeant almost 
stumbles upon Berkeley s actual formulation of it. 2 
It is noteworthy also that the term " notion " which 

1 Op. cit. pp. 340-341. 

* See, for example, Solid Philosophy, pp. 32 ff. and 339 ff. 
And for other points at which Sergeant s attitude to Locke is 
very similar to Berkeley s, see op. cit. p. 265, 318 and 321. 

Berkeley would have done well to take to heart one of 
Sergeant s criticisms of the use of God by Locke and Descartes. 
" God was brought in at every hard pinch, to act contrary to 
what the natures of things required ; without which, they could 
not lay their principles, or make their scheme cohere ; that is, 
they would needs make God, as he is the Author and Orderer of 
Nature, to work either preternaturally or else supernaturally ; 
which is a plain contradiction." (Epistle Dedicatory, op. cit.) 


later came to play an important part in Berkeley s 
philosophy is very prominent indeed in Sergeant s 
Solid Philosophy. 1 Whether in any of these points 
Berkeley directly derived anything from Sergeant 
must remain a matter of opinion ; but, whatever 
be our judgment, we may at least agree that the 
striking similarities between them bear a remarkable 
testimony to the existence at the time of an atmo 
sphere of opposition to Locke in which the develop 
ment of such a theory as Berkeley s is only what 
might have been expected. 

When compared with the influence exerted upon 
Berkeley by Locke and this atmosphere of reaction 
against him, the influence of other thinkers is so 
slight as to be almost negligible. Almost, but not 
quite ; and, before bringing our account of the origin 
and early development of Berkeley s thought to a 
close, we must indicate briefly his relation to the 
Cartesians, and to the mathematics of the day. 


If we may judge from the references to Descartes 
and his followers in the Commonplace Book, Berkeley 
did not make a detailed study of them till the set 
of his mind was already determined by opposition 
to Locke ; amyii^r^isr^i^ej:^ 
criticisms of those points in which the Cartesians 
agree with Locke. 2 Thus, it seems fair to assume 

1 Berkeley s relation to Sergeant s doctrine of "notions" is 
considered below, Chap. IV. ii., and see also Appendix II. 

2 The entries in the Commonplace Book pp. 48-54 consist mainly 
of critical remarks on Descartes Meditations and on the Objec 
tions and Replies. 


that Berkeley criticises them simply because the. 
attitude he had already adopted towards Locke 
made it essential, if he was to be consistent, that he 
should oppose them. But in one matter, while he 
was far from blindly concurring in the Cartesian 
doctrine, he was certainly profoundly influenced by 
the followers of Descartes, especially Malebranche. 
This was the theory of Occasionalism. 

The Occasionalism that was made explicit by 
Geulincx and Malebranche was derived from three 
fundamental and closely-related doctrines of Des 
cartes, viz. his theory of representative perception, 
his spiritualism, and his view of the nature of 
causation. 1 And it is precisely these three doctrines, 
more especially perhaps in the form which they 
assumed in Locke, that led to Berkeley s Occasion 
alism. But his Occasionalism differs from that of 
Malebranche in an important respect. He carries 
out more consistently than Malebranche the pre 
suppositions involved in Descartes fundamental 
thesis. Descartes had, indeed, recognised, as one 
of the consequences of his theory of representative 
perception, that, if matter did not exist, then, so 
long as sensations were produced in our minds with 
the same regularity as they actually are, we should 
still have the same ground for believing in the 
independent existence of matter as we do have. 
The intuitive and theological grounds on which 
Cartesianism posits the existence of an external 
world have no inherent connection with its meta 
physics. Berkeley refuses to accept these irrelevant 
reasons for the existence of the material world ; and 

1 Cf. Stein in Archivf. Gesch, d. Phil. i. 53 ft. 


on his premisses has no difficulty in showing that, 
even on Cartesian assumptions, since matter is both 
imperceptible and inert, it cannot exist. Hence, 
Berkeley retains in a one-sided form the Cartesian 
Oecasionalism. He insists, and here ho is directly 
following Malebranche, that the only ultimately xeal 
causation is creation. Matter being incapable of 
productive causality, the only real cause is spirit. 
Spirit as infinite, i.e. God, creates from moment to 
moment, the ideas which we perceive, and spirit as 
finite,,, i.e. selves, creates the ideas which .they 
imagine. Each man s world is really his own. He 
may call his ideas " ideas " or " things," but the 
essence of Berkeley s view is that they are numeri 
cally distinct for each man. Every mind has its 
separate and private world, which is correlated with 
the other worlds of other minds by God. From 
moment to moment God adjusts the several worlds. 
Berkeley, it is true, does not express his view in this 
extreme Occasionalist way ; but there is no doubt 
that, in the Commonplace Book at least, this is his 

Berkeley s other references to Cartesianism in the 
Commonplace Book are mainly criticisms of doctrines 
which Locke followed, and to which his attitude has 
already, with reference to Locke, been explained. 
He criticises Descartes arguments for the existence 
of the self and of God, the former on the ground that 
the proposition cogito ergo sum is a tautology, 1 and 
the latter because the ontological proof is invalid. 
" Absurd," says Berkeley, " to argue the existence 
of God from lys idea." 2 This criticism rests on an 

1 i. 44. 2 i. 48. 


intentional misrepresentation of Descartes concep 
tion of the meaning of idea. 1 For Descartes idea and 
conception are synonymous terms, and if his proof 
be attacked it must be along Kant s lines. Berkeley 
simply interprets " an idea of God " according to 
his own terminology as " a perception of God," and 
he is able to show that we never do have . this 
knowledge of God. 

Berkeley points out that his theory is more 
realistic and less sceptical than Cartesianism. The 
Cartesians make both primary and secondary 
qualities dependent on what is particular or con 
tingent. Primary qualities inhere in matter, which 
is contingent, and secondary qualities depend on the 
perception of particular selves. Berkeley claims that 
he is able to secure the equal reality of primary and 
secondary qualities. Both alike are real, not because 
they are independent, but inasmuch as they are 
directly dependent on God, the ultimate reality. 
Yet while Berkeley holds that the reality of things 
depends on their being referred directly to God, he 
maintains, against Malebranche, that actions owe 
their reality only ultimately to God, and proximately 
to finite selves. " We move our legs ourselves." 

Yet Malebranche influenced Berkeley more than 
any other Cartesian. Malebranche had developed 
Cartesianism by ascribing to God functions of over 
whelming importance, functions almost identical 
with those which Berkeley assigned to God. Male 
branche goes much further than Descartes in re 
ferring knowledge, from the standpoint of its validity, 

1 Berkeley knew well enough what Descartes meant by " idea." 
(Commonplace Book, i. 52.) 


to God. All 4oaewtedge4ns^4ve knowledge of God. 1 
of being at all, the .infinite is 

poterjjQr^ all things in God ; and it is only in God that 
of things. 3 ^We can know all 
God. .only beca.use allideasare^^ God. 
God., has in himself the ideas of all finite beings, 4 
and finite minds are entirely dependent for their 

practical life. Just as men are entirely dependent 
on,G^o3.Jpr_their ideas^sp^inTtJae practicaL^eab^-tneir 
actions are really produced by his activity. Dieu 
fait tout en toutes choses." God is ultimately the 
only^agent as he is the only knower. 5 

So .far as. knowledge goes, Berkeley follows Male- 
branche very closely in ascribing everything to God. 
The constancy and regularity of our knowledge is 
due to the -fact that God has himself the power to 
create all ideas, and that he graciously wills to create 
them in a uniform and regular way. All the ideas 
we perceive are God s ideas: it is because they 
are God s ideas that they are real. Ideas that 
are our own, i.e. that we can call up at will, are 
imaginative. But this imaginative knowledge is 
itself dependent on our perceptual knowledge. 
Had we not had this real knowledge, we could 

1 Recherche de la Verite, p. 295. 2 Ibid. p. 298. 

3 The chapter in which Malebranche s doctrine on this point 
is chiefly contained (Recherche, m. ii. 6) is entitled " Que nous 
voyons toutes choses en Dieu." 

4 " II est absolument necessaire que Dieu ait en lui-meme les 
idees de tous les etres qu il a crees (p. 295). 

8 Ibid. p. 300. 


not have recalled in imagination the ideas which 
God gave us in perception. But Berkeley differs 
from Malebranche on the question of our re 
sponsibility for our actions. Berkeley insists that 
in our actions we exercise a real causality. If God 
were the sole cause of our actions and volitions, our 
apparent freedom would be the cruellest delusion. 
Berkeley believes in moral responsibility and moral 
freedom ; x and he sees no way of securing them 
without maintaining the real activity and produc 
tivity of finite will. In the whole Commonplace 
Book no other single point receives such reiterated 
emphasis as this. 

Malebranche is ready to admit that though we 
know all things in God, knowledge may be of different 
sorts. But, however different these kinds of know 
ledge are, they are all ultimately mediated by God. 
Malebranche distinguishes sense-perception, imagina 
tion, and pure intellection, as different sorts of know 
ledge, under God. Berkeley was certainly influenced 
by Malebranche s elaborate psychological analysis 
of these different ways in which the mind may 
apprehend its object ; and his account of sense- 
perception is very similar to Malebranche s, except 
that Malebranche retains material substance to make 
impressions, under God, on the sense-organs. (Yet 
Malebranche admits (a) that sense knowledge is 
possible without impressions caused by material 
objects, e.g. a current of animal spirits may make an 
impression on the brain ; and (6) that the only 
reasons for the existence of material substance are 

1 So does Malebranche. But his definitions of will and liberty 
did not satisfy Berkeley. 


theological.) Berkeley also follows Malebranche in 
his analysis of imagination, the only difference being, 
as I have already pointed out, that while Berkeley 
assigns a real creative activity to the soul in imagina 
tion, Malebranche reserves such activity entirely to 
God. But to correspond to Malebranche s third 
and most important type of knowledge, Berkeley 
has, in the Commonplace Book, nothing, and, in his 
doctrine as a whole, very little. Malebranche 
believes that by pure understanding or intellection 
we obtain all our most important knowledge, e.g. 
universal ideas, common notions, and spiritual 
truths. Such conceptual knowledge Berkeley abso 
lutely refuses to admit in the Commonplace Book. 
But it seems clear from what he says about notions, 
in the second edition of the Principles, that notional 
knowledge would have comprised as its objects 
precisely those which Malebranche knows by 
" entendement pur." 

Apart from Malebranche and Locke, Berkeley owed 
very little, in his early period at least, to any other 
philosopher. In later life, when he wrote Alciphron 
and Siris, references to the thinkers of antiquity are 
frequent ; but in the Commonplace Book he is 
essentially the child of his time, and, as the two 
philosophers who at that day attracted most attention 
were Locke and Malebranche, it is naturally of them 
that Berkeley takes most notice. 

Yet in the Commonplace Book we do find one or 
two references to other philosophers. He notices 
Henry More and Ralph Cudworth, the so-called 
Cambridge Platonists, once or twice, but in the days 
of the Commonplace Book he had no sympathy for 


what he calls "the lofty and Platonic strain." 1 
Their conception of universals annoyed him, for he 
believed it was tarred with the same brush as Locke s 
abstract ideas ; and once, in reference probably to 
a fundamental doctrine of Cudworth s Eternal and 
Immutable Morality, he contemptuously ejaculates, 
" What becomes of the aeternae veritates ? They 
vanish." 2 

On Hobbes and Spinoza also Berkeley passes a 
few remarks, but these are of no particular im 
portance, for his religious interest seems to have made 
it impossible for him to feel any sympathy with them. 
He notes that it is " silly of Hobbes to speak of the 
will as if it were motion, with which it has no like 
ness," 3 and that Spinoza " gives an odd account . . . 
of the original of all universals." 4 More important 
is the version of the causal principle which he states 
in emendation of the ancient axiom ex nihilo nihil 
fit which Spinoza approves. " To make this axiom 
have a positive signification," he says, " one should 
express it thus : every idea has a cause, i.e. is 
produced by a will." 5 But neither Hobbes nor 
Spinoza in any sense formed a " source " of Berkeley s 
thought. From the way in which he mentions them 
in the Commonplace Book, it would seem that he 
studied them carefully only after the New Principle 
had been developed in his own mind, and in order 
to see whether any objections could be advanced 
from their standpoint against his doctrine. And 
as the result of this investigation, he is very we 1 
satisfied with his own philosophy. " My doc trim 
rightly understood, all that philosophy of Epicuru 

1 i. 83. 2 i. 44. 3 i. 52. 4 i. 52. 5 i. 53. 


Hobbes, Spinoza, etc., which has been a declared 
enemy of religion, comes to the ground." 

But if philosophers are rarely mentioned by 
Berkeley, the names of mathematicians are constantly 
on his lips ; and we must now consider (it is the third 
line of enquiry which we set before ourselves) the 
influence exerted on the development of Berkeley s 
mind by mathematics. 


No one who reads the Commonplace Book with any 
care can avoid noticing what a great deal of attention 
is paid to mathematical questions, and, in particular, 
how frequently Berkeley refers to Newton and other 
contemporary mathematicians. At first sight it may 
seem strange that the mathematicians referred to so 
greatly outnumber the philosophers ; but a little 
reflection will show that it is perfectly natural. 

It is natural that we should find frequent references 
to mathematicians in the Commonplace Book because 
at the beginning of the eighteenth century mathe 
matics was the science. Mathematical work of all 
kinds had been encouraged in the highest degree by 
the wonderful results progressively achieved in the 
previous century and particularly in the past two or 
three decades. A very brief sketch of the mathe 
matical progress of the preceding seventy-five years 
will make this clear. 

Mathematics was revolutionised in 1637 by 
Descartes with the invention of the so-called cartesian 
or analytical geometry. For all the purposes of 
1 i. 52. 


research analytical geometry is very much more 
useful than Euclidean. Euclidean geometry involves 
special constructions for every separate problem 
attacked, but analytical geometry proceeds on a few 
simple rules which are universally true and by 
subsumption under which any problem may be 
solved. About the same time as Descartes made 
this discovery, Cavalieri, an Italian Jesuit, applied 
the principle of indivisibles, which had previously 
been used by the astronomer Kepler, to the deter 
mination of areas and volumes. His results were 
attained by a process of summation analogous to 
that now employed in the integral calculus. The 
analytical work of Descartes and Cavalieri was 
extended and systematised by Wallis, Professor of 
Geometry at Oxford, in a series of important works, 
extending from 1656 to 1686. These books were 
much more clearly written than those of his more 
original predecessors, and they became the standard 
works on the New Mathematics. Wallis came very 
near to making the important discovery how to 
effect the quadrature of the circle, or, in other words, 
how to determine the value of TT. But, until the 
binomial theorem was invented by Newton, he did 
not quite succeed. 

The next great advance in mathematics was made 
when the fluxional or differential calculus was 
invented almost simultaneously and probably inde 
pendently by Newton and Leibniz. It had always 
been the great difficulty of mathematics to apply its 
principles to cases where continuous and gradual 
changes take place. The properties of mathematical 
figures bounded by consecutive straight lines had 


early been determined, because the changes in the 
direction of the boundaries are made only at certain 
points, i.e. at the angles of the figure, and these 
changes of direction can readily be calculated. But 
in a curvilinear figure the direction of the line which 
forms its boundary is continuously and gradually 
changing, and it is exceedingly difficult to calculate 
the properties of the figure. The work of Descartes, 
Cavalieri, Wallis and others had made it possible to 
calculate directions and areas in the case of some 
curves, but their methods were applicable only to 
certain kinds of curves. There were, indeed, in 
Wallis s work, hints of an organised method of deal 
ing with all cases ; but it remained for Newton to 
universalise the method by the invention of the 
calculus. By means of the calculus it is possible to 
determine accurately the direction of all curves. 
The importance of this invention will be recognised 
when it is remembered that most things in nature 
change continuously according to regularly operative 
laws, and that this change can be represented 
graphically as a curve. Given such a curve, or such 
a quantity in gradual and continuous change, it is 
possible by means of the differential calculus to 
compute the rate of its increase or decrease ; and, 
by the application of the integral calculus, to find 
from this the original quantity, or the principle of 
the curve. 

These discoveries in mathematics, whose import 
ance was only coming to be fully realised when 
Berkeley was a student, led to the reconstruction of 
the science, and rendered possible the further ex 
tremely rapid progress of pure mathematics, and its 


application to the world of nature in mechanics and 
physics. When Berkeley was writing the Common 
place Book much of the important work in the 
application of mathematical principles had already 
been done, or was in process of being done, by Newton 
and his contemporaries. 

By the use of the calculus Newton was enabled 
to unriddle several problems which previous mathe 
maticians had found insoluble, or of which they had 
given ridiculous or erroneous solutions. A mere 
enumeration of the departments of applied mathe 
matics which Newton created or extended is enough 
to indicate the tremendous advance made by mathe 
matics in the few years previous to Berkeley s 

Newton was the first to place dynamics on a sound 
basis by the application of his new mathematical 
methods to the determination of fluids and solids ; 
and from dynamics he deduced the theory of statics. 
Further, he was the creator of the theory of hydro 
dynamics, and he greatly extended the science of 
hydrostatics. By the application of mathematics to 
the mechanics of the solar system he achieved even 
more remarkable results. He established the law 
of gravitation, disproved the vortex-theor}?- of 
Descartes, and created the science of physical 
astronomy. In optics he made many experiments 
with spectra, and explained the decomposition of 
light and the theory of the rainbow. 1 

1 This brief sketch of the development of mathematics in this 
period is almost entirely derived from the Histories of Mathe 
matics of W. W. R. Ball, M. Cantor, and F. Cajori, and various 
writings of De Morgan and Brewster on Newton. 


And his mathematical principles were also applied 
by him and his followers in more " practically 
useful " ways. His astronomical work (combined 
with the observations of Flamsteed, the Astronomer 
Royal), and his invention of the sextant did much 
for the science of navigation. And Sir Christopher 
Wren made use of some of his mathematical methods 
in his famous architectural work. In these and 
many other ways the New Mathematics was being 
applied in the advancement of science and for the 
benefit of life. 

It is therefore not strange that, in Berkeley s day, 
mathematics was, as he tells us himself, " the 
admired darling of the age." And it is fairly clear 
that the conceptions of mathematics exercised on 
Berkeley the same sort of influence as the idea of 
evolution exerted on the philosophy and literature 
of the second half of the nineteenth century. The 
place of mathematical and physical science at that 
time was precisely similar to that occupied 150 years 
later by biological conceptions. One or two illus 
trations will perhaps help to give point to the 
analogy. When Richard Bentley, the great classical 
scholar, was appointed to give the first course of 
Boyle lectures on the being of God, he wrote to 
Newton asking him for instructions how to read the 
Principia, and in his lectures he applied the con 
ceptions of the Principia, just as theologians of later 
days applied the conception of evolution in their 
apologetics. Again, Locke, in spite of mathematical 
incapacity, assimilated as best he could the argument 
of the Principia, after having carefully enquired 
whether the mathematical calculations which he was 


unable to follow might safely be accepted. Mathe 
matical conceptions form the warp and woof of the 
thought of the day ; and Berkeley, like everybody 
else, was exposed to their influence. 

At two points, one of them of central importance 
in his philosophy, Berkeley attempted to " apply " 
mathematical conceptions. He applied algebra to 
the solution of the problems of morality, and thus 
endeavoured to found an Algebra of Ethics ; and 
by making use of the recently discovered methods 
of calculation by signs and symbols, he sought to 
give an explanation of nature and its laws by means 
of the relation of sign and thing signified, and thus 
establish an Algebra of Nature. How far he was 
successful in the attainment of these objects it will 
be convenient to consider, not at this point, but in 
connection with his theory of ethics and his doctrine 
of causality respectively. It is enough, in the mean 
time, to bear in mind that in these two theories 
he is definitely influenced by the mathematical 
conceptions of his time. 

We now proceed to examine how, in Berkeley s 
mind, so far as it can be discerned in the Common 
place Book, his own new principle is related to the 
new mathematics. 

Berkeley very early perceived that his new 
principle involved difficulties with regard to the 
nature of mathematics. The new principle implies 
that lines consist of a finite number of points, that 
surfaces consist of a finite number of lines, and that 
solids l consist of a finite number of surfaces. Thus 

1 How, it may be asked, on Berkeley s theory of minima 
jsensibilia, 79 t possible for him to maintain the existence of 


ultimately all geometrical figures consist of complexes 
of points, which are regarded by Berkeley as ultimate 
indivisibles. These indivisibles are minima sensi- 
bilia, the minutest possible objects of sense. It is 
impossible that the minima sensibilia should be 
divisible, because in that case we should have some 
thing of which our senses could not make us aware ; 
and that, Berkeley believes, is simply a contra 
diction. 1 

Sensation, then, is the test of all geometrical 
relations. Thus geometrical equality depends simply 
on our inability to distinguish in sense-perception. 
" I can mean nothing by equal lines but lines which 
it is indifferent whether of them I take, lines in which 
I observe by my senses no difference." 2 Berkeley 
explicitly considers the claims of imagination and 
pure intellect to judge of geometrical relations ; and 
summarily rejects their pretensions. Imagination, 
he holds, is based on sensation, and has no other 
authority than that of the senses. It has no means 
of judging, but what it derives from the senses, and, 
as it is removed by one stage from immediate sense- 
perception and has its knowledge, as it were, only 

solids ? A solid, on his theory, should consist of a finite number 
of surfaces, each of which is composed of a finite number of lines, 
each of which is made up of a finite number of points. A solid, 
that is, consists in the last resort of minima sensibilia. But only 
the external surfaces of the solid are open to sense -perception. 
Is every solid, then, nothing but an empty husk ? Mathematical 
calculation showed Berkeley that that was impossible. Suppose, 
for instance, a cube, the length of each of its sides being 5 units. 
Then the volume of the cube may be proved to be 5 x 5 x 5 cubic 
units. But, if it were merely a husk, it would contain (5 x 5) x 6 
square units. The only way out of the difficulty is to say that 
God perceives the minima sensibilia inside the solid. 
1 i. 86. 2 i. 22. 


at second-hand, it is, in fact, not so well fitted as 
sensation to judge and discriminate. Pure intellect, 
Berkeley continues, has no jurisdiction in mathe 
matics, for it is concerned only with the operations 
of the mind, and " lines and triangles are not opera 
tions of the mind." l 

Now, this view of the nature of geometry is the 
direct consequence of Berkeley s metaphysical 
theory, but it is interesting to note that it also 
connected itself in his mind with the method of 
indivisibles maintained by the Italian mathematician, 
Cavalieri. 2 " All might be demonstrated," he says, 
"by a new method of indivisibles, easier perhaps 
and juster than that of Cavalierius." 8 What pre 
cisely Cavalieri meant by his conception of indi 
visibles is open to doubt, but it is certain that 
Berkeley s sympathy would be elicited by his 
demonstration that quantities are composed of 
indivisible units, a line being made up of points, a 
surface of lines, and a volume of surfaces. It is 
possible, though he is very obscure, that he regarded 
areas as composed of exceedingly small indivisible 
atoms of area. Berkeley s conception is clearly 
very similar to this ; but whereas Cavalieri main 
tained that the number of points in a line is 
infinite, Berkeley was convinced that no line or 
surface can contain more than a finite number 
of points, points for him being minima sensibilia. 

ii. 22 (cf. 14). 

2 Bonaventura Cavalieri (1598-1647) was the author of Oeo- 
metria indivisibilibus continuorum nova quadam ratione promota 
(1635), and Exercitationes geometricae sex (1647). 

i. 87. 


This, then, is Berkeley s " new method of indi 
visibles." 1 

It will follow that geometry must be conceived 
to be an applied science. The only pure science will 
be algebra, for it alone deals with signs in abstraction 
from concrete things. Geometry may be regarded 
as an application of algebra and arithmetic to points, 
i.e. the minima sensibilia which constitute the whole 
of concrete existence. 2 Berkeley admits that it is 
difficult for us "to imagine a minimum." 3 But 
that is only because we have not been accustomed to 
take note of it singly. In reading we do not usually 
notice explicitly each particular letter. But the 
words and pages can be analysed down to these 
minimal letters. Similarly, though we are not 
explicitly aware of the minima sensibilia, they do 
exist separately, and may be analysed as indivisibles 
in the complex sense-datum presented to us in 
perception. Geometry, then, is an applied science 
dealing with finite magnitudes composed of indi 
visible minima sensibilia. 

If this conception of the nature of geometry be 
adopted, it immediately follows, as Berkeley very 
clearly perceived, that most if not all the traditional 
Euclidean geometry must be rejected. (1) In the 
first place, on the new theory, not all lines are capable 
of bisection. 4 Only those lines which consist of an 

1 Berkeley criticises Barrow s arguments against indivisibles. 
(Commonplace Book, i. 13, 19.) Isaac Barrow (1630-1677), 
Newton s predecessor at Cambridge, published in 1669 his 
Lectiones opticae et geometricae, which had been revised by 
Newton, and in 1683 his mathematical lectures were published 
under the title Lectiones mathematicae. 

2i - 47 - 3 i. 85. i. 79, 80. 


even number of points can be bisected. If the number 
of points comprising the line be odd, then (supposing 
bisection to be possible) the line of bisection would 
need to pass through the central point. But the 
point is ex hypoihesi indivisible ; hence the line 
does not admit of bisection. (2) Again, the mathe 
matical doctrine of the incommensurability of the 
side and the diagonal of the square must be rejected. 1 
For since both the side and the diagonal of the 
square are composed of a finite number of points, 
the relation between these lines will always be 
capable of integral numerical expression. Berkeley 
even makes the general statement, " I say there are 
no incommensurables, no surds." 2 (3) It follows 
that one square can never be double another, for j 
that is possible only on the assumption of incom 
mensurables. And it also follows that the famous 
Pythagorean theorem (Euclid, i. 47) is false. 3 

(4) Further, it is no longer possible to maintain that 
a mean proportional may be found between any two 
given lines. A mean proportional will be possible, 
on Berkeley s theory, only in the special case where] 
the numbers of the points contained in the two lines] 
will, if multiplied together, produce a square number. 4 

(5) Finally, the important work that had recently] 
been done on the problem of squaring the circle is, 
in Berkeley s view, quite useless. Any visible oil 
tangible circle, i.e. any actually constructed circle 
may be squared approximately ; and it is therefore 
time thrown away to invent general methods foi| i( 
the quadrature of all circles. 5 

That his new doctrine necessitated such a clear) 

M. 60, 78, 79. 2 i. 14. 3 i. 19. * i. 14. 5 i. 77. 


sweep of important mathematical results, most of 
which had been accepted for hundreds of years, might 
well have given pause to an even more confident 
man than Berkeley ; for (to take only one instance), 
apart from its startling theoretical consequences, 
serious practical difficulties would arise if some lines 
should prove incapable of bisection. Berkeley 
therefore suggests that, for practical purposes, small 
errors may be neglected. Though we cannot bisect 
a line consisting of 5 points, we can divide it into two 
parts, one containing 3 points, the other 2 ; and, as 
the minimum sensibile is so minute, it makes no 
practical difference if the two lines are only approxi 
mately equal. Berkeley was influenced to make 
this suggestion by the method of neglecting differ 
ences practised in the calculus. 1 If differentials, 
which are admitted to be something, are overlooked 
under certain circumstances in the calculus, are we 
not justified in the new geometry, Berkeley asks, 
in neglecting everything less than the minimum 
sensibile ? 2 The resulting errors will be so slight 
that the usefulness of geometry, which it must be 
remembered is a practical science, will not be 
impaired. 3 

It is of peculiar interest to notice that Berkeley 

1 i. 85. 

2 It might seem that in our approximate bisection of the line 
we have neglected a whole minimum sensibile. But from the 
point of view of the parts of the line we have not done that. 
The two parts ought each to contain 2J points. Now each of 
the two lines got by our approximate method differs from this 
by only \ a point. Hence the error to be neglected in each case 
is less than a minimum sensibile. And this is the condition laid 
down by Berkeley. 

3 Ct. i. 78. 


was influenced to neglect small errors, and to justify 
his procedure, by the example of the differential 
calculus. For, as we shall see in a subsequent 
chapter, nearly thirty years later he very vigorously 
attacked, in The Analyst, this method of ignoring 
small errors in the calculus. What a triumph it 
would have been for his opponents in The Analyst 
controversy if they could have seen the Common 
place Book ! 

But though Berkeley made use of the illegitimate 
method suggested by the calculus, his attitude to 
the calculus itself was, from the first, exceedingly 
critical. And his motive for criticism is not far to 
seek. If the calculus were sound, then his con 
ception of geometry could not be maintained. For 
the calculus, whether in the form of Newton s 
theory of fluxions or Leibniz s method of differ 
entials, rested, Berkeley believed, on the assumption 
of the existence of infinitely small quantities. Now, 
if these infinitesimals were admitted to exist, the 
significance of his minima sensibilia would disappear ; 
and indeed the foundations of his philosophy as a 
whole would be seriously shaken. For if quantities 
could be proved to exist which were neither sensible 
nor imaginable, he would need to revise his theory 
of knowledge and indeed his entire philosophy. 
Berkeley thus had every motive for looking with 
critical eyes on the conception of infinitely small 

In the Commonplace Book he says nothing of 
importance with regard to the use to which infini 
tesimals are put in the calculus. Though he was 
critical, his criticism is not very intelligent. But 


he was certainly acquainted with a good deal of the 
work that had been done on fluxions and differentials. 
His notes contain references, on matters connected 
with infinitesimals, not only to Newton and Leibniz, 
but also to Barrow, in whose Lectiones opticae et 
geometricae (1669) Newton s theory of fluxions was 
first stated ; to Wallis (1616-1703), whose Ariih- 
metica infinitorum (1656) paved the way for the 
invention of the calculus ; to Keill (1671-1721), who, 
in addition to his Introductio ad veram physicam 
(1702), had written on fluxions in the Philosophical 
Transactions of the Royal Society, and took a pro 
minent part in the famous " Priority Controversy " 
in which he accused Leibniz of having derived the 
fundamental ideas of his calculus from Newton ; to 
Halley (1656-1742), who besides his works on 
astronomy and magnetism wrote on fluxions in the 
Philosophical Transactions ; to Cheyne (1671-1743), 
whose Fluxionum methodus inversa (1703) and 
Philosophical Principles of Natural Religion (1705) 
gained for him admission to the Royal Society ; to 
Joseph Raphson, whose De spatio reali seu ente 
infinite (1697) contained a definition of the infinitely 
small, and who was later to write a History of 
Fluxions ; and also to two more elementary writers, 
Hayes (1678-1760), who published in 1704 his 
Treatise of Fluxions, and John Harris, whose New 
Short Treatise of Algebra . . . Together with a Speci 
men of the Nature and Algorithm of Fluxions (1702) 
was the first elementary book on fluxions to be 
published in England. And that he had not confined 
his reading to English works is proved by his refer 
ences to Analyse des Infiniment Petits, and to the 


controversy between Leibniz and Bernhard Nieu- 
wentijt, a Dutch physician and physicist, which took 
place in 1694-5 in the pages of the Leipzig Acta 
Eruditorum. 1 

It is clear, then, that Berkeley was acquainted 
with much of the work that had been done in the 
calculus. But when he wrote the Commonplace Book 
he was not in possession of the arguments which 
subsequently in The Analyst he advanced against it. 2 
In the Commonplace Book he does not venture any 
criticism in detail of the use of infinitesimals in the 
calculus. 3 What he is concerned to do there is to 
prove that infinitesimals have no real existence at all. 

The conception of the infinitesimal rests, Berkeley 
believes, on the supposition that extension is infin 
itely divisible. And mathematicians who maintain 
the doctrine of divisibility ad infinitum commit, in 
his estimation, three serious errors. 

"1. They suppose extension to exist without the 
mind, or not perceived. 

2. They suppose that we have an idea of length 
without breadth, or that length without breadth does 
exist, " or rather," as Berkeley says in the margin, 
" that invisible length does exist." 

3. That unity is divisible ad infinitum." 4 

1 The last-mentioned references are made not in the Common 
place Book, but in the contemporary essay, " Of Infinites " 
(Works, iii. 411). 

2 Some of his remarks show that he was at this time far from 
understanding its principles and methods. (Cf. Commonplace 
Book, i. 84, 85.) 

3 There is some criticism of the calculus itself in the essay " Of 
Infinites " (Works, iii. 411). And cf. Commonplace Book, i. 

4 i. 86 


It will be noticed that, with the exception of the 
third, 1 these are faults only on Berkeley s own 
metaphysical theory. 

He now makes his criticism " more homely " a 
favourite phrase of his and maintains that infini 
tesimals are wholly inconceivable. The line of 
argument is indicated twice over, 2 and is again based 
on his own metaphysic. For the purposes of his 
proof he posits two axioms : (I) " No word to be used 
without an idea," and (II) " No reasoning about 
things whereof we have no idea." 3 Now, we have 
no idea, Berkeley says, of an infinitesimal. By this 
he means, according to his terminology, that infini 
tesimals cannot be either objects of sense-perception 
or objects of representation in imagination. Hence, 
as we have no idea of an infinitesimal, it is simply a 
word. Further, according to axiom I, it is a word 
which means nothing ; and, according to axiom II, 
we have no right to use it in our calculations. 4 

The general principle that infinite divisibility is 

1 A word of explanation on the third point. Berkeley proves 
that it is an error as follows. It assumes that the integer 1 ia 
infinitely divisible, i.e. divisible into an infinite number of parts. 
But, says Berkeley, that which has an infinite number of parts 
must itself be infinite. Hence the integer 1 must be infinite ; 
or, in other words, unity and infinity are identical. But that is 
absurd. Hence the original proposition must be false. We 
conclude, then, that unity ia not infinitely divisible. (Common 
place Book, i. 87 and 89.) 

2 i. 87 and 89. 

3 This axiom is clearly inconsistent with Berkeley s theory of 
algebra. In algebra we reason on signs of which we have no 

4 Berkeley s own views on infinity were very vague. Thus 
he sometimes uses ad infinitum and ad indefinitum as though 
they were synonymous. (Commonplace Book, i. 67, 78.) 


a fiction is applied by Berkeley to the two special 
relations of space and time. He holds that time 
is not infinitely divisible, because " time is the train 
of ideas succeeding each other." Since time is 
simply this series of particular indivisible ideas, it is 
not infinitely divisible, for, however far you may 
divide it, you come eventually to unitary ideas 
incapable of further division. 

The same argument applies to the doctrine of the 
infinite divisibility of space. Since, on his theory, 
space consists simply of a compages of co-existent 
ideas, the process of division, however far it be 
carried, will eventually be checked by the indi 
visibility of the simple ideas of which it is composed. 
The doctrine of the infinite divisibility of extension 
rests, Berkeley thinks, on the mistaken belief that 
extension has real external existence. " The latter 
is false," he says, "ergo ye former also." * Exten 
sion, then, is not infinitely divisible. Further, it is 
not infinitely extended. " Our idea we call exten 
sion neither way capable of infinity, i.e. neither 
infinitely small or great." 2 No extended object can 
exist smaller than the minimum sensibile, and no 
extended object can exist larger than we can picture 
in imagination. This is Berkeley s theory. 

We have now considered, in outline, Berkeley s 
attitude, as revealed in the Commonplace Book, to 
contemporary mathematical problems. His willing 
ness to throw overboard the. solid achievements of 
the established geometry simply because they did 
not accord with an apergu of his own does not 
encourage us to rate his mathematical ability very 

i i. 59. 2 i. 63. 


highly. 1 Or perhaps it would be truer to say that when 
he wrote the Commonplace Book he had not had time 
to steady his outlook upon science and the world ; 
and allowance may fairly be made for his youthful 
dreams of a New Idea which was destined to 
revolutionise the sciences, when we remember that 
it was only about seventy-three years since Galileo 
expounded the Copernican theory and thus changed 
entirely the orientation of astronomy, and indeed of 
science as a whole. Another " Copernican change," 
Berkeley believed, was not an impossibility ; and, 
in any case, he was inclined to think that the wonder 
ful mathematical renaissance of the previous few 
decades had, among all its triumphs, grown not a 
few excrescences and callosities, which it would do 
no harm to pare off. And it was his boast that his 
theory would simplify the sciences and abridge the 
labour of study. 

Is it possible for us, gathering up the strands of 
our long investigation of the early development of 
Berkeley s thought, to estimate concisely the philo 
sophical position of the Commonplace Book ? If it 
can be summed up in a single word, that word is 
Particularism. In every department of knowledge 

1 Berkeley makes a good many foolish and supercilious 
remarks on mathematics and mathematicians in the Common 
place Book. This is especially the case in regard to Newton. 
Such entries as " Newton begs his principles : I demonstrate 
mine," and " Newton s harangue amounts to no more than that 
gravity is proportional to gravity " read strangely in comparison 
with the contemporary estimates of men who were better 
qualified than he to judge of the value of Newton s work. Cf., 
e.g., Halley s " Nee fas est propius mortali attingere divos," and 
de FHopital s almost serious question whether Newton ate, 
drank, and slept. 


which Berkeley touches his emphasis is laid on the 

The universe consists of particular persons, each 
with innumerable particular ideas or sensations. 
These groups of particular ideas form the particular 
worlds in which particular persons live. The worlds 
are private and particular, and Berkeley is forced 
to introduce God to correlate them, in order 
to make knowledge and social life possible. 
Hence his occasionalism, which means the continual 
correlation of particulars, his view of time as a 
succession of particular instants differing for each 
particular being in whose experience it exists, and 
his theory of space as not merely private to each par 
ticular person, but private to each particular sense. 

His theory of knowledge also is frankly particu- 
larist. The particular ideas which constitute the 
experience of each particular person may be aggre 
gated in various ways, but they never form a uni 
versal : they always remain a bundle of particulars. 
Reasoning is carried on by particular words, which, 
though general in their signification, still remain 
particular words. And the syllogism is either a 
tautology or a paradox. 

This particularism is obtrusive in his mathematics. 
Lines consist of particular points, surfaces of parti 
cular lines, and solids of particular surfaces. Infinity 
is impossible, because the infinite can never be made 
up of particulars, however many we take ; and, for 
the same reason, a true theory of continuity is 

Everywhere the particular and concrete is em 
phasised ; everywhere the general and abstract is 


depreciated or denied. Almost every philosophical 
term which connotes a tendency to particularism 
may be predicated of the Berkeley of this early period. 
Sensationalist, atomist, empiricist, singularist, pheno- 
menalist, solipsist, occasionalist all these may be 
applied with greater or less truth to the writer of 
the Commonplace Book. But suggestions of a more 
adequate view are, as we have seen, to be found even 
in the Commonplace Book. The development of his 
philosophy was to involve a gradually deepening 
realisation of the importance of the universal, both 
in knowledge and in reality. That evolution of 
thought will be traced in subsequent chapters. 


BERKELEY S method, as we have seen, is psycho 
logical. Psychology forms the basis of his work. 
And apart from his general psychological interest 
and attitude, he introduces into his writings from 
time to time much special psychology, inextricably 
interwoven with metaphysics, theory of knowledge, 
and philosophy of religion. It would be an almost 
impossible task, and not a very profitable one, to 
try to isolate completely Berkeley s psychology. 
That task will not be attempted in this chapter. 
The chapter will be confined to a statement and 
examination of Berkeley s theory of vision, perhaps 
the most original of all his work, and certainly his 
most solid contribution to psychology. 

Berkeley s theory of perception is strictly psy 
chological. This is worth noting, for it was the first 
strictly psychological theory of visual perception 
ever advanced. Berkeley s significance for psycho 
logy rests largely on the fact that he was one of 
the first thinkers to suggest the modern view of 
psychology as the positive science of individual 
experience. His treatment of the special problem 
with which we are now concerned differs both from 



Aristotelian and Scholastic physiological doctrines 
on the one hand, and from the mathematical theories 
of the Cartesians on the other. 

Instead of criticising in detail the Scholastic 
method of dealing with the problem, Berkeley 
simply rules it out of court as irrelevant. The 
problem of vision, he says, is a psychological one, 
and physiological considerations do not require to 
be taken into account. Berkeley s protest against 
Scholastic physiological psychology is not only 
perfectly justified on his own philosophical premisses, 
but is also notable as the first demand in the history 
of philosophy that psychological questions should 
be treated as psychology, and should not be solved 
by referring them to physiology. In spite of 
Berkeley, physiological psychology has returned in 
a new form ; and while most psychologists would 
now admit that a psychological theory of vision must 
take into account the physiology of the eye, Berkeley s 
attitude is still valuable as a protest against the 
tendency, still too prevalent, to suppose that a 
physiological explanation is necessarily psycho 
logically adequate. 

Against the geometrical optics, which Cartesianism 
had been developing, Berkeley brings a special 
criticism, which is quite unanswerable. The Car 
tesians maintained that we perceive distance by 
means of the angle formed by the concurrence on 
the object perceived of two imaginary lines extending 
from the eye to the object. The greater the angle 
subtended, the less is the distance of the object from 
the eye. Thus we perceive varying distances by 
means of the varying angles. Now the fatal defect 


of this theory, Berkeley argues, is precisely its mathe 
matical demonstrability. It could be proved, so 
that even the blind would have to admit it. This 
fact proves its inadequacy as a theory of vision. 
For if the born-blind are as capable of understanding 
a theory of vision as those who actually have the 
experience of sight, the theory must have abstracted 
from the real facts of vision, because these are facts 
which must remain forever unknown to the born- 
blind. Thus since the born-blind can understand 
this mathematical science of optics, it must, as an 
account and interpretation of the actual facts of 
vision, be either false or inadequate. 1 

Another vital criticism is advanced by Berkeley. 
It applies equally to the physiological psychology 
and the geometrical optics of the day. Berkeley 
insists that the problem of vision is a problem solely 
of vision ; and thus tactual data are strictly irre 
levant to its solution. Berkeley has much to say, 
as we shall see below, on the relation of visual and 
tactual sensations. But these tactual sensations are 
concerned not with vision pure and simple, but 
with inferences. The physiological and geometrical 
sciences of optics, with which Berkeley was familiar, 
depended on tactual data ; and therefore in 
Berkeley s opinion, whatever else they might be, 
they were not really sciences of optics, which must 
be concerned solely with vision. 

Leaving aside all physiological and geometrical 
considerations, Berkeley attempts to construct a 
theory of the perception of distance and magnitude, 
based solely on the data of vision. He takes into 

1 New Theory of Vision, i. 146. 


account only "the proper and peculiar facts of 
sight the facts, the whole facts, and nothing but 
the facts of that particular and isolated sense." 1 
In dealing with these facts, Berkeley s method is 
definitely empirical and introspective. Here again 
he differs from both Scholasticism and Cartesianism. 
He states the results he has himself obtained by 
examining his own visual experience, and he appeals 
to others whether the result of their introspection 
does not confirm his conclusions. 2 Berkeley s task 
is thus an introspective examination of the facts of 
vision. But he restricts the immediate area of his 
enquiry to two particular problems, (i) " the manner 
wherein we perceive by sight the distance, magnitude, 
and situation of objects " ; and (ii) " the difference 
there is betwixt the ideas of sight and touch, and 
whether there be any idea common to both senses." 3 
It is perhaps worth while to have made quite clear 
what Berkeley s problem really is, for much of the 
criticism directed against his theory arises from a 
misapprehension of the exact scope of his enquiry. 

Berkeley begins by stating two points, which are 
" agreed by all," and which form the assumptions on 
which his own theory is built. The first of these is 
that distance is by itself invisible. Distance is a 
line directed endwise to the eye, and whatever the 
length of the line, i.e. whatever the distance, only an 
invisible point, which remains always the same, is 
projected on the retina. It is also generally agreed 
that the distance of "considerably remote" objects 
is not immediately perceived by sense, but is judged 

1 Ferrier : Philosophical Remains, ii. 325. 

2 New Theory of Vision, i. 130, 133, 148, 152. Ibid. i. 127. 



or estimated on the basis of past experience. With 
both these accepted views Berkeley thoroughly 
agrees. His own contribution consists in extending 
the accepted theory with regard to the perception of 
the distance of considerably remote objects to objects 
near at hand. To account for the perception of near 
distance contemporary optics had suggested a theory 
which Berkeley considered entirely false. Berkeley 
therefore criticises this theory, and substitutes for it 
an extension of the accepted theory of the perception 
of remote distance. It has sometimes been assumed 
by Berkeley s disciples as well as by his critics that 
the theory that distance is not immediately perceived 
but is suggested by experience is Berkeley s great 
discovery. He has then been criticised for merely 
stating it, without any attempt at proof. 1 But the 
fact is, as Berkeley himself explicitly points out, that 
he simply takes over the theory from contemporary 
speculation. He does not attempt to prove it, 
partly because it was a commonplace of contem 
porary psychology, and partly because he regards it 
as self-evident. 2 

Both points, (a) that distance is invisible, and 
(6) that magnitude is suggested rather than per 
ceived", sLre to be found in Malebranche. But Male- 
branche also holds the theory which Berkeley 

1 Cf . S. Bailey : A Review of Berkeley s Theory of Vision, and 
T. K. Abbott : Sight and Touch. 

2 A strong argument that it is logically impossible to perceive 
distance by sight has been advanced by Ferrier (Philosophical 
Remains, ii. 330 sqq.) and Lipps (Psychologische Studien, 69 sqq.). 
They maintain that a visible distance must be between visible 
termini. In the case of the distance of an object from the eye, 
one of the termini is the eye itself, which 13 not seen. Thus 
distance cannot be seen. 


attacks- that the distance of near objects is per 
ceived by a system of lines and angles. 1 For the 
rest, Berkeley certainly owes a good deal to the 
French Father. Malebranche gives an account of 
the six kinds of signs by which we learn to estimate 
the distance of remote objects, and the most im 
portant of these are also mentioned by Berkeley. 
Berkeley extends Malebranche s theory of the per 
ception of remote distance to the perception of all 
distance. And with regard also to the perception 
of magnitude, Berkeley s theory owes much to 
Malebranche. Malebranche points out that real 
magnitude is not immediately perceived, but is, like 
distance, estimated or inferred. 2 Every sense- 
perception, according to Malebranche, involves 
judgment. Bare sensations require to be interpreted 
and only with the help of certain natural judgments 
can they become significant parts of our mental 
experience. It would have been well for Berkeley s 
theory if he had appreciated as keenly as Male 
branche the importance of the element of judgment 
or estimate. On the other hand, Berkeley improves 
on Malebranche by taking into account the relation 
of tactual and visual sensations, in the determination 
of distance and magnitude. Malebranche almost 
completely ignores the importance of tactual sensa 
tions. Berkeley very probably thought that his 
recognition of tactual experience as a main deter 
minant of our knowledge of distance and magnitude 
rendered superfluous Malebranche s elaborate system 
of natural judgments. 

1 Recherche de la Verite, i. ix. 3. 
8 Cf, Reponse a M, Regis, i. 1-3. 


It is clear from the Commonplace Book that no other 
thinker influenced Berkeley s theory of vision so 
much as Malebranche. The same two points on 
which Berkeley was specially indebted to Male 
branche appear also in Molyneux and Locke. In 
almost the same words as Berkeley subsequently 
used, Molyneux says, " Distance of itself is not to be 
perceived ; for tis a line (or length) presented in 
our eye with its end towards us, which must therefore 
be only a point, and that is invisible. ... In plain 
vision the estimate we make of the distance of 
objects ... is rather the act of our judgment than 
of sense." l But Molyneux still believes the 
traditional view of the perception of near objects. 
The importance of the question of the relation of 
tactual and visual sensations may well have been 
suggested to Berkeley by the problem proposed by 
Molyneux, which Locke discusses in the second 
edition of the Essay. The problem is this. Suppose 
a born-blind man has been taught to distinguish by 
touch a cube and a sphere. If he were then made 
to see, would he at first be able by sight to distinguish 
between a sphere and cube standing on a table out 
of his reach ? Both Molyneux and Locke answer 
in the negative. 2 The born-blind man would have 
to learn by experience which object previously 
known by tactual experience is referred to by each 
set of visual sensations. The connection between 
tactual sensations and visual sensations involved in 

1 Treatise of Dioptrics, i. 31. 

2 Essay, n. xi. 8. The passage is quoted by Berkeley in the 
New Theory of Vision (i. 193), where he somewhat disingenuously 
regards it as "a confirmation of our tenet." 


our sense-knowledge of the same object is wholly 
empirical. This is precisely Berkeley s view. 

On the whole, then, while claiming for Berkeley 
real originality, we do not suggest that he discovered 
any previously unknown truth. It would be more 
correct to say that he sought to make the traditional 
view, purged of all its physiological and geometrical 
excrescences, self-consistent. The traditional view 
was inconsistent in drawing a distinction between 
near and remote distance, and in giving different 
explanations of our perception of these kinds of 
distance. Berkeley maintains that there is only one 
kind of distance, and only one explanation of our 
awareness of it. 

We may now proceed to state and examine 
Berkeley s theory in some detail. Berkeley main 
tains that our awareness of distance is an inference 
from experience. It is not immediately perceived, 
but is suggested to the mind by some other idea or 
sensation. We know by experience that when we 
look at any object with the two eyes, we alter the 
relative position of the eyes, according as the object 
approaches or recedes from us. The turning of 
the eyes is accompanied by certain sensations, and 
these sensations are connected in experience with, 
and come to suggest, greater or less distance. The 
connection between these muscular sensations and 
objects is purely empirical, customary, and arbitrary. 
"Because the mind has by constant experience 
found the different sensations corresponding to the 
different dispositions of the eyes to be attended 
each with a different degree of distance in the object, 
there has grown an habitual or customary connection 


between those two sorts of ideas." l Berkeley also 
mentions two other marks or signs of distance. 
(a) If objects are very close to the eye, our vision of 
them is confused ; and the confusion increases as 
the distance decreases. (6) But this confused 
appearance may for some time be prevented by 
straining the eye. In such a case, the sensation of 
strain is connected empirically, in the same way as 
the confused appearance, with the distance of the 
object. 2 

Berkeley is at special pains to point out that the 
connection between these sensations and the 
distances of objects is entirely arbitrary. They are 
connected not by any necessary tie, but solely by 
association. None of the signs of distance have, 
in their own nature or necessarily, any relation or 
connection with it. From constant experience of 
the coexistence of sign and distance signified, we 
come to infer from a given collocation of signs a 
certain distance. " That one idea may suggest 
another to the mind, it will suffice that they have 
been observed to go together, without any demon 
stration of the necessity of their coexistence." 

1 New Theory of Vision, i. 132. 

2 Berkeley states (i. 135) that this list of visual signs does not 
pretend to be an exhaustive enumeration. Other marks had 
been mentioned by his predecessors, e.g., Malebranche, who 
mentions the size, force, definiteness, and distinctness of the 
retinal image, and the number and kind of the intermediate 
objects (Recherche de la Verite, I. ix. 3). But it was not Berkeley s 
purpose to give a complete list of visual signs, such as has been 
given by Helmholtz. His aim was directed to show that, what 
ever visual signs there might be, the connection between them 
and objects could not be other than empirical and arbitrary. 
To attain this result he considered a perfect induction unnecessary. 

3 New Theory of Vision, i. 134. 


Thus, since in our experience the more confused the 
sensation the less the distance, a sensation of con 
fusion no sooner occurs but it suggests the distance 
which in previous experience has been found to 
coexist with it. If it had been our experience, or 
(what is the same thing) if it had been the course 
of nature, that the more confused the sensation the 
greater the distance, then the same series of sensa 
tions which make us think that an object is approach 
ing would then lead us to suppose that it was re 
ceding. 1 The connection is purely empirical and 

The proof that distance is not immediately 
perceived, but is suggested by various signs, though 
Berkeley hints at it in 18, is not explicitly stated 
by him. But as Mill has shown, " the evidence of 
the doctrine is of that positive and irrefragable 
character which cannot often be obtained in psy 
chology ; it amounts to a complete induction." 2 
The actual arguments which Berkeley suggests are 
those afterwards named by Mill the methods of 
Agreement, Difference, and Concomitant Variations. 
When a certain sign is present, a certain distance is 
indicated ; when the sign is absent, the distance 
cannot be inferred ; and every change in the distance 
is proportionate to the alteration in the signs. From 
these arguments Mill would infer a causal relation 
between distance and sign. But Berkeley does not, 
in the New Theory of Vision, go beyond the assertion 
of uniform coexistence, though later, e.g. in the 
Theory of Vision Vindicated, he shows that this 

1 New Theory of Vision, i. 134. 

2 Dissertations and Discussions, iv. 160. 


empirical connection, though arbitrary, is not 
capricious, but depends on the will of God, and is 
thus in Berkeley s sense a causal relation. 

Having shown that all perception of distance is 
an inference from experience, Berkeley proceeds to 
prove that the only things directly perceived are 
colours. It was generally agreed in contemporary 
speculation that colour is immediately perceived, 
but Berkeley goes further and holds that nothing 
but colour is immediately perceived. 1 Thus the real 
magnitude and situation of objects is as imper 
ceptible as their distance. By the " distance " of 
an object we mean the distance of the object from 
the eye. " Situation " depends on the distance of 
one object from another, and " magnitude " on the 
distance of the parts of an object from one another. 
In every case the conception of distance is involved, 
and in every case sight properly supplies only colour. 
Colours appear in certain arrangements which are 
called apparent figure, apparent position, and 
apparent magnitude. Now apparent figure, apparent 
position, and apparent magnitude have existence in 
two dimensions only. They have length and breadth 
but no depth, for in immediate perception we 
perceive only coloured plane surfaces. One differ 
ence between distance from the eye and distance in 
a plane surface may be noted. The former kind of 
distance is entirely imperceptible, because every 
distance projects only a single point on the retina. 
But lateral or transverse distance, i.e. distance 
between two objects in a plane, projects a line on 
the retina. This line on the retina is immediately 

1 New Theory of Vision, i. 146. 


perceived, but is perceived only as an apparent 
distance. The real distance must be estimated or 
inferred. In immediate visual experience we per 
ceive only colour. All else is an inference from other 
experience. 1 

Before examining the nature of this other experi 
ence, we may notice a question of importance in its 
relation to Berkeley s general metaphysical theory. 
When Berkeley says that distance or outness is not 
immediately perceived by sight, does he mean that 
we are unable to perceive visible objects as external 
at all, or that, while we can and do perceive that 
objects are external, i.e. at some distance from the 
eye, we are incapable of perceiving their relative 
distance from it and from one another ? One of 
F^i 7r 3 1 "" VTT s critics (Bailey) has said, " Whether 
objects are seen iJ I - external or at some distance, 
is one question entirely distinct from the enquiry 
whether objects are seen by tnA rnassisted vision 

1 James, among others, maintains that distance io ir mediately 
perceived. He denies the Berkeleian hypothesis, and though he 
holds that its logical arguments are irrefragable, he holds thti 
its introspective analysis is mistaken. " The feeling of depth or 
distance, of farness or awayness, does actually exist as a fact of 
our visual sensibility " (The Perception of Space, Mind. 1887, 
p. 330). James maintains that all sensations are voluminous, 
and that a sensation of depth or distance is as immediate as one 
of the other two dimensions. But James s introspective account 
of sensation comes perilously near to committing the fallacy 
which he himself christened the psychologist s. He examines 
his own experience, and because he finds in that experience what 
appears to be a sensation of depth, he assumes that distance is 
immediately and originally perceived. Even if James s intro 
spective result be strictly accurate, the proper inference from it 
is not that distance is immediately and originally perceived, but 
only that in our developed experience it seems to be sensed, 
though it may really only be estimated and inferred from a 
collocation of previous visual and tactual sensations. 


to be at different distances from the percipient." 
Bailey then attacks Berkeley on the ground that he 
uniformly assumes these problems to be the same, 
or at least takes it for granted that they are to be 
determined by the same arguments. Now Berkeley 
does not assume the questions to be the same, and 
he distinctly points out that the immediate objects 
of vision are not external. They are at no distance 
from the eye. 1 

But in Terrier s statement that the theory of 
vision is an " idealism of the eye " 2 there lurks a 
suggestio falsi which comes forth naked and un 
ashamed in Abbott s words, " There is indeed only 
one dogmatic system consistent with the Berkeleian 
theory of vision, and that is Berkeleian idealism." 3 
This is not so. The theory of visual t^^p^n 
rests on its own evidence, .and. Vv^nie Berkeley could 
and did regard it as a a anticipation of his meta 
physical doctrin-.i^nas in point of fact been accepted, 
and qui^e consistently, by most subsequent philo 
sophers, however much their metaphysical positions 
might differ from his. 

Berkeley himself supplies the best proof that the 
theory of vision does not necessarily imply imma- 
terialism, by his explanation of tactual experience. 
He everywhere speaks as though touch bears witness 
to an external non-mental reality. 4 It is from this 

1 New Theory of Vision, i. 150, 152. 

2 Philosophical Remains, ii. 324. 3 Sight and Touch, iii. 

4 It is clear from the Commonplace Book that when Berkeley 
wrote the New Theory of Vision he had already excogitated his 
thoroughgoing immaterialism. Berkeley tells us also that he 
used the old terminology in dealing with touch in the New Theory 


tactual experience, taken in conjunction with the 
various visual signs, that we are able to infer the 
real magnitude, distance, position and size of objects. 
Tactual experience is the other experience, to which 
we referred a moment or two ago, that is necessary 
to our cognition of objects. Tactual sensations 
become connected in our experience with visual 
sensations, and the visual sensation becomes the 
sign of the tactual sensation, so that on every 
occurrence of certain visual sensations we infer that 
under certain conditions certain tactual sensations 
will ensue. " Having of a long time experienced 
certain ideas perceivable by touch as distance, 
tangible figure, and solidity to have been connected 
with certain ideas of sight, I do, upon perceiving 
these ideas of sight, forthwith conclude what tangible 
ideas are, by the wonted ordinary course of nature, 
like to follow. Looking at an object, I perceive 
a certain visible figure and colour, with some degree 
of faintness and other circumstances, which, from 
what I have formerly observed, determine me to 
think that if I advance forward so many paces, miles, 
etc., I shall be affected with such and such ideas of 
touch. So that in truth and strictness of speech, 
I neither see distance itself, nor anything that I take 
to be at a distance. . . . And I believe whoever 
will look narrowly into his own thoughts, will agree 
with me, that what he sees only suggests to his under 
standing that, after having passed a certain distance, 
to be measured by the motion of his body, which is 

of Vision, in order to attempt, by insinuating his viev/s gradually, 
to win for them a more favourable reception than they were 
likely to obtain, if they appeared too paradoxical. 


perceivable by touch, he shall come to perceive such 
and such tangible ideas, which have been usually 
connected with such and such visible ideas." x 
Berkeley points out that two kinds of objects are 
apprehended by the eye. One sort consists of 
colours, and is immediately and primarily perceived. 
The other kind comprises tangible qualities which 
are secondarily suggested by the former kind. It 
may seem strange, Berkeley adds, that in ordinary 
experience we never discriminate between the two 
sorts of objects ; and further, that those objects 
which by reflection we know to be suggested and not 
immediately perceived are usually those which make 
the greatest impression on us. The difficulty may 
be explained, according to Berkeley, by the analogy 
of language. The words of a familiar language are 
not themselves deliberately attended to : the ideas 
which the words, as signs, suggest make an impres 
sion on us, though the mere words rarely do. Again, 
an unreflective mind does not explicitly differentiate 
words and ideas. At a low level of mental develop 
ment a man no more distinguishes them than he does 
visible and tangible qualities. 

Nevertheless, the difficulty is a real one, and 
Berkeley s critics are right in expressing their 
dissatisfaction with his explanation. The strongest 
objection advanced is that Berkeley s explanation 
does not account for the fact that the tactual experi 
ences, which according to him are suggested by 
visual experiences, are not, as we might expect, 
clear-cut and definite, but vague and uncertain. If, 
it may be asked, objects seen at a distance consist 

1 New Theory of Vision, i. 148. Italics mine. 


simply of tactual sensations suggested by visual 
sensations, how is it that our recollection of tactual 
sensations is so indefinite ? If visual sensations 
are mere signs, which the mind rapidly glides over, 
and hastens to the tactual sensations with which 
they are connected, we ought to be distinctly aware 
of the tactual sensations thus suggested. But intro 
spection assures us that when we look at objects 
we have the greatest difficulty in recalling tactual 
sensations. Instead of being bright and lively, they 
are dull and shadowy. Taking these considerations 
into account, some of Berkeley s critics, e.g. Bailey, 
maintain that wliile we do not perceive distant 
objects immediately, we estimate their magnitude 
and distance, not by inferring tactual impressions 
from visual, but by comparing original visual 
impressions of distance with other visual impressions 
otherwise received. 

The problem which these critics raise is a real one, 
and it is impossible to give a satisfactory solution of 
it without admitting that on one vital point Berkeley 
made a serious mistake. The explanation of the 
difficulty depends on the general nature of the 
relation of sign and thing signified. 1 In the first 
place, signs are not noticed so much as the things 
they signify. But, in the second place (and this is 
the point of special importance in connection with 
Bailey s objection), the thing signified may be repre 
sented to the mind in the vaguest possible way. To 
take Berkeley s analogy of language, while it is true 
that words are not generally themselves attended to, 

1 Locke approached very near to giving this explanation, 
Essay, 11. ix. 8. 


but only the things or ideas which they signify, it is 
also true that the ideas or things signified are not 
represented to the mind in toto. The name of the 
thing recalls usually only one or two significant 
elements in the thing, not the thing with all its 
details. Now, this analogy is exactly applicable 
to the relation between visual and tactual sensations. 
Visual sensations, through long experience, come to 
suggest tactual sensations so directly and so rapidly 
that the tactual sensations in their turn become only 
signs, from which the mind runs on to the identical 
thing, of which the visual and tactual sensations 
alike supply only partial appearances. This is what 
Berkeley would not admit. For him, tangible 
extension is not a sign of anything else : it is the 
thing signified, and nothing but this. But if 
Berkeley s view be correct, it seems impossible to 
account for the vagueness of tactual sensations. 
On the other hand, if we admit that tactual sensa 
tions are both things signified and, in turn, the signs 
of the real extension, it becomes possible to see 
how the mind may run rapidly on from the sign to 
the thing signified, and then, without paying special 
attention to this signified thing, but regarding it in 
turn merely as a sign of something else, may proceed 
to anything else that it does suggest. 

We have already seen that the same arguments 
that apply to distance hold also of magnitude and 
lateral distance, but Berkeley has still to show that 
the visual signs which suggest magnitude do so as 
immediately as they suggest distance. According 
to the geometrical optics of Berkeley s day, the 
magnitude of an object is estimated by its distance 


from the eye. The distance of an object from the 
eye is first found, and then mediately its magnitude. 
But Berkeley maintains that visual ideas " have as 
close and immediate a connection with the magnitude 
as with the distance ; and suggest magnitude as 
independently of distance as they do distance 
independently of magnitude." l At first sight, this 
view would seem to be difficult to uphold. It might 
be pointed out that our estimate of the real magni 
tude of an object must depend on our knowledge 
of the distance of the object. We estimate the size 
of the moon from the distance at which it is. 
Because we know the sun s distance from us to be 
greater than the moon s, we judge that though the 
visual appearances in the two cases represent closely 
similar apparent extensions, yet the real magnitudes 
are very different. Now all this is perfectly true. 
But it is also true that we can, and do, estimate 
distance from magnitude. From previous experi 
ence we have formed a conception of the visual 
magnitude of a man. When we see a man at a 
distance, we judge his distance from us by comparing 
the actually seen magnitude with that which we 
know him to possess. Berkeley s doctrine is per 
fectly sound. We may infer distance from magni 
tude, or magnitude from distance. But we do not 
necessarily infer either from the other. 

But in connection with magnitude a problem 
arises, which does not vex the discussion of distance. 
Distance is not perceived at all, only inferred. But 
magnitude is both perceived and inferred. Thus we 
have only one kind of distance, but two kinds (or, 

1 New Theory of Vision, i. 152. 


as will be shown later, three kinds), of magnitude. 
There is visible magnitude and tangible magnitude. 
But magnitude may be distinguised in another way, 
as apparent or real. Now Berkeley has no hesitation 
in identifying apparent with visible magnitude, and 
real with tangible magnitude. Thus for him, there 
are only two kinds of magnitude, (i) visible or 
apparent, and (ii) tangible or real. Visible magni 
tude cannot be real, for it changes as the object 
approaches or recedes from the eye. On the other 
hand, tangible magnitude remains invariably the 
same, and thus when we speak of the magnitude 
of anything, " we must mean the tangible mag 
nitude." l 

Berkeley uniformly insists on the difference 
between tangible and visible magnitude. "It is 
plain there is no one self-same numerical extension, 
perceived both by sight and touch." 2 Thus, (a) 
tangible and visible extension are numerically 
different. And, (6) they are also qualitatively 
distinct. Not only is there no one idea common to 
both senses, but there is not even one kind of idea 
common to both. Extension, figure, and motion 
as perceived by sight differ and differ generically 
from extension, figure, and motion as perceived by 
touch. Three main arguments in support of this 
thesis are stated by Berkeley. 3 (i) We are apt to 
confuse visual with tactual sensations, partly because 
we have grown up to awareness of both simultane- 

1 New Theory of Vision, i. 153. 2 Ibid. i. 186. 

3 Berkeley also mentions ( 132) in corroboration of his doctrine 
Locke s solution of Molyneux s problem of the born -blind man 
with the cube and the sphere. (Locke s Essay, IT. ii. 8.) Cf. 
supra, p. 100, 


ously, and partly because we have always given them 
the same name. But a man born blind would not, 
on receiving his sight, identify his visual sensations 
of an object with his previously acquired tactual 
sensations. He would require to be taught to refer 
the two kinds of sensations to the same object. 1 
(ii) It is impossible that visible and tangible extension 
should be the same, because the only immediately 
perceptible objects of sight are colours, and these 
cannot be perceived by touch. Thus no object can 
be immediately perceived by both senses, (iii) It is 
a geometrical axiom that " quantities of the same 
kind may be added together to make one entire sum." 
We can add lines together, or solids together ; but 
a line cannot be added to a solid. So, says Berkeley, 
we can add tangible extension to tangible extension, 
or visible extension to visible extension ; but the 

1 In corroboration of his thesis Berkeley is fond of referring to 
the first visual experience of the born-blind man made to see. 
(41, 42, 79, 92-99, 103, 106, 110, 128, 132-137.) And in the 
appendix (added in the second edition) he refers to the case of 
William Jones, a born-blind man restored to sight at the age of 
twenty. (An account of this case is to be found in the Taller of 
August 16, 1709.) Very little fresh evidence on the point has 
come to light. The most important is Cheselden s case (Philo 
sophical Transactions, 1728), which has usually been regarded as 
confirmatory of Berkeley s theory, though Hamilton (Reid s 
Works, i. 137n) and Abbott (Sight and Touch, 145-148) think 
otherwise. Descriptions of a few other cases are to be seen in 
the Philosophical Transactions for 1801, 1807, 1826 and 1841. 
An interesting recent case of successful operation on a born -blind 
man, which seems to support the Berkeleian view, is described 
by Prof. Latta in the British Journal of Psychology, i. 135. (But 
cf. T. K. Abbott in Mind, N.S. xiii. 543.) Inferences have also 
been drawn from the first experiences of infants and the young 
of animals. But in no case have these inferences been made on 
sufficient data. They therefore do not justify any confidence in 
their evidence. 


addition of visible to tangible extension is as 
impossible as the addition of a line to a solid. 

Berkeley is so anxious to insist on the difference 
between visible and tangible extension, that he 
entirely overlooks the problem of their unity. For 
Berkeley visible and tangible extension are entirely 
distinct, and the only connection between them is 
the arbitrary tie of their happening always to coexist. 
But this is really only the statement of the problem, 
and not its solution. The modern psychologist 
agrees with Berkeley that " the relation between 
Ev, the extension of visible sensation, and Et, the 
extension of tactual sensation, apart from the general 
similarity which is implied in applying the word 
extension to both, consists merely in their regular 
empirical conjunction in certain successive and 
simultaneous combinations." l 

But such a view hardly does justice to the fact 
that there is one extension which is referred to 
equally by tactual sensations and visual sensations. 
Berkeley could not give any adequate account of the 
unity of extension, because he did not distinguish 
between our sensations and the sensible qualities of 
objects. For him, the term " idea " covers both 
sensible quality and the sensation. Now, we may 
point out that while visual and tactual sensations 
are entirely different, yet the visible and tangible 
qualities of objects have a real unity. They seem 
at least to be spatially coincident. This would have 
been denied in toto by Berkeley. In the first place, 
he would have denied the possibility of separating 

1 G. F. Stout, Some Fundamental Points in the Theory of Know 
ledge, p. 29. 


the mental sensation from the non-mental quality. 
In the second place, he would not have admitted 
any spatial identification of visible and tangible 
ideas. So far as the New Theory of Vision goes, 
tangible ideas may be spatially extended, but 
visible ideas, i.e. colours, can be only " in the 

Berkeley identifies tangible with real extension. 
This is a mistake. As we have seen, he regards 
visible extension as apparent, and tangible extension 
as real. Apparent or visible extension merely 
suggests or signifies real or tangible extension. As 
against Berkeley we must maintain that (a) real 
extension is other than tangible extension, and that 
(6) tangible extension, equally with visible extension, 
is a sign of real extension, which is not immediately 
perceived, but constructed out of the data supplied 
by sight and touch, plus a judgment or estimate of 
the circumstances, conditions, and relations in which 
the extension is apprehended. Thus we may say 

I &u 

that E =x \ . where E stands for the real extension, 

ev for visible extension, et for tangible extension, 
and x for the element of judgment or estimate 
involved in the mental construction. Real ex- 


tension is the complex unity in difference x -{ which 


may be signified equally by its appearance to sight 
(ev), or its appearance to touch (et). Thus tangible 
extension is as far from being real extension as 
visible extension is ; and, further, the simple co 
existence of tangible and visible extension is not 
enough to constitute real extension. This simple 


coexistence may be represented as ^. But real 

extension involves, in addition to these sensible data, 
an element of reflective estimate or judgment, (x). 


Berkeley s view of the relation might be repre 
sented thus : E=et=xev. Berkeley believes that 
we may construct real, i.e. tangible, extension from 
visual data. He insists that this is always an infer 
ence. It always involves judgment. We cannot 
immediately perceive real extension by sight. So 
far Berkeley is right. But he went wrong in 
supposing that we can perceive real extension 
immediately by touch. Our tactual experience does 
not give us immediate acquaintance with real 
extension. To know real extension we require to 
construct or judge on the basis of both tactual and 
visual data. 




BERKELEY believes, like Kant, that the desire for 
knowledge would not be implanted in man if the 
satisfaction of that desire were for ever impossible. 
" We should believe," he says, " that God has dealt 
more bountifully with the sons of men than to give 
them a strong desire for that knowledge which he 
had placed quite out of their reach." 1 Let us not 
depreciate our faculties : let us rather suspect the 
use we make of them. If we are sceptics, our 
scepticism is self-imposed. There is nothing in 
reality to force us into scepticism. Knowledge is 
possible, but " we have first raised a dust, and then 
complain we cannot see." 2 Now, Berkeley believes 
that this dust has been raised partly by our use of 
language, but mainly by the doctrine of abstract 

In order to clear away this dust which blinds the 
eyes of philosophy, Berkeley draws attention, in the 

1 Introduction to the Principles, 3. 2 Ibid. 3. 



Introduction to the Principles, to. (a) the ambiguity 
and unsuitability of ordinary language as a philo^ 
sophical medium, and (b) the confusion caused in_ 
philosophy by the doctrine of abstract ideas. With 
regard to (a) nothing need be said : Berkeley s 
critique of language follows thrice-familiar lines. 
But his criticism of abstract ideas is of the first 
importance, both for the interpretation of his own 
positive doctrine, and on account of the fundamental 
philosophical problems to which it gives rise. To 
this, then, we now turn our attention. 

There is a good deal of misapprehension as to the 
precise nature of Berkeley s criticism of abstract 
ideas. This misapprehension is due to a failure to 
notice that his criticism is really a twofold one. 
Partly it is an objection, on psychological grounds, 
to previously given accounts of the process by which 
abstract ideas are formed in individual experience ; 
and partly it is a metaphysical examination of the 
problem whether any abstract ideas at all are 
possible. Berkeley himself, it is true, is not as 
careful as he ought to have been to distinguish these 
two lines of criticism ; but in examining his argu 
ments it is necessary to bear in mind that there are 
two lines. 

Berkeley first argues that the received theory of 
the formation of abstract ideas is indefensible. It 
has been too rashly assumed that the view which 
Berkeley states is intended to represent Locke s 
theory. Now, in reality, what Berkeley meant to 
state and attack was not exclusively Locke s theory, 
but the generally accepted doctrine, mainly a legacy 
from Scholasticism, which had been supported by 


Locke. The paragraphs x in which Berkeley ex 
pounds the theory of the formation of abstract ideas 
which he wishes to criticise are introduced by the 
statement "It is agreed on all hands," and Locke 
is never referred to. It is only later, when Berkeley 
is examining " what can be alleged in defence " of 
the theory, that he mentions Locke as one who has 
given the doctrine of abstraction " very much 
countenance." 2 His procedure is to state and 
criticise generally a theory, and then examine in 
detail some particular arguments in favour of such a 

This view of Berkeley s procedure is confirmed by 
his rough draft of the Introduction to the Principles. 
In that document he points out that he is attacking 
the general theory, accepted by philosophers, that 
there are " abstract ideas or general concejjtions of 
things," 3 or ^_etemal ? immutable, unr^r8aOda&.l!_ 4 
His criticism is perfectly general, and is directed 
against "genera, species, universal notions, all which 
amount to the, same thing," in addition to what are 

^^^^^^^^^^ " ^^^^^**^^*^^^^^^^^^^^^mimmm***m**mi^mmm*i^*~***^* 

properly called "abstract ideas." In this rough 
draft, which was written in 1708, Berkeley denied 
entirj3ly_the_ universal element in knowledge. His 
later work was to consist in a gradually increasing 
recognition of the importance of the universal. 

To return to the Principles. It is clear, I think, 
that Berkeley s arguments against (a) the general 
theory which he states (and which he attributes to 
nobody in particular), and (6) the particular argu- 

1 Introduction to the Principles, 7-9. 

2 Introduction to the Principles, 11. 

3 Draft of Introduction, iii. 359. * Ibid. iii. 370. 6 iii. 360. 


ments advanced by Locke in support of such a theory, 
are both perfectly sound. The general theory which 
Berkeley states is neither a travesty nor a faithful 
reproduction of Locke s theory, because it pretends 
to be neither. Berkeley s method of argument is 
astute almost to disingenuousness ; but it cannot 
fairly be charged aginst him that his criticism of 
Locke in the Introduction to the Principles involves 
an ignoratio elenchi. 

Berkeley s statement of the generally received 
theory of the process of abstraction runs as follows. 
We start with particular concrete existing things. 
These things consist of a mixture of different 
qualities or modes, which have no individual and 
independent existence, but only coexist along with 
other qualities in a particular thing. But the mind, 
taking a particular coloured, extended, moved thing, 
i.e. a particular thing having the qualities of colour, 
extension, and motion, abstracts these qualities 
from one another, and forms an abstract idea of 
each by itself, as if it actually existed by itself. Thus 
if the .thing jw_exe Ted and moving rectilinearly, the 
mind would form an abstract idea of red colour by 
itself, and rectilinear motion by itself. But the 
process of abstraction can be carried still further. 
The .mind compares together all its abstract ideas of 
particular colours, and hence forms " a most abstract 
idea " of colour in general, neither red nor blue nor 
any determinate colour whatever. It is possible 
also to form abstract ideas of substances or beings, 
by abstracting from the particularity of the qualities 
which coexist in that substance. Thus the abstract 
idea of a substance includes the abstract ideas of the 


qualities which are essential to it. The abstract idea 
"oTman, for instance, includes abstract ideas of oolour- 
in-general, size-in-general, and go orL ^This abstract 

Idea has beelTmrmed_ by regarding particular 
isolating tlio qualities which they have in common, 
and then isolating the abstract nature of those 
qualities from the particular manifestations in an 
individual man. 

To this theory Berkeley objects, on psychological 
grounds suggested by his own introspective analysis, 
that if we follow such a procedure as it presupposes, 
we shall obtain, not abstract ideas, but concrete 
images^ Berkeley Ts quitfe ftMp&Eea to admit that 
it is possible to image or represent in imagination 
5^hat has already been perceived. What he denies, 
from first to last, is that such an image is an abstract 
idea. What we represent in imagination is always 
concrete and particular. The theory which Berkeley 
is attacking makes two assumptions. It assumes v 
(a) that in the^ac^uisition of knowledge, wn for+. 
always and exclusively witST the particular^ and 
(6) that nihil est in inteUectu quod non prius fuerit in 
sensu. Now, Berkeley says in effect that on these 
assumptions, and by the method of abstraction 
employed, no abstract universal can be reached. If 
all our knowledge is derived from original sense - 
perception of particulars, then our knowledge can 
never extend beyond (a) immediate sense-perception 
itself, and (6) representation in imagination. In 
both these classes of cases the object of knowledge 
is a concrete fact. Abstract ideas do not exist, 
because logically the system of knowledge pre 
supposed by this theory has no place for them. 


Thus, if universals are reached only in the way this 

theory avers, universals are both psychologically and 
logically impossible. 

Berkeley now proceeds to criticise two or three of 
Locke s arguments in support of such a theory as 

(1) Locke maintained that man is distinguished 
from the brutes chiefly by the possession of the 
faculty of abstraction. Berkeley denies this on the 
ground that neither man nor brute can form an 
abstract idea. And in any case, he continues, even 
if man could form an abstract idea, it is imagination 
which really differentiates him from the brutes. 
No brute can imagine. That is man s exclusive 

(2) Locke held, in answer to his own question, 
" Since all things that exist are only particular, how 
come we by general terms ? ", that " Words become 
general by being made the signs of general 

Berkeley objects to this also. What really happens, 
he says, is that words become general by being used 
to signify or stand for particulars. Berkeley s point 
is the perfectly sound ^ne_that^_we jio_n^tj_jis_a_ 
matter of fact, form an abstract universal by abstrac 
tion from particulars, and then give it a name. The 
word is made the sign, without any intermediary, 
of a group of particular things, any one of which, 
however they differ among themselves in detail, is 
indicated by the word. 

(3) Locke believed that by a comparison of parti 
cular triangles it is possible to frame the general idea 
of triangle, which, though derived from particulars, 
" must be neither oblique nor rectangle, neither 


equilateral, equicrural, nor scalenon ; but all and 
none of these at once. ... It is an idea, wherein 
some parts of several different and inconsistent ideas 
are put together." x Berkeley maintains, on psycho 
logical grounds, that it is impossible that any man 
should come to have such an idea. In Locke s 
account, inconsistent ideas are put together to form 
an abstract idea, which, if it be possible, is necessarily 
imperfect, because it is a congeries of inconsistencies. 
Berkeley challenges every man to introspect, and 
discover for himself whether he can form an abstract 
idea in any such way as this theory assumes. To 
this challenge, Berkeley says, only one answer can 
be given. The formation of abstract ideas in this 
way is an impossibility. 

So far, Berkeley has not examined the general 
question whether universals are possible _at__alL 
but hasjnerely criticised tfte view tha* t^nae. " rt^^ 
are formed by abstraction in the manner premised "; 2 
and at every point, both in his attack on the theory 
as a whole, and in his detailed objections to Locke s 
arguments in support of it, his criticism seems sound 
and effective. 3 

But, in addition to this psychological criticism, 
Berkeley examines, on more metaphysical grounds, 
the question of the possibility of universals. It is 
often said, but quite wrongly, that in the Principles 
Berkeley denies altogether the existence of uni 
versals. In reality he is perfectly willing to admit 

1 Quoted by Berkeley, Introduction to the Principles, 13. 

2 Introd. to the Principles, 15. 

3 A more popular and less guarded re-statement of the criticism 
of abstract ideas was given in Alciphron (ii. 323 ff.), but was 
withdrawn in the third edition. 


universals. " It is, I know," he says, " a point 
much insisted on, that all knowledge and demon 
stration are about universal notions, to which I 
fully agree." l That universality is necessary for 
knowledge is simply taken for granted. 

Now, it is one thing to admit universals, but quite 
another to say wnat ihey ftTB. This question 
Berkeley finds it very difficult to decide. One thing, 
at any rate, they certainly are not. They are not 
abstract ideas. On his terminology, an abstract idea 
is a manifest contradiction. For an idea, in Berkeley s 
view, is_aj_ways_cpncreje, being either a concrete. 
particular thing, e.g. this man, or a concrete parti 
cular image, e.g. a mental picture of this man. And 
it is quite oBvious thaf(a) it is impossible to perceive 
" this man " abstractly, and (6) it is impossible to 
form an image of " this man " abstractly. In other 
words, since _, an, abstract idea, if it means_anything, 
must either be an abstract concrete thing or an 
abstract concrete image, and as_ both" of these^ 

definitions involve the same Mmh^LrJirfin in adiectn 
it necessarily follows from Berkeley s premisses that 
there can be no abstract ideas. But in denying the 
existence of abstract ideas, it must be repeated, 
Berkeley has not denied, nor does he intend to deny, 
the necessity of universality. 

There remain, after the abolition of abstract ideas, 
six possible views of the nature of universals, to 
all of which Berkeley pays some attention. The 
functions of universality in knowledge may be dis 
charged by (1 ) jmrtuvnlar thJTi^^^ 

1 Introd. to the Principles, 15. Cf. A Defence of Free -thinking 
in Mathematics, 45 ; and Three Dialogues, i. 382. 

- Ys tf i 


images, or (3) jaames*. or (4) meanings, or (5) signs, 
or (6) notions. 

Each of these views of the nature of universality 
is considered by Berkeley, or, it might be truer to 
say, they all struggle together in his mind for 
supremacy. 1 Yet, for all their conflict, they do not 
occur absolutely at haphazard. A certain process of 
development may be discerned in the order in which 
each in turn becomes prominent in his mind. That 
development takes place along two main lines ; and 
the relation of theory to theory becomes tolerably 
clear, if we consider first (1) and (2) in close connec 
tion, and then (3) and (4). In each case we shall 
find that there is a more or less continuous evolution, 
and that the development is roughly parallel, so that, 
starting with (1) and (3), i.e. the initial views in each 
of the two lines of development, Berkeley gradually 
arrives at (2) and (4) respectively, and eventually 
the process of development culminates in (5). 2 

It should, however, be pointed out at the outset 
that it is idle to pretend that any hard and fast lines 
may be drawn between these theories, or that we 
can definitely and exclusively assign each view to 
some particular period in Berkeley s mental history. 
The possibility of doing that is effectually excluded 

1 The difficulty of discovering what precisely Berkeley s theory 
is is due partly to a real confusion in his mind, and partly to the 
ambiguity of the terms he uses. For a man who is always com 
plaining of the mischief wrought by words, his own terminology 
is surprisingly loose. Thus he uses " conceive " and " imagine " 
synonymously, " idea " for both " thing " and " image," and 
so on. 

2 Theory (6) is what the biologists would call a discontinuous 
variation. It occurs first in the second edition of the Principles 
(1734), and in the meantime we postpone our examination of it. 


by the fact that four of the views are stated or at 
least suggested in the Principles. But the order in 
which they arose in Berkeley s mind is certainly that 
which we have mentioned ; and it is also the order 
in which they become prominent in his writings. 

Thus, in the days of the Commonplace Book 
(1706-8), the dominant theories are (1) and (3). 
Berkeley believes, that is, that the functions of 
universals (he insists that there are strictly no 
universals) are performed by particular things ; and 
that, for certain purposes of reasoning, the names 
which these particular things bear may be of im 

While both of these views are mentioned in the 
Principles (1710), Berkeley had by that time passed 
slightly beyond them, and the theories of univer 
sality which occupy his mind are now (2) and (4). 
The functions of universality are no longer performed 
solely by -the actual pariicular thi^g, hiiFTathe^ fry 
the image of the thing. And he also recognises that 
his early nominalism must be developed by insisting 
that what is of importance for reasoning in the name 
is not its mere nominality but its meaning. 

And the most important view, which we have 
numbered (5), though it existed in a nascent form 
in the Principles, was not actually developed till 
1732-1733. In Akiphron (1732) and The Theory of 
Vision Vindicated (1733) the theory of universals as 
signs is most fully developed. We now regard the 
particular tiling or its image not in themselves but as 
signs, and on the basis of these signs we reason. 

Bearing in mind that the distinctions which we 
have drawn are merely relative and approximate, 


we now proceed to explain, in greater detail, the 
nature of the views which successively occupied 
Berkeley s mind. 

(1) According to the first theory, particular things 
perform the functions of universality by standing . 
for or representing all other particular things of the 
same kind. To make this clear, Berkeley uses 
several examples taken mostly from mathematics. 
Suppose a geometrician is demonstrating the method 
of cutting^ line into two equal parts. For the pur 
poses of his proof he first draws a black line an inch 
in length. This is a particular concrete line. But 
the proof demonstrated with reference to this parti 
cular line will be true of all particular lines of the 
same kind,, because the particular line, as it is used 
in this proof, stands for or represents all particular ... 
lines of the same kind. 1 

But every instance of a particular performing the 
functions of~umversaTrEy Is not so simple as this.\X / 
Suppose, for example, that in proving the theorem 
which says that the interior angles of a triangle are 

together finna.1 t.n two ricrhf. angles, the figure which 

"* * * o 

we actually have on the paper in front of us is an 
isosceles right-angled triangle. What justification 
have we for taking this particular triangle, of a 
peculiar type, to represent all other triangles ? 
Berkeley answers that while it is true that the 
diagram which we have in view in such a case does 
^inolude_pardcular features (the right angle and the 
equality of the two sides) which are not common to 
all triangles, yet the conclusions reached with regard, 
to the diagram are true"oTaHlfflier triangles^ 

itroduction to the Principles, 12, 


in our proof we made no mention of the peculiar 
features of the triangle, but used only those charac 
teristics which are common to all. triangles. The 
actually drawn triangle is considered with regard to 
the purpose for which it is being used, and whereas 
in one case the right angle may be of no significance, 
in other instances, e.g. in the proof of the Pythagorean 
theorem, it is essential. 1 The particular line or 
triangle performs the functions of universality, and, 
though still remaining particular, may be reasoned 
upon and give rise to general conclusions, by being 
regarded as a type-case, i.e. an instance of a class of 
lines or triangles. 

(2) But we do not always have a concrete type- 
case before the mind. In simple mathematical 
demonstration it is possible to do without an actually 
draw r n figure. ^Ve may simply~lmagine rE. TEe^ 
actual figure is a picture drawn on paper, the 
imagined diagram is a picture in the mind. In such 
a demonstration a previously drawn figure, or some 
combination of previously drawn figures, is repre 
sented in imagination^; and the type-case which we 
now use is not the actually drawn figure but the 
mental image of it. The^ image is itsglfji particular 
concrete existent, which stands for or represents all 
particular things of the same type as-the -particular 

1 Of course the question arises, What right do we have to 
abstract in this way ? The very fact that we can consider the 
particular with reference to a purpose or class of purposes shows 
that it is not a bare particular. In the second edition of the 
Principles Berkeley notices the difficulty. " It must be 
acknowledged," he says, " that a man may consider a figure 
merely as triangular, without attending to the particular qualities 
of the angles or relations of the sides. So far he may abstract. " 
(Introd. to Principles, 16.) 


thing of which it is an image. Thus the image is, in 
regard to the discharge of its functions of universality, 
doubly representative. It represents a particular 
thing which in turn represents the class of things of 
its type. 

Thus the particular, whether thing or image, 
" becomes general," or rather, for the purposes of 
reasoning discharges the functions of uuiversals, 
by being- considered as a type-case. The two 
different views should be regarded, not as mutually 
contradictory, but as to some extent complementary ; 
and they are, in fact, both comprehended in one of 
Berkeley s general formulae : " An idea, which con 
sidered in itself is particular, becomes general, by 
being made to represent or stand for all other 
particular ideas of the same sort." l And, since idea 
for Berkeley may mean either (a) a particular.ihing, 
or (6) a particular image, this formula covers both 
views (1) and (2). /^u& 

(3) Along parallel, but significantly 
Berkeley develops another theory of universality. 
tlmversality may be considered to i>elong 1 not to the 
actual particular things, but to the name^ whinh 
designate them. Thus, instead of saying that we 
reason on an actually drawn particular triangle, we 
may say alternatively that we reason on the name. 
triangle, and~that it is nothing but this name that 
ye have in view when we enunciate general propofli- 
tions about the angles of a triangle. This extreme 
iJominahsm is prfffninAnt" in tViPi Cnmmfmplace Book^ 
but in the Principles it has been almost aban 
doned, or rather, its implications have been so 

* Introd, to Principles, 12. 
B.P, X 



fully developed that little of the original theory 
remains. 1 

The plausibility of the crude nominalist view rests 
on the apparent^jjbejTninateness and universality 
of names. A name seems to have a regular and 
uniform signification admirably fitted to perform the 
functions of universality. But, after having been 
attracted by these characteristics of the name, 
Berkeley gradually comes to the conclusion that they 
are largely illusory. In the Introduction to the 
Principles he declares roundly, " There is no such 
thing as one precise and definite signification annexed 
to any general name." 2 He believed that the 
ambiguity and inrl^|fin1tr i P rn8 f Tyoyds is a chief 
source of the unsatisfactory state of philosophy. If 
then, he concluded, words are so indeterminate7they 
cannot be fitted to HyAharg e the duties of universals. 

But though the extreme nominalist view was, in the 
end, entirely rejected by Berkeley, it paved the way 
for a more adequate conception of universality. 
(4) The attractiveness of nominalism was 

the belief that names supply us with universally true_ 
meanings. That belief having been shown to be 
false, why not simply say (omitting all reference to 
names) that the meaning itself is the universal ? 
Berkeley insists, though perhaps without seeing the 
full implication of his words, that what is important 
is the meaning or signification. A particular can 
stand for or represent other particulars, because all 
have the same meaning. 3 It is the meaning, the 
identical reference, that supplies the element of 

1 Cf. Introd. to the Principles, 18-23. 2 18. 

3 Introd. to the Principles, 1 2. 


universality. 1 Berkeley points out that when we 
consider the meaning of a thing, we do abstract ; but 
this kind of abstraction, he says, is admissible. Thus, 
there is, after all, a universal " triangularity," for it 
is a meaning which omits all reference to the parti 
cular qualities of the angles or relations of the sides. 2 

(5) These two lines of thought, viz. that developed 
in (1) and (2) according to which we reason on a 
concrete type-case, and that evolved in (3) arid (4), 
which says that we reason on a universal meaning, 
are both wrought together into some semblance of 
coherence in a theory which, though adumbrated in 
the New Theory of Vision and the Principles, was not 
expounded by Berkeley till his Philosophy of Signs 
was developed in Alciphron. The general bond of 
connection between the views is that they all imply 
in some degree a theory of representative knowledge. 

The concrete type-case is, as we have seen, either 
immediately representative (if such a collocation of 
terms is permissible), or mediately representative. 
In other words, the type-case may represent other 
?ases either at first-hand or at second-hand. Again, 
the name with its meaning owes its importance in the 
theory of knowledge to its representative function. 
Though, unlike the particular thing or the mental 
image, it gives us no picture of the thing represented, 
it does represent, by standing for and signifying, all 
things bearing the same name. In one aspect, 
indeed, the name is representative at third-hand ; 
for it may be regarded, as it sometimes is by Berkeley, 
as representing the mental image which represents 
the particular thing which represents the type or 

1 Introd. to the Principles, 15. 2 Ibid. 16. 


class of which it is a member. But such a trebly- 
mediated relation between the name and the class of 
things it represents is not necessary. If we say, as 
Berkeley in his better moments does, that what is 
important in the name is its universal meaning, then 
we may state directly that the name is the meaning 
:of the class of things to which it is applied as a 

This represejitative function of knowledge is 
developed in Berkeley s theory of signs. The 
particular thing, the image, the name^ ancT the 
meaning may all be included, under certain circum 
stances, and so far as their importance in connection 
with universality is concerned, under the general 
category of signs. Of the vital importance of the 
conception of signs in Berkeley s philosophy we shall 
speak in detail later ; it is enough, in the meantime, 
to say that the characteristic of signs which peculiarly 
fits them, in Berkeley s estimation, to play the part 
of universals, is their identical reference. The 

m^g-riOg-O* a sig i fiyftd dogTna.tip.fllly ; jf jf. jgj^_ 

true sign it will be understood in prc.ui^ely tho_. 
same sense by all who have occasion to use it, 
and thus it is admirably adapted fn anpply t.hft 
medium of reasoning and demonstration. Berkeley 
is so convinced of the merits of this epistemological 
doctrine of representation by signs, that he states 
roundly that all universal knowledge depends on 
demonstration by representative signs. " If I mis 
take not, all sciences, so far as they are universal and 
demonstrable by human reason, will be found con 
versant about signs as their immediate object," l 

1 Alciphron, vii. 13, 


This theory of representation is, as we have 
mentioned, present, at least in germ, in all that 
Berkeley writes on the question of universality. We 
must now submit it to criticism, and show that, so 
far from providing any real solution of the problem 
of universality, it succeeds only in throwing into 
relief the great difficulties inherent in it. With a 
view to making this clear, let us examine a little 
more closely what Berkeley says and does not say. 

(a) In the first place, it must be pointed out that 
Berkeley does not attempt any critical scrutiny of 
the notion of "representation. What exactly he 
means by representing or standing for he does not 
explain. And it results from this lack of definition, 
as one consequence, that he uses indifferently repre 
sentatives of different status. The Representative, 
aa we have seen, may be either a partionlflr thing, or 
a particular image, or a word, or a meaning. Now, 
the status of these representatives with respect to 
r ^hat they represent is not uniform. What is repre 
sented is always a particular thing or a class of 
particular things. When the representative is also 
a particular thing, the status of both is, of course, 
the same. But in all other cases of representation 
the status of sign and thing signified differs in 
greater or less degree. The image is representative 
at second-hand, since it reallv_reprfisents first the 
particular tiling^ and th^nga frfl nther pftffcjnnbi.r 
things of the same kind ; the word at third.-hand r - 
and so on. Or we may say, varying the termin 
ology, that the particular thing is a representative 
of the first degree, the image a representative of 
tlta second degree, and so on. 


In Berkeley s earlier theory the predominant form 
of representation is that of the first degree, but in his 
later work representation of the third degree is the 
typical form of relation. Between these two forms 
of relation there is an important logical difference, 
to which, however, he never draws attention. Repre 
sentation of the first degree is necessarily a sym 
metrical relation, representation of greater degrees 
is properly asymmetrical. A relation is called 
symmetrical, when if it holds between A and B, it 
also holds between B and A. Thus the relation of 
equality is symmetrical, because if A is equal to B, 
B is also equal to A. But some relations are not 
symmetrical, the relation, for instance, of greater 
than. If A is greater than B, B cannot be greater 
than A. Such relations we will call asymmetrical. 1 

If we apply this distinction to the question of 
representation, it is clear that, when the represen 
tative is a particular thing, the relation it bears to 
the particular things it represents is symmetrical. 
Any particular thing it represents may also be taken 
to represent it. The representative function it 
performs might equally well have been performed 
by any one of the indefinitely numerous things it 
represents. If A represents B, then B represents A. 
But when the representative is a name or an image, 
its relation to the things it signifies is asymmetrical. 
The name dog represents or stands for all actually 
existent dogs, but we cannot strictly say that an 
actually existent dog represents or stands for the 

1 This distinction was suggested by, but is not identical with, 
that of Mr. Russell. (Our Knowledge, of the External World, pp. 47 
and 124.) 


name dog. Similarly, the mental image of the dog 
represents the actually existing dog, but the actually 
existing dog cannot properly be said to represent the 
mental image of it. In these cases A represents B, 
but B does not represent A. 

The importance of this distinction is entirely 
overlooked by Berkeley. Yet his instincts led him 
aright, for, while he gathered together his earlier 
lines of thought in his doctrine of signs, he allowed 
what we have called representation of the first degree 
(which was at first, in his view, all-important) to 
slide into the background ; and in the latest form 
of his theory representation is entirely performed by 
signs having a status differing from that of the things 
which they signify, and therefore related to them 
asymmetrically. And this seems to be the only 
proper sense in which to use representation. When 
we speak of representation in common parlance, it 
seems to be always the case that (a) the status of the 
representative differs from that of the person or 
thing represented, and (6) the relation between them 
is asymmetrical. We speak, for instance, of an 
ambassador being representative of a king, a lawyer 
representative of his client, a commercial traveller 
representative of his firm, and so on. In all these 
cases the representative differs in status from the 
person or persons he represents ; and in no case is 
the relation between them symmetrical, for the king 
does not represent the ambassador, nor the client 
his lawyer. And we may say that the conception 
of representation seems properly applicable only in 
cases in which these two characteristics are present, 
only, that is, when (a) the representative differs in 


status from what is represented, and (b) the relation 
between them is asymmetrical. Now, these de 
siderata occur only in the case of representation by 
signs of the second or any higher degree. A name, 
or image, or algebraic symbol differs in status from 
what it stands for, and the relation which it bears to 
the object represented is asymmetrical. And this 
is the theory of representation implied in Berkeley s 
later doctrine of signs. 

But it should be noticed the point is important 
that there is even a sense in which Berkeley s earlier 
theory of the mutual representability of particulars 
is valid. Under certain conditions representation 
is possible even though (a) the status of represen 
tative and object represented is the same, and (6) the 
relation between them is symmetrical. Cabinet 
ministers, for instance, may agree that one should 
represent another, e.g. at Question-time in the House ; 
and the partners in a large firm may, for certain 
purposes, represent one another in the transaction 
of the firm s business. In such cases there is real 
representation, though neither of the conditions we 
originally laid down are observed. Similarly, it may 
be urged, we are justified, under certain conditions, 
and for certain purposes, in regarding a particular 
thing as the representative of other particular things, 
any one of which might equally well be regarded as 
its representative. And so we may. 

It should, however, be noted, and here we come 
to the important point, that such representation is 
possible only under certain circumstances and for 
certain purposes. Cabinet ministers and partners in 
a firm may represent one another only under the 


conditions imposed by their office and in accord 
ance with the purposes of their common work. In 
other words, they perform mutually representative 
functions only because they are not isolated parti 
culars. Cabinet ministers are officially committed 
to the same policy, and partners represent one 
another in so far as they are related by the common 
interests of the firm to which they belong. It is 
this fact of prior relatedness that enables them to 
represent one another. They can do it, because they 
are not barely particular. They already form some 
sort of unity that is more than a mere aggregate of 
isolated units, and it is only because they are thus 
related that they are able to perform representative 
functions. Thus the conclusion to which Berkeley 
would be forced, along this line of argument, is that 
particulars can perform, by representative operation, 
the offices of universals only because they are not 
mere particulars, but are already related by some 

(6) This conclusion may also be reached, along 
another Hue of criticism, by drawing attention to a 
persistent ambiguity which runs through the whole 
of Berkeley s theory of representation. As we 
pointed out in tracing the evolution of his view, the 
development proceeds on two parallel lines. But 
these lines are not kept rigorously distinct by him ; 
and, in the end, he tries to bring them together in 
his developed theory of signs. Now, there is, though 
Berkeley does not seem to notice it, a most important 
logical difference between the conception of sign 
looked at from the standpoint of the first line of 
argument and the conception which we find to be 


implied in the second. In the first case the sign 
must be regarded in denotation in the second in 
connotation. We consider in the first case the 
extension of the sign, in the latter its intension. 1 

If we take as a sign a particular thing or image, 
then we read it in denotation. The extension of the 
sign is in these cases the important thing. It 
represents, Berkeley holds, an indefinite number of 
other things of the same kind. Names also are 
regarded by Berkeley mainly in denotation. They 
are useful as signs because they stand for all the 
particular things that bear the same name. But 
when we insist on the meaning of the name, as 
Berkeley sometimes does, our interest shifts to its 
connotation or intension. What is now important 
in the sign is not the particular things it signifies, but 
the qualities connoted by it, in virtue of which it is 
able to denote particular things. It is only because 
these qualities are connoted that the thing is able 
to signify all things of a similar kind. The very 
conception of similarity implies the recognition of 
the common qualities in virtue of which things are 
similar. Thus, it is only because the sign does 
involve this connotative aspect, only because it 
already possesses universality, that it is able to 
represent at all. A sign, then, we conclude, is fitted 
to fulfil the functions of universality, because it is 
not merely a particular which calls up by association 
other bare particulars, but is already in virtue of 
the qualities it connotes universal in meaning or 

1 Cf. E. G. Husserl, Logische Untersuchungen, ii. 178ff. ; and 
E. Cassirer, Erkenntnisproblem, ii. 221 ff. 


(c) This conclusion, reached along two slightly 
different but convergent lines of criticism, implies 
that Berkeley s sensationalism forms an inadequate 
basis for the theory of signs. In a bare sensationalism 
the only possible relation is that of association. 
Things naturally, in virtue of being constantly 
associated in our experience, suggest other things 
and are suggested by them. But though the theory 
of signs begins in this associationism, it passes beyond 
it. For it involves mental operations which differ 
in kind and principle from mere sense -perception. 1 
In sense -perception we are immediately aware of a 
succession of particulars, but this mere aggregate 
will never give the universal meaning which enables 
us to use any one particular to stand for others of the 
same kind. Further, in using a particular to serve 
as a sign we do not take it simply at its face-value 
with all the features which we observe it to possess. 
Before we can use it as a sign we must have some 
acquaintance with the purpose it is to serve and the 
thing it is to signify. Thus, when we use it as a 
sign, we perform certain mental operations upon it. 
Suppose to take Berkeley s example we are using 
an isosceles right-angled triangle as our sign. If we 
are using it to prove the truth of the proposition that 
the interior angles of a triangle are together equal 
to two right angles, then we abstract from it its 
qualities of being isosceles and right-angled, for these 
are irrelevant to the purpose we have in view ; but 
if we are using it to prove the Pythagorean theorem, 
its right angle is relevant to our purpose, but we may 

1 Cf. Berkeley s distinction between suggestion and inference. 
(Theory of Vision Vindicated, 42.) 


abstract the equality of its two sides ; and so on. 
In each case it can be used as a sign only because the 
mind is able to operate upon it, and thus by means 
of abstraction, selection, and other processes, fit it 
to play the role of a sign. 

Now, in a barely sensationalist philosophy such 
mental operations could have no place. Berkeley 
is aware of this. But he never attempts to justify us 
in the exercise of the right thus to abstract, appar 
ently arbitrarily and even capriciously, certain 
elements from the particulars of whose existence 
sense-perception assures us. It is clear that, in this 
process of abstraction, sense-perception is actually 
overridden by the activity of the mind. If esse is 
percipi, then the triangle that I perceive to be an 
isosceles right-angled triangle is an isosceles right- 
angled triangle. But Berkeley says that it is 
possible to abstract by mental operations these 
qualities of the triangle, so that, although as per 
ceived it is an isosceles right-angled triangle, yet as 
conceived it is simply a triangle. Thus, what is really 
used as a sign is not the triangle as perceived but the 
triangle as conceived. And, in general, we may say 
that words, images, and mathematical symbols could 
not discharge their functions as signs were it not for 
the active operation of the mind, which by consider 
ing their meaning and regarding them conceptually 
enables them to be used as universals in reasoning. 

Our general conclusion, then, is that the doctrine 
of representative knowledge, originating in a bare 
sensationalism, is seen in the end, by a perfectly 
necessary logical development, to imply, as the con 
dition of its validity, a system of mental operations. 


This conclusion was probably reached by Berkeley, 
at least in a subconscious kind of way, when he 
published the second edition of the Principles in 
1734. There he maintains that, in using a particular 
thing as a sign, it is possible to abstract from it the 
features which are irrelevant to the purpose for 
which it is being employed ; and though he is not 
aware of all the implications of this momentous 
admission, he at least realises perhaps the most 
important element of its meaning, viz. that the use 
of signs implies the exercise of mental operations 
distinct from sense-perception. Closely connected 
with this admission, and also appearing for the first 
time in the second edition of the Principles, is 
Berkeley s doctrine of universals as notions. This is 
the sixth possible theory of universals mentioned by 

(6) So far, on all the views which have been con 
sidered, the functions of universality have been 
performed by elements originally acquired in sense- 
perception. But Berkeley came to see that know- 1 
ledge is incomplete without the conceptual element, i 
It was in order to supply this that he developed, 
though very imperfectly, the doctrine of notions. 
Now, as notions are concerned more particularly 
with the knowledge of a special class of objects, it 
will be convenient to give an account of them 
in connection with Berkeley s general theory of 
Knowledge and its Objects. It is to that that we 
now pass. 



So far, in our examination of Berkeley s theory of 
knowledge, we have been concerned only with his 
criticism of abstract ideas, and with his own positive 
views on universality in knowledge. In dealing with 
this aspect of knowledge first, we have been following 
Berkeley s lead, for it forms the subject-matter of the 
Introduction to the Principles. To the argument of 
the Principles itself we must now proceed. 

We have now to consider knowledge under a 
different aspect from that which has been engaging 
our attention. Sofar^ we have not explicitly taken 
into account theTnature of the objects of. knowledge ; 
buVtEis^tandpoint is one which cannot be ignored, 
and consequently, in the Principles, Berkeley regards 
knowledge in connection priT^rily with its r^M^n 
to its objects. Thus, it is with regard to its objects? 
that he distinguishes knowledge into two kinds. 
" Human knowledge," fre gays. " may naturally be 
reduced to two heads, that of ideas and that of 
spirits." l Knowledge of ideas is by way of either 
sense-perception or imagination, knowledge of spirits 
is by way of notions. But in each case knowledge 
is direct. The cognitive relation of the mind and 
I its objects, whether presentative or notional, 

immediate. And this is the second respect in which 
the theory of knowledge, as we are now to consider 
it, differs from the doctrine of representative know 
ledge by signs with which we were concerned in the 
last section. That ^ras indirect, this is direc 

Knowledge, then, from the standpoint of its 

1 Principles, 86. 


objects, is of two kinds, perceptual and imaginative 
acquaintance with ideas, and notional or conceptual 
acquaintance with ^pirits. We shall explain and 
examine first Berkeley s theory of knowledge of ideas, 
and then his suggestions towards a doctrine of the 
knowledge of spirits. 

First, of knowledge of ideas. At the very outset, 
before we can advance, it is necessary to rescue his 
theory of knowledge of ideas from a grave and 
common misrepresentation, for which, it must be 
admitted, his own awkwardness of expression is 
largely to blame. 

The generally accepted interpretation of Berkeley s 
view makes him enumerate three classes of ideas, viz. 
ideas of sensation, ideas of reflection, i.e. those 
obtained by attending to the operations and passions 
of the mind, and mental images. It has always been 
assumed that this is the meaning of the first sentence 
in the Principles. But a careful examination of the 
sentence will show, I think, that it does not mean 
what it is commonly taken to mean ; at any rate, 
the generally accepted interpretation can readily be 
shown to be unnecessary, and a comparison of it with 
the whole tenor of the Principles proves that it is not 
the meaning that Berkeley himself intended. The 
sentence in question runs thus : " It is evident to 
anyone who takes a survey of the objects of human 
knowledge, that they are either iHeas~j ; cjuaIly "_im^_ 
pHntejjTori the~senses ; or else such as are perceived 
by attending- to-tli& jpassions and operations of ihe 
mmctT or, lastly, ideas formed by help of memory 
and imagination." 1 

1 Principles, 1. 


With regard to the meaning of the first and third 
clauses of this sentence there can be no doubt. 
Berkeley tells us, that is, that among the objects of 
human knowledge are included (CT)__" ideas imprinted 
on the senses," and (6) ideas formed by Jielp of 
memory and imagination/^ So far all is clear. It 
is with regard to the meaning of the second clause 
that misapprehension is, as far as I am aware, uni 
versal. It is assumed by commentators on Berkeley 
that the second class of objects of knowledge is a 
class of ideas, i.e. ideas perceived by attending to the 
passions and operations of the mind. Now, this 
interpretation can be shown to be erroneous both 
grammatically and philosophically. 

Grammatically, the antecedent of the relative 
pronoun " such " is not " ideas " but " objects of 
knowledge." It would, indeed, be possible to make 
out a case by special pleading for taking " ideas " as 
the antecedent of " such," but, since the three 
clauses in which classes of objects of human know 
ledge are being enumerated are coordinate, the 
proper construction is to take " such " to refer not 
to any term in one of the coordinate clauses, but to 
the term " objects of knowledge " to which all the 
three coordinate clauses are subordinate. What 
Berkeley really says is that the objects of human 
knowledge include, in addition to the two classes of 
ideas already mentioned, a class of objects of know 
ledge perceived by attending to the passions and 
operations of the mind. He does not say that 
these objects of knowledge are ideas ; he seems, 
indeed, to^use an awkward construction deliber 
ately, in order to ayoid committing himself to 


the statement that these objects of knowledge 
are ideas. 

For proof of our interpretation we are not confined 
to grammatical analysis of a single isolated sentence. 
It is confirmed also by what Berkeley says and does 
not say elsewhere in the Principles and other works. 
It is certain from his other works that he regarded 
knowledge of mental operations as of the same kind 
as knowledge of spirits. It is not perceptual know 
ledge, not knowledge by ideas, but conceptual 
knowledge, the knowledge that he later called 
notional. Thus, in De Motu (1721) he mentions 
that pure intellect, in distinction from sense- 
perception and imagination, is concerned with " res 
spirituales et inextensas, cuiusmodi sunt mentes 
nostrae, earumque habitus, passiones, virtutes, et 
similia." l And in the second edition of the Prin 
ciples the operations of the mind are bracketed 
with spirits as the objects of conceptual notional 

Further, it is significant that, in the first edition 
of the Principles, while Berkeley writes in detail 
on the two classes of ideas, he says not a word in 
explanation of our knowledge of the passions and 
operations of the mind. Now, if such knowledge 
is knowledge by way of ideas, it is difficult to explain 
why Berkeley dealt with the other two classes of 
ideas, and altogether omitted to expound or examine 
this. On the other hand, the omission may be easily 
accounted for on the interpretation which I have 
suggested. The explanation is this. Berkeley did 
not deal with knc-wledge of the passions and opera- 

l 53. 

B.P. K 


tions of the mind in the Principles, because he 
intended to treat of it, along with knowledge of 
spirit, in the projected Part II. of the Principles . l 

And on the negative side, there is an entire absence 
of evidence that he ever did hold the view commonly 
attributed to him. There is no proof that he ever 
regarded knowledge of mental operations as an idea. 
And it seems inconceivable that Berkeley, with all 
his inconsistency, could have considered it possible 
to have an idea, in his sense of the word, of mental 
operations. He must have been aware that pre 
cisely the same arguments as he used against ideas 
of spirits may be advanced against ideas of mental 
operations. 2 We are, therefore justified, I think, in 

1 Berkeley refers several times to the second part of the Prin 
ciples. " As to the Second Part of my treatise concerning the 
Principles of Human Knowledge, the fact is that I had made a 
considerable progress in it ; but the manuscript was lost about 
fourteen years ago, during my travels in Italy, and I never had 
leisure since to do such a disagreeable thing as writing twice on 
the same subject." (Letter to Samuel Johnson, June 25, 1729.) 
The original edition of the Principles had " Part I." on the title- 
page. In the second edition, which was published two or three 
years after this letter was written, " Part I." was omitted. In 
the Commonplace Book there are many references to the subjects 
which will be dealt with in " the Second Book " or the " Second 
Part." From these references we gather that Part II. would 
have dealt inter alia with spirits, mental operations, and 
relations, and also with ethics. Berkeley also refers to Part IT. 
in a letter written in 1711 to Jean Leclerc. There he mentions 
his anxiety to have the criticism of savants on his Principles, in 
order that, either encouraged by their approval, or profiting by 
their criticisms, he may the sooner prepare ad consectaria inde 
deducenda partemque secundam pertexendam. (Archiv f. Oesch. d. 
Phil. xvii. 161.) There is also a reference to it in the Preface to 
the Three Dialogues (i. 376). 

2 Mental operations are, for Berkeley, objects of knowledge. 
But they are not ideas, nor can they be known by way of ideas. 
They are known in the same way as spirits are known. 


believing that Berkeley means to enumerate only two__ 
classes of knowledge of ideas. 1 

TKese tw5 ~ kimfe "of"ideas are, first, "ideas 
actually imprinted on the senses," and, second, 
"ideas formed by the help of memory and imag 
ination. " " 


To take first ideas of the former kind. Idea in 
this sense may mean, for Berkeley, either (a) a 
particular sensible quality, or (b) a collection of 
such qualities, i.e. "a thing." Through the various,. 
sense-organs we become aware of sensible qualities, 
such as heat and cold, colours, tastes, and so on ; 
and all these specific sensible qualities may, he main 
tains, be called ideas. Now, these qualities some 
times cohere with one another, or uniformly accom*. 
pany one ariotner : in such cases these groups or 
collections of qualities, being always observed to go 
together, are given one name, and regarded as one 
thing. And such a thing, as a determinate aggregate 
of sensible qualities, may be termed an idea. But 
though he does use the word idea for either a single 
sensible quality or a determinate group of qualities, 

1 There is only one argument, I think, which can be adduced 
in favour of the universally accepted interpretation of Berkeley s 
sentence. It may be pointed out that in 2 Berkeley distinctly 
states that " besides all that endless variety of ideas or objects 
of knowledge," there is a spirit which perceives them ; and that if 
Berkeley had intended to consider knowledge of the operations 
of the mind as akin to knowledge of spirits, he would have men 
tioned them along with spirits. But in answer to this, it should 
be noted that Berkeley s division in 1 and 2 is not based on 
" kind of knowledge " : the distinction is between objects of 
knowledge (in 1) and knowing subject (in 2). Thus Berkeley 
is perfectly j ustined in mentioning mental operations in 1 , even 
though he believed that the kind of knowledge we have of them 
is not knowledge by way of ideas. Mental operations are objects 
of knowledge, and this is all Berkeley says. 


he seems on the whole to prefer to call specific 

~- - .___ - - _ ^ 

qualities simply qualities, and to reserve the name 
idea for things. 

Ideas of the second sort are reproductions in 
memory or imagination of the former class. These 
mental images are sharply distinguished by Berkeley 
from things. The various marks of distinction which 
he mentioned are those which Hume repeated and 
psychology accepts. 1 " The ideas of sense aremore 
strong, lively, and distinct than those of the imairhia- 
tiou.; they have likewise a steadiness, order and 
ioherence ; and are not excited at random, . . Tbut 

Ja regular train or series." 2 Images, on the_otjie]f 
ind, are entirely ^^"flpni-. ran i.hp. irjrh viflflp.1 

mindP 1 * ItTs no more than willing, and straightway 

this or that idea arises in my fancy." 3 Images are 
representations, and they may represent ^rffier real 
things or chimeras, according to the will of the 
individual who gives them existence. 

Our apprehension of ideas of both classes is im- 
\! mediate. 4 Ideas of the former class, or idea-things, 
as we may call them, are immediately perceived ; 
; ideas of the latter type, or idea-images, are immedi- 
; ately imagined. In both cases alike Berkeley s 
1 analysis of the knowing process reveals only the 
conscious subject on the one hand, and on the other 

V V v 

^ V. the idea-thing or idea-image, the relation between, 
the knower and the object known being regarded as 
necessarily direct. Now, this doctrine of the im 
mediacy of knowledge brought Berkeley into conflict 

1 Cf. G. F. Stout, Some Fundamental Points in the Theory of 
Knowledge, p. 14. 

2 Principles, 30. 3 Principles, 28. 4 Dialogues, i. 383. 



with previously accepted philosophical conclusions 
at two points. 

(a) Philosophy had previously been more or less 
agreed that while the relation between the mind 
and its mental" image" is direct, this mental image 
yet represents some third thing actually existing 
apart from it, so that when, as we say, we imagine 
a house, though the mind is related immediately to 

^^ ^ .^^^^^^^^^^^^^^^M* 

the mental image of the house, this image performs 
a representative function with regard to some 
probably actually existing and previously perceive 
IIOUSQ, This reference of the image to something 
external to it is always presupposed. Now, Berkeley 
simply cuts out this external jrejerence_altogethe ; 
an jib at, 3 on hia"t.hftnry > jh imagination what we knpw __ 
is a mental image, and a mental image only. Just 
as the idea which we perceive is the thing, and not 
a copy of the external thing, so the mental image is 
(not, certainly, a thing, but) what we actually know, 
^jyid not merely a copy of it. In other words, if I 
f .imaffine_ji house~what I am oognitively related to is 
the mental image ; and in simple 

mental image does not necessarily refer to anything 

n certain. cases, indeed, the mental image may be 
taken to represent something not itself, whether 
^Eat_something be another mep^ftH JTflftg 6 Qr class Qf 

images or an idea-thing or class of idea-things. In 

- _. ** ^^ g 

such instances, Berkeley holds, what we have is not 
simple imagination, but a process of Jnference, in 
which the mental image is regarded as a sign, which 
represents or stands for something not itself, and 
on the basis of which we carry on reasoning. But 



in such representative knowledge, Berkeley s view 
of which has already been explained, we have 
passed beyond mere imagination, which is always 
immediate and direct. 

(6) Berkeley s theory of immediacy also comes 
into conflict with the doctrine of Representative 
Perception. That doctrine, as maintained by Locke 
and Descartes, according to whom the mind perceives . 
the external world by means of intermediate ideas 
which are regarded as copies of the real things, must 
be clearly distinguished from Berkeley s own theory 
of representative knowledge by signs. According 
to Berkeley s theory, which is a theory of interence. 
in universal knowledge we must have intermediate 
s and representative factors on which to reason! But 
perception is in an entirely different position from 
that : perception involves, Berkeley believes, no- 
inference or reasoning ; it is a direct and immediate 
relation of "the mind to idea-things. Whereas in 
reasoning we Enow only aSowTEKe tiling of which we 
reason, in perception we are immediately aware of 
the thing. I see the blue paper on which I write 
immediately and directly ; I do not see about it, nor 
do I see anything intermediate between me and it. 
Berkeley insists that if the thing is itself percept 
ible, there is no need of intermediate ideas to relate 
it to the percipient subject, for the thing itself is 
immediately presented to the percipient, and is 
accordingly, in Berkeley s terminology, itself an idea. 
In perception, then, we have only two factors, the 
percipient subject and the idea-thing perceived. 

Berkeley s theory of sensf -perception suffers both 
from over-simplification and from lack of discrimi- 

jQtUu*> I O^ujfat I 


native analysis. These two faults are quite different, 
and, though it has always been recognised that his 
theory of perception is in some way deficient, it has 
not been sufficiently emphasised that there are two 
mistakes which it commits, and that these two 
errors should be carefully distinguished. 

That Berkeley is betrayed by his eagerness " to 
abridge the labour of study" into a superficial 
simplification that overlooks distinctions already 
established can readily be shown by reference to 
his criticism of the doctrine of Representative^. 
Perception. According to that theory, all perception 
involves at least three elements, viz. the percipient, 
the idea perceived, and the external tiling ; and it 
is~&Sumed. that the thing is somehow a copy of the 
external reality. Now, Berkeley saw clearly the 
difficulties of this theory. If the mind is confined 
to its own ideas, he argues7~and is cut off from_ /i 
Immediate knowledge of the real world, how is it /\ 
to know if its ideas do or do not agree with things ? 
In order to compare two things, it is necessary to 
know both. Thus we cannot compare ideas with 
the things which they represent, because we can 
rmvefr ffloape the circle of our ownjdeag7 And the* 
further objection is "advanced that, if the external 
world does exist, it cannot be like our ideas (for 
nothing but an idea can be like an idea), and there 
fore cannot in any way be known, 

It is therefore clear, Berkeley avers, that Locke 
has gone wrong somewhere ; and he argues that 
Locke s error lies in the postulation of something 
which does not really exist at all. This non-existent 
thing is Locke s external material world. What 


Berkeley does, then, is simply to accept Locke s view 
that the relation of the mind and its ideas is 
immediate, and to deny that there is anything over 
and above the mind and its, ideas. In other words, 
Berkeley reaches his view of the immediacy of per 
ception by this drastic Procrustean method of 
" simplifying " Locke s theory. 1 

But Berkeley s doctrine is defective also by reason 
of its lack of psychological analysis ; it is too undis- 
criminating and too facile, and it does not account 
for the complexity of the process of perception. He 
may have been right in his criticism of Locke, for 
Locke may, indeed, have postulated a supposititious 
element ; but, after having discharged this duty of 
negative criticism, he had only half-completed his 
work. He ought to have made a careful psycho 
logical analysis of the perceptual process, with a 
view to discovering whether the simple relation 
mind-idea tells the whole truth about perception. 

Now, he never, in fact, attempted any exhaustive 

1 It is interesting to note how similar in method and how 
different in result is Reid s " simplification " of Locke. Reid, 
like Berkeley, arguing as an advocate of the plain man and 
common sense against the subtleties which metaphysics had 
introduced into philosophy, agrees with him that Locke had 
obscured the nature of knowledge by interpolating a spurious 
factor. But on the question which of Locke s three factors is 
unreal he differs from Berkeley toto coelo. By Berkeley it was 
maintained that Locke s third factor the material world has 
no real existence. But Reid denied the existence of Locke s 
second factor. Locke s imitative and intermediate ideas are 
simply creatures of phantasy ; they have no real existence. 
Thus Berkeley is left with mind plus ideas, and Reid with mind 
plus matter. For both, the relation between mind and its 
objects is immediate ; and both, we may safely say, commit the 
error of over-simplification. (Cf. my Introduction to Selection* 
from the Scottish Philosophy of Common Sense, pp. 4 ff . ) 


analysis of the actual process of perception. He 
draws no distinction, as we have seen in dealing with 
his theory of vision, between sensations and sensible 
qualities ; and he even identifies sensations and 
sensible things or objects. 1 For him the word idea 
means at one andthe^ ja-me time a sensation_injbh.e . 
mind and a thing presented to the mind. He never 
examined what difference there might be between a 
sensation or group of sensations and a thing. 2 He 
made no such analysis of the perceptual process as 
has been undertaken in recent years by Meinong, 
Husserl, and others. These writers differ much in 
detail and in terminology, but they all agree in 
drawing a fundamental distinction between what 
the mind means or intends in perceiving or having 
ideas, and the actual experiences which it has as a 
particular psychical existent. The former is called 
"thing" or. "object," the latter "experience" or 
" act." 3 Again, in mental experience we may dis 
tinguish what are called by Prof. Stout and some 
other psychologists " presentations." Not all 
mental experiences are presentations, for certain 
mental experiences may refer to nothing outside 
themselves, and it is characteristic of presentations 
to be presentative of something beyond themselves. 
Presentations are always contents of immediate 
experience ; but they are not themselves the things 
that they present. They perform the function of 
presenting objects that are not themselves contents 

1 Dialogues, i. 405. 2 Ibid. i. 384, 469. 

3 " Gegenstand " is often distinguished from " Objekt," and 
" Erlebnis " from " Akt," but the specialised meanings which 
have been assigned to them do not concern us here. 


of immediate experience. And a distinction is also 
commonly drawn by recent epistemologists between 
the physical objects thus presented, the presentations 
that present them, and the sensations that actually 
arise from the stimulation of our sensory receptors. 

Berkeley makes no analyses of this kind. What 
he calls ideas bear much resemblance to presenta 
tions, but in distinction from them they are. pre- 
sentative of nothing apart from themselves. Ideas_ 
for Berkeley are both presentations and what presen 
tations are presentative of. He does not distinguish 
carefully between the actual process of perception, 
the particular experience in the psychical individual, 
and the thing or object perceived. His theory 
suffers seriously, in fact, from absence of psycho 
logical analysis. 

Berkeley s eagerness to attain his results by a 
short and easy method is responsible also for his 
failure to give any adequate solution of a difficulty 
which he himself raises with regard to the self- 
identity of perceived things. 

Do different people really live in the same world ? 
Do different people really perceive the same thing ? 
The question at issue is simply stated by Hylas : 
" The same idea which is in my mind cannot be in 
yours, or in any other mind. Doth it not therefore 
follow, from your principles, that no two can see the 
same thing ? " l 

Berkeley s answer is thoroughly unsatisfactory. 
The difficulty, he says, is purely verbal, whether we 
consider it from the standpoint of the plain man or 
from that of the philosopher. The word same is 

1 Dialogues, i. 466. 


commonly used, he says, to apply to things in which 
no distinction or variety is perceived, and if we use 
the term in this popular sense, then the same thing 
or idea may exist in different minds^ Philosophers 
may wrangle about sameness, but little attention 
need be paid to them till they have reached some 
agreement in the definition of terms. Yet he insists 
that, though they profess to diverge from one 
another, they are all fundamentally at one in what 
they mean ; they differ only in their explanations of 
what they mean. " Some regarding the uniformness 
of what was perceived might call it the same thing : 
others, especially regarding the diversity of persons 
who perceived, might choose the denomination of dif 
ferent things. But who sees not that all the dispute 
is about a word ? " l In this cavalier way Berkeley 
dismisses the problem. Had he not burked this 
difficulty, he would have been forced to make a 
careful analysis of the facts of perception. Idea for 
him covers, as we have seen, both thing and presen 
tation. Now qua presentation it is a particular 
psychical existent in the mental process of a single 
individual. But qua thing it is regarded by the 
plain man as one and the same for different percipient 
individuals. The plain man believes that the thing 
that is seen by different people is numerically 
identical. In this sense it is the same thing. Berke 
ley does not notice that the word same conceals a 
distinction of the utmost importance for philosophy. 
Same may mean either (1) numerically identical, i.e. 
the same, or (2) numerically distinct, i.e. similar. 
When the plain man says that ten men look at the 

1 Dialogues, i. 467. 


moon he means that the object perceived by the ten 
men is one and the same, is numerically identical. 
But Berkeley s theory implies that when ten men 
look at the moon each man has a presentation of his 
own in his mind, numerically distinct from those of 
the others. In the former case one moon is seen, 
in the latter ten. Berkeley believes that the ideas 
men have in looking at what is commonly called the 
same thing are numerically distinct. But men 
realise that these numerically distinct ideas are 
similar : " they agree in their perceptions." And 
Berkeley says it is of no consequence whether we 
attend to the agreement of the presentations and call 
them the same, or regard the diversity of the persons 
who have the presentations, and call them different. 
He thus reduces all sameness or identity to similarity. 
A further question immediately arises. How does 
A know that J3 s presentation is similar to his ? A 
cannot get outside the circle of his own presentations. 
If all his presentations are private, and are presen- 
tative of nothing outside themselves, how can he 
come to know that they are similar to -B s ? A lives 
in a world of his own, and so does B. How is any 
communication at all possible between A and B ? 
Now there are two distinct questions here, and to 
each, though he does not consider them at all fully, 
he has an answer to give. (1) What causes A a 
presentations to be similar to -B s when they both 
look at the moon ? (2) How do A and B come to 
know that their presentations are similar ? l (1) 

1 This is essentially the same problem as is discussed with 
reference to Reid and Hamilton by Ward. (Naturalism and 
Agnosticism, ii. 165 sqq.) 


/ Berkeley holds that God causes the similarity of 
J^presentations. When A and B are both looking at 
what is commonly called the moon, God causes 
similar ideas to occur in their minds. These similar 
ideas persist in their minds so long as, they continue 
to look at the moon. If A turns away, God instan 
taneously causes his idea of the moon to cease as a 
presentation. If A and B both alter their positions 
and their attitudes to the moon, God causes their 
similar ideas to change similarly and concurrently 
with their changing positions and attitudes. God^ 
is wholly responsible for the similarity of presenta 
tions. (2) A and B come to recognise the similarity 

Wap***"- " - T~"~!~"" 

of their presentations by each forming images or 

representations of the presentations which God has. 
cause^L God does not cause the representations ;. 
A and B cause them themselves, and are able to call 
them up at will. They can describe these images 
to one another, and thus come to recognise the 
similarity of the images. Hence they infer the 
similarity of the original presentations.^^/ 

From all this it is clear that in perception more 
than bare sensational awareness is involved. When 
our sensory receptors are stimulated, we experience 
certain sensations. But this in itself is not enough 
to give us the perception of an object. In addition 
to the various sensations, an element of interpreta 
tion is needed to weld the sensations into a perception. 
Further, we do not really perceive a thing as a thing 
unless we know at the same time that it is a thing 
not only for ourselves, but also for others. In other 
words, the processes of interpretation and inference, 
on which depends our recognition of the respects in 


which our sensations resemble those of other people 
when we say that we perceive the same thing, are 
essentially implied in all actual perception. 

Thus, the identical thing that we perceive is not 
immediately given in sensory experience, but is a 
construct which we make by conflating the specific 
data of the various senses. Berkeley himself puts 
the matter very lucidly. " Strictly speaking, Hylas, 
we do not see the same object that we feel ; neither 
is the same object perceived by the microscope which 
was by the naked eye. . . . Therefore . . . men com 
bine together several ideas, apprehended by divers 
senses, or by the same sense at different times, or in 
different circumstances, but observed, however, to 
have some connection in nature, either with respect 
to coexistence or succession ; all which they refer 
to one name, and consider as one thing." l It is 
clear, then, according to his own admission, that the 
whole thing is not immediately presented in direct 
/ perception. All that we are immediately sensorily 
L aware of when we say that we perceive a house is a 
4 fragmentary and disconnected olla podrida of sensa- 
i tions : everything else is inference and interpreta 
tion, involving past experience and present mental 
operations. 2 

We have thus seen that Berkeley s theory of 

knowledge of the first kind, purporting at the outset 

to be simple and direct, involves in reality relations 

and mental operations of a very complicated nature. 

We now turn to his doctrine of the second main 

1 Dialogues, i. 463-4 ; cf. i. 469. 

8 Cf. New Theory of Vision, 49 ; Theory of Vision Vindicated, 
9, 10, 15. 


type of knowledge, which deals explicitly with 
spirits, mental operations, and relations. What he 
says of this kind of knowledge is fragmentary, in the 
sense that it is both disconnected and defective. In 
the Principles he does indeed distinguish knowledge 
of spirits from knowledge of ideas, but without 
making very clear wherein the difference consists. 
From the first, however, it was obvious to him that, 
if all knowledge is sense-knowledge, then knowledge 
of spirits and selves, of laws and relations, is im 
possible. But he believes in the existence of spirits 
and relations ; and, as whatever exists must be 
knowable, it follows that we must be able to cognise 
spirits and relations somehow. Now, since we do 
not, as a matter of fact, perceive spirits or relations, 
our knowledge of them must be other than sense - 
knowledge. Hence it is absurd to wish, as Locke 
did, for a new sense by which to perceive spirit, for 
a new sense could give us nothing but sense-know 
ledge, and sense-knowledge could never be adequate 
to reveal the nature of that which is supra-sensible. 1 
But though we have, and can have, no idea of spirit, 
it is not absolutely unknowable. It has a meaning, 
which is recognised as soon as the name is uttered. 
< Soul, spirit and substance ... do mean or signify 
a real thing." 2 Our knowledge of spirits and rela 
tions is not by way of particular ideas, but by way 
of universal meanings or notions. 

The germs of this theory of a conceptual knowledge 
of spirits are present in the Principles, though the 
distinctive terminology which he later adopted to 
express it was unthought of when the Principles was 

1 Principles, 136. * Ibid. 139. 


written. Still, even in the Principles he distin 
guishes, as we have seen, two kinds of knowledge 
and distinguishes them with reference not only to 
their objects, but also to the particular way of know 
ing followed. Knowledge of spirits is differentiated 
from knowledge of ideas ; and, with regard to the 
method of knowing, a parallel distinction is intro 
duced between rational knowledge and sense- 
knowledge. But in the Principles this distinction 
is not explained. It is, however, kept in view, and 
perhaps developed a little, in De Motu (1721), where 
he draws a sharp distinction between imagination 
(defined as " the representative faculty of sensible, 
or actually existing, or at least possible, things "), 
and pure intellect (which is concerned with spirits, 
mental operations, relations, and so on). 1 In Alci- 
phron 2 (1732) and in the Theory of Vision Vindi 
cated 3 (1733) essentially the same distinction is 
employed, the contrasted terms being either imagina 
tion and reflection, or sense and reason, or perception 
and judgment, or sensation and understanding, the 
first-named in each case being on the perceptual 
level, the latter on the conceptual ; but no attempt 
is yet made to work it out, or to develop in any way 
the theory of conceptual knowledge. By the time 
the second edition of the Principles was published 
(1734), he had entirely abandoned his early design 
to write in detail on knowledge of spirits 4 ; conse 
quently, when he revised the Principles for the 
second edition, he simply added two or three para- 

1 De Motu, 53. 2 Alciphron, vii. 11-14. 

3 Theory of Vision Vindicated, 9-12, 42. 
* h Cf. supra, p. 146 n. 



graphs, in which his theory of conceptual knowledge 
is briefly sketched, and made the few alterations 
rendered necessary by the new terminology. To the 
universal element of meaning in knowledge he gives 
the name notion. In the first passage in which the 
new term is introduced, its relations to his former 
inchoate theory of universal meanings is evident. 
" We have some notion" he says, " of soul, spirit^ 
and the operations of the mind, such as wil] 
"lovin ""Rating inasmuch as we know ._pr._m 

e meaning of these words." 1 Thus, instead . 

of mm-ly saying that spirits have meaning, lie now 
says that we have a notion of spirits. Though the 
two statements really amount to the same thing, 
the introduction of the new and distinctive term 
marks a notable step in the direction of a systematic 
theory of universal knowledge of spirits. 

What suggested to Berkeley that the term notion 
should be used to signify the universal element in 
knowledge ? In the philosophical writings of his 
contemporaries no word is used more frequently or 
more vaguely than notion. It is the most inde 
terminate term in an age when looseness and 
ambiguity of language was the rule rather than the 
exception. And Berkeley himself uses it quite as 
freely and ambiguously as his contemporaries. Thus 
it often appears, in all his chief works, in a popular 
vague sense. 2 It may mean any sort of sensation 
or perception or impression or conception, any 

1 Principles, 27. 

2 Cf. i. 119, 403, 427, 432, 435, 444, 455, 462, 463, 464, 473, 475, 
476, 477, 478, 480, 483 ; ii. 47, 49, 50, 51, 56, 57, 61, 62, 63, 64, 
65 ; iii. 241, 263, 266, 272, 273, 275, 280, 294. 

B.P, L 


mental process or content or operation. It is, indeed, 
perfectly indeterminate. 

Hence, in his earlier works, he sometimes uses it 
as an equivalent of idea, in his special terminology ; 
so that whatever can be predicated of an idea can 
be predicated of a notion. 1 And he even goes so far 
as to say, "It is evident there can be no idea or 
notion of a spirit." 2 It is, of course, clear that when 
he wrote these words he can have had no intention 
whatever of giving a specialised meaning to notion. 

Now, it is possible, I would suggest, that Berkeley 
was influenced to introduce the term notion in a 
specialised sense by John Sergeant, the only philo 
sopher of the period, with whose work he was 
acquainted, to give a determinate and technical 
significance to the word. This suggestion can hardly 
be established, since there is no positive evidence for 
it ; but, on the whole, it seems exceedingly plausible, 
especially when we bear in mind the similarities 
which we have already discerned in their writings. 

That the question of the nature of the knowledge 
of spirits troubled Berkeley greatly admits of no 
doubt. The problem is always shelved, in the 
Principles and Dialogues, when we should expect 
him to say something about it, partly, no doubt, 
because he intended to treat of it in Part II. of the 
Principles, but mainly because he simply* did "not 
know what to say. 

Now, in the Commonplace Book he states that he 
does not agree with Sergeant s Solid Philosophy, and 

1 Cf. i. 239, 242, 247, 260, 270, 275, 335. 

2 Principles, 138. This passage was altered in the second 


it is just possible that one reason why he abstains 
from using notion as a technical term in his earlier 
philosophy is that he did not wish to be obviously 
beholden to Sergeant. For Sergeant uses the term 
in a technical and specialised sense, and sharply 
distinguishes it from idea. In fact, when Berkeley 
came to introduce the distinction between the terms 
in his own philosophy, it followed, to a very consider 
able extent, the lines suggested by Sergeant. 

In order to make clear the similarity between their 
views, we must state Sergeant s exposition of the 
distinction between ideas and notions ; and, as his 
book is so rare, it will be well to quote the most 
important passages verbatim. The general dis 
tinction is that ideas are " objects of the fancy," 
notions " objects of the understanding." Ideas are 
merely " copies, similitudes, representations, images, 
pictures, portraitures, phantasms." Notions, on the 
other hand, though they exist " in the under 
standing," are the real things as known. "A notion is 
the very thing itself existing in my understanding." l 
" Notions are the meanings, or (to speak more 
properly) what is meant by the words we use : but 
what s meant by the words is the thing itself ; there 
fore the thing itself is in the meaning ; and conse 
quently in the mind, only which can mean." 2 

Sergeant mentions four general criteria to dis 
tinguish ideas from notions. (1) " My first criterion 
shall be the sensibleness of the former, and the 
insensibleness of the other. When we shut our eyes, 
or walk in the dark, we experience we have ideas or 
images of our way, or of other things we have seen, 

1 Solid Philosophy, p. 27. * Op cit. p. 33, cf. pp. 387-8. 


in our fancy : and this, without the least labour of 
ours, or any reflection. And there is also, beyond 
that, something else in the mind, which tells us of 
what nature, or what things those are, which 
appeared superficially to our fancy ; which costs 
us labour and reflection to bring it into the under 
standing, so that we cannot get perfect acquaintance 
with it, unless we define it. Nor is this sensible, as 
the other was, but only intelligible : not superficial 
or uppermost, but hidden, retruse, and (as we may 
say) stands behind the curtain of the fancy : nor 
easy to comprehend at the first direct sight of our 
inward eye, but costs us reflection, or some pains, 
to know it distinctly and expressly. Which latter 
sort, in each of these regards, are those we call simple 
apprehensions, conceptions, or notions." 1 

(2) " The next criterion shall be this : we find we 
have in us meanings ; now the meanings of words, 
or (which is the same, taking the word objectively, 
what s meant by those words) are most evidently 
the same spiritual objects as are our notions, and 
tis impossible those meanings should be the same 
with ideas or similitudes, but of a quite different 
nature. Let it be as like the thing as tis possible, 
tis not the likeness of it which we aim at in our 
language : for we do not intend or mean, when we 
speak of anything, to talk or discourse of what s like 
that thing, but of what s the same with it, or rather, 
what that thing itself is. ... Wherefore the mean 
ing, which is the immediate and proper object of the 
mind, and which gives us, or rather is, the first notice 
of the thing, must be of a quite different nature from 
1 Solid Philosophy, Preface, 20, 



an idea or likeness of it ; and since there can be no 
middle between like and the same ; nor any nearer 
approach or step, proceeding from likeness, towards 
unity with the thing, but it falls into identity, it 
must necessarily be more than like it ; that is, the 
same with it ; which an idea or likeness cannot 
possibly be." l 

The remaining two criteria may be stated very 

(3) Ideas, Sergeant says, may be perceived by 
brutes, for brutes have sense-organs, and knowledge 
of ideas comes by way of the senses. But brutes 
have no notions, for notions or meanings belong to 
the mind (as distinct from sense-organs), and brutes 
have " no spiritual part or mind." 2 

(4) Lastly, ideas are always particular. Sergeant 
argues, as we have seen, that general abstract ideas 
are impossible. Notions, on the other hand, though 
they may be particular, are naturally universal. 3 

Now, in all this there is, of course, a great deal of 
loose or confused analysis ; but from our standpoint 
the importance of the theory lies not in its soundness 
or unsoundness, but in its very evident anticipation 
of Berkeley s distinction between ideas and notions. 

For Berkeley is in agreement with Sergeant with 
regard to all the marks which distinguish notions 
from ideas. (1) Ideas, for him as for Sergeant, are 
sensible, while notions are intelligible or conceptual. 
(2) For both, our notional knowledge is direct and 
immediate, essentially different from any indirect 
or mediated ways of knowing. (3) Berkeley also 

1 Op. cit. Preface, 21. 2 Op. cit. Preface, 22. 
3 Op. cit. Preface, 23. 


agrees that the capacity for universal knowledge is 
a diacritical point which differentiates man from the 
brutes. (4) And he believes, with the Solid Philo 
sopher, that all knowledge of ideas is particular, 
whereas notions give us universal knowledge. 1 

1 The differences between the two thinkers are many, and need 
not be mentioned in detail. But we may draw attention to two 
points, (a) Sergeant invariably regards ideas in the light of his 
crude interpretation of Locke s theory, i.e. they are always 
merely copies or images of real things. Idea for Sergeant thus 
means pretty much what on Berkeley s theory we have termed 
an idea-image : he has nothing corresponding to Berkeley s 
idea-thing, (b) Whereas notional knowledge, in Berkeley s 
theory, is confined to special classes of objects, e.g. spirits and 
relations, Sergeant holds that we may have notional knowledge 
of all existent things. All our real knowledge of things, on his 
view, comes to us by way of notions. 

The term notion is also used in a highly technical sense by 
another little -known philosopher of the day, Richard Burthogge, 
who published in 1696 his Essay upon Reason and the Nature of 
Spirits. To show the drift of his theory, which assigns a quite 
different meaning to notion from that which it bears in Berkeley 
and Sergeant, a sentence or two may be quoted from this rare 
Essay. There is no evidence that Burthogge s work was known 
to Berkeley. 

" As the eye has no perceivance of things but under colours, 
that are not in them (and the same with due alteration must be 
said of the other senses), so the understanding apprehends not 
things, or any habitudes or aspects of them, but under certain 
notions, that neither have that being in objects, or that being of 
objects, that they seem to have ; but are, in all respects, the 
very same to the mind or understanding, that colours are to the 
eye, and sound to the ear. To be more particular, the under 
standing conceives not anything but under the notion of an 
entity, and this either a substance or an accident, or the like ; 
and yet all these things and the like are only entities of reason 
conceived within the mind, that have no more any real true 
existence without it than colours have without the eye, or sounds 
without the ear. . . . Things are nothing to us but as they are 
known by us. ... In sum, the immediate objects of cogitation, 
as exercised by men, are entia cogitationis, all phenomena ; 
appearances that do no more exist without our faculties in the 
things themselves, than the images that are seen in water, or 


But, it may be said, what really are notions ? It 
is easier to say what they are not than what they are. 
It is clear, in the first place, that they are not ideas. 
Though in Berkeley s earlier work idea and notion 
are used synonymously, as soon as the special 
doctrine of notions is suggested, he takes pains, as 
we have seen, to make clear that notions differ from 
ideas, whether ideas be regarded as presentations or 
representations . 

Are notions, since they deal with universal rela 
tions, to be conceived as abstract ideas ? This inter 
pretation of Berkeley s notions has been advanced 
by Georges Lyon, 1 who bases it not so much on any 
definite statement of Berkeley s as on the argument 
that it is the only thing that he could have meant. 
But Berkeley really makes it clear that, whatever 
he meant, he did not mean that. For he allowed 
his attack on abstract ideas to stand side by side 
with his new doctrine of notions, and it is therefore 
clear that he cannot have intended to identify 
notions and abstract ideas. He showed incon 
sistency on many occasions, but he is never guilty 
of such a glaring " repugnancy " as is involved in the 
assumption that he identified notions and abstract 
ideas. For he reprinted, without modification, his 

behind a glass, do really exist in those places, where they seem 
to be." 

Thus our knowledge " does not enter us into the knowledge 
of the reality itself (may I so express it) of that which is, which 
we only apprehend inadequately under the disguise and mas 
querade of notions. We apprehend not any at all just as they 
are, in their own reality, but only under the top-knots and dresses 
of notions which our minds do put on them." (Essay on Reason 
and the Nature of Spirits, in. i. 57 ff.) 

1 L ldealisme en Angleterre, p. 341. 


criticism of abstract ideas, in the second edition of 
the Principles, in which he introduced, for the first 
time, the doctrine of notions. 

Another interpretation of the meaning of notion 
has been suggested by Edmund Husserl. 1 Berkeley s 
notions, says Husserl, are identical with Locke s 
Ideas of Reflexion, and include both the Simple 
Ideas of Reflexion and the Complex Ideas of Re 
flexion. But while this comparison is suggestive, 
the statement that the two doctrines are identical 
is misleading. Notions resemble Locke s Ideas of 
Reflexion in so far as both are concerned with " the 
notice which the mind takes of its own operations " ; 2 
but notions are more restricted in their compre 
hension than Ideas of Reflexion. For Ideas of 
Reflexion include perception ; and their source is a 
sense, though an internal one. But Berkeley con 
sistently differentiates notional knowledge from per 
ception ; notions have no connection at all with any 
sense. Thus notions cannot be regarded as identical 
with Locke s Ideas of Reflexion. 

All that Berkeley himself justifies us in saying 
positively about notions may be stated very briefly. 
The notion is a concept or universal, present to the 
mind, and having as its objects (a) spirits, (6) mental 
operations, and (c) relations. Now, all these objects 
of notional knowledge are, in Berkeley s view, 
mental or spiritual. For (a) spirits are minds, 
(6) mental operations are the acts of minds, and 
(c) relations always include an act of mind. 3 Spirits, 
mental operations, and relations are all ulti- 

1 Logische Untcrsuchungen, ii. 176. 2 Locke, Essay, n. i. 4. 
3 Principles, 142. 


mately of the same nature, and that is mental or 

Further, these objects of notions, though they are 
not themselves ideas, and though ideas cannot be the 
objects of notions, are all essentially concerned with 
ideas. For (a) it is the essence of spirit to perceive 
and cause ideas, (6) it is the essence of mental 
operations to be " acts about ideas," and (c) it is the 
essence of relations to be " between ideas." : Ideas, 
then, though they cannot be the objects of notions, 
may be the objects of the objects of notions, for an 
idea is the object of a mind, and a mind is the object 
of a notion. 

To sum up. The important thing about the 
notion is its universal and conceptual character. 
Berkeley always asserts that of such objects as 
spirits, mental operations and relations we can have 
no perceptual knowledge ; hence, if we are to know 
them at all, our knowledge must be notional or 
conceptual. Thus, he consistently sharply differ 
entiates the sensational and perceptual knowledge 
which we have of things from the notional and 
conceptual knowledge which we have of spirits. 

A similarly sharp distinction is drawn by Berkeley 
between the existence of things and the existence of 
spirits. The nature of spirits, in his view, differs 
toto coelo from that of things ; and our account of 
their way of existence must accordingly follow 
different lines. In the next two sections we shall 
state and examine his doctrines of the Existence of 
Things and the Existence of Spirits. 

1 Ibid. 89. 



Berkeley believes firmly in the existence and 
reality of the world of things. " By the principles 
premised," he says, " we are not deprived of any one 
thing in nature." * " Whatever we see, feel, hear, 
or anywise conceive or understand, remains as 
secure as ever, and is as real as ever. There is a 
rerum natura." 2 With regard to his belief in the 
reality of things he is at one with most previous 
philosophers. Where he differs from his prede 
cessors is in the interpretation he puts upon the 
meaning of reality. 

It had previously been held by many philo 
sophers that the reality of things depends on the 
support of a material substratum. " The reality of 
things," says Hylas, the defender of materialism in 
the Dialogues, " cannot be maintained without 
supposing the existence of matter." 3 Thus, before 
Berkeley can establish his own view of reality, he 
must remove this erroneous conception of matter as 
the substratum of reality .\ 

His attack on matter is perhaps the most serious 
task he ever undertook ; and in the criticism of 
materialism he enters into considerable detail. He 
does not himself classify the various views of matter 
which he examines, but they may be reduced to 
three main heads. (1) According to the first theory, 
matter is immediately perceived. (2) On the second 
view, matter is not perceived, but is inferred to be 
either, (a) like our ideas, though imperceptible, or 
(6) unlike our ideas, but the cause of them, or (c) the 

1 Principles, 34. 2 Ibid. 34. 3 Dialogues, i. 439. 


instrument of our ideas, or (d) the occasion of our 
ideas. (3) And according to the third main theory, 
matter is simply postulated as an unknown but 
indispensable Somewhat. We shall examine, in 
order, Berkeley s criticisms of each of these 

(1) Matter, according to the first theory, though 
absolute and permanent, is capable of being im 
mediately perceived. And, it is argued, since it is 
immediately perceived, we have direct evidence of 
its existence. 

To this argument Berkeley replies by examining 
what actually takes place when we say that we 
perceive a thing. Suppose I say that I see a cherry. 
What is it that I am really sensible of ? I have 
certain sensations, Berkeley says, of softnej,g. l _jnois- 
ture, redness, and tartness^Hand that is all. " A 
cherry, I say, is nothing but a congeries of sensible 
impressions, or ideas perceived by various senses." : 
In our perception of the cherry we never have any 
sensation of matter ; and we conclude that, whatever 
matter may be, it is certainly not immediately 
perceptible. p, | 

Again, if matter were perceptible, our actual 
perceptions would not vary as they do ; for matter 
is always regarded as stable and permanent. Now, 
tHe sensations which we actually experience in per 
ceiving an object vary from time to time according 
to the light in which the object is seen, the position 
from which we perceive it, and the distance we are 
from it. And, Berkeley argues, _i_the sensible 
qualities of which we are aware were really material. 

1 Dialogues, i. 469. 


these varifriflOTifl in sp.nsft-pypftripnnft would be im 
possible, because matter is IxtTfi/ypotfiesi absolute and 

Further, to draw a positive inference from what 
has been said, it is clear that as a thing, e.g. a cherry, 
is nothing but a combination of ideaj^ the thingjmmst 
be mental, In the sense that its existence depends 
on the mind. Now, matter and mind are mutually 
exclusive ; if, then, the thing is mental, it cannot be 
either material or dependent upon matter. 1 

*mtm___ r .^ __ jiiip " ^^ L.U_^_^^^_^__J.___^___^-, .......... , - "*" 

On all these grounds Berkeley thereioreTiolds that 
the first theory of matter is untenable. Matter is 
noJ^krmwjri imin.e_diatelyjiy^ensje^^jc^ption. Now, 
if matter is to bejknown at all, Berkeley says, it jnust 
be cognised in one of two ways ; it must be known 
either immediately by sense-perception, or mediately 
by a process of inference. 2 We have already 
established that it cannot be known immediately, 
and we must now consider the arguments by which 
endeavours have been made to prove that it may be 
inferred to exist. 

(2) If we infer matter to exist, various views of its 
nature are possible. 

(a) According to the first variety of this materialist 
doctrine, matter may be inferred to be like our ideas. 
Even if we admit, the materialist argues, that matter 
is imperceptible, there may exist material entities 
corresponding with, and similar to, the ideas that 
we actually perceive ; and these material entities 
guarantee the regularity and self -consistency of the 

1 Berkeley s positive theory of the mind -dependent reality of 
things will be examined in detail later. 

" Dialogues, i. 435. 


groups of sensations which we experience under 
determinate sets of circumstances. 

Against this view Berkeley brings two objections, 
(i) He points out that it is universally acknowledged, 
even by materialists, that our sensations, differing 
according to the conditions under which we are 
affected, are exceedingly variable. If, then, as the 
materialist assumes, the material thing resembles the 
idea, it must at one and the same time, while still 
remaining the same material thing, be like several 
dissimilar ideas. And that, Berkeley holds, is a 
contradiction in terms. 1 (iij He argues, further, that 
since we perceive_only^)ur^own ideas,_or ,aje...a.war-e. 
only of ourown sensations, jnattfij:, .if. it-coasts-, -canno.t 
be like these ideas or sensations. For a sensation 
cannot be similar in nature to what is ex hypothesi 
ultimately insensible. It is contradictory, he urges, 
"to assert, a colour is like something which is 
invisible ; hard or. soft, like something which is 
intangible ; and so of the rest." 2 An idea of sensa 
tion cannot be like what is not an idea of sensation. 
Contrariwise, what is given as~ insensible, i.e. matter, 
cannot be like a sensation. " Can a real thing," he 
asks, " in itself invisible, be like a colour ; or a real 
thing, which is not audible, be like a sound ? " 3 

For both these reasons he concludes that matter 
cannot be like our ideas. 

(6) We have now proved that (1) matter is not 
perceptible, and (2a) it is not like our ideas. But 
the materialists maintain that matter, admitted now 
to be both imperceptible and unlike ideas, may yet 
be^the -cause of them._ With a view to examining 

1 Dialogues, i. 417. 2 Principles, 8. 3 Dialogues, i. 418. 


this theory, Berkeley puts a clear statement of it 
in the mouth of Hylas. " I find myself," says Hylas, 
" affected with various ideas, whereof I know I am 
not the cause ; neither are they the cause of them 
selves, or of one another, or capable of subsisting by 
themselves, as being altogether inactive, fleeting, 
dependent beings. Theybave_therefore some cause 
distinct from me and them : of which I pretend to 
know no more than that it is the cause, of my ideas. 

And this thing, whatever it e, !- imi f f f fe>r "J^ 

Against this view Berkeley brings two criticisms. 
(i) Matter, he urges, cannot be a cause at all. The, aflftiTist. whioji hfi argH ftS j ajflrflffa 

by him, in common with his contemporaries, to be 
necessarily and by definition "inert," "passive," 
and " inactive." And it is impossible that what is 
inactive should be a cause, for that would involve 

the contradiction in terms that the inactive is active, 
(ii) But, even if matter could be a cause, it could not 
be a cause of ideas. For by definition, and here 
again he is following the consensus of the time, 
matter is " unthinking." The material is, in other 
words, exclusive of the mental. If the " unthinking" 
could be a cause, it would be a cause only of un 
thinking things. Hence it could not be the cause 
either of minds or of ideas, both of which are 
" thinking," in the sense that they are either spirits 
or dependent on spirits. 2 Matter, then, he con 
cludes, being inactive, cannot be a cause ; and, being 
unthinking, cannot be a cause of ideas. 3 

1 Dialogues, i. 429. 

2 Note that ideas are " thinking " only in the sense that they 
are perceived by thinking spirits. 

3 Dialogues, i. 430. 


But even admitting that the causal theory of 
matter, like those which we have already examined, 
is untenable, it is still open to the materialist to 
maintain either the instrumental or the occasional 
theories of matter. 

(c) " Though ^matter may not be a cause." says 
Hylas, " yet what hinders its being an instrument, 
subservienFto the supreme Agent in the production 
of our ideas ? " 1 Berkeley s answer is that such a 
material instrument would be quite useless to God. 
Analysing the meaning of instrument, he finds it to 
be something which we use to assist us in doing those 
things which cannot be performed by a mere act of 
will. I do not normally employ an instrument to 
move my finger, because I can do that by simple 
volition. But I use an instrument to cut down a 
tree, because I cannot achieve that result immedi 
ately by a mere act of will. Now. evervthing-in. the 
world, 33jr^ej.ej__bejieyes^is in a rejation of absolute 
and immediate dependence on God, who is able to 
perform all his operations in and on the world by 
simple volition. And as God does not need a 
material instrument with which to produce his 
effects, the principle of parcimony justifies us in 
holding that it is non-existent. 

(d) The criticism of the occasional view of matter 
follows precisely the same lines. 2 He shows that 
an occasion, as defined by materialism, i.e. " an 
inactive, unthinking being, at the presence whereof 
God excites ideas in our minds," is not needed for 
the fixed and regular production of effects by God ; 

1 Dialogues, i. 431. 

2 Dialogues, i 433-4; cf. Principles, 68-69. 


and, since the material occasion is unnecessary, 
Occam s Razor may be applied to cut it away 

(3) And now we come to the materialist s last 
ditch. Having been driven from all his previous 
positions the materialist may take refuge in the 
conception of matter asjan utterly unknown and 
indefinable quiddity, wholly without attributes and 
qualities. Me may " stand to it that MatteFljran 
Unknown Somewhat neither substance nor accident, 
spirit nor idea inert, thoughtless, indivisible, im- 
moveable, unextended, existing in no place." 1 

For use against this last despairing conception 
of matter Berkeley has still plenty of shot in his 
locker, (i) He points out, in the first place, that 
such an " obscure idea of somewhat," which cannot 
be perceived, of which nothing can be predicated, 
and which can perform no function, differs riot at 
all from nothing.* (ii) And, if the materialists urge 
that matter, as above defined, gives us the positive 
conception of quiddity, entity, or existence, Berkeley 
argues that this positive conception is a mere 
abstract idea, and as such is open to all the criticisms 
which he has already brought against the general 
theory of abstract ideas. Again, therefore, it seems 
that matter -means nothing* (iii) Further, those 
who maintain this view constantly assume, in 
effect, that they know something, however little, 
about matter ; and any plausibility the theory 
possesses springs from the fact that its supporters 
tacitly presuppose that the matter which they 
postulate has some qualities, however indefinite, and 

1 Principles, 80, * Principles, 80. Principles, 81. 


is thus in some way known. 1 And, Berkeley urges, 
if matter exists, it must either be known or unknown. 
If it is absolutely unknown, and there is no necessity 
to postulate it, we may safely take it to be non 
existent. If, on the other hand, it is known, it 
must fall under one or other of the conceptions of 
matter already considered ; and, as he believes that 
he has disproved all these theories, and that his 
criticism is thus absolutely exhaustive, it follows 
that he regards as irrefutable the conclusion that 
matter is non-existent. 

Lastly, and in some ways this is Berkeley s most 
fundamental criticism of materialism, the conception 
of a material substance involves a regress ad infinitum. 
What we perceive, e.g. an extended object, is said 
by the materialists to rest upon a material sub 
stratum. But thisjnaterial substratum must itself 
be extended Jn,,order_ to > support the extended object ; 
and, as it is extended, we must postulate ano~Ker 

material substratum to support it; and" so on ad_ 
injmitum? To this tHe~niateriaKsts might rejoin 
that, though the material substratum supports 
extension, it^is not itself extended. Berkeley s 
answer to this argument would be that, if the view 
of the materialist apologists were persisted in, it 
would reduce matter, in the last resort, 
conceptipn of a qualitiless Somewhat which may be 
shown, as we have just seen, to be indistinguishable, 
from nothing-at-all. 

Throughout this whole criticism of materialism, 
which really forms the burden of all his works, 
Berkeley has presupposed two general canons, which 

1 Principles, 16. 2 Dialogues, i. 409. 


he states thus : (I) " Strictly speaking, to believe 
that which involves a contradiction, or has no 
meaning in it, is impossible." l (II) " It is to me 
a sufficient reason not to believe the existence of 
anything, if I see no reason for believing it." 2 Apply 
ing these axions to the problems of matter, we find 
that, as matter, conceived in any positive way, has 
been proved to be either self-contradictory or 
unmeaning, it is impossible ; and since, when con 
ceived in the negative form of "an obscure idea of 
somewhat," there is no reason to believe it, we have 
a sufficient reason for not believing it. Matter, then, 
cannot be in any sense the ground of reality. 

But Berkeley is convinced, as we have mentioned, 
that reality does exist ; and he must therefore look 
for its ground elsewhere than in matter. Now,as 
existence ^ ftitib ftr flitfTJftl or spiritual, the frfltf" -f 
reality must be found, if anywhere, in spirit or mind. 
The real significance, for his own theory, of the 
criticism of matter lies in the conclusion that, as 
matter is the only possible non-spiritual ground of the 
existence of things, and as matter, regarded in every 
possible way, has been shown to be non-existent, 
the only real ground of the existence of things is 

^According to Berkeley s own theory of reality, the 
existence of things depends on spirit in the double 
sense, (a) of being perceived by spirit, and (6) of 
being caused by spirit. We shall now state, in detail, 
the arguments by which he reaches this conclusion. 

Starting with the ordinary things of common 
sense, with which we come in contact every day, 
1 Principles, 54. 2 Dialogues, i. 432. 


Berkeley proves that their existence consists in .being : 
perceived. " Wood, stones, fire, water, flesh, iron, 
and the like things, which I name and discourse of, ] 
are things that I know. And I should not have j 
known them but that, I perceived them by my 
senses; and things perceived by the senses are. 
immediately perceived ; and things immediately 
perceived are ideas ; and ideas cannot, exist without: 
the mind ; their existence therefore consists in being, 
perceived." * 

~Tnis conclusion is proved in detail in the first of, 
the three Dialogues and in the Principles. Berkeley! 
reduces J&a_Jibing_-tQ_Jts component elements, and] 
shows that each and all of these consist in being 
perceived. A thing is nothing but an aggregate of. 

Sensible qna1|+if>g nr> ^, ]f y ft ftrflp_fftrmr fliaf. T|flpA nf 

these can exist apart from perception, we shall have 
proved that the existence of the thing itself consists 
in being perceived. 

The qualities of things had been distinguished by 
Locke, Descartes, and others into two, classes, called 
respectively primary and secondary. Primary quali 
ties comprise extension, figure, motion, rest, solidity, 
and number ; all others, e.g. colours, tastes, sounds, 
and the like being termed secondary. According to 
the distinction previously accepted, primary qualities 
exist in the things, though secondary ones do not ; 
so that a red billiard ball that we perceive is in 
itself, apart from our perception, extended, figured, 
solid, and at rest ; but it is not in itself coloured, for 
its colour depends on perception. 

This distinction between primary and secondary 
1 Dialogues, i. 440. 


qualities was questioned by Berkeley^ He agrees 
that secondary qualities have no existence apart from 
perception, but he maintains, in additiop 

exisence~oT all primary qualities also consists in 
beingj>erceived . All the arguments "13y~ which the 
mind-dependent existence of secondary qualities had 
been supported apply also, in his judgment, to 
primaries. That such qualities as heat and cold are 
mind-dependent is agreed on the ground that, as a 
body may appear hot to one hand and cold to the 
other at one and the same time, and as it is self- 
contradictory to suppose that the body in itself, 
apart from perception, is both hot and cold simul 
taneously, we must conclude that these qualities are 
in the body only when it is being perceived. Similarly, 
he argues, we may prove that such so-called primaries 
as extension and motion do not really exist in the 
extended moving objects, apart from perception. 
For the extension of one and the same object appears 
different to the same eye in different positions, and to 
different eyes in the same position. Such variation 
in the extension of a body would not be possible, he 
urges, if the extension were really in the body ; and 
we must conclude^ that its extension, like its colour^ 
Depends on being perceived. Arid, as what is true 
of extension is true also of all other so-called primary 
qualities, we may say that all the qualities of bodies 
are dependent for their existence on being perceived ; 
and further, since things are nothing but the collec 
tions of their qualities, they are thus proved to be 
wholly dependent on perception. 1 

Now, all that Berkeley has said with regard to the 

1 Principles, 9-15 ; Dialogues, i. 382 ff. 


variability of primary and secondary qualities might 
be admitted, and yet it could be argued that, though 
qualities are relative to perception, they are caused 
by something not dependent on perception. With 
this, so far, Berkeley agrees. But, he urges, the real 
question is, Of what nature is this cause ? x Now, 
the cause cannot be material, for we have already 
proved thaT matter is^jion^existent and impossible; 
and, as everything that is is either material or 
spiritual, the cause must be spiritual. The cause of 
the reality of things is mind or spirit. 2 

Thus, it is "rrot a complete account l)f the reality 
of things to say that their esse is percipi. We must 
say also that their esse consists in being caused. 
Reality consists (a) in being perceived, (6) in beingj^. 
caused, by spirit. 

Such, in outline, is Berkeley s doctrine of the 
reality__of^things. In order to fill in this bare sketch, 
it will be convenient to consider the theory in 
reference to three problems of great difficulty, (1) 
the externality of things, (2) the permanence of 
things, and (3) the distinction of Appearance and 
Reality. - 

(1) If things are nothing but combinations of 
ideas, In what sense, if any, are we justified in 
regarding them as external ? It might be objected 
at once that, on Berkeley s view, all externality 
should be denied to things, since they are always 
taken by him to be (a) "ideas," and (6) "in the mind," 
and neither of these expressions seems at first sight 
to be compatible with externality. Let us, then, 
examine what Berkeley means (a) by calling things 

1 Dialogues, i. 430, 437. * Principles, 26. 


ideas, and (6) by speaking of their existence in the 

(a) He admits that he is breaking with convention 
in calling things ideas : "It sounds very harsh to 
say we eat and drink ideas." 1 But if we refuse to 
be misled by words, he says, and consider what we 
really mean, we shall recognise that, as what we 
eat and drink is nothing but the immediate objects 
of sense, there is no absurdity in saying that we eat 
and drink ideas. Though he often conforms to 
custom and speaks of things, he prefers to term them 
ideas ; and that for two reasons. In the first place, 
the customary linguistic associations of the word 
thing suggest that it necessarily denotes " somewhat 
existing without the mind." And since for Berkeley, 
as we have seen, the essence of thinghood is its 
existential dependence on mind, he thinks it best 
to call things ideas, for ideas are universally ad 
mitted to be mind-dependent. 2 In the second place, 
" idea " denotes more exactly than " thing " what 
Berkeley means. The word thing, as commonly 
used, may include spirit (res cogitans) as well as the 
class of things which he terms ideas. Now, it is 
essential for his view to distinguish sharply between 
spirits and mere things (what he calls ideas) ; and 
to avoid misapprehension it is best, he avers, to 
speak of spirits and ideas as the constituents of 
existence. 3 

y (b) Ideas or non-spiritual things exist, as Berkeley 
always says, " in the mind." How is this consistent 
with their externality ? It must be pointed out, 
in the first place, that in saying that things exist only 

1 Principles, 38. 2 Dialogues, i. 453. 3 Principles, 39. 


in the mind, he does not mean to suggest that they 
actually have their locus within the ego, or that they 
are particular psychical existents falling within the 
mental process of an individual mind. The phrases 
" in the mind " and " without the mind " are apt to 
suggest spatial considerations, for they seem to 
indicate that mind is a sort of receptacle, " an empty 
casket " in Locke s terminology, into which ideas 
may or may not be put. But when Berkeley speaks 
of mind he means mind, and not brain. " When 
I speak of objects as existing in the mind, or im 
printed on the senses, I would not be understood in 
the gross literal sense ; as when bodies are said to 
exist in a place, or a seal to make an impression 
upon wax. My meaning is only that the mind 
comprehends or perceives them." l 

In other words, when we say that a thing exists 
in the mind, all we mean is that it exists, not in the 
brain, but in the subject-object relationship. 2 The 
existence of things consists in being in mind in the 
sense that they are in relation to mind. And when 
he insists that nothing exists " without the mind," 
he means that the subject-object relation is universal, 
and that nothing can exist apart from this relation. 
To put the same thing otherwise, " without the 
mind " means sine mente rather than extra mentem. 
" No mind, no thing " epitomises Berkeley s philo 
sophy. Everything in the world is necessarily, qua 
existent, in the mind-idea or spirit-thing or subject- 
object relationship. 

So far, we have been arguing that there is no 
reason why Berkeley s idea-things should not be 

1 Dialogues, i. 470. 2 Dialogues, i. 453 ; cf. i. 455. 


called external ; and now we have to show, in 
addition, that there are positive reasons why they 
should be termed external. 

(i) Idea-things may be regarded as external in the 
sense that they are objective. They fall on the 
objective side of the omnipresent subject-object 
relationship : they are " objects of the under 
standing." 1 And he insists that so far is he from 
subjectifying things that he is really objectifying 
ideas. " I am not for changing things into ideas," 
he says, " but rather ideas into things." 2 

(ii) Things are external also in the sense that they 

fall outwith the real personality of the self. He 

believes that personality is centred in the will. Now, 

/iny perceptions do not depend on my will, for, when 

/vl look at a mountain in daylight, if my sense of 

/ vision is normal, I must have certain groups of 

sensations and no others. So long as my eyes are 

fixed on the mountain I cannot help having these 

sensations. Ideas, then, are independent of my 

will, and therefore external. 3 

(iii) Things are external to the individual per- 
X cipient with respect to their cause or origin. A 
finite spirit, as we have seen, cannot manufacture 
its ideas of sense ; for they are not generated by the 
mind itself from within, " but imprinted by a Spirit 
distinct from that which perceives them." 4 All 
ideas of sense are caused by God, and are thus 
external to the finite mind which is aware of them. 

(iv) Berkeley even suggests twice 5 that, con 
sistently with his principles, we may postulate " an 

1 Dialogues, i. 471. * Dialogues, i. 463. * Dialogues, i. 458. 
4 Principles, 90 ; cf. Dialogues, i. 470. * Dialogues, i. 468, 458. 


external archetype " of our ideas. Such archetypes 
will be external to finite minds, and exist eternally 
in the mind of God. They must be external to my 
mind, for otherwise they would not be archetypes ; 
but still they are regarded as ideas, and have their 
existence as Ideas (with a capital) in God s mind. 

(v) Finally, ideas that I am not actually perceiving 
at thp moment may be called by me external in the 
sense that they do not exist in my mind, though they 
do exist in the mind of God, and possibly also in the 
minds of other finite spirits. 1 

On all these grounds, then, we are justified in 
saying that things, though called ideas and existing 
only in the mind, preserve their externality. 

(2) But suppose we admit, it may be argued, the 
externality of things, can we maintain their perma 
nence ? Things may be external to the finite mind 
in the senses enumerated above, and yet not be 
permanent and self-consistent. If a thing is not 
actually being perceived by me, in what sense does 
it actually exist ? To this question Berkeley 
suggests more than one answer. 2 A thing not 
actually being perceived by me may be said to exist 
in the sense (a) that if I were in a position to perceive 1 
it I should perceive it, or (6) that it is actually beings 
perceived by some other finite spirit, or (c) it is being 
constantly perceived by God. But though these 
grounds of permanence are all suggested by Berkeley, 
he does not press the first two solutions, for it is 
possible to imagine a thing in a position where it is 
not being perceived by any finite spirit, and where 
it could not be perceived by any finite spirit ; and 

1 Principles, 90. 2 Cf. Principles, 3, 6, 48. 


even if it could be perceived under appropriate con 
ditions, it is self-contradictory to make the actual 
permanent reality of a thing consist in the continuous 
possibility of being perceived. In the end, therefore, 
is content to assert that the permanence of things 
is guaranteed by their continuous existence in the 
mind of God. 1 

But it is not enough that they should simpty be 
perceived by God. They must also be willed or 
caused by him. It is only because things are not 
/produced by the capricious wills of finite beings, but 
created in a fixed and uniform order by the 
eternal will of God, that they are really self -consistent 
and permanent. 

The introduction of God s creative activity gives 
rise, however, to a fresh difficulty. By the perma 
nence of things, on this theory, do we mean anything 
more than the constant creation by God of similar 
things ? Do the same things really persist, or is 
God continually in process of creating similar things 
to take the place of those that are every moment 
being annihilated ? 

In connection with this problem Berkeley once 
or twice suggests the Scholastic view that things 
are in an unending process of annihilation and 
re-creation, and that, apart from this " constant 
creating," there is no permanence. " There is a 
Mind," he says, " which affects me every moment 
with all the sensible impressions I perceive." 2 When 
I gaze at a house, the same house does not really 
continue to exist, but God causes a constant succes 
sion of similar impressions which affect my mind. 3 

1 Dialogues, i. 452. 2 Dialogues, i. 428. * Principles, 46. 


The permanence of the physical order is thus 
equivalent to a constant creation of particulars by a 
benevolent God who in this way displays his power 
and providence. 1 But though this doctrine is 
suggested by Berkeley, he is of opinion, on the whole, 
that a creationism of this sort is inadequate to 
guarantee the permanence of things. 

He therefore advances what he regards as a more 
satisfactory theory, and holds that things have a 
really and absolutely permanent existence in the 
mind of God. They are not created from time to, 
time by God ; they are created once and for all, and 
continue to exist perpetually in the mind of God. 2 
On the other hand, it is obvious that from the human 
standpoint things are continually perishing and 
coming into being again. To harmonise these two 
truths (for he regards them both as truths) he has 
recourse to a distinction between absolute and relative 
existence. 3 " When things are said to begin or end 
their existence, we do not mean this with regard to 
God, but His creatures. All objects are eternally 
known by God, or, which is the same thing, have an 
eternal existence in His mind : but when things, 
before imperceptible to creatures, are, by a decree of 
God, perceptible to them, then are they said to begin 
a relative existence, with respect to created minds." 4 

1 Alciphron, iv. 14. 

2 Berkeley expressly dissociates himself from Malebranche s 
doctrine of " Seeing all things in God," Dialogues, i. 426. 

3 Berkeley elsewhere denies that things have an absolute 
existence. But the kind of absolute existence he has in view 
there is existence independent of God. And he would still agree 
that absolute existence in that sense is an impossibility. Cf. 
Principles, 24. 

4 Dialogue*, i. 472. 


Now, even if this distinction between relative and 
absolute existence were accepted, it would solve only 
one of Berkeley s difficulties. 

For the solution of the other difficulty he would 
need to introduce a distinction between relative 
existence and potential relative existence. The body 
of a man, for instance, has, on his view, a relative 
existence. But it has this relative existence only 
when it is actually being perceived by man. Berkeley 
would have to say that its existence when it is not 
actually being perceived by man is potentially 
relative. Though not actually being perceived, it is 
capable of being perceived. This potential relative 
existence clearly differs from absolute existence. 
Things have an absolute existence in the mind of 
God, but in addition to this they have a relative 
existence only when they are capable of being 
perceived by man. When they are not actually 
being perceived, they have a potential relative 
existence, and when they are being perceived an 
actual relative existence. 

>rhe root of the whole difficulty is the assumption 
of God as the cause of the permanence and reality 
of the world. But if we start, and on Berkeley s 
psychological method we must start, with our own 
ideas, presentations actually present to us, we could 
never have any reason to expect them to exist other 
wise than as actually presented to us. And even if 
we suppose them also to exist in the mind of God, 
how do we know that as presentations in my mind 
and presentations in God s mind they are the same ? 
The presumption seems to be decidedly against such 
an identification. We know that the sense-experience 


of animals differs among themselves and also differs 
as between them and men. The actual perceptions 
of various animals vary according to the number and 
structure of their organs of sense. The dog s world, 
for instance, differs from my world. As Mr. Bradley 
has pointed out, the dog s judgment is probably 
" What smells is real." As the world of man differs 
from the world of the lower animals, it would be 
natural to expect that man s world will differ from 
God s. For, whereas all our ideas are sense- 
impressions, none of God s are. " God perceives 
nothing by sense as we do," * for he cannot be 
affected with any sensation at all. " God knows, 
or hath ideas ; but his ideas are not conveyed to 
him by sense, as ours are." 2 

If, then, God s ideas differ from ours so radically,- 
what justification is there for asserting that when 
an idea is not being jperceived by me it is being 
perceived by God ? The it that is perceived by God 
is different from the it that is perceived by me. It 
is not the same it that Remains permanent. Its 
absolute existence in the mind of God is .permanent, 
but its relative existence in my mind is a process of 
constant annihilation and re-creation, and the process 
in my mind differs from the processes in the minds 
of other men for whom it exists. 

Our criticism of Berkeley might seem to be, so 
far, on the merely ; psychological level. But the 
argument cuts deeper than that. For he is forced 
to assume ultimately two orders of existence, which 
are taken to be in constant correspondence. The 
first order is the " archetypal and eternal," which 

1 Dialogues, i. 459. 2 Ibid. i. 459. 


has existed from everlasting in the mind of God, the 
second is the " ectypal or natural," which is in 
process of constant creation. Now, the archetypal 
order is perceived by God, but is imperceptible to 
man ; and the ectypal is that which is caused by 
God, and perceived by finite spirits. Thus we know 
that the particular things or ectypes that we perceive 
are caused by God, but are not perceived by him, 
though they correspond with the archetypes which 
he does perceive. Ultimately, then, what we mear 
by the permanence of things is that (a) they are ir 
process of constant creation by God in our minds 
and (6) they correspond with eternally existen 
archetypal Ideas in God s mind. In this 
Berkeley brings together, at the cost of introducing 
a dualism into his theory, his two views of the natur 
of permanence. 

It is fairly clear that in the course of his argumen 
Berkeley has been forced to change completely th 
meaning of his fundamental principle. At th 
beginning of his psychological enquiry, " esse 
percipi " means that presence in my experience, 
long as it lasts, is a sufficient account of the existem 
of a thing. But the difficulties we have mentione 
have forced him away from that position. Tl 
existence of a thing must mean more than me 
presentation in my experience, for simple expei 
ments prove that it exists even when I do n 
perceive it. He is thus gradually compelled to ho 
that the existence of a thing, even while I am p* 
ceiving it, is not exhausted by its presentatior 
existence in my mind. Hence, whether I a 
actually perceiving a thing or not, esse is percipi 


his first sense is untrue. If, then, the dictum is to 
be retained, a new meaning must be given to it. 
It must now be interpreted to mean that a thing 
exists really and completely only as a presentation 
in God s experience. 

From this alteration in meaning a sinister con 
clusion follows. Since real existence is exclusively 
presentation in God s experience, presentations in 
my finite mind cannot be ultimately real, for presen 
tation to finite minds implies only relative and 
ectypal existence. What finite persons know is thus 
not real reality but relative reality. Such a con 
clusion was extremely unpalatable to Berkeley, and 
he never explicitly drew it himself. But none the 
less it certainly is a consequence of his theory that 
finite persons are debarred from knowledge of that 
complete and archetypal reality which is known to 
God alone. 

(3) Are we then to conclude that finite persons 
can know nothing but appearance ? Though this 
conclusion seems to follow from what we have just 
been saying, Berkeley never acknowledges it. He 
always maintains that we do know reality. But 
this reality, it must be remembered, can be nothing 
more than ectypal reality ; for it is not the perfect 
reality of which God is aware. For most purposes 
that reality is simply left out of account by Berkeley ; 
and the distinctions he does draw between appear 
ance and reality all imply that reality means the 
concrete things or collections of ideas caused in our 
minds by God. 

The distinction between the real and the apparent 
is based on two principles. In the first place, ideas 


which are real things, i.e. presentations, are perceived 
with greater steadiness, vividness, order, and 
regularity than those which are merely images or 
representations. Reality is distinguished from the 
unreal and apparent by the vividness and steadiness 
with which it appears in consciousness. Berkeley 
admits that it may be said that this distinction 
is merely relative, presentations having ."more 
reality " in them than representations. /But in 
addition to this relative ground of distinction he 
mentions one which is absolute. The difference 
between presentations and representations, the real 
and the apparent, things and chimeras, depends on 
the cause of the ideas. If ideas are caused by finite 
spirits, they may be chimeras or fictions of fancy, 
and at the best are merely representations, copies, 
or images of the real thing. Real things are caused, 
not by finite spirits, but by the one Infinite Spirit. 
Thus the distinction between the real and the 
apparent is suggested by the vividness and steadiness 
of ideas, and is confirmed by the cause of ideas. 

Berkeley s theory of the existence of things 
involves, it is clear, a conception of degrees of reality. 
The mental images which finite spirits cause have 
less reality than the ectypal ideas which finite spirits 
perceive and God causes ; and the ectypal ideas, in 
turn, are less real than the archetypal ideas which 
God knows. 

So far, we have been dealing with the permanence 
and reality of things or ideas, and not of the spirits 
on which ultimately they depend for what reality 
they have. But the conclusions which we have 
reached raise further problems. Granted that the 


permanence of things depends on spirits, on what 
does the permanence of spirits depend, and in what 
sense are we justified in believing in their reality ? 
To the examination of this question (it is the culmi 
nating point of our enquiry) we now proceed. 


In order to account for the permanence and reality 
of the physical world Berkeley assumes the existence 
of spirits. He does not strictly prove their existence, 
and the arguments he does advance show that an 
explicit proof would proceed on different lines, 
according as the existence to be established is my 
own, that of other finite selves, or that of the Infinite 

My own existence, he holds, requires no proof, 
for I am intuitively aware of it : " We comprehend 
our own existence by inward feeling." 1 In two 
ways our own immediate experience guarantees the 
existence of the self. In the first place, I am im 
mediately aware of the existence of my ideas of sense 
as mine. I know that I do not cause them, but I 
know that it is I who perceive them. 2 Again, I have 
an immediate feeling-consciousness of activity, for 
I know that (a) I cause my mental images, and (6) I 
exercise productive operations, by means of volition, 
in the world. My own experience, then, both per 
ceptual and volitional, assures me of the existence 
of my self immediately. 

The existence of other spirits, on the other hand, 

1 Principles, 89. * Dialogues, i, 447. 

B.P. N 


whether finite or infinite, is not immediately evident, 
but is an inference from experience. The general 
lines of the argument for the infinite spirit and for 
finite spirits are very similar ; but there are certain 
significant differences which render it advisable to 
consider them separately. 

The argument in favour of " the existence of an 
infinite spirit as the cause of ou?, ideas is outlined by 
Berkeley in the Principles* and may be more 
systematically restated thus : (1) I am immediately 
aware of a continual succession of ideas. (2) There 
must be some cause of these ideas. (3) Now x _a 
priori, there are three and only three conceivable 
causes of an .idea, viz. another idea, matter, and 
spirit. (4) But he has shown that matter does not 
exist, therefore it cannot be the cause_of ideas. 
(5) Ideas, for their part, are necessarily inert and 
passive, and therefore cannot cause ideas. (6) There 
fore the cause of ideas must be spirit, either finite or 
infinite. (7) Now, finite spirits cannot cause ideas 
of sense, for these are passively received, independent 
of our volition. (8) The cause of ideas of sense is 
therefore an infinite spirit. (9) And the regularity, 
harmony, and order of the created world proves that 
there is only one infinite spirit, i.e. God. 2 


2 Berkeley has also another proof, based not on causation, 
but on perception. It is stated briefly in the Dialogues as 
follows : " Sensible things do really exist ; and, if they really 
exist, they are necessarily perceived by an infinite mind ; there 
fore there is an infinite Mind, or God" (i. 425). This argument 
comes perilously near a circulus in probando. We prove the 
existence of God by inference from the reality of things ; and 
then we use the existence of God to prove the reality and per 
manence of things. 


The inference of the existence of finite spirits other 
than- myself is made on somewhat different lines. 
It also starts from my own immediate experience, 
but, whereas the proof of God s existence depends, in 
one of its links, on the passivity of finite spirits in 
receiving ideas of sense, the proof of the existence of 
finite spirits is based on their activity in exciting 
ideas. Finite spirits are passive in immediate sense- 
experience, because ideas of sense are perceived in 
spite of ourselves, being created by God and by him 
impressed on our minds. But though finite spirits 
cannot create presentations, they can under appro 
priate circumstances excite them, and in addition 
they can cause representations or mental images. In 
sum, finite spirits are (1) passive in receiving presen 
tations, but (2) active in (a) creating representations, 
and (6) exciting presentations. 

Now, we cannot infer the existence of finite spirits 
from their passivity in perception. Nor can we 
infer it from their activity in creating representations, 
for these images are private and qua images incom 
municable. The existence of other spirits is inferred 
from their productive activity in exciting presenta 
tions in my mind. I am immediately aware of my 
own activity in operating and producing effects in 
the world, and when I see effects similar to those 
which I could have produced, I infer that they were 
produced by some other finite spirit. 1 Berkeley s 
meaning is very simple. I make a box. When I 
look at it, a certain presentation is in or before my 
mind. This presentation is ultimately caused by 
God, but the box which I have made is in some way 

1 Principles, 145. 


the occasion of it. 1 Now, if a presentation similar 
to the one which I have when I look at the box that 
I have made is excited in my mind at another time 
and place, I infer that its occasion is a box similar 
to the one made by me. Now, as I did not make 
this box myself, I infer that it was made by some 
finite spirit like myself. Other finite spirits therefore 

The general characteristic of spirit, whether finite 
or infinite, is its activity. It is the activity of spirit 
that cuts it off with a hatchet from ideas. " All the 
unthinking objects of the mind agree in that they 
are entirely passive, . . . whereas a. soul or spirit is 
an active being." A spirit is an active principle 
of motion and change. The essence of spirit is 

This proof of the existence of spirits has been 
criticised, e.g. by Hume, on tfre ground that it is 
logically on the same level as the materialist proof of 
matter ; and that, as matter has been disproved by 
Berkeley, he has no right to use the same type of 
proof to establish the existence of spirits. Spiritual 
substance, it may be argued, is no more secure from 
his criticisms than material substance ; and if we 
accept his conclusions with regard to material 
substance, it must follow that spiritual substance 
also is impossible. This, in effect, is the criticism 
of Berkeley s theory of spirits that Hume ad 
vanced ; but his objections were anticipated 
and answered by Berkeley himself in an im- 

1 This argument is inconsistent with Berkeley s criticism of 
the " occasional " theory of matter. Vide supra, p. 175. 

2 Principles, 139. 


portant passage in the third edition of the Dia 

He draws attention, in the first place, to his reason 
for rejecting matter. He has denied matter, he 
reminds us, not because we have no idea of it, but 
because the conception- of it is inconsistent. On the 
other hand, though we can have no idea of spirit 
either, there is nothing " repugnant " in its con 
ception. Matter, in other words, has been rejected 
because it involves an ultimate contradiction in its 
nature ; but since there is nothing inconsistent in 
the definition of spirit, no reason exists for its 

Spirit differs from matter, in the second place, with 
respect to its necessity. There is no reason to 
believe that matter exists ; and therefore, in accord 
ance with the general canon which he has already 
laid down, 2 we are justified in assuming that it does 
not exist. But with spirit the case is different, for 
the whole of experience depends on the existence of 
spirit, and as we cannot suppose that the sum-total 
of our experience is illusory, we are forced to main 
tain the existence of spirit. 

On these grounds, then, he argues that his con- 

< - ? 

ception of spirit is not open to the criticisms which 
he has brought against matter ; and therefore we may 
perfectly consistently reject matter and admit spirit. 
In connection with the theory of spirits two 
important problems arise with regard to (1) the 
identity and permanence of spirits, and (2) their 
degrees of reality. These two problems must now 
be investigated. 

1 i. 449-451. 2 Cf. supra, p. 178. 


(1) From the very first, the problem of personal 
identity puzzled Berkeley greatly. In the Common 
place Book we find the following entry : " Mem. 
Carefully to omit defining of person, or making much 
mention of it." l This memorandum he bore in 
mind all his life ; he always assumes that we are 
immediately aware of personal identity, and if we 
did not have the Commonplace Book we could never 
guess from his published works that he appreciated 
the difficulties of the problem. In the Principles 
and Dialogues he always writes as though perfectly 
convinced that personality implies a unity over and 
above the person s ideas and volitions. In addition 
to ideas, " there is Something which knows or per 
ceives them ; and exercises divers operations . . . 
about them." 2 " / myself am not my ideas, but some 
what else, a thinking, active principle that perceives, 
knows, wills, and operates about ideas." 3 

Such phrases as these sound very dogmatic ; but 
the Commonplace Book allows us to see that when he 
wrote these words he had already passed through a 
scepticism as absolute as that which Hume after 
wards reached. It is clear from the Commonplace 
Book that at one time he was inclined to analyse 
personality away into ideas. " Mind," he says, 
"is a congeries of perceptions. Take away per 
ceptions, and you take away the mind. Put the 
perceptions, and you put the mind." 4 Had he 
finally acquiesced in this view, his doctrine would 
have become a pure phenomenalism, akin to that 
of Hume and his followers, according to which the 

1 i. 41. 2 Principles, 2. 3 Dialogues, i. 450. 

4 Commonplace Boole, i. 27-28. 


only. objects known to exist are passing sensations, 
of which we can say neither that they are qualities 
of a permanent thing, nor that they are states of a 
permanent subject. In such a view as that Berkeley 
could not rest. He therefore tried to escape by 
showing that, in inner experience at least, there is 
something which is lost sight of when we analyse 
experience into a mere succession of ideas ; and this 
element, which is the feeling-consciousness of 
activity, guarantees the existence of personality. 
" Substance of a spirit is that it acts, causes, wills, 
operates, or if you please (to avoid the quibble that 
may be made of the word " it "), to act, cause, will, 
operate." 1 

So far, he is not convinced of the existence of 
personality as an entity distinct from isolated acts 
of volition or cognition ; but further meditation on 
the importance of the activity of spirit forces him 
to the conclusion that personality does possess an 
identity over and above the mere succession of ideas 
and volitions. 

Personal identity is connected, he believes, more 
closely with conative experience than with cognitive. 
" Wherein consists identity of person ? " he asks ; 
and replies, " Not in actual consciousness ; for then 
I m not the same person I was this day twelvemonth, 
but while I think of what I then did." 2 Thinking, 
then, only partly constitutes identity of personality, 
inasmuch as it is only as I reflect on the experience 
I had a year ago that I recognise my identity with 
what I then was. And this is not the whole truth 
about personality. Again, he does not believe that 

1 Commonplace Book, i. 53. 2 Commonplace Book, i. 72. 


it is a sufficient account of the self -identity of spirits 
to say that their esse is percipere. He certainly did 
believe at one time that the esse of the physical 
order is merely per dpi. But from the first he saw 
that the esse of spirits is more complex. It was 
impossible for him to hold that the existence of 
spirits is percipere and nothing but percipere, for the 
attitude of percipere is not active in sense-perception, 
but only in imagination, and, as he consistently 
maintains, the essential characteristic of spirit is its 
activity. Hence, as the activity of spirit is what 
really constitutes its existence, it is improbable that 
its self-identity will consist in one aspect of its 
existence which manifests its activity only very 
imperfectly. The activity of spirit, he holds, may 
take the two forms of knowing and willing. 1 Now, 
whereas in knowing the self is not wholly active, in 
willing it displays complete activity ; and Berkeley 
accordingly maintains that its self-identity consists 
chiefly in the will. 

What, then, is the will ? Berkeley s doctrine of 
volition was to have been developed in Part II. 
of the Principles* along with the general theory of 
spirit ; and as it is, we have only suggestions towards 
a doctrine. The first and most important point is 
that the will is not a separate faculty. On his view, 

1 " A spirit is one simple, undivided, active being as it 
perceives ideas it is called the understanding, and as it produces 
or otherwise operates about them it is called the will. (Principles, 

2 Berkeley says of will in the Commonplace Book, Regard 
must not be had to its existence at least in the first book " 
[sc. of the Principles} (i. 49). (The form in which this entry is 
printed in the Oxford edition is erroneous. See Lorenz in 
Archiv. f. Gesch. d. Phil, xviii, 555.) 


faculties are vicious abstractions, and all he means 
by the will is spirit as willing. In the attitude of 
willing spirit is active and causative, exercising a 
real productivity in the world. We are immediately 
aware of our ability to cause or construct mental 
images, and to produce bodily movements. Further, 
in willing we are self -determining : " Folly," he 
says, " to inquire what determines the will." l It 
is folly because, since will contains within itself the 
principle of action and movement, it is obviously 
self-determining. And as the will is merely one 
aspect of the spirit, the activity of the will is present 
in all the experience of a finite spirit. Presenta 
tional experience as such is not, it is true, active ; 
but, inasmuch as it is the experience of a spirit, it is 
accompanied by or pervaded with volitional activity. 
:; While I exist or have any idea, I am eternally, 
constantly willing ; my acquiescing in the present 
state is willing." 2 For him, willing is thus simply 
the conative or active aspect of experience ; and, 
as activity is the most fundamental characteristic of 
spirit, the will is the most fundamental aspect of the 
unity of the mind. 

It is willing, then, rather than knowing that con 
stitutes personal identity. Berkeley answers in the 
affirmative the question which he asks himself, 
Whether identity of person consists not in the 
will ? " 3 The ultimate unity of personality resides 
in the will. 

In the Principles this position (to which he has 
attained by passing through a scepticism as absolute 

1 Commonplace Book, i. 34. 2 Commonplace Book, i. 49. 
3 Commonplace Book, i. 72. 


as Hume s) is everywhere assumed without question. 
Personality is a unity, which, as cognitive, is called 
Understanding, and, as conative, Will. But will 
and understanding are simply names for the opera 
tions of the self in different aspects of its life. A self 
is a single unity, which is responsible for its operations 
in all their diversity. 1 He emphasises the unity of 
the self, as opposed to the variety of its ideas ; and 
its permanence, as contrasted with the transitoriness 
of its ideas. The identity of the self is implied in 
the regular epithets " simple " and " indivisible " ; 
and the retention of the category of substance in 
connection with spirits has at least the merit of 
laying stress on their permanence. 

The existence and permanence of other finite/ 
spirits is, on Berkeley s view, an inference from my 
own existence and permanence. Their existence isj 
as inferential, less certain than my own ; and much 
less certain than God s. But he does not waver in 
his belief that other selves have a permanent 
embodied existence like his own. I am one and the 
same self, and I have a body which I use in my 
operations on the physical order. In one aspect my 
own body is a cluster of sensations for me, and a 
combination of presentations for others ; but it is 
more than this, for it gives rise to the unique feeling- 
experience of purposive activity. Similarly, in one 
aspect, the bodies of my fellow-men are complexes 
of sensations to them and congeries of presentations 
for me ; but they are not merely this. His practical 
interest in life prevented him from saying that other 
human beings are merely clusters of perceptions 

1 Principles, 27. 


suggested to me in a fixed order. Such a view 
would render impossible all social and ethical rela 
tions. He infers that as my self appears to others 
simply as a presentational complex, so other pre 
sentational complexes or selves, which to me appear 
simply as presentational complexes, have the same 
immediate feeling of personal identity as I have. 
But this is an inference, from my own experience. 

This view that the existence of our fellow-men as 
identical and permanent selves is known only by 
analogy from our conviction of our own existence is 
saved from some of the criticisms that have been 
brought against more modern restatements of it, 
e.g. by Avenarius, by Berkeley s insistence that the 
inference is made on the basis of the evidence of the 
activity of selves. I am conscious of my own 
activity, and I can see the products of that activity. 
From my observation of similar products, which I 
know I did not make myself, I infer the agency of 
active beings similar to myself. This argument is 
not open to the criticisms that may be brought 
against the cruder type of analogical proof. 1 But 
it seems fairly clear that the analogical argument in 
general, and therefore Berkeley s version of it, rests 
on an unjustifiable assumption. It is assumed, on 
the analogical argument, that we attain a full 
consciousness of our own selfhood in isolation from, 
and independence of, other human beings. But this 
assumption is psychologically false. Our awareness 
of our own selves and of other selves develops con 
currently. From our earliest days we exist in a 
society ; and only as our own inchoate purposes 

1 Cf. A. E. Taylor, Elements of Metaphysics, p. 204 ff. 


partly coincide with, and partly conflict with, other 
purposes, do we become fully aware that our purposes 
are ours. Our awareness of our own and of others 
identity shows a wonderful parallel evolution. 1 

(2) So far, in dealing with the permanence and 
self -identity of spirits, we have not considered them, 
in relation to one another, with respect to the grades 
of reality which they occupy. A conception of 
grades of reality is implied, as we have already seen, 
in Berkeley s view of the world ; and we must now 
examine how far his theory of spirits harmonises 
with it. 

For Berkeley, the world consists, as we have seen, 
of spirits and ideas. But ideas are entirely dependent, 
if they are presentations, on God ; and if they are 
representations, on finite spirits. Thus spirits alone 
have an independent existence, and accordingly, 
seeing that the reality of things is relative to that 
of spirits, a doctrine of grades of reality will have 
reference mainly to spirits. Is it possible to classify 
spirits according to their degrees of reality, or are 
all spirits equally and completely real ? 

In Berkeley s, all-spiritual universe spirits ..differ 
in the degree of their reality, the gradation being 
conceived in terms of activity. God is pure activity, 
and is thus completely and ultimately real. Finite 
spirits are active, inasmuch as they will, operate in 
the world, and cause representations ; but, since 
they can create neither selves nor presentations, 
their activity is inferior to God s ; and, as percipient 
of presentations created l>y God, their nature in 
cludes the element of passivity, which is entirely 

1 Cf . Broder Christiansen, Vom Selbstbewusstsein, p. 2 9 ff . 


absent from God. Thus, as (a) incompletely active, 
and (6) partially passive, finite persons are less real 
than God ; and they may be considered to occupy 
a position intermediate between God and things. 
Least real of all, possessing, indeed, only relative and 
dependent reality, come things or ideas. These are 
entirely inactive ; their nature is wholly passive 
and inert. Thus, any reality that may be ascribed 
to things is merely a courtesy-title : they are real 
only by the grace of God. 

Berkeley s metaphysic, then, comes in the end to 
be a hierarchic pampsychism. His doctrine is not 
really solipsistic, for he explicitly holds (a) that the 
world contains, in addition to me and my ideas, 
other finite spirits with their ideas, and (6) that I am 
not the source of my presentations, but am dependent 
for them on God, who causes them to occur in a fixed 
and regular order. But, since what really exists is 
nothing but a hierarchy of spirits, the doctrine is 
necessarily a pampsychism. 

As therealit of the hvsical 


indispensable r6(3 n Becketey^g jjpppryjrf causation. 
Berkeley f viffSF <a existence involves,"^ as*~wehave 
seen, a conception of three degrees of reality. In 
precisely the same way his theory of causation 
implies three types of causes, differing in the extent 
and power of their operation. As G 
real^sj^jts^cjimpietely tea^ ,anc[ 
in a derivative sense, so God is the only complete 

^ s * t s^ uJ ^r^^*^i^^^^^^ M ^^ *"*~ ^^-^ t t ^^ ..... < h 1 1 i i|_i ~ ~^ 


and real cause, spirits being incompletely causal, and 
tilings exercising a merely derivative causality, which, 
indeed, can be called causality only by courtesy. 
This conception of degrees of causality must now be 

In accordance with the whole trend and spirit 
of Berkeley s philosophy, GnH is ^flajflflfij HIP -*^ A 
supreme .and fundamental cause. Jt is God who 

produces every effect by a fiat or act of his will." 
But God does not simply create the world of things 
aixd then leave it to go by itself like a clock that, havS 
been^j^ound up to_g^jOT_acerta^ Yet 

Berkeley allows that, if we really understand 
what we mean, we may speak of " the clockwork of 
Nature." 1 What we mean by this is that j3 very 
event that occurs .in the physicalx>rj^r jg Jhe direct 
result of God s volition. It is God s good will that 
the successions of events should follow -one^another 
ui_a fixed and harmonious order. But the fact 
remains that every fiat of Trod s will is entirely 
arbitrary ; and that, just as we may call up any 
image at will, so Qod CJJJQ jjau^^aii^^y^nj^a^^ill. 
At any moment, God may depart from the order 
which he normally maintains. That he does not, 
in general, perform miracles, is due to his desire to 
enable us to regulate our actions for the benefit of 
life ; for unless events occurred in a fixed and 
uniform sequence, " we should be eternally at a loss : 
we could not know how to act anything that might 
procure us the least pleasure, or remove the least 
pain of sense." 2 

1 Principles, 60. 



it --is., entirely d,epen^nt ,pn,. the gja.ce.of 
though not capricious. 

as an- omnipresent, infinitely active spirit. It is as 
essential to maintairi the conservation of nature as 
its. creation.; and Berkeley concludes " that all things 
necessarily depend on Him as their Conservator as 
well as Creator, and that all nature would shrink 
to nothing, if not upheld and preserved in being by 
the same force that first created it." 1 

In addition to God, Berkeley admits two other 
sorts of cause. BuLjaist^S-fitesMft^feW 


reality-~oi. finite spirits is^ derivative and imperfect, 
so _ia... their causality. Thus Berkeley recognises 
" spiritsiofaSerent orders, which may be termed 
active causes, as acting indeed though by limited 
and derivative powers." 2 The causality of spirits 
manifests itself in two main forms. They are 
capable of creating images, and they are able, at 
least to a limited extent, to produce motions in their 
own bodies, in other persons bodies, and in things. 
But compared with God s causality, the powers of 
finite spirits are doubly limited, inasmuch as their 
ability to produce motions in the physical order is 
imperfect, and they are impotent to create either 
selves or things. 3 

When we consider the causality of things, we find 
that, precisely as things, being passive and inert, 
are denied the name reality in a full and proper sense, 

1 Letter to Johnson, ii. 16, 17. * Letter to Johnson, ii. 16. 
3 Three Dialogues, i. 431. 


so they cannot properly be causey. It is, indeed, a 
contradiction that a thing totally devoid of activity 
should be a cause. Berkeley therefore denies that, 
strictly, there is such a thing as natural causality. 
He finds no difficulty in disproving the contem 
porary Corpuscularian hypothesis, on the ground 
that as corpuscles are, qua ideas, passive and inert, 
no possible combination of them, in extension, 
figure, or motion, could possibly be a cause. 1 Nature 
in Berkeley s sense of " the visible series of effects 
or sensations imprinted on our minds, according to 
certain fixed and general laws," cannot produce 
anything at all. 2 Nature is passive, and therefore 
cannot be a cause. The belief that there are real 
natural causes arises from an erroneous analysis of 
our own immediate experience. We are immedi 
ately aware of a uniform succession of presentations 
in our experience ; we know, further, that we did 
not cause them ; and we hastily infer that they must 
cause one another. But Berkeley points out, as 
Hume did later, that all we actually perceive is the 
uniform succession of our presentations. The infer 
ences that the connection between them is necessary, 
and that one can be the cause of another, areTboth 
alike false. The only ultimate cause is God, and 
though his causality issues in " a consistent uniform 
working," it implies no necessary connection between 
things. " There is nothing necessary or essential in 
the case." 3 

The relation between cause and effect is thus a 
purely arbitrary one. Cause and effect are con 
nected by no necessary tie ; they bear to one another 

* Principle?, 25. 2 Ibid. 150. 3 Ibid. 106. 


merely the relation of sign and thing signified. By 
experience we learn that such and such ideas are 
followed or attended by such and such other ideas ; 
certain sequences and concurrences occur regularly 
and uniformly. The preceding ideas are not, 
Berkeley avers, the causes of the subsequent ideas ; 
they are merely the signs that warn us that they will 
be followed by certain other ideas. Thus Berkeley s 
theory of causality becomes a doctrine of signs. 1 

The doctrine of signs occupies a highly significant 
place in Berkeley s philosophy. " I am inclined," 
he says, "to think the doctrine of Signs a point of 
great importance, and general extent, which, if duly 
considered, would cast no small light upon Things, 
and afford a just and genuine solution of many 
difficulties." 2 The part which signs play in dis 
charging the functions of universality in Berkeley s 
philosophy has already been explained, and we have 
indicated the logical weaknesses of the theory. 3 We 
have now to estimate the importance of the doctrine 
of signs in Berkeley s philosophy of causation. 

Although the importance of the doctrine of signs 
has been very generally recognised, it has never been 
made clear, so far as I am aware, that the use of signs 
in mathematics did much to suggest to Berkeley, 
or at least to confirm his belief in, the importance 
of a metaphysical theory of signs. This point is 
important from the historical standpoint so im- 

1 In Locke s classification of the sciences (Essay, iv. xxi.) 
the third division of knowledge is termed " S^eiam/cr;, or the 
doctrine of signs." But by this Locke means little more than 
logic ; and on this account Berkeley is indebted to him only 
for the name. 

2 Alciphron, ii. 343. 3 Vide supra, p. 133. 
B.P. o 


portant as to justify a digression of some length, in 
order to explain how the value of signs in mathe 
matics impressed Berkeley. 

It must be remembered that Berkeley s great 
object, as he tells us again and again, is to simplify 
philosophy, and abridge the labour of study. Now, 
in mathematics it is the great function of signs to 
abridge the labour of study and to simplify methods 
and explanations. This function of signs is apt to 
be overlooked by us, for we take the use of signs in 
mathematics simply as a matter of course. We 
could not conceive mathematics without the use of 
signs. But in Berkeley s day the extended employ 
ment of signs in mathematical operations was still 
almost a novelty ; and he takes pains to point out 
the value of those branches of mathematics, which 
are specially concerned with signs, in the simplifica 
tion of the sciences. " Modern algebra," he says, 
" [is] in fact a more short, apposite, and artificial 
sort of language." J Now, philosophy has always 
suffered, Berkeley believes, from the ambiguity and 
unsuitability of the language with which it has been 
forced to work. What advances, then, might we 
not hope for, if we could employ in philosophical 
investigation a perfectly determinate and suitable 
terminology ? Such a terminology, Berkeley hoped, 
might be supplied by signs akin to those employed 
by algebra. Algebra is par excellence the science of 
signs, and Berkeley believes that a little attention 
to algebra and the way in which it uses its signs 
" may possibly help us to judge of the progress of 
the mind in other sciences ; which, though differing 

1 Alciphron, ii. 344. 


in nature, design, and object, may yet agree in the 
general methods of proof and enquiry." 1 

It will help us to appreciate Berkeley s application 
of the doctrine of signs to the special problem of 
causation, if we explain (1) how, sJiorJisL. before 
Berkeley s day, signs had come to be used in mathe 
matics and especially in algebra ; and (2) what 
exactly Berkeley understood by the application of 
algebraic methods in other sciences. 

(1) First, then, of the development of the use of 
signs in mathematics in the decades immediately 
preceding the time when these problems began to 
occupy Berkeley s attention. The first signs to be 
used were naturally those of addition and sub 
traction ( + and - ) ; yet even such elementary 
and indispensable signs were not generally accepted 
symbols till about 1630. And it was much later 
before uniformity was reached in the use of the other 
chief signs. 

From 1631 onwards English mathematicians used 
the sign x to denote multiplication, but many 
French mathematicians, following the usage of 
Descartes, indicated the operation by a dot. And 
it was denoted by Leibniz in 1686 by the sign "-. 

A similar lack of agreement existed as to the 
symbols with which to represent division. It was 
usually indicated by the method, copied from the 
Arabs, of writing down the quantities to be operated 
upon in the form of a fraction by means of a line 
drawn between them, in any of the forms a - b, a/b, 

or -. English mathematicians, however, frequently 

1 Ibid. ii. 342. 


indicated it by a dot. In 1686 Leibniz used the 
sign ^. 

The symbol = for equality was not commonly 
used till the time of Newton, say about 1680. 
Previously the word was written out fully, or the 
signs oc or were used. The sign : : to denote the 
equality of two ratios was brought into common use 
in 1686 by Wallis. 

The relations is greater than and is less than were, 
at the beginning of the eighteenth century, indicated 
either by our present signs > and <C, or by -D and 
_a. The negative symbols =f= for is not equal to, 
> for is not greater than, and <fc for is not less than 
had not been introduced in Berkeley s time. 

In Berkeley s day the use of indices to denote the 
power to which a magnitude is to be raised had only 
comparatively recently become general. As early 
as 1637 Descartes used indices, but only positive 
integral ones, e.g. a z , a 3 . In 1659 Wallis used and 
explained fractional and negative indices, e.g. 
x~ l , x* ; and Newton was the first to use an index 
infinitely large, e.g. a n . 

The invention of the calculus necessitated the 
introduction of certain symbols. In Newton s 
notation x means a first fluxion, x a second fluxion, 
and so on ; and the corresponding differentials were 
represented by Leibniz by dx, ddx, and so on. 1 

Now practically all these symbols, it must be 
repeated, were comparatively new in Berkeley s 

1 On the development of the use of signs in mathematics see 
further W. W. R. Ball, A Short History of Mathematics, pp. 212 ff. ; 
M. Cantor, Geschichte der Mathematik ; and F. Cajori, The Works 
of William Oughtred, in the Monist, July, 1915, pp. 441 ff., to 
all of which the above account is indebted. 


student days ; and their use had not yet become 
common. Still, it was already clear how wonder 
fully they had contributed to the success of mathe 
matics. They had helped it to advance by simpli 
fying its methods, for before their introduction all 
mathematical operations had to be written out fully 
in words, and mathematical demonstrations, unless 
they could be represented geometrically, were 
cumbrous and tedious. 

Berkeley himself was greatly interested in the use 
of signs in mathematics. In the Miscellanea Maihe- 
matica (1707), he indulges in a perfect orgy of 
symbols. And he suggests, in a short paper 
De Radicibus Surdis (1707), as a simplification of 
the usual method of representing surd quantities, 
the introduction of a new symbolic notation of his 
own. 1 Roots, he points out, might conveniently 
be represented by the use of Greek letters ; /3, for 
instance, would express s /6, <5 would stand for Jd, 
and so on. Similarly, Jbc would be written /3r, 

and A/ . But Berkeley sees that, if this 
e . e 

notation were adopted, it would not enable us to 
distinguish square roots from cube roots and those 
of still higher powers ; and he therefore makes the 
alternative suggestion that roots should be ex 
pressed by the same method of dots as was then 
used for fluxions, e.g. a would stand for Ja, a for 
I/a, a for \la t and so on. 

Now, worthless as all this is in itself, it is yet of 
importance on account of the light it throws on 

1 iv. 43-47. 


Berkeley s interest in symbols as such. He was 
interested in them because they were still so new 
that alterations such as he advocated might even 
yet be suggested with some hope that they might 
be accepted. But another consideration impressed 
Berkeley in connection with signs. Though fifty or 
even twenty-five years before his student days they 
had been used by mathematicians with little uni 
formity, they had already by the time he began to 
write become fairly standardised, so that the same 
symbols everywhere and always meant the same 
thing. This meaning was, indeed, arbitrary and 
artificial ; but for Berkeley the important thing was 
that it was a definite and determinate meaning. 
Thus by the use of similar signs in philosophy he 
hoped to be able to introduce exactness and accuracy, 
and at the same time secure results which could be 
demonstrated so that all who agreed in the meaning 
of the signs would be forced to give assent to the 
conclusions. And finally, Berkeley hoped that by 
such an introduction of signs in philosophy it would 
be possible to simplify it and rescue it at once from 
the meaningless subtleties of the Schoolmen, and 
the occult complexities of the Cartesians. Hence he 
believes that the hope of philosophy lies in the applica 
tion to its problems of algebra, the science of signs. 
(2) What exactly does Berkeley mean by the 
application of algebra to the problems of philosophy ? 
Berkeley s interest in algebra is proved not only by 
the numerous references to it in his works, but also 
by the juvenile publication De Ludo Algebraico 
(1707). This tract gives a description, with a figure, 
of an algebraic game invented by him, and advocated 


on the characteristic grounds that it is both as 
pleasant a recreation as chess and a useful exercise 
in algebra. After explaining the game he concludes 
by making the most extraordinary claims for algebra. 
It may usefully be applied, he declares, " to the whole 
extent of mathematics, and every art and science, 
military, civil, and philosophical." " Through all 
of these," he continues, " is diffused the wondrous 
power of algebra. By all it is regarded as a great 
and wonderful art, the topmost pinnacle of human 
knowledge, and the kernel and key of all mathe 
matical science." x 

After thus giving his own testimony to the value 
of the application of algebra in the sciences, Berkeley 
proceeds to appeal for confirmation to the evidence 
of Descartes, Malebranche and Locke. 2 Unfor 
tunately the passages in these authors to which 
Berkeley refers shed very little light on the applica 
tion of algebra. Locke, whose Conduct of the Under 
standing Berkeley refers to, speaks very favourably 
of algebra, but he says nothing about the possibility 
of applying its methods directly to other sciences. 3 
And Malebranche, to whom Berkeley also refers, 
though he expresses himself with more vigour and 
enthusiasm than Locke, does so with equal vague 
ness. He merely insists, as Berkeley does, on the 
simplicity and ease with which, by means of algebra, 
we are able to abridge the labour of study ; and he 
declares that algebra (along with arithmetic) forms 
the foundation of all the sciences, and supplies the 
means by which they may be acquired. 4 The point 

1 iv. 60. 2 Miscellanea Mathematica, iv. 62. 

3 Op. cit. 7. 4 Recherche de la Virile, vi. i. 5. 


on which both Malebranche and Locke insist is the 
value of algebra in simplifying the sciences to which 
it is applied. 

To them and their readers it was perfectly clear 
what was meant when it was said that algebra 
simplifies the work of the sciences ; but to us, to 
whom algebra is no novelty, this aspect of it is not so 
obvious. And it may, perhaps, help us to realise 
what Berkeley hoped for from the application of 
algebra in philosophy, if we have before us an 
example of the way in which algebra had rendered 
possible this work of simplification. 

Algebra had been employed by Descartes to 
simplify geometry. Descartes invented analytical 
geometry in 1637 and substituted simple algebraic 
methods, which could be applied universally, for a 
cumbrous geometry requiring new constructions for 
each particular problem it attacked. Analytical 
geometry gives us a method of representing curves 
and curved surfaces by means of simple algebraic 
equations. Descartes saw that a point in a plane 
could be determined if its two co-ordinates were 
given, i.e. if its distances (x and y) from two straight 
lines drawn at right angles to one another in the same 
plane were known. Such an equation as f(x, y)=0 
represents a plane curve described according to a 
certain law. The equation is indeterminate and is 
satisfied by every point in the curve ; but its merit 
is precisely that it is general and contains in itself 
every property of the curve. Thus, instead of 
having to draw a special figure for each case, as we 
must do in ordinary geometry, it is only necessary 
to know the general equation to the curve, and any 


particular property may then immediately be de 
duced by an application of ordinary algebra. In 
this way the application of algebraic methods 
to geometry immensely simplifies what would 
otherwise be exceedingly complicated geometrical 

The possibility of applying algebra outside mathe 
matics had occurred to many thinkers in Berkeley s 
day, and algebraic methods had been applied, 
often very foolishly and fantastically, to all sorts of 
problems. Berkeley himself notes its application 
in medicine and natural philosophy ; and he refers, 
with evident appreciation, to the use that had been 
made of it in demonstrating the credibility of human 
testimony. As an example of this he gives a refer 
ence to an article in the Philosophical Transactions 
of the Royal Society ; and it seems worth while, as 
an instance of the kind of " application " he thought 
feasible and valuable, to indicate the scope and 
argument of the article in question. 

In the article, 1 which is anonymous, the writer 
considers the credibility of evidence, e.g. the report 
that 1200 has been given to him by somebody. 
He assumes that the credibility of the average report 
is g absolute certainty, and thus if the report be 
at second-hand its credibility will be only | (i.e. ^ 
of |), and so on. This may be expressed algebrai 
cally as follows, if we put a for the share of certainty 
given by a single reporter, and c for what is lacking 
to make the certainty complete. The degree of 

1 " On the Credibility of Human Testimony," Philosophical 
Transactions, 1699, vol. xxi. no. 257, p. 359. The author may 
have been John Craig (v. infra). 


certainty at first-hand is - , at second-hand 

a +c 

2 a 3 

at third-hand - , and so on. Take 

(a+c) 2 

another case, rather more elaborate. Suppose the 
narrative reported contains six particular articles or 
statements. If the degree of certainty of the whole 
be |, the degree of certainty for each article will be 
|-f . For there is 5 to 1 against any error at all in 
the report, and there is another 5 to 1 against the 
error falling in any one particular article. The 
recipient of the news has ^ certainty for the whole, 
and (|- x jl) certainty additional for each particular 
article taken separately, i.e. -|+^% or |-^ certainty 
for each particular article taken separately. This 
result also may be expressed algebraically. For 

suppose as before that is the proportion of 

a+c m 
certainty for the whole, and that - - is the chance 

m +n 

of the rest of the particular articles (m) against any 
one or more of them (n), then the certainty in the 
case of each particular article will be unity diminished 

by - . Other problems considered in the 

(m +n)(a 

articles are the credibility of oral tradition over a 
period of years, and the accuracy of written tradition 
involving several copies of the original document. 
By a strange coincidence a book was published 
in the same year as this article appeared (1699) 
bearing a title copied from Newton (Theologiae 
Christianae Principia Mathematica), and dealing 
with the same problems as the article. The author, 


John Craig, calculates by mathematical methods that 
the evidences of Christianity, gradually deteriorating, 
will be reduced to nil in 3150 A.D., and that a new 
revelation will then become necessary. 

Berkeley avoided the absurdities and extrava 
gances of such " appli cations " of algebra, but the 
spirit which actuates him is the same. What he 
does in developing his theory of signs is to apply 
what he regards as the principles of algebra to the 
study of nature ; and his Natural Philosophy may 
well be called an Algebra of Nature. 1 

Just as algebraic signs suggest to us, or enable us 
to infer, the things they signify (e.g. from the collec 
tion of signs x 2 +y 2 = c 2 we infer, according to the 
Cartesian system, a circle with its centre at the 
origin), so the signs which we see in nature suggest 
to us, or enable us to infer, the things they signify. 
Thus, to use Berkeley s illustrations, a fire which 
I see suggests to me, or enables me to infer, that if 
I approach too near to it I shall suffer pain. 2 Simi 
larly, the noise that I hear suggests to me, or enables 
me to infer, that some sort of collision or concussion 
has taken place. 3 

The relation between the sign and the thing 
signified is not necessary. The sign does not im 
mediately and inevitably suggest the thing it signi 
fies ; the relation between them must be learnt. 
To the savage the group of signs x 2 +y 2 = c 2 does 

1 Berkeley also applies algebra to ethics. Vide infra, Chap. VI. 

2 Principles, 65. 

3 Between suggestion and inference there is an important 
epistemological distinction. See Theory of Vision or Visual. 
Language Vindicated, 42. 


riot immediately ugget a circle ; trie expression 
HuggMt* ft circle only to the mail who ha* Iftanii by 
4-/ experi tfuje itw relation between the wign and what 
/ Jt ignifie, Ho, the fire doe# not mcett&rily Kn%%<&i 
Win ; it ugg<^t pain only to Uw " burnt chiH," 
j-r only if) thti fHtrwttt who haw burnt thv relati/jn 
nd what it 

It i uniform lx> UMJ a m<xJrn t;rrn 
which w<?JI <^|/n?hw<^ JJ<;rk?Jj?y meaning within 
a certain universe of <Jiwourw. Within the univerwi 
of diwjourw*} of Cartx^ian ttwtmvtry ar 2 -l-y*=e 2 
uniformly ermbix^ u t/> infer a circle ; arid within 
the universe of <li#courhe of the Earth fire uniformly 
enablfc u* to infer pain if we approach txx> clr>ely. 

Jiut JierkeJjey in^bitn that the relation i an 
arbitrary one. The choice of the particular group 
of ttign* ar 2 -4 //*= c* to reprewint a circle in perfectly 
arbitrary. Yet it alwayw enable** UH U> infer a circle, 
because there ix universal agre<;rnent among mathe- 
maticianx a to the meaning of thetse >si^n. Simi 
larly, the / :J;ii,ion between pain and (ir<* in arbitrary, 
but the latter always alJowH UH Ixj infer the former, 
bfccau it I >>.. \> . .n f^o decreed by <i<>d. It w due 
to the arbitrary, though Jiofc capricious, will ul CJod, 
Oi.-fi. /:)]/! n.-j.t.uf.-il ;-i^/j-: uJway;-i KU^ewt certain 
n:t.u/;tl Uun; j;;/iJfi;<J. The f;onnection i purely 

And thi*, JJr;rkeley argueH, i all that we mean by 
causality. Cauality v- not the relation of cause and 
fleet, it UJ the / J;j.1i ;n < >\ i; fi afj J Oiin^ signified. 
I }, fin that J HCC w not the cause of the pain T feel 
Qn"ppnwu?hing it too clonely, it is the mar A; or 


thai forcwarriH inc of it. 1 Similarly, the nome that 
I hear i! not- I. he < ff< < t of the "Hi ion, l.ul, the ni{fn 
that ejjaMen mo to Infer that a colIiHion IHIM taken 
pluxe. The, nign may thim lie either what in coin 
monly called the caune, or what in commonly called 
th($ (!Jlo(!t. If it in \)\<> " cauHc-," it Hiif/tfcxtH, JIH thn 
tiling Hi^rii(i(!<l, the- " (tHect " ; and if it in tho " ofToct," 
it HU^tsHtH, an the thin^ Hignified, the " eaune," 

Borkdoy thuH irriplu^ the, Htriot cot-relativity <f 
" cauHO " and " c,flect " ; and witii Hiich a doctrine 
aH the plurality of cauMcu ho would havo no sympathy, I 
livery tii^ri ifi nature in corrcluLul l<y (^lod with Homo 
one tiling which itnigniiieH ; th(rr<HH a_pre < i,, ,hed 
ii arm otiy between them, and an the wigri Htrictly 
n only the one thing Hignifled, HO the 

HU^geHtH "only the one niprn. A 
Minified cannot he Higriified hy a plurality of 
it ifl Hug^ent;d only hy itn own proper Hign. 

Nature JH HyHtematically organised hy (jod HO that 
nignH and thingM nullified prenerve thin one-one 
relation. AH the Languag<; of Nature, to UNO 
Berkeley s own term in a perfect language (for it 
in the language of God), each word in it ntandn for 
Home one particular thing, arid each particular thing 
in the univerne han itn Appropriate and peculiar name. 
ThuH, in the mind of_God^ jy^pULJ^jdiMtliifaiy 
Hyntematic, and 8Jgn8 arid llnu^ ujMnln-d are 
perfectly adjuHtwi; 

ThiH di UK l.-i.ny.uiLge conntituteH, for Berkeley, the, 
nytittim of tlie lawn of njitimj. The language, of 
nature revealn itn " connintent uniform working " 
arid nhowH that itn lawn are " eonnectionH entahlinhed 

1 / rincirilf., 65, 


by the Author of Nature in the ordinary course of 
things." * These laws__of nature, representing a 
pre-established connection in the mind of God, are 
absolutely settled and fixed, and in accordance 
with them everything in nature takes place with 
perfect uniformity. 

Now, men often doubt the uniformity of nature 
and the universality of its laws. The reason for 
this is that the laws of nature are not self-evident. 
They need to be learnt. The universe may well 
seem a chaos before we have learnt its meaning. 
This meaning is not supernaturally revealed to us 
at birth. God, it is true, excites in us from time 
to time certain ideas which are connected by set 
rules in his mind ; but he does not explain their 
connection to us all at once. We must learn by 
experience which ideas are connected with which. 
We have to acquire God s notation, as we have to 
learn that of Descartes or Newton. We understand 
the laws of nature, " the set rules or established 
methods wherein the Mind we depend on excites in 
us the ideas of sense," 2 only when we are able to 
interpret God s symbolism, just as we understand 
the theorems established in the Principia only when 
we are acquainted with the notation which it 
employs. Hence it is the great .task of science to 
try to understand the divine symbolism. "It is 
the searching after and endeavouring to understand 
this Language (if I may so call it) of the Author of 
Nature that ought to be the employment of the 
natural philosopher." 3 

1 The Theory of Vision or Visual Language Vindicated, 40. 

2 Principles, 30. 3 Ibid. 66. 


In the process of seeking to understand this divine 
language of the laws of nature we may often attain 
some knowledge of the sign without fully or exactly 
comprehending what it signifies. The sign may 
suggest something to us, and we may be able to make 
use of it, though we may be quite unable to formulate 
precisely what it does suggest. Here again the 
analogy of mathematics makes Berkeley s meaning 
clear. Such signs or groups of signs as J - 1 and TT 
mean something and may be used in mathematical 
operations, though it is impossible to express numeri 
cally exactly what they suggest. So, even though 
it be impossible to explain precisely what certain 
signs in nature suggest to us, we may make use of 
the symbols, and may, indeed, maintain that, 
though we cannot formulate them exactly, there is 
something that they suggest. 1 

But in general we are able by experience to learn 
the relation between sign and thing signified. God 
follows certain rules in the organisation of nature, 
and, as men succeed in discovering these rules, the 
connection of sign and thing signified becomes ever 
clearer. God creates certain organisms and con 
structs certain machines, in much the same way as 
men combine letters in words and words in sentences. 
As the relations of words are clarified when they 

1 In this argument Berkeley has a theological motive. He 
wishes to justify our belief in the mysteries of religion. He 
maintains that though these mysteries are above reason, they 
are not contrary to reason. According to his argument, we see 
certain " effects " in the world which seem to be signs of certain 
supra -rational " causes " ; and, even though we are unable 
to give a rationale of what we conceive to be signified by these 
ideas, yet, so long as our assumptions do not contradict reason, 
we are entitled to make use of them. 


appear in sentences, so the relations of things are 
elucidated when they are seen in a proper context 
as parts of machines or organs in organisms. 1 

The question may be raised, why, if God is the 
ultimate and omnipotent cause, he requires organisms 
of complex structure to produce effects which he 
could equally well have created by a single fiat of 
his will. To this question Berkeley s answer is that 
all the elaborate organisation and mechanism is 
" for our information." It is not necessary for the 
production of the results themselves, but it is 
essential in order that they should occur according 
to the laws of nature. 2 - Things must be produced by 
God by the same methods and in accordance with 
the same processes, in order that we, perceiving the 
appropriate signs, may have due warning that the 
things signified will follow. 

Thus the two functions of the laws of nature or 
the methods of God s operations are (a) to guarantee 
the uniformity of experience, and (6) to enable us 
to use foresight for the benefit of life. Without 
these two conditions of experience knowledge and 
action would be alike impossible. But as it is, we 
are able to acquire scientific knowledge of nature, 
to pass judgments of value on actions, and to 
predict the future with sufficient accuracy to make 
practical activity fruitful. 3 

In^_allthis Berkeleyis 

between a theocentric and an anthropocentric view 
o the universe. From the point of view of kiio.w- 
ledge the balance dips 

Principles, 65. = Ibid. 62. 3 Ibid. 62. 


theory, but in regard to practice Berkeley is de 
cidedly ajithropocentric. 


of tfra ui 

due entirely to God. From the Human point of 
view the laws of nature according to which the world 
is governed seem to have no reality. They are 
simply convenient names which indicate the regular 
order with which, in our experience, sign and thing 
signified constantly occur. ^_la.w_pf nature is not 
even a category which we apply. 1 It is nothing but 
an arbitrary relation devised by God for our infor 
mation. But the apparent unreality of the laws of 
nature vanishes when we survey them sub specie 
aeternitatis. For they exist in the mind of God, and 
thus they have perfect reality ; they are not only 
real, but the forms in which all reality exists. From 
the point of view of science the world is necessarily 

On the other hand, from the practical standpoint, 
the centre of the universe is man. Though God is 
the, ultimate cause, and acts always in accordance 
with his will, all his activity is directed to secure the 
greatest value for life to finite persons. He goes to 
the trouble of putting countless cogs on machines 
and innumerable organs in organisms (all from his 
point of view useless), solely " for the benefit of life " 
of finite spirits. The whole universe is benevolently 
ordered by God for man s advantage, and thus, 
varying a well-known title, we may say servus 
servorum Deus. 

1 Principles, 66. 



Berkeley s general attitude to the problems of 
motion, space and time might be inferred from his 
theory of causation. AsL.Gqd.Js t&eJSujDr^mj^ Cause, 
sa.God is the Prime Mover. As God enables finite 
causes to operate in virtue of their relation to Jaim, 
so God exercises a normative function with respect 
to the private spaces and times of which alojje our 
own immediate experience assures us. Causation 
would be impossible, apart from God. Similarly, 
space, time and motion would be impossible, apart 
from_Gpd. Berkeley holds that physics does not 
require the postulate of mechanical causation or 
infinitely extended matter. But it does require the 
existence of God. 

The theory of motion, space and time is most 
fully set forth in the Latin treatise De Motu, which 
Berkeley wrote in 1720 and published in the following 
year. In 1720 the Academy of Sciences at Paris 
offered a prize for an essay on the nature, origin and 
communication of motion. Berkeley s tract was 
written with a view to this, but there is no evidence 
that it was ever submitted to the Paris Academy. 
In any case, the prize was gained by Crousaz (1663- 
1749), a well-known logician, with his Discours sur 
la Nature, le Principe, et la Communication du Mouve- 
ment. If Berkeley was a candidate, his failure is 
not surprising, for the essay is superficial and ill- 
arranged, supercilious in its criticism, and vague in 
its positive conclusions. But its significance be 
comes greater when we consider it in connection 
with what Berkeley elsewhere says about motion, 


and in relation to his metaphysical theory as a 

De Motu forms a half-way house between the 
sensationalism of Berkeley s earlier period and the 
spiritual realism which he developed in his latest 
phase. On the whole, its assumptions are those of 
the early period, but these assumptions are not 
obtruded. Berkeley s disinclination to emphasise 
his own metaphysical theory was no doubt largely 
due to the fact that he was writing De Motu for the 
approval of a French committee, most of whom 
would be unacquainted with his work hi the 
Principles, and therefore he did not care to bring 
into the foreground a theory of his own which might 
prejudice them against him. But it is also possible 
to detect in De Motu traces of the process of develop 
ment which finally culminated in Siris. 1 The author 
of De Motu is a more mature Berkeley than the 
writer of the Principles. 

In proceeding now to sketch the outlines of 
Berkeley s natural philosophy, we shall deal first 
with motion, and then pass on to consider his 
theories of space and time. 

The nature of motion occupied Berkeley s attention 
from the very beginning of his speculation. In the 
first page or two of the Commonplace Book he is 
troubled about the relation of tangible and visible 
motion, 2 and the difficulty of reconciling Newton s 
two kinds of motion (i.e. absolute and relative), 
with the New Principle. 3 In the New Theory of 
Vision, these problems are briefly considered, 4 in 
the Principles his own views are very clearly though 

1 Vide infra, Sect. VII. 2 i. 59. 3 i, 60. 4 137, 


summarily stated, 1 and the arguments which he 
adduces are reinforced in the Three Dialogues? De 
Motu is, of course, devoted almost entirely to it. 
This, then, is the corpus of material with which we 
have to deal. 

To take first the origin of motion. On this 
problem Berkeley at once intimates his disagreement 
with currently accepted theories. 3 He credits 
Newton with the doctrine that the origin of motion 
is to be found in gravity, and objects to this theory 
on the ground that it is no explanation at all. It 
succeeds only in committing the fallacy of obscurum 
per obscurius. For it does not tell us what gravity 
is. " Newton proves," says Berkeley, " that gravity 
is proportional to gravity. I think that s all." 4 
As Newton does not tell us what gravity is, it is 
rash and indeed futile for him to ascribe the origin 
of motion to it. He is explaining by means of that 
which itself needs explanation. This is Berkeley s 
preliminary criticism of Newton. It is, as a matter 
of fact, an ignoratio elenchi, for Newton does not 
assign gravity as the ultimate cause of motion. He 
holds that gravity is of value in the explanation 
of the world of phenomena, but gravity itself needs 
to be caused by something else, and what this ulti 
mate cause may be Newton never pretends to say. 5 

Leibniz also, Berkeley holds, is at fault in the 
account he gives of the origin of motion. 6 As the 

1 10, 14, 27, 99, 101-117. 2 i. 400-403. 

3 De Motu, 3 ff. * Commonplace Book, i. 31. 

5 Rationem vero harum Gravitatis proprietatum ex Phaeno 
menis nondum potui deducere, et Hypotheses non fingo. 
(Principia, 1713, p. 483.) 

6 De Motu, 8. 


ultimate cause of motion Leibniz assigned an active 
primitive power, present in all bodies and produc 
ing relations of attraction and repulsion between 
them. 1 

Now, Berkeley says, Newton and Leibniz both 
admit that nothing real corresponds to what they 
call respectively gravity and power. Newton uses 
gravity simply as a mathematical hypothesis, and 
Leibniz agrees that the nisus and sollicitatio of bodies 
do not really exist in rerum natura, and are, in fact, 
simply convenient abstractions. Berkeley argues 
that such explanations as these which rest on obscure 
and occult abstractions explain nothing. The 
qualities which they assign as causes of motion are 
neither apprehensible in sense-perception, nor intelli 
gible by reason. Therefore, they are, Berkeley 
concludes, " just nothing," and those who have 
posited them are little better than quibblers. 
" Dixisse aliquid potius quam cogitasse censendi 
sunt," 2 

1 It is noteworthy that De Motu is the only one of Berkeley s 
works in which much attention is paid to Leibniz. That he 
mentions him there is sufficiently explained by the considera 
tions that (a) the tract was written when Berkeley was returning 
from a prolonged sojourn on the Continent, where Leibniz s 
reputation was much greater than it was in England or Ireland, 
and that (b) the essay was intended to be offered to a society 
among whom Leibniz s work was peculiarly well known. But 
Fraser is mistaken in saying that Leibniz is mentioned for the 
first time in De Motu. There are at least two earlier references, 
one in the Commonplace Book (i. 85), and the other in the early 
essay Of Infinites (iii. 411), in both cases the references being to 
Leibniz s Differential Calculus. Berkeley had every opportunity 
of making himself acquainted with Leibniz s work, as he had 
access at Trinity College, Dublin, to the Acta Eruditorum, in 
which many of Leibniz s important papers were published. 

*DeMotit, S20. 


Berkeley lays down, as a general canon of pro 
cedure, that in the philosophy of nature an explana 
tion is valid only (a) if it can be verified by actual 
sense-perception, or (6) if it is rationally demon 
strable. Unless it satisfies either one or other of 
these conditions, it cannot be admitted. And he 
objects to Newton s and Leibniz s explanations on 
the ground that they conform to neither of these 
principles. It is obvious that neither Newton s 
" gravity " nor Leibniz s " power " is the object of 
sense-perception. Berkeley also maintains that 
neither is capable of rational proof. So far as 
Leibniz is concerned, Berkeley s criticism is justified, 
because Leibniz s principles of explanation were 
obscure, occult, and indeed fictitious. On the other 
hand, the criticism of Newton is not sound. Berkeley 
asserts that the law of gravitation does not hold 
universally, and supports this criticism by mentioning 
instances of motion and rest which do not conform 
to it. These exceptional cases to which he draws 
attention are the perpendicular growth of plants, 
the elasticity of the air, and the absence of attraction 
in the fixed stars. It can now be shown that these 
exceptions are only apparent, and that they really 
conform to the law of gravitation comprehensively 
conceived. Thus on this count also Berkeley s 
criticism of Newton falls to the ground. But more 
interesting than the criticism itself is the frame of 
mind which it reveals in Berkeley. For Berkeley 
was perfectly content that the exceptions which he 
mentioned should remain exceptions. With the 
scientist s demand for universally true principles 
he had little sympathy. " Methinks," he says 


deliberately in the Principles, " inethinks it is 
beneath the dignity of the mind to affect an exact 
ness in reducing each particular phenomenon to 
general rules, or showing how it follows from them." l 

After this criticism of Newton and Leibniz, 
Berkeley proceeds to give an explanation of the 
origin of motion consonant with the general criteria 
of perceptibility or intelligibility. The world, he 
reminds us, consists of two sorts of things bodies 
and minds. 2 Bodies, which we know by sense- 
perception, are extended, solid, impenetrable, and 
movable. Bodies do not and cannot contain in 
themselves the origin or efficient cause of motion. 
All the separate qualities of bodies, and bodies them 
selves as the complexes of these qualities, are wholly 
passive in nature. They contain absolutely nothing 
that is active and that can be regarded as the source 
of motion. 3 

But in addition to corporeal entities there are 
spiritual entities. Thinking beings are not known 
by sense-perception, but by what in De Motu 
Berkeley terms conscientia quadam internet,. By a 
kind of intuition, he means, we realise that we are 
sentient, percipient and intelligent beings. Further, 
we know, by the same inner experience, that we are 
active beings and have the power to cause motion 

! 109. 

2 " Bodies " would have been called " ideas " in the Principles. 
Though in De Motu Berkeley never obtrudes his " immaterial - 
ism," he says nothing really inconsistent with it. He uses the 
regular scientific language of the day, and speaks of bodies 
as solid, extended, and so on ; but he still believes that a body 
ia nothing but the compages of its qualities, and that these 
qualities are all mind-dependent. 

3 De Motu, 21-24. 


in bodies. Our minds can initiate or inhibit the 
movements of our limbs at pleasure, and thus, since 
our bodies are moved by our minds, we may call the 
mind the source of motion. 1 

The source of motion, then, is a vital principle. 
Now, vital principle is possessed only by minds. 
" Those," Berkeley says, " who ascribe vital principle 
to bodies devise an obscure fiction." 2 It is charac 
teristic of beings endowed with vital principle, 
i.e. living creatures, to be able to change their own 
states and sometimes also the states of others. On 
the other hand, it is indisputable, Berkeley declares, 
that no body can of itself initiate any change in its 
state. It is the nature of body to continue in what 
ever state it happens to be in, whether that state be 
rest or motion. Body is naturally inert and passive, 
entirely at the mercy of external impulsion. That 
impulsion, which is the proximate cause or rather 
the occasion of motion, is due either immediately 
or mediately to some active mind. 

But, if we say that mind is the origin of motion, 
wa must remember that finite mind is only a sub 
ordinate and proximate .cause. The ultimate source 
of motion is what Berkeley calls primum etuniversale 
Principium, i.e. <3o.d. In De Motu Berkeley gives 
no account of what he means by this conception. 
He leaves the nature of God, and his methoda^of 
originating and communicating motion, in complete 
obscurity. AH he does is to claim the support of 
Plato and Aristotle, the Cartesians and Newton for 
the cpnception of God as the creator and conservator 
of motion in the universe. 

1 De Motu, 21. "- Ibid. 33. 


4s Or little amusing and a little pathetic to notice 
that Berkeley seems to be perfectly satisfied to leave 
theMiia^_ejr.94th i at^ After all his f ulminations against 
mere words which mean " just nothing," he seems 
seriously to believe that the four thinkers whom he 
has mentioned mean the same thing as he does when 
they all speak of God as the ultimate cause of motion. 
But, in reality, their conceptions of the being of God 
and his methods of operation in the world differ 
absolutely. Plato s God, for instance, is a wise 
Sii/u.iovpyos with a purely external relation to the 
world which he makes and remakes. Aristotle, after 
protesting against Plato s poetic metaphors, ends by 
giving us a serenely self-contemplative God, who 
moves the world by being " the object of the world s 
desire." Newton s God is a very fine mathematical 
physicist, who has worked out all the delicate 
adjustments of the universe and keeps everything 
going absolutely harmoniously. The God of the 
Cartesians is a^ Master ; jClockmakei;, or ratber_.a yery 
superior Choirmaster. And Berkeley s Cod is -a 
Benevolent Bishop, who- though absolutely suprema 
in .his diocese allows a certain amount of latitude 
tp his people. 

It is clear, o_f course, that merely to ascribe to God 
the OTigij^^^mpi^njjyiL^^ at explajia- 

tion, is to say nothing at all. 1 Before the ascription 

1 When we blame Berkeley for his failure to bring God and 
motion into really intimate connection, we should remember 
that Newton did not succeed in making hia theory of their 
relation at all clear. It is only in a very vague and general way 
that Newton ascribes to God the ultimate causation of gravity. 
In the second edition of the Principia he adds a general scholium 
in which he pays to the Deity a somewhat lengthy but apparently 
perfectly sincere tribute ; but apart from the prefatory statement 


becomes significant, we must know how God origi 
nates motion, how he communicates it to finite 
spirits, why he communicates it directly to bodies 
in some cases, and in other cases only through the 
mediation of spirits or other bodies. None of these 
questions is squarely faced by Berkeley. Ii^jSim, 
indeed, he makes use of the mystical Fire-philosophy 
which is prominent in that work, and suggests that 
God^jhe Prime Mover, is able to communicate_.ini- 
pressions to the finer and subtler parts of the 
elementary fiery spirit which moves or animates 
every portion of the world. The motion that is 
communicated by God to the subtle spirit i^jgassed 
on by it to the gross and corporeal things in the 
world. Thus, as fine fiery spirit transfuses minds, 
and gross fiery spirit bodies, God communicates 
motion directly to minds and indirectly to bodies. 
Invisible fiery ether is the medium of communi 
cation, and motion is the actually perceptible mani 
festation of its operation. 1 And that is all that 
Berkeley has to say of the manner in which God 
communicates motion to the world. 

So far we have been considering Berkeley s account 

that the universe proceeds from God s counsel and power, he 
makes little attempt to connect God with the actual operation 
of the force of gravity. In the third edition, however, Newton 
expressly denied the causality of blind necessity or caprice, and 
definitely ascribed causality to God. " Blind metaphysical 
necessity," he says, " which is certainly the same everywhere 
and always, could produce no variety of things. All that 
diversity of natural things which we find suited to different 
times and places could arise from nothing but the ideas and will 
of a Being necessarily existing." (Cf. P. E. B. Jourdain, 
" Newton s Hypotheses of Ether and Gravitation," The Monist, 
xxv. 247-8.) 
1 161 ff. 


of the origin of motion. We are now to examine his 
theory of what he calls the nature of motion. 

In De Motu he confuses the discussion by referring 
in vague and general terms to Aristotle and the 
Schoolmen. In the Principles, on the other hand, 
his account is orientated by Newton s distinction 
of absolute and relative motion, and his treatment 
of it is much more clear and adequate. 

Berkeley argues against Newton s conception of 
absolute motion on three grounds. 

(1) First of all, he raises a doubt whether, after 
all, Newton s absolute motion is really absolute. 
He points out that all motion, as we know it, is 
relative. Take, for instance, Newton s example of 
a man pacing the deck of a ship. If he stands still, 
he is at rest with relation to the sides of the vessel, 
but he is in motion with relation to the land. If the 
universe of motion and rest to make Berkeley s 
meaning clear by using a convenient term be 
regarded as the Earth, then he is in motion ; if it 
be the ship, then he is at rest. Normally, Berkeley 
holds, we regard the Earth as our universe of motion 
and rest, and what is at rest in that universe is 
considered to be absolutely at rest. But, Berkeley 
urges, that rest is not really absolute ; it is still 
relative to a certain universe of motion. However 
comprehensive we care to make our universe of 
motion, motion in it will always be relative, in the 
last resort, to some even more comprehensive 
universe. Berkeley is thus inclined to suspect that 
those who speak of absolute motion really posit 
nothing more than a very comprehensive universe 
of motion, which does have limits, e.g. the fixed stars, 


and is thus relative to some still more comprehensive 
universe. If this is really what they do, then it 
follows, as he justly says, that all motion is ulti 
mately relative. 1 

(2) Further, the conception of absolute motion is, 
Berkeley affirms, unnecessary. Newton believed 
that it was essential, for the purposes of mathematics 
and mechanics, to assume absolute motion. If we 
allow nothing but relative motion, Newton urged, 
we will be involved in serious difficulties and am 
biguities, for one and the same thing may be in 
relative motion in different directions at the same 
time. The man pacing the deck of the vessel may 
be stepping westwards. Relatively to the vessel he 
is moving in that direction. But if the vessel is 
sailing eastwards at a greater rate than he is walking, 
he will really be moving, relatively to the Earth, 
eastwards. Such ambiguities and difficulties as these 
are removed, Newton held, by the assumption of 
absolute motion. But Berkeley maintains that the 
difficulties arising out of the relativity of motion may 
be overcome, without postulating absolute motion, 
if our universe of motion be sufficiently comprehen 
sive. And he holds, though without adducing 
proofs, that all the laws of motion can be proved on 
the assumption that the only kind of motion is 
relative. 2 This, it is now safe to say, is quite true. 

(3) In the last place, Berkeley holds that absolute 
motion is not only unnecessary but is also impossible. 
In support of this contention he uses two arguments, 
one of which seems to be sound, the other being 
certainly absurd. To take the latter first. " No 

1 Principles, 111-115, De Motu, 64. 2 Principles, 111. 


motion," he says, " can be distinguished or measured 
except by means of sensible objects." x It can now 
be shown that there is nothing in this argument. 
We now know that it is possible to measure the 
motions of certain things, e.g. the undulations of 
light-waves, which are not themselves objects of 
sense -perception, and do not require objects of 
perception as means to their measurement. But 
Berkeley s second argument seems to be a perfectly 
valid one. " Determination or direction," he says, 
" is essential to motion ; but that consists in relation ; 
therefore it is an impossibility to conceive absolute 
motion." 2 Motion must always take place in some 
direction or directions, and be in some respect 
determinate ; and as direction is meaningless unless 
it includes some relation, and determination is always 
determination with reference to something, it follows 
that motion must always be relative. 3 

So far, we may agree, Berkeley is, on the whole, 
right in his opposition to absolute motion, and in his 
positive insistence on the relativity of motion. But 
he goes further, and in this case that means too far. 
He extends the relativity of motion to mean rela 
tivity to sense -perception. The motion of bodies is 
reduced to the succession of ideas in the mind of the 
person who perceives the motion of the body. Thus 
the rate of motion of the body is proportionate to 
the rapidity with which ideas succeed one another 
in the mind of the percipient. 4 Now, it is, of course, 
obvious that a moving body may be perceived by 
more than one person, and further that the succession 

1 De Motu, 63. 2 Ibid. 63. 

3 Principles, 112. * Principles, 14. 


of ideas in A s mind may be twice as quick as in jB s. 
In such a case one of two conclusions must follow. 
Either the same body at one and the same time is in 
motion at different rates ; or the body is not in 
motion at all, motion being nothing but the succes 
sion of ideas in A s mind and in B s. The latter 
conclusion is the one which he adopts. In accordance 
with his New Principle, motion, one of the so-called 
primary qualities, does not really differ from the 
secondary qualities, and is therefore, like them, 
wholly dependent on the mind by which it is per 
ceived. 1 All motion, then, is relative to the parti 
cular percipient mind. 

But in the end Berkeley is forced to re-introduce 
the distinction between relative and absolute motion. 
Just- as, in his theory of knowledge, he found it 
necessary to postulate the mind of God to give 
permanence to things, so here he finds it essential 
in the interests of practical life to assume, the exist 
ence of a kind of normal motion, determined by the 
succession of ideas for God s mind. This motion 
which is perceived by God is absolute motion. It 
provides the standard of motion, and with respect 
to it we correlate our private motions. The motion 
which we actually perceive, i.e. the succession of 
ideas in our minds, is doubly relative. It is relative 
to the sense-organs of the particular percipient being, 
and it is relative to the standard of motion which 
exists in the mind of God. Berkeley never admits 
thatjbe has reinstated the old distincjiim^beissceen 
absolute and relative motion." None the less, his 

* * 1>I . **** .. 1 

premises inevitably drive him to it. 

1 Three Dialogues, i. 400-401, 


So far of motion. We must now consider the 
closely similar attitude which Berkeley adopts 
towards the cognate problems of space and time. 

Berkeley s views on space and time are determined 
by the theories of Newton and Locke. If he is to be 
consistent with his philosophy as a whole, it is 
essential for him to maintain, against Newton, that 
space and time are relative ; and, against Locke, that 
they consist of particular instants and points. On 
Berkeley s premises, Locke s pure space and time 
must be as impossible as Newton s absolute space 
and time ; space and time, he is forced to hold in 
conformity with the particularism and relativism 
which are the keynotes of his whole philosophy, 
cannot be other than particular and relative. 

If we consider first Berkeley s attitude to time, we 
find that he reduces time to an experienced succes 
sion of ideas. As the world consists of minds plus 
ideas, so time consists of a succession of ideas ex 
perienced by a mind. Now, Locke admitted that 
this succession of ideas is an important element in 
our awareness of time : it supplies, he thought, the 
sensible measure of time. 1 We are unable to measure 
time, says Locke, which is, in its own nature, pure 
and absolute, except by means of the sensible canon 
of time which is supplied by the succession of ideas. 
But this mere succession is not, Locke insists, in 
itself time : it is merely the measure of time. In 
opposition to Locke Berkeley argues that it is mis 
leading to distinguish the measure of time from time 
itself. Nay more, he urges, time itself does not 
exist apart from the ideas which we experience. 2 

1 Essay, n. xiv. * ii, 19. 


The succession of ideas wholly constitutes time, for 
such notions as Pure Time and Time-in-general are 
merely fictions which owe their plausibility to the 
doctrine of abstract ideas. 

Along very similar lines Berkeley criticises New 
ton s conception of absolute time. Newton had dis 
tinguished time as mathematical, true and absolute, 
from time as relative, apparent and vulgar. 1 The 
former kind of time, to which Newton gave the 
alternative name of duration, is a constant process 
bearing no relation to anything not itself. Relative 
time, on the other hand, is defined as a sensible 
and external measure of duration, e.g. " hour " or 
" month." Now, on Berkeley s view, the only time 
which we can know, and which we need allow to 
enter into our calculations, is relative time. It is 
this alone of which we can have any experience. 
Not only, Berkeley argues, is Newton s absolute, 
true and mathematical time unnecessary, whether 
for the purposes of ordinary life, or for the investiga 
tions of the physicist, but, since we can form no idea 
or notion of such time, it is logically impossible. 

From this criticism of Locke and Newton Berkeley 
concludes that all time consists of particular instants, 
i.e. particular passing sensations in the minds of 
percipient beings ; hence all time will be relative 
to these percipients. 

1 Tempus absolutum, verum & mathematicum, in se & natura 
sua sine relatione ad externum quodvis, aequabiliter fluit, 
alioque nomine dicitur duratio : Relativum, apparens & 
vulgare est sensibilis & externa quaevis durationis per motum 
mensura (seu accurate seu inaequabilis) qua vulgus vice veri 
temporis utitur ; ut hora, dies, mensis, annus (Principia, Scho 
lium ad def. viii.). 


Two or three notable consequences follow from 
this view. " Time," says Berkeley, " being nothing, 
abstracted from the succession of ideas in our minds, 
it follows that the duration of any finite spirit must 
be estimated by the number of ideas or actions 
succeeding each other in that same spirit or mind." 1 
From the first Berkeley is aware of the difficulties of 
this conclusion. If time is measured simply by the 
succession of ideas, then the age of a fly may really 
be as long as that of a man. 2 But not only is the 
succession of ideas, and therefore time, relative to 
the particular percipient ; it is also relative to the 
particular state of the same percipient. For instance, 
the succession of ideas passes more slowly in pain 
than in pleasure. Are we then to say that one hour 
of pain is really a longer period than one hour of 
pleasure ? Berkeley admits, in the Commonplace 
Book, that this seems to follow, and in accordance 
with his extreme relativism, maintains that " the 
same TO vvv is not common to all intelligences." 
Thus each man s time is private. If the succession 
of ideas is more rapid for one man than for another, 
the times of the two men also vary. In the Common 
place Book Berkeley has no way out of the difficulty 
to suggest, though he must have seen then, as he 
did later, that the very description of the succession 
of one man s ideas as swifter than another s implies 
some standard. 

This standard of time, as Berkeley points out in 
Siris, is supplied by God. God causes ideas to occur 
normally with uniform regularity, and though the 
sequences of actually experienced ideas may, vary 

1 Principles, 98. 2 Commonplace Book, i. 61. 


from person to person they may bo co-ordinated 
with the standard process established by God. But 
Berkeley insists that this normal succession. of ideas, 
though it exists for God s mind, is not in it. In other 
words, God is aware of the ideas which, he causes, but 
the actual ideas which he causes do not pass in 
succession through his mind. 

It is fairly clear that, as in the case of motion, 
Berkeley has simply reintroduced, though from a 
different standpoint, the old distinction between 
relative and absolute time. 
as the experienced succession of 
but social relations and practical activity depend on 
the fact that, over and above these private times, 
there is a normal order of events, uniformly produced 
by God. Time as it is for God is absolute, for, 
though it is of course relative to God s mind, it is 
absolutely independent of auy finite percipient being, 
and therefore supplies a norm with reference to 
which the differing particular times, of finite indi 
viduals ruiiy be standardised. 

The problem of space is treated by Berkeley on 
closely similar lines, and, as in the case of time, he 
has in view throughout the distinction drawn by 
Newton and Locke between relative and particular 
space on the one hand, and absolute and universal 
space on the other. Absolute space for Newton 
remains always self -identical and immovable, whereas 
relative space or dimension is the measure of absolute 
space, and is known by the relation which objects 
bear to our faculties of sense-perception. 1 Newton s 

1 Spatium absolutum, natura sua sine relations ad externum 
quodvis, semper manet similare & immobile : Relativum est 


theory is repeated, in essence, in Locke s distinction 
between pure space and place, Locke s place corre 
sponding roughly with Newton s relative space, and 
his pure space with Newton s absolute space. Pure 
space Locke regards as a perfect continuity, having 
parts, indeed, but parts which are inseparable and 
immovable. This pure space, which is continuous 
and infinite, might be called, Locke suggests, not 
extension but expansion. The term extension would 
then be applied " only to matter, or the distance of 
the extremities of particular bodies ; and the term 
expansion to space in general." l Extension, then, 
is relative, expansion is absolute or pure. 

In opposition to Locke and Newton Berkeley 
argues that, as absolute or pure space is an impossi 
bility, the distinctions which they had been at such 
pains to establish are strictly meaningless. And 
why does he hold that pure space is simply nothing 
at all ? Because we cannot know it. He examines 
with some care, in De Motu, the characteristics of 
such knowledge as sense-perception, imagination, 
and pure intellect ; and concludes that absolute 
space is in nowise knowable, and must accordingly 
be admitted to be merum nihil. 2 

He points out, in addition, the reason why absolute 
space has been thought to be possible. Any plausi 
bility it may have rests, he declares, on a faulty 
psychological analysis. The notion of pure or empty 

spatii huius mensura seu dimensio quaelibet mobilis, quae a 
sensibus nostris per situm suum ad corporum definitur, & a 
vulgo pro spatio immobili usurpatur : uti dimensio spatii sub- 
terranei, aerii vel coelestis definita per situm suum ad terram 
(Principia, Scholium ad def. viii.). 

1 Essay, n. xiii. 27. z De Motu, 53. 


space is reached by a process of abstracting all bodies 
from the relative space with which we are acquainted. 
But, Berkeley argues, when those who defend the 
conception of empty space perform this feat of 
abstraction, they forget one most important thing. 
They omit to abstract their own bodies. Thus the 
so-called absolute space which they reach by this 
process of abstraction is really still relative to their 
own bodies. 1 

Berkeley mentions still another difficulty attaching 
to the conception of absolute space a difficulty to 
which he ascribes very great importance. The con 
ception of absolute space threatens to toss us on the 
horns of a very awkward dilemma. Absolute space, 
if it exists, must be conceived to have the same 
characteristics as God, i.e. it is " eternal, uncreated, 
infinite, indivisible, immutable." 2 Hence we must 
say either that God and space are identical, or that 
there exist two eternal and infinite beings. Both 
of these conclusions offend Berkeley s religious sense. 
The former is dangerous to religion, because it makes 
God extended ; and the latter sets up a dead being 
pari passu with God, and thus destroys God s 
authority and supremacy. 3 Berkeley insists that 
there is one and only one infinite and eternal being, 
and that that being is a God who is neither space 
nor spatial. 

For all these reasons, then, Berkeley maintains 
that absolute space is impossible ; and he refuses to 
admit any view of space that is not relative to experi 
ence. As he points out in the New Theory of Vision, 
distance and extension are not perceived by sight, 

1 De Motu, 55. 2 Principles, 117. 3 Ibid. 117, cf. ii. 19. 


but are suggested by touch ; and thus extension and 
distance are relative to each individual s tactual 
experience. Space for me is the extension that is 
actually suggested to me by touch, or in other words, 
space for me consists in the series of my tactual 
sensations. Similarly, space for you is nothing but 
the series of your tactual sensations. Thus each 
individual has his own private space. The paradoxes 
to which the extreme relativist view would lead are 
perhaps not so obvious in the case of space as we 
have seen them to be in connection with time ; but 
a little reflection shows that if each man had his own 
private space, and if it were impossible to correlate 
these private spaces, social and practical relations 
would be impossible. 

But Berkeley does not really rest in the extreme 
relativist view. He assumes, as in the case of time 
and motion, that God exercises a normative and 
correlating function. God regulates motion in space, 
so that, in general, the distances moved by bodies 
in fixed times under the same conditions are similar. 
By observation of the regular working of the laws of 
motion, the private spaces with which finite persons 
start gradually approximate to the normal space in 
which God causes motion to take place. Berkeley 
has thus again rehabilitated the distinction between 
the absolute and the relative. 

As the foregoing pages sufficiently demonstrate, 
Berkeley s treatment of the problems of motion, time 
and space is of but little intrinsic value. But it is 
interesting as an example of the application of his 
relativism and particularism, and interesting too for 


the light it throws on his dissatisfaction with rela 
tivism and particularism, and his attempts to reach 
a more adequate position. 


Siris was published in 1744. Thus more than 
thirty years had elapsed since the appearance of the 
Principles and the Three Dialogues. And though 
since that time much had been written by Berkeley, 
he had published little dealing directly with the great 
problems of the two early works. But during the 
intervening years his dissatisfaction with the bold 
conclusions of his youth had been steadily growing. 
In a letter written in 1729 he apologises for these 
early works on the ground that he was very young 
when he wrote them. " I do not therefore pretend 
that my books can teach truth. All I hope for is 
that they may be an occasion to inquisitive men to 
discover truth, by consulting their own minds, and 
looking into their own thoughts." 1 Yet along with 
this modest appreciation of his works, so different 
from his sanguine attitude when he wrote them, he 
retains the conviction that what he has to say is true, 
though his way of saying it may be faulty. While 
continued reflection caused him to modify his views 
on many points of importance, he still held fast to 
his architectonic conception of the mind-dependent 
existence of the universe. He admits that his inter 
pretation of this truth in his earlier work was defec 
tive, but the truth itself remains. Thus the task 

1 Letter to Johnson, ii. 18. 


of Siris is to re-interpret, on a more adequate basis, 
the main conceptions of the earlier books. Different 
as Berkeley s earlier and later work is, the later is 
reconstructive rather than revolutionary. 

Siris is fairly well described on the title-page as 
" A chain of philosophical reflexions and enquiries 
concerning the virtues of tar-water and divers other 
subjects connected together and arising one from 
another." Berkeley s experiments with tar-water, 
commenced during his stay in America, suggested 
that it was a universal medicine, suited to cure every 
disease. It was natural for Berkeley to meditate on 
the ultimate cause of the provision of this panacea ; 
and reflection on the problem led him from link to 
link along the chain. The book seems to have no 
prearranged plan : it follows whithersoever the 
argument leads. Thus the fact that tar is a vegetable 
product gives rise to a dissertation on vegetable life, 
with special reference to pines and firs, from which 
tar is obtained. The juice secreted by pines possesses 
mysterious virtues : it contains an acid spirit or 
vegetable soul, which forms a most noble medicine, 
" the last product of a tree perfectly maturated by 
time and sun." * After this an investigation of 
acids in general leads him through much curious and 
antiquated chemistry ; and thence, as the acid 
spirit is supposed to reside in air, to an enquiry into 
the constitution of air. Berkeley finds that air con 
sists of a treasury of active principles, through which 
a latent vivifying spirit is diffused. This is Fire, 
Light, or Aether, the Vital Spirit of the universe. 
Thence the chain leads to speculation about fire, 

1 Siris, iii. 157. 


which continues for nearly a hundred sections, in 
which a perfect cloud of witnesses is adduced in 
favour of the view that fire is the " Animal Spirit 
of the Visible World." 

So far Berkeley has devoted two-thirds of the book 
to physical, chemical, and biological questions ; he 
has not yet touched metaphysics. But he believed 
that natural science can give no ultimate explanation 
even of natural facts. Nature can be interpreted 
only by a metaphysic which postulates that the 
natural causes which seem to be responsible for 
changes in the realm of nature are. only natural signs, 
which presuppose the constant operation of Mind in 
and on the universe. The world of nature is mind- 
dependent : its reality is spiritual. So far as this 
great principle goes, Berkeley still remains true to 
the conception which has inspired his philosophy 
from the beginning. But the content of the principle, 
from the point of view of knowledge, is now very 
different. The first and last periods agree that the 
world is dependent on mind, but while in the first 
period Berkeley interprets this to mean that its 
existence consists in being perceived, he believes in 
the last phase that reality consists not in being 
perceived, but in being known or thought. From 
the philosophical standpoint Siris thus contains both 
a metaphysic and a theory of knowledge. 

In his metaphysic Berkeley repeats his criticism 
of mechanical explanations of the world. He does 
not deny the validity, and within proper limits the 
value, of the laws of natural philosophy. But merely 
mechanical principles cannot explain or account for 
anything. The only way to explain a thing is to 


assign its appropriate efficient and final causes, and 
these are never mechanical principles. 

Mechanical principles such as the laws of motion 
are not real but only valid. 1 The laws of nature 
discovered by " mechanical philosophers " are 
merely mathematical hypotheses, and do not really 
exist in nature. The laws of nature have no power 
and they can produce no effects in the world. Laws 
of nature are simply statements which we have 
formulated as rules on observing the uniform pro 
duction of natural effects in the world. Things 
happen in a fixed and regular order, which is called 
" the Course of Nature." Seeing this method and 
order in the world, we construct, for our own infor 
mation and practical advantage, general rules to 
which we believe the world will continue to conform. 
These mechanical laws teach us what to expect, 
and direct us how to act. Laws of nature, then, 
have no real existence : they are simply valid hy 

Further, they are arbitrary hypotheses. We 
observe a certain constancy and regularity in the 
world, and we construct statements, based on our 
observation, which we call laws. But the constancy 
of the universe, and consequently the natural laws 
which we ascribe to it, depend wholly on the arbitrary 
though not capricious will of God. Berkeley insists 
on the arbitrariness of the action and reaction, the 
attraction and repulsion, which we observe in the 
world. " For instance, why should the acid particles 
draw those of water and repel each other ? Why 
should some salts attract vapours hi the air, and 

1 Siris, iii. 232-234. 


others not ? " l Berkeley admits that natural philo 
sophers have discovered certain laws of gravity, 
magnetism, and electricity. But the Author of 
nature might have decreed that the world should be 
organised according to entirely different rules or 
laws. Berkeley therefore suggests that in reality 
events in the world depend not on " the different 
size, figure, number, solidity, or weight of those 
particles, nor on the general laws of motion, nor on 
the density or elasticity of a medium, but merely and 
altogether on the good pleasure of the Creator." 2 

It follows, as Berkeley points out, that events in 
the physical world and laws of nature cannot be 
causes. " Nothing mechanical is or really can be a 
cause." 3 All that the natural philosopher can give 
us is an account of the relation of sign and thing 
signified. Berkeley repeats in Siris, without deve 
loping it, this dominant idea of his whole philosophy. 
Now a sign is not a productive or active cause. It 
merely gives information that in the course of nature 
such and such another event, the thing signified, will 
occur. But ascajieJoJB^keley, in the strict sense, 
must be " productive." It must be able to make 
things occur. All causes in the strict sense are 

o ... - n i -*___!"""" "^ "*"~ ~- -^^ -* - * w - -*"** 

agents ; and " all agents are incorj 

The only real cause, then, is spirit. As infinite-, 
this is God ; as finite, selves. The only causality 
which Berkeley admits to be real is efficient and .final 
causality. God is the supreme efiicienjLajid_Jinal 
cause. Berkeley will admit no tampering with the 
omnipotent and omnipresent efficiency of God. It 
is " vain and imaginary " of Descartes to suppose 

1 Siris, iii. 235. 2 Ibid. iii. 237. 8 Ibid. iii. 241. * Ibid. iii. 240. 


that if God merely set his vortices going, the whole 
world might have been produced as a necessary 
consequence by the laws of motion. Leibniz has a 
more adequate theory, for he held that God by his 
immediate causality actually created the world as it 
now stands. But Leibniz denies the omnipresent 
causality of God, in so far as he believes that God 
may simply leave the world " going like a clock or 
machine by itself, according to the laws of nature, 
without the immediate hand of the artist." x Berke 
ley has no sympathy with efforts to extrude God 
from the universe by allowing him the doubtful 
privilege of being a " remote original cause." " We 
cannot make even one single step in accounting for 
the phenomena, without admitting the immediate 
presence and immediate action of an incorporeal 
agent, who connects, moves, and disposes all things, 
according to such rules, and for such purposes, as 
seem good to him." 2 

God is also the supreme final cause. All nature 

^ ***^^b*^^^^^^*^^f^~*^^^^^**^ 

is under his direction, and lie concerts it all for one 
end, the $uprem^j2Q37 Gfo(l is himself the Supreme 
Good, the great principle of attraction in the world. 
Throughout Siris Berkeley gives a strong teleological 
cast to his thought. " All things areTHrade f or the 
Supreme Good, all things tend to that end ; and we 
may be said to account for a thing when we show 
that it is so best." 3 

In Siris finite selves exercise only a very limited 
causality. Finite selves cause only those actions 
which are strictly their own. And only those actions 
are their own for which they are responsible. Finite 

1 Ibid. iii. 233. 2 Ibid. iii. 235-6. 3 iii. 247 ; cf. iii. 278-9. 


selves are not the causes of natural movements such 
as the systole and diastole of the heart. They have, 
in fact, a real causality only in the moral realm. 
They cause only those actions that are definitely 
willed, and for which they have therefore a moral 
responsibility. 1 In Siris not only is ,the .-efficient 
causality of finite selves thus limitecL,. but- they are 
never regarded _as final causes. In the Three Dialogues 
and Alciphron Berkeley s universe was really. anthro- 
pocentric ; God sustained it for man s benefit. But 
in the metaphysical parts of Siris, man and his 
interests are entirely subordinate to God. 

Berkeley takes pains to develop ms conception of 
the world as a spiritual system and organic unity. 
He insists, on the one hand, on the element of differ 
ence and multiplicity in the world. At first sight, 
we are impressed with the apparent confusion and 
disorder in the universe. But this is not the last 
word. Evil, it is true, must exist ; otherwise good 
would be unmeaning : all natural productions are 
not perfect ; if they were, perfection also would 
cease to be. But, as Berkeley everywhere main 
tains, it is the harmony and not the confusion, the 
unity and not the difference, that is ultimately 
characteristic of the universe. Yet Berkeley s uni 
verse is not perfectly organic. The symbol of its 
unity is a chain, and the concatenation of the links 
of a chain is external. Still, the chain is one chain, 
and thus bears witness to the unity of the universe. 
In Siris Berkeley has a mystical veneration for unity, 
derived largely from his study of the Neoplatonists. 
" The One " or "TO "Ev " appears frequently in his 
1 Siris, iii. 246. 


pages as a name for God, or alternatively for the 
universe. The uprejne principle is jinity^, which is 
spiritual ; and whether we call, it God or the world 
makes very little difference. But Berkeley prefers 
to regard the unity of God as original, a-nd that of the 
universe as derivative. " One and the same Mind 
is the Universal Principle of order and harmony 
throughout the world, containing and connecting 
all its parts, and giving unity to the system." 1 

This general conception of a mind-dependent 
reality is carried out also in Berkeley s theory of 
knowledge. It was always his fundamental idea, 
but in Siris the precise meaning of it has changed. 
If the -pre-Siris point of view be represented by esse 
is percipi, that of Siris is esse is concipi. The pro 
gress of Berkeley s thought has resulted in a gradually 
increasing recognition of the importance of the 
universal element in knowledge. Concurrently the 
value and significance of sense-perception has 
declined, and in Siris it is regularly disparaged. 
Take, for example, such a passage as this. " Sense 
and experience acquaint us with the course and 
analogy of appearances or natural effects. Thought, 
reason, intellect introduce us into the knowledge 
of their causes. Sensible appearances, though of a 
flowing, unstable, and uncertain nature, yet having 
first occupied the mind, they do by an early preven 
tion render the aftertask of thought more difficult ; 
and. as they amuse the eyes and ears, and are more 
suited to vulgar uses and the mechanic arts of life, 
they easily obtain a preference, in the opinion of most 
men, to those superior principles, which are the later 

1 Ibid. iii. 262. 


growth of the human mind arrived to maturity and 
perfection ; but not affecting the corporeal sense, 
are thought to be so far deficient in point of solidity 
and reality, sensible and real, to common appre 
hensions, being the same thing. Although it be 
certain that the principles of science are neither 
objects of sense nor imagination ; and that in 
tellect and reason are alone the sure guides to 
truth." ! 

Another interesting passage reads like an apology 
for his early sensationalism. " Sense at first besets 
and overbears the mind. The sensible appearances 
are all in all : our reasonings are employed about 
them : our desires terminate in them : we look no 
further for realities or causes ; till Intellect begins 
to dawn, and cast a ray on this shadowy scene. We 
then perceive the true principle of unity, identity, 
and existence. Those things that before seemed to 
constitute the whole of Being, upon taking an 
intellectual view of things, prove to be but fleeting 
phantoms." 2 But though the universal element in 
knowledge is now by far the more important, 
Berkeley still retains his original division of know 
ledge into sense-knowledge and notional knowledge. 
" There are properly no ideas or passive objects in 
the mind but what were derived from sense : but 
there are also besides these her own acts or opera 
tions ; such are notions." 3 

Sensible things, which used to be called ideas, are 

now usually termed phaenomena. Berkeley no 

longer believes that sensible things are real. " All 

phaenomena are to speak truly appearances in the 

1 Siris, iii. 249. 2 Ibid. iii. 265. 3 Ibid. iii. 272. 


soul or mind." * They are gross, 2 and fleeting 3 ; 
they exist only in the mind, a fact which does not 
prove their reality, but rather how far removed they 
are from reality. 4 Perception gives us knowledge 
only of the surface of things ; it cannot enable us to 
reach their causes, and we know a thing only when 
we know its causes. 

" Strictly," Berkeley says, " the sense knows noth 
ing." 5 " As understanding perceiveth not, that is, 
doth not hear, or see, or feel, so sense knoweth not : 
and although the mind may use both sense and fancy, 
as means whereby to arrive at knowledge, yet sense 
or soul, so far forth as sensitive, knoweth nothing." 6 
In order to have knowledge, the element of judgment 
is necessary. Berkeley always believed that know 
ledge is possible only for a judging self, and that the 
real unit of knowledge is judgment. The significance 
of this side of Berkeley s earlier philosophy has been 
strangely overlooked. Yet this is precisely the 
philosophical significance of the Theory of Vision. 
Distance, for example, is not immediately perceived, 
it is judged. And this element of judgment is 
involved in all perception. The difference between 
his earlier and later view is that while in the New 
Theory of Vision he holds that sense-perception 
includes judgment, in Siris the element of judgment 
is excluded from sense. In Siris he says, " We 
perceive, indeed, sounds by hearing, and characters 
by sight. But we are not therefore said to under 
stand them." 7 We do not understand them, 
because in order to understand, we must judge them 

1 Ibid. iii. 243. 2 Ibid. iii. 269. 3 Ibid. iii. 290. * Ibid. iii. 264. 
6 Ibid. iii. 244. 6 Ibid. iii. 271. Ibid. iii. 244. 


in relation to other sounds and characters. The 
element of judgment is essential to all interpretation, 
and we do not understand a thing fully till we can 
interpret it and tell what it means. 

In Siris the supreme importance of the conceptual 
or notional element in knowledge is always implied ; 
but very little definite information is given about 
it. Instead of the term notion Berkeley now prefers 
to use Idea. But Idea (spelt with a capital) in Sins 
is very different from idea in the earlier works. 1 
The new doctrine of Ideas, which is not really a new 
one, but simply an old one rejuvenated, shows very 
clearly the influence of Plato and the Neo-platonists. 
Berkeley makes no secret of his indebtedness to 
Plato, and he agrees with Plato that Ideas are 
(1) not "inert, inactive objects of the understanding," 
i.e. not ideas in Berkeley s old sense ; (2) not " fig 
ments of the mind," i.e. not the products of the 
imagination ; (3) not " mixed modes," i.e. not 
complex ideas produced by the operation of the 
mind ; (4) " not abstract ideas in the modern sense." 
What then are Ideas ? They are " the most real 
beings, intellectual and unchangeable ; and therefore 
more real than the transient, fleeting objects of 
sense, which, wanting stability, cannot be subjects 
of science, much less of intellectual knowledge." 2 
These Divine Ideas, which are abstracted from every 
thing corporeal, and which constitute the reality of 
the world, are so difficult to know, that even the 
most refined intellect can obtain only a glimpse of 

1 But cf. the archetypal Ideas mentioned in Principles, 76. 

2 Siris, iii. 286. 


This supreme universal knowledge, in which we 
see all things in God, or sub specie aeternitatis, is 
therefore impossible for the ordinary man. But he 
is not entirely debarred from knowledge. Berkeley 
attempts to bridge the gulf between this pure 
universal knowledge and sense-perception by making 
use of Plato s conception of grades of knowing and 
being. This gulf may be conceived to exist both 
logically as between the two types of knowledge which 
appear sharply distinguished in Siris, and historically 
between the sense-intoxicated enthusiasm of the Com 
monplace Book and the mystic rationalism of Siris. 

(1) Berkeley is at pains to show that sense and 
reason, as he conceives them in Siris, are not cut off 
with a hatchet from one another. They are logically 
related, and a psychological transition may be 
traced from one to the other. The two extremes of 
what is grossly sensible and what is purely intelligible 
are connected by memory, imagination, and dis 
cursive reason. " By experiments of sense we 
become acquainted with the lower faculties of the 
soul ; and from them, whether by a gradual evolution 
or ascent, we arrive at the highest. Sense supplies 
images to memory. These become subjects for fancy 
to work upon. Reason considers and judges of the 
imaginations. And these acts of reason become new 
objects to the understanding. In this scale, each 
lower faculty is a step that leads to one above it. 
And the uppermost naturally leads to the Deity ; 
which is rather the object of intellectual knowledge 
than even of the disc 7 ->. ive faculty, not to mention 
the sensitive." * 

1 Siris, iii. 269. 
B.P, B 


(2) This gradual ascent from sense to reason may 
be exemplified, as Berkeley himself sees, in the 
progress of his own philosophical activity. Histori 
cally, the relation of Siris to Berkeley s early work 
is one rather of evolution than of revolution. He has 
travelled far since the days of the Commonplace Book, 
but he has made no volte face. His steps have 
always been turned in the same direction, and each 
one of his books marks a stage in his gradual pro 
gress. From the very first his architectonic con 
ception has remained the same. The universe is an 
organic system dependent on God for its reality and 
its knowability. It is a spiritual unity, and the only 
forces that can work in it are spirits. This general 
Weltanschauung, remains unchanged from first to 
last. The problem in which the development of 
Berkeley s thought is notable is the question of the 
relative importance, within the whole, of sense and 
reason. Berkeley begins in the Commonplace Book 
(1705-8) by regarding the sense-element as practi 
cally the only one in knowledge. In the Principles 
(1710) he recognises that knowledge requires a 
system of universal meanings, but postpones the 
treatment of the difficult question of their precise 
place in knowledge. The Three Dialogues simply 
repeat the general argument of the Principles in a 
more popular form. But in De Motu (1721) we 
find once or twice a sharp opposition between sense- 
perception and rational knowledge, and an evident 
disinclination on Berkeley s part to adjudicate 
between them. In Alciphron (1732) the question is 
for the most part avoided, but. the whole atmosphere 
of the dialogues shows that the trend of Berkeley s 


sympathies is away from sense and towards the 
rational element of universality. In the second 
edition of the Principles (1734) hints are given, in 
the introduction of the term notion, of a doctrine of 
universal knowledge which connects itself closely 
with Berkeley s original appreciation of the im 
portance for knowledge of a system of universal 
meanings or identical references. But so far there 
is no disparagement of sense. It is only, as we have 
seen, when we come to Siris (1744), that Berkeley 
explicitly degrades it. And concurrently, reason and 
the universal element in knowledge proportionately 
increase in importance. 

Berkeley s philosophy ends, as it begins, with a 
commonplace book. For Siris is nothing but a 
commonplace book, in which the thoughts and 
reading of his later years are concatenated. Much 
as Siris differs from the Commonplace Book, there are 
some startling similarities which bear testimony to 
the underlying unity of the life of the Bishop of 
Cloyne. In both books the practical aim of Berkeley s 
life is conspicuous. The ultimate purpose of the 
studies of the Commonplace Book is to defend the 
truth of Christianity, against sceptics and free 
thinkers, and in Siris Berkeley expresses again and 
again the same opposition to " atheism." All his 
life he regarded philosophy as the handmaid of the 
Church. Again, in both books Berkeley is inspired 
by the conviction that he has discovered a panacea. 
In the sanguine pages of the Commonplace Book 
" the new principle " is destined to solve all the 
riddles with which the mind of man is plagued, 
while in Siris tar-water is to cure all the diseases to 


which flesh is heir. But in Siris the juvenile enthusi 
asm of the Commonplace Book is tempered by the 
moderation of age. Berkeley is much less sure of 
himself, and sets his claims for his work very much 
lower, than in the days of his youth. In the Common 
place Book other thinkers views are mentioned only 
to be rebutted : in Siris he accumulates the testi 
mony of philosophy ancient and modern to the truth 
of his spiritual conception of the world. In the 
Commonplace Book all things seem transparent : in 
Siris he is forced to admit that " through the dusk of 
our gross atmosphere the sharpest eye cannot see 
clearly." And this is doubtless the reason why in 
his later thinking the emphasis shifts from theory of 
knowledge to metaphysics. Metaphysics is more 
congenial to the spirit of the man who, in following 
out the causes of things, is trying in vain to pierce 
the veil past which he cannot trace his clues. Omnia 
abeunt in mysterium : but though we cannot know 
in full, we can at least speculate. 



IN this chapter we shall consider Berkeley s view of 
the relation of mathematics to philosophy, and 
examine the criticism of mathematical conceptions 
which he developed in The Analyst. 

Mathematics is, on Berkeley s theory, an essentially 
practical science. The view suggested in the Common 
place Book, according to which mathematics is con 
cerned not with theoretical aKpifieiai, but with 
practical problems of measuring and counting actual 
things, is strongly emphasised in the Principles, 
where Berkeley states that he looks upon all 
enquiries about numbers only as so many difficiles 
nugae, " so far as they are not subservient to practice, 
and promote [not] the benefit of life." l To the 
objection that the New Principle destroys geometry 
Berkeley rejoins, " Whatever is useful in geometry, 
and promotes the benefit of human life, does still 
remain firm and unshaken on our principles." 2 
And in The Analyst he suggests again that " the 
end of geometry is practice." 3 

Now, Berkeley believes that this practical science 
of geometry is lower than first philosophy. As early 

1 Principles, 119. 2 Ibid. 131. 3 The Analyst^. 58. 


as the Commonplace Book he considers, as an objec 
tion to his sensationalist theory of mathematics, the 
view that mathematics is the object not of sense 
but of reason. To this objection he immediately re 
joins, " lines and triangles are not operations of the 
mind." l To make the point of this reply clear, it 
should be remembered that on his view the operations 
of the mind are the proper objects of reason or pure 
intellect ; and, as the subject-matter of mathematics 
consists, not in operations of the mind, but in 
sensations, it is the province of sense-knowledge and 
not of reason. " The folly of the mathematicians," 
he ejaculates, " in not judging of sensations by their 
senses. Reason was given us for nobler uses." 2 

In his published works Berkeley sometimes states 
quite sharply a distinction between mathematics and 
mathematical physics, forming the subject-matter 
of sense-knowledge, and the higher and more ultimate 
" transcendental philosophy," which is the sphere of 
pure intellect. Thus, in the Principles he distin 
guishes mathematics from the " enquiry concerning 
those transcendental maxims which influence all the 
particular sciences." 3 And in De Motu he insists 
on the difference between the practical and pedestrian 
work of the physicist and the " speculations of the 
highest order" belonging to " a more exalted science " 
with which the metaphysician is concerned. 4 " The 
physicist has in view," he says, " the series or succes 
sions of sensible things, studying the laws by which 
they are related, and the order they preserve ; and 

1 Commonplace Book, i. 22. 

2 Commonplace Book, i. 88 (italics mine). 3 Principles, 118. 
4 De Motu, 42. 


observing what precedes, as a cause, and what 
follows, as an effect . . . But it is only by 
reflection and reasoning that the truly active causes 
can be elicited from the darkness that envelops them, 
and thus in any way at all become known. Such 
enquiries are the concern of first philosophy or meta 
physics." * And in The Analyst he suggests, in the 
tentative manner which in later life masks his 
convictions, " Whether there be not really a philo- 
sophia prima, a certain transcendental science, 
superior to and more extensive than mathematics, 
which it might behove our modern analysts rather 
to learn than despise ? " 2 

This distinction between the lower province of 
mathematics and mathematical physics and the 
higher sphere sacred to first philosophy is thus 
present, in germ at least, throughout the whole of 
Berkeley s work. 3 

Berkeley s early attitude to mathematics has 
already been explained, and we have also pointed 
out the respects in which his own philosophical con 
ceptions were influenced by current mathematical 
views. 4 All this it is unnecessary here to recapitu 
late ; and we therefore, without more ado, proceed 
to consider the argument of The Analyst, which 
contains the most elaborate treatment he gave to the 
problems of mathematics. 

1 De Motu, 71-72. 2 The Analyst, iii. 58. 

3 Possibly, as Cassirer suggests, Berkeley was influenced by 
Scholasticism in making this distinction (Das Erkenntnisproblem, 
ii. 241). 

4 For Berkeley s view of mathematics in the Commonplace 
Book, vide supra, pp. 75 ff. ; for the way in which his theory of 
signs was influenced by mathematical conceptions, pp. 209 ff. ; 
and for his application of algebra to ethics, pp. 288 ff. 


The Analyst was published in 1734. It is a 
curious work, and though its purpose is ultimately 
theological rather than mathematical, it gave rise to 
a mathematical controversy which lasted for several 
years and produced more than thirty controversial 
pamphlets and articles. With the theological argu 
ment of The Analyst we have little concern. But, 
before passing to consider its mathematical and 
philosophical significance, it may be well to mention 
that the essay is primarily intended as a defence of 
Christianity, and Berkeley, acting on the principle 
that the best defence is in attack, criticises the 
foundations of mathematics on the same lines as those 
on which Christianity had been opposed by the 
" mathematical infidels." Christianity had been at 
tacked on the ground that its dogmas are mysterious 
and incomprehensible. In reply Berkeley maintains 
that, even if they are, Christianity is not peculiar 
in that respect. Even mathematics, universally 
admitted to be the most demonstrable department 
of human knowledge, is, in this regard, in exactly 
the same position as Christianity. For it also makes 
use of mysterious and incomprehensible conceptions, 
e.g. fluxions and infinitesimals. If mathematicians 
accept mystery and incomprehensibility in mathe 
matics, they have no right to object to it in Christi 
anity. This is the kernel of Berkeley s argument. 
Primarily his motive is to defend Christianity, not 
to attack mathematics. 

Berkeley has often been regarded, but quite 
unjustly, as an enemy of the infinitesimal calculus. 
In reality, he had no objection in the world to the 
calculus as such. What he did was to submit 


its logical basis to a searching examination. He 
criticised the conception of infinitely small quantities, 
which were at that time vaguely conceived as neither 
zero nor finite, but somehow in an intermediate state. 
They were said to be " nascent " and " evanescent " 
quantities, not quite nothing and not quite anything. 
It was against this vague, mysterious and incompre 
hensible notion that all Berkeley s attacks were 
directed ; and as soon as it was clearly pointed out 
by one of the parties to the controversy, Benjamin 
Robins, 1 that the calculus did not necessarily involve 
this conception of infinitesimals, but might be 
demonstrated by the method of limits, Berkeley 
abandoaed the controversy. He had replied to his 
other critics, such as Jurin of Cambridge (Philalethes 
Cantabrigiensis) and Walton of Dublin, because these 
mathematicians persisted in trying to defend the 
conception of infinitely small quantities. But as 
soon as it became clear, and Robins was the first to 
make it so, that that conception was not essential 
to the calculus, the controversy lost interest for 
Berkeley. For the conception of limits, as Berkeley 
seems to have realised, is not incomprehensible, and 
therefore an attack on it would not have enabled him 
to use his tu quoque argument, and thus would 
no longer serve his purpose, which, it must be 
remembered, was primarily theological. 2 

1 Robins s contributions to the controversy were contained in 
his Discourse concerning the Nature and Certainty of Sir Isaac 
Newton s Methods of Fluxions, and of Prime and Ultimate Ratios 
(1735), and in a series of articles in the Republic of Letters in 1736 
and in the Works of the Learned in 1737. 

2 The course of the " Analyst Controversy," so far as Berkeley 
was concerned, was ag follows. In 1734 The Analyst appeared. 
It was almost immediately attacked by Jurin in an anonymous 


But though Berkeley s motive in writing The 
Analyst is a religious one, the chief importance of the 
book, as we must now try to show, is mathematical 
and philosophical. It is, indeed, an able treatise on 
the logic of mathematics. Berkeley saw that the 
brilliance of the rapidly accumulating results attained 
by means of the calculus had tended to put into the 
background the question of its logical basis and the 
validity of the methods employed by it. And he 
did good service to mathematics by the publication 
of The Analyst, for he forced upon mathematicians 
the investigation of the logical basis of the New 
Mathematics. " I have no controversy," says 
Berkeley, " about your conclusions, but only about 
your logic and method. ... I beg leave to repeat 
and insist that I consider the geometrical analyst as a 
logician, i.e. so far forth as he reasons and argues ; 
and his mathematical conclusions, not in themselves, 
but in their premises ; not as true or false, useful or 

tract entitled Geometry no friend to Infidelity ; or a Defence of Sir 
Isaac Newton and the British Mathematicians. To this Berkeley 
replied in A Defence of Free-thinking in Mathematics, published 
in March, 1735. Jurin then published a rejoinder in July of the 
same year. Berkeley took no notice of it. 

Berkeley had another critic. This was Walton of Dublin, who 
published in 1735 a Vindication of Sir Isaac Newton s Fluxions. 
It was replied to by Berkeley in an appendix to the second edition 
of his Defence of Free-thinking in Mathematics. Walton replied, 
and Berkeley then published his Reasons for not replying to Mr. 
Walton s Full Answer. All this was in 1735. Walton issued a 
rejoinder, but Berkeley took no further part in the controversy. 

It is noticeable that Berkeley participated vigorously in the 
controversy until Robins s book appeared. After that he says 
not a word. The reason is, as we have said, that Robins showed 
that infinitesimals were not essential to the calculus. Berkeley 
must have been convinced by his arguments, and therefore realised 
that it was no longer possible, from his point of view, to take part 
in the controversy. 


insignificant, but as derived from such principles, 
and by such inferences." x As a direct result of this 
investigation, originated by Berkeley, three highly 
important principles were firmly established (1) that 
the calculus must be grounded on the method of 
limits, (2) that the then current conception of 
infinitesimally small quantities must be abandoned, 
and (3) that the calculus does not proceed by means 
of the compensation of errors. 2 

These points will become clear if we examine 
Berkeley s criticism of Newton s theory of fluxions. 
In our investigation there are three main questions 
which we must ask. (1) Is Berkeley s criticism of 
Newton valid ? (2) Is Berkeley s criticism of current 
conceptions of infinitesimals sound ? (3) Did Berke 
ley really expose any fallacies in the calculus ? 

( 1 ) First, then, we must consider whether Berkeley 
is successful in his criticism of Newton. To know 
that, we must know what Newton s theory of 
fluxions really was. To that preliminary question 
we now turn our attention. 

Newton considered that quantities are continu 
ously generated by motion. As the ancients believed 
that rectangles are generated by the movement of 
one side upon the other, so as to describe the area of 
the rectangle, Newton held that the areas of curvi 
linear figures are generated by drawing the ordinate 
into the abscissa. All quantities, including indeter 
minate quantities, may thus be regarded as generated 
by continuous increase. All quantities which thus 

1 The Analyst, 20. 

2 See Prof. G. A. Gibson, Review of Cantor s " Geschichte der 
Mathematik " in Proc. Edin. Math. Soc., 1899, pp. 9-32. 


increase by motion Newton calls flowing quantities. 
The velocities of their increase he terms fluxions, 
and the iniinitesimally small parts of these quantities 
generated by the continuous motion he names 
moments. Motion in time he regards as continuous 
and uniform, and consequently the moments 
generated are all equal. Further, and this is one of 
the points chiefly attacked by Berkeley, Newton is 
prepared to calculate the increase or decrease of the 
fluxions, i.e. the velocities of velocities or the fluxions 
of fluxions. These are called second fluxions. Such, 
in very brief outline, is Newton s position. 

But there is one special point which must be 
examined with some care, for upon it depends the 
applicability of Berkeley s criticisms to Newton. 
The question is this. Did Newton really use the 
conception of infinitely small quantities, in which 
case he would be exposed to the full force of Berkeley s 
arguments, or was his method really that of limiting 
ratios, in which case Berkeley s criticisms would be, 
so far as Newton is concerned, directed against a 
man of straw ? 

It is often held that Newton never used the concep 
tion of infinitely small quantity, but it was con 
clusively established by Do Morgan that this con 
ception does appear in some of his works. Do 
Morgan maintains that, until the year 1704, when his 
Opticks was published, Newton did use infinitely 
small quantities. " In Newton s earliest papers," 
says De Morgan, " the velocities are only dill erential 
coefficients : when A changes from x to x + o, 

B changes from y to y + , the velocities being p 



and <\. Those terms in which o remains an; " in 
finitely less " than (hose in which it is not, and are 
therefore " Moiled out,." And those terms also 
vanish in which o still remains, because they are 
itilinitcly little." l A^ain, in tho (irst edition of the 
ia, published in 1GS7, fluxions a. re founded on 
tesimals, moments beinj^ regarded as infinitely 
small quantities. l)e Morgan confirms this by 
relevant quotations from Newton s Method of 
l ln.ri<ix (written in the period 1(17 I H>7(i) and Ins 
Qwidrat-ura durrarnm, which was originally written 
about the same time. So far, Newton certainly 
made use of the conception of infinitely .small 

liut in 1701 the Qiuidntli<r<t ( nrnirnm was issued 
in an appendix to the Optic. lex. It contained a new 
preface with some most important sta.tements in 
connection with infinitesimals. Ll 1 here consider 
mathematical quantities not as consisting of minimal 
pacts, but as described by continuous motion. 
" 1 was anxious to show that in the method of fluxions 
there is no need to introduce into geometry figures 
infinitely small." 3 Now Berkeley was well aware 
that the conception of infinitesimals had been dis 
claimed by Newton. In the early essay Of liijinilr.* 
he says, " Sir Isaac Newton, in a late 1 realise, 1 

1 " On tho Kurly IliHlory of InfmitoHinuils in Kngluml " (I hilo- 
iitir.inr, lH. r ) J, iv. . t^!2-31!ii). 

8 " Qinuititul(<M MuMiiMiiiiticiis 11011 ut. (^x pti.rlihiis <pimn mini. 
HUH ((iiiHtiuilcH, Hrd ut, iiiotu rnnlimio doHcripLns liici considoro." 

3 " Volui oHtondoro cpiod iu MoUuidi> Kliixioiuun noil optw Hit 
Ki^uniH iiiliiiili* pn.rvii.H in ( Jcoinol riaiu inl.roducoro." 

1 ThiH rofcfH to tho Qinnlratiirti dtirwirti.m. Horkley H Of 
Injiiiitr* wan writton ahout 170(5-7. 


informs us his method of Fluxions can be made out 
a priori, without the supposition of quantities in 
finitely small." 1 

But in 1713, when the second edition of the 
Principia was published, Newton again admitted, 
though very obscurely, infinitely small quantities. 2 
From all this we may conclude that, while Newton 
did not give exclusive adhesion to the method of 
infinitesimals, yet the conception of infinitely small 
quantity does occur in his writings previous to 1704, 
and though it was renounced in that year it re 
appears in the second edition of the Principia in 
1713. It therefore follows that Berkeley s criticism 
is pertinent. Newton, we have decided, did main 
tain the existence of infinitely small quantities, and 
it is against these that Berkeley argues. 

Berkeley points out a serious inconsistency in 
Newton s conception of infinitely small quantities. 
He shows that at one time Newton admits that 
infinitely small moments may under certain circum 
stances be altogether omitted in calculation. Against 
this he arrays Newton s declaration that even the 
smallest possible errors must not be overlooked in 
mathematical operations. Now, the former state 
ment is made by Newton in the Principia and the 

1 Berkeley s Works, iii. 412. 

2 This point has been regarded as open to doubt. It depends 
on Newton s definition of " moment." The definition is stated 
very obscurely, and somewhat differently, in the first and second 
editions, in bk u. lemma ii. But Edleston cites a letter from 
Newton in May, 1714, to Keill, in which Newton says explicitly, 
" Moments are infinitely little parts " (J. Edleston, Corre 
spondence of Sir Isaac Newton and Professor Cotes, p. 176). This 
seems to be conclusive evidence that Newton still clung to in 


latter in the Quadratura Curvarum. The two state 
ments are obviously inconsistent. Berkeley s critics 
tried to defend Newton in various ways, but neither 
of them dared to admit, even if they perceived it, 
that the inconsistency was due to a change in 
Newton s system. In the Principia, holding a con 
ception of infinitesimals, he is forced (precisely as 
the continental exponents of the Differential Calculus 
were forced) to admit that infinitely small quantities 
are, in calculation, negligible in comparison with 
those of finite magnitude. On the other hand, in 
the Quadratura Curvarum, having renounced infini 
tesimals, he is free to assert that even the smallest 
errors cannot be permitted. Robins was the first 
of Newton s defenders to see clearly that the systems 
were different ; and that, if Newton s position were 
to be seriously defended, it would be necessary to 
admit frankly the change of system, and to maintain 
that for Newton the really fundamental method is 
the method of limits. 1 

1 Berkeley has been accused of bad faith in advancing this 
criticism. He must have seen, it is argued, that the Newton of 
the first edition of the Principia held a different position from the 
Newton of the Quadratura Curvarum, and therefore he was not 
justified in arraying the statements of these two periods against 
one another as evidence of present inconsistency (cf. A. de Morgan, 
op. cit., p. 329). But such an argument overlooks two or three 
very material facts. The first is that Newton himself nowhere 
explicitly admits a change of system ; in fact he seems anxious 
to conceal that such a change had taken place. Further, with 
the exception of Robins, Newton s followers were far from clear 
whether or not a change had taken place, and, in any case, Newton 
seems to have returned to the conception of infinitely small 
quantities in 1713. Now, The Analyst was not published till 
1734, and at that distance of time Berkeley may quite well have 
regarded the renunciation by Newton of infinitesimals in 1704 
as a temporary aberration. 


This is what Robins did, and it has come to be 
realised that the conception of limits forms the true 
logical basis of the calculus. Berkeley s general 
criticism of Newton is perfectly valid, and it was 
largely owing to his objections that the difference 
between the two methods came to be fully appre 
ciated, and that eventually a method of limits akin 
to that of Newton was established as the foundation 
of the calculus. 

But in two respects Berkeley is unfair to Newton. 

(a) He never lets his reader know that Newton 
used the method of limits, and always speaks as if 
Newton had always held that the method of infini 
tesimals was essential to his doctrine of the calculus. 
Now, the truth is, as Robins pointed out, that every 
thing of fundamental importance in Newton s work 
is perfectly consistent with the method of limits. 

(6) He gives Newton no credit for his doctrine of 
continuity. Newton s infinitesimals are, after all, 
never so self-contradictory as those of Leibniz or 
even of his own followers. His infinitely small 
quantities are not, like Leibniz s differentials, dis 
crete particulars. The Leibnitians hold that the 
" difference " of a line is an infinitely little line, the 
" difference " of a plane an infinitely little plane, and 
so on. And Newton s own followers used the con 
ception of infinity in an equally rash way. Thus 
De Moivre regards the fluxion of an area as an 
infinitely small rectangle, 1 and Halley, to whom 
Berkeley refers in the Commonplace Book, speaks of 
infinitely small ratiunculae and differentiolae in much 
the same way as the Leibnitians. 2 Hayes, again, 

1 Philosophical Transactions, 1695, no. 216. 2 Ibid. 


another follower of Newton, to whom Berkeley also 
refers, maintains the conception of infinitely small 
quantities with much frankness. " Magnitude," he 
says, " is divisible in infinitum. Now those infinitely 
little parts, being extended, are again infinitely 
divisible ; and those infinitely little parts of an 
infinitely little part of a given quantity are by 
geometers called Infinitesimae Infinitesimarum or 
Fluxions of Fluxions." l Now, Newton himself does 
not speak in that way. He never forgets that his 
whole system is based on the continuity of motion. 
Lines are generated by the motion of points, planes 
by the motion of lines, and solids by the motion of 
planes. Fluxions, as we have seen, are strictly the 
velocities of the generating motions. The continuity 
of motion, generating lines, surfaces, etc., with 
varying velocities, involves the conception of prime 
and ultimate ratios. But to Newton s theory of 
continuity Berkeley seems to be blind. 

(2) Having considered the respects in which 
Berkeley s criticism of Newton is sound, we may now 
proceed to ask whether his criticism of infinitesimals 
in general will bear examination. 

The general criticism of infinitesimals consists of 
two arguments, one only of which seems to be valid. 

(a) Berkeley argues to take first the contention 
that seems unsound that infinitesimals are im 
possible because imperceptible. An infinitely small 
quantity cannot be the object either of sense- 
perception or imagination, and, in accordance with 
the formula esse est percipi, it can therefore have no 

1 A Treatise of Fluxions, 1704 (quoted by A. de Morgan in 
Essays on the Life and Work of Newton, p. 91). 


existence. " As our Sense is strained and puzzled 
with the perception of objects extremely minute, 
even so the Imagination, which faculty derives from 
Sense, is very much strained and puzzled to frame 
clear ideas of the least particles of time, or the least 
increments generated therein ; and much more so 
to comprehend the moments, or those increments of 
the flowing quantities in statu nascenti, in their very 
first origin or beginning to exist, before they become 
finite particles." l 

Now, this argument is simply at the level of 
picture-thinking. It does not follow that what we 
are unable to perceive in sense-perception or to 
represent in imagination is non-existent. At one 
time Berkeley s New Principle would have necessi 
tated this argument, but when The Analyst was 
written he had outgrown the cruder form of his early 
theory, and in his doctrine of notions he admitted 
that we can have knowledge which comes neither 
through sense nor imagination. He was prepared 
to allow that we might have real knowledge not 
sensuous in its origin. His retention of the argu 
ment here is a sign that he was not yet completely 
emancipated from his early sensationalism. 

(6) Berkeley s second general argument against 
infinitesimals is perfectly sound. He points out that 
the conception of the infinitely small, whether in the 
form in which it appears in Newton and his followers, 
or as maintained by Leibniz, is impossible. It is 
impossible because it is self -contradictory. Whether 
we regard infinitesimals with Leibniz as differences, 
i.e. infinitely small increments or decrements, or 
1 The Analyst, 4. 


with Newton as fluxions, i.e. velocities of nascent or 
evanescent increments, they involve in their nature 
an ultimate contradiction. On the one hand, an 
infinitesimal seems to be something, for otherwise it 
would not be used in mathematics ; but, on the 
other, it seems to be nothing, for mathematicians say 
it may be neglected in calculation without affecting 
the accuracy of their results. Sometimes it is called 
a nascent quantity, i.e. one which has left being 
nothing, but has not yet quite become anything ; 
at other times it is called evanescent, i.e. a quantity 
which is still something, but almost (though not 
quite) nothing. This conception, Berkeley insists, 
is ultimately incomprehensible and contradictory. 
His criticism here is, of course, perfectly sound. 
Infinitesimals, conceived in this vague and loose way, 
have now. very largely owing to the process of criti 
cism initiated by Berkeley, been entirely extruded 
from the calculus. 

(3) The last problem which we set before ourselves 
is this. Did Berkeley, apart from stimulating the 
investigation of the logical basis of the calculus, 
expose any real errors in it ? From Berkeley s 
argument in The Analyst it would seem that two 
main errors infect the calculus. Berkeley maintains 
(a) that any attempt to demonstrate the value of a 
fluxion involves the violation of ultimate logical 
principles, and (6) that the maxim that infinitely 
small errors compensate one another is vicious. A 
word or two must be said on each of these points. 

(a) In order to prove the illogicality of the methods 
of determining the value of fluxions, Berkeley 
examines, in some detail, the two independent demon- 


strations given by Newton. In the Principia Newton 
gives a geometrical proof, in the Quadratures Curva- 
rum an algebraic one. In each case, Berkeley seeks 
to show, a closely similar error is committed. 

Take first Newton s geometrical demonstration. 
We wish to find the fluxion of the rectangle AB 
generated by the continuous motion of one side upon 
the other. Let the moments or momentaneous 
increments of A and B be a and b respectively. 

When the sides of the rectangle are each diminished 
by half their moments, the rectangle becomes 

i.e. AB - \aE - \bA + %ab. 

Similarly, when the two sides are increased by 
half their moments, the rectangle becomes 

i.e. AB +^aB +\bA + \ab. 

Subtract now the former rectangle from the latter, 
and the remainder is aB +bA. This remainder is 
the moment of the rectangle generated by the 
moments, a, b of the sides. Such is Newton s proof. 
In criticism of it Berkeley maintains that the 
natural and direct method of obtaining the moment 
of the rectangle AB, when the moments of its sides 
are a, b, is to multiply into one another the sides 
increased respectively by their whole moments. 1 
The moment of the rectangle is therefore 


i.e. AB +aB +bA +ab - AB, 

i.e. aB +bA +ab. 

1 The Analyst, 9 ff. 


This, Berkeley says, is the true moment or incre 
ment. It differs from that obtained by Newton s 
proof by the quantity oh. Now, as it was essential 
for the method of fluxions to eliminate the term ab, 
Newton and his followers said that it was so infinitely 
small that it could simply be neglected. But against 
this defence Berkeley quotes Newton s own words, 
" In rebus mathematicis errores quam minimi non 
sunt contemnendi." i 

Berkeley also shows that Newton s algebraic proof 
rests on illegitimate assumptions. 2 In this demon 
stration we are given the uniformly flowing quantity 
x, and it is required to find the fluxion of x n . 

Suppose that x, in process of constant flux, 
becomes x +o, then x n becomes (x +o) n . Expanding 
this by the method of infinite series, we get 

fy\ I /yi _ "I \ 

x n +nox n ~ 1 + v -oV*- 2 +... 

/y\ I /yi _ 1 \ 

(i.e. the increment of x n is nox n ~ l + - - - o*x n ~ 2 + ...). 


It follows that the increments of x and x n are 

yi (M _ 1 \ 

to each other as o to nox n ~ l +- o 2 x n ~ 2 +... ; 


or, dividing by the common quantity o, as 

Now, " let the increments vanish," and the last 
or limiting proportion is 1 : nx n ~ 1 . The ratio of the 
fluxion of x to that of x n is as 1 is to nx n ~ l . 

1 These words occur in the Introduction to the Quadratura 

2 The Analyst, 13 ff. 


Berkeley points out that this reasoning is illogical. 
If we say, " Let the increments vanish," we must 
imply that the increments are really nothing, seeing 
that they are negligible. But we are enabled to 
arrive at the proportion between the fluxions only 
by assuming that the increments are something. 
Berkeley accordingly maintains that it is illogical 
to reject the increments and still retain an expression, 
i.e. the proportion of the fluxions, obtained by means 
of them. If we let the increments vanish, we must 
also in consistency let everything derived from the 
supposition of their existence vanish with them. 

This criticism Berkeley supports with a lemma, 
which he states as follows, " If, with a view to 
demonstrate any proposition, a certain point is 
supposed, by virtue of which certain other points 
are attained ; and such supposed point be itself 
afterwards destroyed or rejected by a contrary 
supposition ; in that case, all the other points 
attained thereby, and consequent thereupon, must 
also be destroyed and rejected, so as from thence 
forward to be no more supposed or applied in the 
demonstration." l 

(b) Berkeley goes on to urge that, even though 
correct results are attained by the application of the 
method of fluxions, that does not validate the 
method as method. That the conclusion of a syllo 
gism is true does not necessarily imply that the 
process of reasoning is correct. The conclusion may 
be true, and yet logical errors may have been com 
mitted in the process of proof. It is possible to 
reach a true conclusion from false premises by 

1 The Analyst, 12. 


erroneous reasoning. One error compensates the 
other. Though the conclusion is true, the logic is 
faulty. Precisely similar is the case of the calculus. 
True conclusions may be attained by it, and results 
of great practical value may be achieved, but its 
method is unsound, because it is based upon the 
vicious principle of the compensation of errors. 

These, then, are the arguments which Berkeley 
advances in The Analyst. In the controversy which 
ensued all the points that he raised were traversed 
and retraversed, with the result that (1) the vague 
conception of infinitesimals is abandoned, (2) the 
method of limiting ratios becomes firmly established, 
and (3) the principle of the compensation of errors 
is seen to be inconsistent with the logical foundation 
of the calculus. 

But the result of the controversy may be stated 
in more philosophical terms. It may be said to have 
established the principle of continuity as opposed 
to that of discreteness. Discreteness, whether in 
the form of the indivisibles of Cavalieri, or the 
momentaneous increments of Newton s followers, or 
the differentials of Leibniz, was found to be incom 
prehensible. But the principle of continuity is 
firmly grounded. 

Thus, though Berkeley was successful at most of 
the particular points in the controversy, the philo 
sophical conclusion to be based upon these results 
was alien to his way of thinking. For his own 
philosophy lays all the stress on discreteness at the 
expense of continuity. For him, there are no really 
continuous lines, for every line consists of an infinite 
number of atomic and therefore discrete points. 


A curve is not to be regarded as generated by a 
continuously moving ray ; it also is composed of a 
finite number of discrete points. The objects of 
perception are not continua into which differentia 
tion is introduced ; they are complexes of numeri 
cally distinct and atomic minima sensibilia. 
Berkeley does, indeed, use the term " continuity," 
but by that he means nothing but discreteness. He 
says, for instance, in the Commonplace Book, " Why 
may not I say visible extension is a continuity of 
visible points, tangible extension is a continuity of 
tangible points ? " 1 What he really means by con 
tinuity here is that, according to his theory, visible 
extension is a mere aggregate of discrete minima 
visibilia, and tangible extension a mere aggregate of 
minima tangibilia. His conception of mathematical 
knowledge is completely atomistic. 

Everywhere in Berkeley s philosophy we find the 
same penchant to discreteness. Throughout he 
lays emphasis on the discrete, the finite, the parti 
cular, as against the continuous, the infinite, and the 

But this emphasis is very considerably modified 
in Siris, Berkeley s only important work after The 
Analyst. In Siris, as we have seen, he shows very 
much greater appreciation than before for what may 
be called, for short, universality and absoluteness. 
But his theory of mathematical knowledge has 
neither part nor lot in this change of attitude. 
Mathematics remains on the old plane of sense and 
particularity. Thus is consummated the tendency, 
suggested even in the pre-Siris works, to distinguish 

1 i. 63. 


sharply between mathematical science and trans 
cendental philosophy. It is only because this 
distinction is present in Siris that Berkeley is able 
to maintain his sensationalist view of mathematics 
alongside his altered metaphysics. In his view, 
mathematics is in a different compartment of know 
ledge from first philosophy ; therefore it may be left 
to itself at its lower station, for it will not be 
affected by the speculations carried on at the 
heights of transcendental philosophy. 



THOUGH Berkeley published no systematic ethical 
treatise, it is certain that at one time he intended to 
write in detail on the problems of morality. In the 
sanguine pages of the Commonplace Book, the New 
Principle is destined to simplify all sciences and solve 
every difficulty. In the expectation of its author, it 
will " remove the mist or veil of words," 1 and enable 
men to see things as they really are. And in the 
Principles the claims which he puts forward on 
behalf of the New Principle are as insistent as ever. 
It will " abridge the labour of study, and make 
human sciences more clear, compendious, and 
attainable than they were before." 2 After this 
assertion, he goes on to state some of the conse 
quences of the theory in mathematics and natural 
philosophy. Now, in his view, these branches of 
science form two of the three departments of 
useful knowledge, the third being ethics. He 
believed that there are three kinds of truth 
natural, mathematical, and moral which are to be 
found respectively in what he calls the three depart 
ments of useful knowledge, viz. natural philosophy, 
1 i. 33. 2 Op. cit. 134. 



mathematics, and ethics. 1 Thus, in order to com 
plete his scheme in the Principles, as he has already 
mentioned the consequences of the New Principle in 
two of the three departments of useful knowledge, 
he ought to have given some indication of the 
application of the theory to ethics. But only the 
vaguest hint is dropped. If the Principle be applied 
to morals, he says, " errors of dangerous consequence 
in morality . . . may be cleared, and truth appear 
plain, uniform, and consistent." " But," he con 
tinues, " the difficulties arising on this head demand 
a more particular disquisition than suits with the 
design of this treatise." 2 That Berkeley himself 
regarded this non-committal statement as tanta 
mount to a promise to deal specially with ethics is 
suggested by the fact that this sentence was omitted 
in the second edition of the Principles, which was 
published after he had abandoned the design of 
the special dissertation. And, indeed, we know 
definitely from a statement in the Commonplace Boole 
that the treatise in which it was his purpose to deal 
with ethics was the projected Part II. of the 
Principles* But, as we have already mentioned, 
the unfinished manuscript of it was lost during his 
travels in Italy, and he never attempted to re 
write it. 

But though accident has deprived us of this 
specifically ethical work, yet there is a fair amount 
of material on ethical subjects scattered up and down 

1 Commonplace Book, i. 37. 2 Principles, 144. 

3 " The two great principles of morality," he says, "to be 
handled at the beginning of the Second Book." There is no 
doubt that the " Second Book " refers to Part II. of the Principles. 


Berkeley s writings. It is enough not only to enable 
us to reconstruct the main outlines of Berkeley s 
views, but also to trace their development. The 
Commonplace Book teems with suggestive remarks 
which probably give some idea of the argument of 
the lost Part II. of the Principles, Passive Obedience 
is, in the main, an ethical treatise, two of the essays 
in the Guardian and three of the dialogues in 
Alciphron are chiefly concerned with morals, and 
there are a few hints in the Principles and Siris. 

In the Commonplace Book the facts of morality are 
prominently before Berkeley s mind. In ethics, as 
in other departments of philosophy, he was deeply 
influenced by Locke. Many of the entries in the 
Commonplace Book are unintelligible unless it is 
remembered that they have Locke in view. We 
find, for example, such isolated entries as, " Morality 
may be demonstrated as mixt Mathematics," i 
" Three sorts of useful knowledge that of Co 
existence, to be treated of in our principles of Natural 
Philosophy ; that of Relation, in Mathematics ; that 
of Definition or inclusion, or words (which per 
haps differs not from that of relation) in Morality." 2 
Most of Berkeley s memoranda on ethics in the 
Commonplace Book reveal or conceal a reference to 
Locke ; and in order to appreciate their significance, 
it is necessary to bear in mind Locke s theory of 

For Locke ethics is a perfectly demonstrable 
science, because in ethics we have real knowledge. 
He treats of the reality of knowledge in Book IV. 
Chapter iv. of the Essay a chapter which Berkeley 

1 i. 46. 2 i. 55. 


reminds himself in the Commonplace Book " to 
discuss nicely " and maintains that our knowledge 
is real only so far as there is a conformity between 
our ideas and real things. 1 Locke is aware of the 
difficulty how the mind, which perceives nothing 
but its own ideas, can yet know that these ideas 
agree with things ; but he thinks that there are 
" two sorts of ideas that we may be assured agree 
with things." These are (A) all simple ideas, and 
(B) all complex ideas, except those of substance. 
But the grounds on which we ascribe reality to 
knowledge in the case of these two sorts of ideas are 
very different. Simple ideas give us real knowledge 
because they are regularly and naturally produced 
in us by the operation of things outside us. This 
uniform production guarantees the conformity of 
ideas to things. On the other hand, complex ideas 
are produced by the mind itself, independently of 
things. They are ideas which the mind puts 
together without considering any connection they 
may have in nature. Ideas are the archetypes, and 
things are considered at all only in so far as they 
conform to them. In (A) ideas conform to things ; 
in (B) things conform to ideas. In both cases 
conformity can be predicated, and therefore in both 
cases we have real knowledge. 

Locke gives two examples of sciences in which we 
have this real knowledge, mathematics and ethics. 
Both these sciences consist of perfectly demonstrable 
propositions. Both are concerned not with simple 
ideas, which always imply as their archetypes con 
crete things, but with complex ideas, which are their 

1 Essay, iv. iv. 3. 


own archetypes. Mathematics and ethics deal 
entirely with those abstract ideas, which Locke calls 
mixed modes and relations. These have no concrete 
existence, but they give us real knowledge. " Mixed 
modes and relations, having no other reality but 
what they have in the minds of men, there is nothing 
more required of those ideas to make them real but 
that they be so framed that there is a possibility of 
existing conformable to them." * In mathematics 
we abstract from all the implications of concrete 
existence. The mathematician considers the pro 
perties of circle or triangle as abstract ideas. It is 
true of the idea of a triangle that the sum of its 
angles is equal to two right angles. The idea of a 
triangle is so framed as to make it possible that a 
real concrete triangle should exist conformable to it. 
But whether such a " real " triangle exists is quite 
irrelevant to the mathematician. 

Similarly, in ethics we deal only with abstract 
ideas. " When we speak of justice or gratitude, we 
frame to ourselves no imagination of anything 
existing, which we would conceive ; but our thoughts 
terminate in the abstract ideas of those virtues." 2 
Ethics is thus a purely abstract science. To the 
moral philosopher it is of no moment whether a 
concrete just act anywhere exists. " The truth and 
certainty of moral discourses abstracts from the lives 
of men, and the existence of those virtues in the 
world of which they treat." 3 

Mathematics and ethics are both demonstrated on 
the basis of certain axioms and definitions. Between 
moral ideas there are the same necessary relations 

1 ii. xxx. 4. 2 in. v. 12. 3 iv. iv. 8 ; cf. in. v. 12 and iv. iv. 8. 


as hold between mathematical ideas. Locke admits 
that ethics is not popularly placed on the same level 
of demonstrative certainty as mathematics, but that 
is because it is more difficult in ethics than in mathe 
matics to reach agreement with regard to the names 
to be applied to ideas. In mathematics there is 
universal agreement with regard to the idea signified 
by the word triangle. But in morals there is no such 
agreement. 1 The prevalence of misnaming, though 
it detracts from the obviousness of the certainty of 
our knowledge in ethics, does not affect the certainty 
itself. If men could reach agreement in their 
definitions of moral ideas, then the whole science of 
ethics would be seen to follow analytically from 
these definitions. " I doubt not but from self- 
evident propositions, by necessary consequences, as 
incontestable as those in mathematics, the measures 
of right and wrong might be made out." 2 

Mathematics and ethics alike are pure a priori 
sciences, independent of the matter-of-fact of 
experience. If they had to do with concrete experi 
ence, they would consist of (a) simple ideas, or 
(6) complex ideas of substance. In neither case 
would the science be demonstrative, or consist of 
universal propositions. For, (a) simple ideas give 
us knowledge that is " barely particular," from which 
no universal propositions can be inferred ; and 

1 Locke mentions two other reasons why ethics is more difficult 
to demonstrate than mathematics. (1) Mathematical ideas are 
capable of sensible representation, e.g. in diagrams, but not so 
moral. (2) Moral ideas are generally more complex than mathe 
matical (Essay, iv. iii. 18). 

z iv. iii. 18 ; cf. m. xi. 16. 


(6) the general knowledge we gain from complex 
ideas of substance is " merely probable." 

Locke never abandoned his belief in a mathemati 
cally demonstrated science of ethics, though he came 
to feel less and less able to demonstrate it himself. 1 
This is clear both from the changes which he intro 
duced in the fourth edition of the Essay? and from 
his letters to Molyneux. Molyneux repeatedly 
requested him " to oblige the world with a treatise of 
morals . . . according to the mathematical method." 
Locke replied (September 20, 1692), expressing dis 
trust of his ability to undertake the task ; but 
promising to consider it. Nearly four years later 
he finally declined to undertake it. 

It is thus not strange that Berkeley, already keenly 
interested in mathematics, should have felt that the 
mathematical demonstration of ethics was a task 
ready-laid to his hand. Locke had given one hint 
of the precise way in which the mathematical method 
might be followed in a demonstrative moral science. 
Locke held that certainty means simply the agree 
ment or disagreement of our ideas, and that demon 
stration consists in making clear that agreement by 
employing intermediate ideas or media. Now in 
mathematics algebra had been of use in supplying 
these intermediate ideas, and Locke is inclined to 
think that by applying algebra in ethics a demon- 
strably certain system will be produced. 3 

1 The examples which Locke gives (iv. iii. 18) are justly said 
by Berkeley to be " trifling propositions " (Commonplace Book, 
i. 39). 

2 Compare the fourth edition with the first at iv. ii. 9. 

3 Cf. iv. iii. 20 ; and IV. xii. 14. 


Berkeley was not slow to fasten on this hint. 
" N.B.," he says in the Commonplace Book, " To 
consider well what is meant by that which Locke 
saith concerning algebra that it supplies inter 
mediate ideas. Also to think of a method affording 
the same use in morals &c. that this doth in mathe 
matics." 1 At this time Berkeley was much inter 
ested in algebra, 2 and he saw that if algebra were 
applied to morals, the result could not be a pure 
mathematical science. Algebra is itself a branch of 
pure mathematics, for it deals with signs in abstrac 
tion from the things they signify. 3 But the algebra of 
ethics would be a department of applied mathematics. 4 

1 i. 40. 

2 Cf. the many references in the Commonplace Book, and the 
article " De Ludo Algebraico " in Miscellanea Mathematica, 1707. 

3 i. 47 ; cf. supra, 209 ff. 

4 It is a noteworthy fact that nearly every philosopher of the 
seventeenth century believed in the possibility of a mathematical 
treatment of ethics. The instance that leaps to the mind is, of 
course, Spinoza s Ethica Ordine Geometrico Demonstrata. In the 
Ethica of Geulincx there are suggestions towards a mathematical 
system of ethics. Leibniz also holds that it may be convenient 
to treat ethics on the geometrical method (Nouveaux Essais, 
in. xi. 17 and iv. xii. 8). In England both Cumberland and 
Locke held the view. Suggestions towards it are also to be found 
in Hobbes. 

There are probably two main reasons for these persistent 
attempts to apply mathematical reasoning to ethics. 

(1) So long as Scholasticism held the field, the validity of 
ethical criteria rested on the authority of the Church. Moral 
judgments on which the Church set its seal could never be called 
conventional or contingent. The Church drew a line between 
what was right and what was wrong. The line might be exceed 
ingly sinuous and tortuous, but the authority that drew it was 
unquestioned. But with the coming of the Renaissance and the 
Reformation all this was changed. The question of the authority 
of the moral standard became a very real one. If the sxipreme 
moral authority of the Church was denied, how was moral 
heterodoxy to be met ? To this question only two answers could 


Thus, " morality may be demonstrated as mixt 
Mathematics." l 

Morality, then, for Berkeley, may be demon 
strated as " mixt " or applied mathematics. It was 
fresh in his mind that Newton had applied mathe 
matics, with wonderful success, to the solar system ; 
and it required no great stretch of imagination to 
hope for significant results from the application of 
mathematical methods to the study of human 
conduct. What Berkeley understood by the appli 
cation of mathematics to a certain subject-matter 

be given. Either ethics must become theological again, or it 
must become mathematical. These were the alternatives. 
Therefore those who for any reason disliked the idea of a theo 
logical ethics or thought it philosophically inadequate, were 
driven to attempt to demonstrate ethics mathematically. For 
Descartes, for Spinoza, for Locke, and for the philosophers of 
the seventeenth century as a whole, science means, in the main, 
mathematics and mathematical physics. Thus when the seven 
teenth century philosopher attempts to treat ethics on the mathe 
matical method, he is simply feeling after a truly scientific system 
of ethics. Cf. Glanvill s Scepsis Scientifica, p. 179, and John 
Sergeant s Method to Science, 1696, Pref. p. 6 ff . 

(2) It was largely owing to Descartes that mathematics came 
to be the only science of the day, and the influence of Descartes 
was mainly responsible for the unanimity with which the seven 
teenth century sought to attain a mathematical science of ethics. 
Descartes himself produced an example of a philosophical argu 
ment treated mathematically. An objector remarks, in the 
second set of Objections, " It would be well worth the doing if 
you advanced as premises certain definitions, postulates, and 
axioms, and thence drew conclusions, conducting the whole proof 
by the geometrical method." In his reply Descartes elaborately 
distinguishes geometrical method from geometrical order, and 
then gives a sample treatment of metaphysics more geometrico. 
This undoubtedly had a direct influence on both Geulincx and 
Spinoza. The latter threw his version of Descartes philosophy 
(Principia Philosophiae Cartesianae) into geometrical form. 
Whether in this matter Descartes exercised any direct influence 
on Hobbes and Locke is more open to doubt. 


has already been explained ; x and we have discussed 
his attempts to construct a theory of nature on 
algebraic lines. 2 Though he hoped for equal success 
in the application of algebra to human conduct, he 
never worked out his Algebra of Ethics. 

Yet he said enough to show that his system 
would have diverged widely from Locke s. The 
difference between their theories of ethics would 
have been exactly parallel to that between 
their conceptions of mathematics. For Locke 
mathematics is a pure science, dealing with re 
lations of universal ideas, abstracted from all 
concrete existence. On the other hand, as we have 
already seen, Berkeley holds that mathematics is 
essentially practical. The speculative parts of mathe 
matics, which are concerned with difficiles nugae. are 
cut away by the New Principle ; and only those 
portions of arithmetic and geometry that are 
" useful " and " practical " will remain. 3 

In precisely the same way Berkeley s theory of 
ethics differs from Locke s. Ethics is for Locke a 
pure science, having as its subject-matter relations 
of ideas, and omitting all question of the realisation 
of these ideas in the concrete matter-of-fact of moral 
experience. But Berkeley s view is very different. < 
Ethics is an applied or practical science. It is 
concerned throughout with actual conduct : its 
subject-matter is moral experience, not theories 
about moral experience. And its great aim is the 
improvement of conduct, and the advancement of 
" the good cause of the world." 

1 Vide supra, p. 214. 2 Vide supra, p. 219. 

3 Gf. Principles, 121 and 131. 


Ethics, again, is for Berkeley a demonstrative 
science. But by that he does not mean, as Locke 
would have said, that its demonstrability consists 
in proving relations of ideas by means of intervening 
ideas. 1 In Berkeley s view, ethics is not concerned 
with ideas at all, but with words or signs ; and it is 
by means of these words or signs that it must be 
demonstrated. " We have no ideas," Berkeley 
asserts, " of virtues and vices, no ideas of moral 
actions." 2 In other words, we can neither perceive 
nor imagine virtue or vice in abstraction from 
concrete particular virtuous or vicious actions. Thus 
if the demonstrability of ethics depends on the 
consideration of relations between ideas, as Locke 
maintained, Berkeley fears that it will be impossible 
to arrive at demonstrative truth in ethics ; and he 
insists that those who agree with Locke that we may 
have ideas of morals have given themselves, in the 
demonstration of ethics, an impossibly difficult task. 3 
It is impossibly difficult, because we can have no 
certainty about ideas, as Locke supposed, but only 
about words. 4 We may, indeed, reason about ideas ; 
but by doing so we shall never attain demonstrative 
certainty : " demonstration can be only verbal." 5 
Perfect demonstration, that is, is possible only when 
we are dealing with words or signs. And Berkeley 
states as his conviction that " to demonstrate 
morality it seems one need only make a dictionary 
of words, and see which included which." 6 

1 Cf. Commonplace Book, i. 40 and i. 43. 2 Ibid. i. 36. 

3 Commonplace Book, i. 38. 4 Ibid. i. 43. 5 Ibid. i. 50. 

6 Ibid. i. 39. Cf. John Sergeant s view, infra, p. 390. 


This utterance in itself is perhaps rather cryptic, 
but, if we bear in mind Berkeley s general view of the 
applicability of algebra in the various departments 
of knowledge, its meaning becomes plain. In his 
view, algebra is " purely verbal " and " entirely 
nominal " ; 1 it deals with relations of arbitrary 
signs, and demonstration is possible, when they are 
employed, because there is uniformity in their use. 
Though they are arbitrary, their meaning is uni 
versally agreed upon ; and therefore demonstration 
by their means is of absolute cogency. Now, words 
are not so suited for demonstration as signs, because 
there is not universal agreement as to the meaning 
of words. Mathematicians are absolutely agreed on 
the meaning of such signs as + or - or J ; but 
the meaning of the word " truth " or " good " is 
not a matter of universal agreement. 2 But Berkeley 
believed that this was not a fatal or ultimate defect 
in words. It was only in the last half -century before 
he wrote that mathematicians had attained uni 
formity in the use of signs, and he hoped that it 
would soon be possible to reach similar agreement 
as to the meaning of words. To this end it would be 
necessary to make a universal dictionary, whose 
definitions would be sufficiently authoritative to 
command universal assent. If, then, the meaning 
of words were settled, propositions in ethics could be 
demonstrated as readily as propositions in mathe 
matics. It is universally agreed among mathema- 

*/ o o 

ticians that such propositions as 
2 +2 =4 or log(l 

Commonplace Book, i. 47. 2 Ibid. i. 69. 


are true. 1 In these cases the meaning of all the terms 
used is a matter of universal agreement. And if 
there were similar agreement with regard to the 
meaning of words, then such ethical propositions as 
" Man is free " or " God ought to be worshipped " 
would be universally admitted to be true, for they 
would be absolutely demonstrable. The latter pro 
position, for instance, would be readily demonstrated, 
as Berkeley says, " when once we ascertain the 
signification of the words God, worship, ought." 2 

Berkeley s former example of a demonstrable 
proposition in ethics gives a good illustration of what 
he means by saying, as he frequently does, that ethics 
deals with the relation of inclusion. He mentions, 
as we have seen, that it is part of the task of demon 
stration in ethics, after we have constructed our 
universal dictionary, to see which words include 
which. And elsewhere in the Commonplace Book he 
points out that ethics is concerned with " Definition, 
or inclusion, or words " ; 3 and that it deals with 
" signification, by including." 4 What he means by 
this is that if we take such a proposition as " Man 
is free," it is possible to demonstrate it when we 
know that " free " is included in " man." Given 
definitions in our universal dictionary such that the 
definition of " free " is comprehended within the 
definition of " man," and the proposition " Man is 
free " is universally demonstrable. 5 

1 This series was discovered independently by Mercator and 
Saint -Vincent in the seventeenth century. It was not used by 
Berkeley, but it serves well to illustrate his meaning. 

2 Commonplace Book, i. 41. Cf. i. 32. 3 Ibid. i. 55. * Ibid. i. 37. 
5 The conception of such an analytic or deductive philosophy 

was finally destroyed by the criticism of Kant. 


In this theory of the nature of " inclusion," 
Berkeley has been influenced by mathematical 
analogies. The expression log(l +x) includes the 
series x - ^x z + J# 3 - |# 4 +... . The series is analysed 
out of it. So, Berkeley believes, by an application, 
of analytical methods in ethics we shall be able to 
demonstrate relations of inclusion and exclusion 
between words ; and all propositions in ethics will 
thus be analytical. 

Berkeley s mathematical Ttheory of ethics is 
entirely in harmony with his general philosophical 
position. According to his theory of knowledge, we 
reason on a particular, which stands for all other 
particulars of the same kind. As representing other 
particulars it becomes a sign and performs the 
functions of universality. But Berkeley insists that 
this particular is not an idea, and he objects to Locke s 
theory of ethics on the ground that the abstract 
ideas which he had posited do not exist either in 
mathematics or in ethics. It is impossible, Berkeley 
has shown, to frame an abstract idea of triangle. 
Equally impossible is an abstract idea of justice. 
In ethics we are never concerned with the abstract, 
but always with particular instances of just or unjust 
actions. What we do is to take this or that just act, 
ignore all irrelevant features, and make it stand for 
all other just acts. On these particular cases we 
may reason in precisely the same way as we do in 
mathematics. In mathematics we give names to 
these particulars, and these names or signs are 
universal. Similarly in ethics signs are used, these 
signs being words and not ideas. 

The only obstacle which Berkeley mentions in the 


way of such a system of ethics is the very great diffi 
culty of reaching agreement in its definitions. The 
definitions which mathematics employs are not 
questioned, because the learner comes to them with 
no preconceived ideas or prejudices. He is willing 
to take them on trust. But in ethics it is otherwise. 
Men approach the subject with presuppositions of 
their own. They cling to these primitive convictions, 
and refuse to come to any agreement in the definition 
of terms. 

One very real difficulty which Locke had raised is 
denied by Berkeley. Locke had pointed out that 
the complexity of moral ideas increases the difficulty 
of dealing with them on the mathematical method. 
But Berkeley sees nothing in this difficulty. 1 Yet if 
we extend the term " complexity " to include the 
relations and context of moral experience, 2 the 
difficulty becomes a very pertinent one. On 
Berkeley s theory if we take a particular triangle, it 
is possible to abstract what is irrelevant to its 
triangularity, and the particular may be taken to 
stand for or signify all other particulars of the same 
kind. And, as we have seen, Berkeley thinks the 
same thing may be done in ethics. But it is not 
thus possible to isolate a particular just act. If it 
be cut loose from its context, it may no longer be a 
just act. Its justice may consist precisely in the 
complex relations in which it stands to its environ 
ment. What in one context might be irrelevant 
to its justice in another might be that in which its 
justice consisted. But though Berkeley was not 

1 Commonplace Book, i. 51. 

2 This involves a departure from Locke s meaning of the term. 


aware of this difficulty in the days of the Common 
place, Book, it is clear from Alciphron that he came 
to appreciate it later. This may well have been one 
of the reasons why he seems to have abandoned the 
project of writing a mathematical treatise on ethics. 

And it may be suggested that another reason 
weighed with Berkeley. If ethics is a science demon 
strable in the same way as mathematics, why has 
God allowed so much diversity of opinion with regard 
to its definitions and propositions ? There is uni 
versal agreement that 2+2 = 4, and that the sum of 
the angles of a triangle equals two right angles. This 
agreement Berkeley attributes to God. God brings 
it about, arbitrarily but not capriciously, that all 
men should agree that 2+2 = 4. But there is no 
similar universal agreement that polygamy is wrong. 
Now why did not God secure that all men should 
agree on moral matters ? Locke, indeed, had 
suggested that God has laid down in the Gospels 
" So perfect a body of ethics that Reason may be 
excused from the enquiry." l But Berkeley saw 
that the ethical ideas of the Gospels were accepted 
by only a portion, and as he seems to have feared, 
by a diminishing portion, of mankind. If God had 
intended ethics to be as demonstrable a science as 
mathematics, he would have arranged that the 
definitions and axioms of ethics should be recognised 
by all men to be eternal and immutable. But as God 
has not done this, it cannot be his will that there 
should be a demonstrable science of ethics. 

In Berkeley s works subsequent to the Principles 
no mention is made of a possible mathematical 

1 Letter to Molyneux, March 30, 1696. 


science of ethics. In itself this does not prove that 
he had entirely abandoned all hope of developing the 
theory. No argument is weaker or more rash than 
the argumentum a silentio. In this particular case, 
there is some probability that Berkeley kept a place 
in his mind for an Algebra of Conduct until he finally 
decided not to attempt to re- write Part II. of the 
Principles, in which, as we have seen, his ethical 
theory was to have been expounded. 

It may, indeed, seem strange that, even in the 
Discourse on Passive Obedience, which was published 
in 1712, when he certainly still cherished the project 
of founding a mathematical system of ethics, not a 
word is said to show that he had ever conceived such 
a possibility. 1 But when the circumstances in which 
Passive Obedience was written and re-written are 
taken into account, the omission does not seem so 
remarkable. It was composed first in the form of 
three sermons which he delivered in the chapel of 
Trinity College. False reports of these sermons, 
Berkeley tells us, were scattered broadcast, with the 
result that his loyalty to the House of Hanover came 
under suspicion. At that time " Passive Obedience " 
was a dangerous topic : only two years before, 
Sacheverell s sermons on Non-resistance at St. 
Paul s had given rise to an important trial and 
occasioned a violent controversy. Berkeley thought 
it wise, with a view to dispelling these suspicions 
about his loyalty, to publish the sermons " under 
the form of one entire discourse." The volume had 
a large circulation, but it did not succeed in removing 
the cloud under which its author rested ; and for 
1 But cf. 53. 


several years the suspicion of disaffection stood in 
the way of his advancement in the Church. 

Under these circumstances, the last thing we 
should expect to find in Passive Obedience is such 
novel, technical and controversial matter as an 
Algebra of Conduct. Even if Berkeley were con 
vinced at the time that a scientific system of ethics 
must be mathematical, he had enough sense of the 
fitness of things not to obtrude it in a sermon. 
Further, on re-writing the sermons for publication, 
he would be little likely to wish to introduce it. 
Passive Obedience, as published, was intended to be 
in part an apologetic, and, above all, to be readily 
intelligible and entirely free from ambiguity. And 
he definitely tells us, in the Commonplace Book, that 
in order that an ethical demonstration " may go 
down with " people, it must avoid the " dry, strigose, 
rigid way " of mathematics. 1 Now, he certainly 
intended the Discourse to "go down with " people. 
And, in his view, that was a perfectly adequate 
reason for keeping clear of mathematical discussion 
in it. 

There is also some reason why suggestions towards 
a mathematical system of ethics, even though 
Berkeley still believed in it, should not appear in 
his later works. For these works, and especially 
Alciphron, in which his more mature ethical views 
are most completely stated, are almost wholly con 
troversial. It is, indeed, characteristic of Berkeley 
always to have opponents in view ; and if he is not 
criticising somebody, he is thinking of the criticisms 
that others will bring against him. He never writes 
1 i. 69. 


as if a demon is sitting on his pen, for he is always 
preoccupied with what people will think of his work. 
When his early writings appeared, he was at almost 
ridiculous pains to discover what judgments were 
passed on them by the scholars and wits of the day. 
And in general he takes every care in his books to 
put himself at the point of view of possible objectors, 
and to state and answer their possible criticisms. In 
Alciphron, however, he is not primarily developing 
a theory of his own ; he is himself playing the part 
of the critic, and to have said anything there about 
a mathematical theory of ethics might have seemed 
irrelevant. He was criticising other people s ethical 
views, not developing one of his own. 

From the absence of reference, in his middle and 
later works, to a possible mathematical system of 
ethics, it would thus be rash to infer that he had 
altogether abandoned that theory. But we have no 
means of knowing in detail how the theory would 
have been developed ; and it would be futile to 
speculate. The views which he does state in Passive 
Obedience and Alciphron take us into an entirely 
different field of ethical interest. 

In the former work, to which we now turn our 
attention, Berkeley is concerned, in the first place, 
with the problem of moral obligation. There he 
makes " some enquiry into the nature, origin, and 
obligation of moral duties in general, and the 
criterions whereby they are to be known." l 

The possibility of morality, Berkeley believes, 
depends on the existence of certain fundamental 
moral rules which are closely connected with the 

Mv. 104. 


three postulates of the moral life God, freedom, and 
immortality. These three principles occupy much 
the same place in Berkeley s system as in Kant s. 
But Berkeley s reason for regarding them as funda 
mental is very different from Rant s. For Berkeley 
they are ultimate because they are natural. These 
three great principles form the groundwork of all 
Berkeley s ethical structure. All the moral rules 
based on them, Berkeley finds, display three main 

(1) Berkeley holds that natural principles are also 
rational. In saying that moral rules are natural 
principles or laws of nature, we interpret nature in 
the highest sense. Nature in this sense is a perfectly 
natural rational system. The best moral principles 
and at the same time the most natural are not those 
which are most primitive and rudimentary, but those 
which may be rationally deduced by the maturest 
thought. These natural-rational principles are 
" agreeable to, and growing from, the most excellent 
and peculiar part of human nature." l They are 
laws of nature, but they are also eternal rules of 
reason, because they naturally and necessarily result 
from the nature of things, and may be demonstrated 
by the infallible deductions of reason. 

(2) Natural-rational principles of morality are also 
divine. This follows from the whole course of 
Berkeley s philosophy, and is also explicitly stated 
by him. For Berkeley nature consists of divine 
symbols, and its general laws are simply the arbitrary 
but not capricious volitions of God. " Nature," 
says Berkeley, " is nothing else but a series of free 

1 Alciphron, ii. 61. Cf. Passive Obedience, iv. 108. 


actions, produced by the best and wisest Agent." x 
But though these actions are free, they are neither 
casual nor contingent. The laws of nature, including 
moral rules, are all necessary. God sustains them 
invariably and immutably. God is the " Author of 
Nature," and he does not permit Nature to deviate 
from the path which he has willed. 2 

(3) It follows that natural laws constitute a 
system. Berkeley insists strongly on this charac 
teristic of nature. " The Law of Nature is a system 
of such rules or precepts as that, if they be all of 
them, at all times, in all places, and by all men 
observed, they will necessarily promote the well- 
being of mankind." 3 The systematic and organic 
nature of reality is everywhere evident. Even at 
such a low level of organic life as vegetable existence 
organisation and system are present. " The several 
parts of it are so connected and fitted to each other 
as to protect and nourish the whole, make the 
individual grow, and propagate the kind." Take 

1 Passive Obedience, iv. 110. 

2 The question of miracles gave Berkeley some trouble. He 
does not disbelieve the miracles recorded in Scripture, but holds 
that while these miracles did involve violation, or at least sus 
pension, of the laws of nature, they were decreed by God, not in 
a capricious spirit, or to forward the interest of any particular 
person, but solely to advance God s own world -plan. Berkeley 
does not mention, though he can hardly have failed to notice, 
that this explanation involves the admission that the laws of 
nature are inadequate to attain the ends of their Author. Ber 
keley also attempts to defend miracles on the more hopeful 
ground that our knowledge of the laws of nature is so slight that 
apparent violations of them may really be quite consistent with 
them sub specie aeternitatis. Cf. Passive Obedience, iv. 110 ; 
Principles, 63; Alciphron, ii. 310-311; Sermon before the 
S.P.G., iv. 400-402. 

3 Passive Obedience, iv. 111. 


nature anywhere and everywhere, and it will manifest 
the same organic life. In animal existence, all the 
parts contribute to the good of the whole, and the 
whole to that of each of the parts. The well-being 
of the whole system and of every member of it is 
advanced by every part. And this participation 
of each and all in acting for the benefit of all and each 
extends even to " inanimate unorganised elements." 

Now moral rules are natural laws, and all the 
characteristics of natural laws belong to moral rules. 
Hence the same order and regularity which we 
perceive in the natural world exist also in the moral 
realm. The moral and natural worlds are partly, 
though not entirely, coincident. The moral realm 
is necessarily natural, but the natural world is not 
necessarily moral. Vegetable existence possesses 
all the attributes of the natural, but we cannot 
predicate morality of it. On the other hand, all the 
marks of the natural belong to the facts of morality. 
At all levels, the moral world, as we find it existing 
among self-conscious beings, is a realm of ends, in 
which man, living in accordance with nature, con 
siders himself not as an isolated and independent 
individual, but " as a part of a whole, to the common 
good of which he ought to conspire." x 

Berkeley is convinced that rational moral rules are 
absolutely essential for morality. He criticises the 
theory according to which it is sufficient that a man 
should on each particular occasion do what seems 
to him most likely under the circumstances to con 
duce to the general good. This view, says Berkeley, 
is untenable for two main reasons, (a) It is im- 

1 Alciphron, ii. 67. 


possible to compute the consequences of each 
particular action ; and even if it were possible, it 
would take too much time to be of practical use in 
the guidance of life. But it is possible and compara 
tively easy to say whether a given action contra 
venes a universal law or not. (6) Further, on this 
view, we should have no universal standard, and 
consequently a system of ethics would be impossible. 
Each man would act in accordance with his own 
private opinion of what at a particular juncture 
would most conduce to the public good ; and as no 
man need divulge what his opinion is, no man s 
action could be judged either good or bad by other 
men. Thus moral appraisement and moral judgment 
the essence of ethics would be impossible, and 
all distinction between good and evil would be lost. 
On every count Berkeley concludes that it is essen 
tial for morality that there should be eternal and 
immutable moral rules. 

These moral rules may be either positive or 
negative. Positive rules are not so absolute and 
necessary as negative ones. A negative precept is 
obligatory always and everywhere. It admits of 
no exception. It has no respect either for persons 
or for circumstances. But positive precepts are 
different. It is impossible always and everywhere 
to observe all positive precepts, partly because they 
are so numerous, and partly because the actions they 
prescribe may be inconsistent with one another. But 
it is possible to observe all negative precepts, even 
though this should involve total abstinence from 
action. 1 

1 Passive Obedience, iv. 118, 134. 


Berkeley introduces another distinction, which 
bears a closer relation to his philosophy as a whole. 1 
The term " law of nature " may be understood in 
either of two senses. In one sense it is a moral law, 
in the other it is not. If it means " any general rule 
which we observe to obtain in the works of nature, 
independent of the wills of men," it implies no duty 
and is no moral law. But it may also signify " a 
rule or precept for the direction of the voluntary 
actions of reasonable agents." In this sense duty 
is involved, and the rule is a true moral law. Thus 
the distinction between moral and non-moral natural 
laws depends on whether they imply human duty 
or not ; and this always involves a reference to the 
will. Natural laws are moral only if they imply 
voluntary human actions. 

The essential connection of morality with the will 
is strongly emphasised in the Commonplace Book. 
The morality of an action, Berkeley says, depends 
chiefly on the volition. Only those actions admit 
of moral valuation which are our own ; and only 
those actions are our own which are consequences 
of our volition. Thus we ought not to blame or 
praise a man for his congenital abilities or capacities, 
for these are not due to his volition. 2 A man is 
responsible only for voluntary actions. In per 
forming such actions man is free. JBerkeley simply 
takes it for granted that the will is free. To say 
that man wills is tantamount to saying that he is 
free. An unfree will is a contradiction in terms. 

1 Ibid. iv. 122-123. 

2 Commonplace Book, i. 39. Of. Siris, iii. 246. 

B.P. U 


" Folly to inquire what determines the will." l The 
will is self-determining, and no external force can 
act upon it so as to limit or determine it. No idea 
can affect it, because all ideas are passive and inert ; 
and no passion can move it, because it is the nature 
of the self to be superior to the passions. The will 
is simply another name for the self in the conative 
side of its activity. 

Berkeley distinguishes moral freedom from natural 
freedom. Both the natural world and the moral 
world are free. Mechanical necessity is absent from 
both worlds. The sharp distinction which we find 
in Kant between the necessity of the natural world 
and the freedom of the moral realm has no counter 
part in Berkeley. For Berkeley mechanical necessity 
is non-existent, because nature, as we have seen, 
consists of the free actions of God. Both the 
natural and the moral worlds are free. But because 
both are free, it does not follow that both are free 
in the same way. The distinction between them 
depends on the quarter in which responsibility rests. 
God is responsible for the natural world : for this 
we have no responsibility, because our responsibility 
ends with those actions which are in our power. On 
the other hand, we are responsible for actions in the 
moral world. Finite beings are accountable for 
their own actions ; and with regard to them God 
has no responsibility. But while God is not 
responsible for the actions of finite selves, these are 
consistent with his will and hence truly natural, so 
long as they are right. Thus it may be said that the 
distinction between right and wrong actions is that 

1 Commonplace Book, i. 34. 


what is right is both natural and moral, while what 
is wrong is not natural, though it is moral in a wide 
sense, as involving the responsibility of a finite self. 

Berkeley holds that the criterion of good and evil, 
which can be comprehended only by free and rational 
beings, is tendency to promote or thwart happiness. 
It is a natural principle that we consider things in 
the light of our happiness, for self-love is extensively 
the most universal, and intensively the most 
profound, principle in human nature. Good, then, 
is what augments our happiness, and evil that which 
impairs it. The summum bonum consists in happi 
ness, and duty lies in the endeavour to attain the 
good and avoid the evil, with a view to happiness. 

The content of happiness is defined by self-love. 
When our acquaintance with nature is shallow, self- 
love, being in an embryonic state, regards sensible 
pleasure as the invariable characteristic of good, as 
pain is of evil. But as self-love develops and we 
come to know nature better, it becomes evident that 
this formulation of the criterion is doubly erroneous. 
In the first place, experience teaches that present 
sensible good is often followed by greater evil, and 
that present evil often brings forth greater good. 
Thus, if we have regard only to present sensible good 
and evil, and seek to avoid the one and secure the 
other, we may fail in the main aim which self-love 
sets before us the attainment of personal happiness. 
And even if happiness consisted simply in sensible 
good, this would be attained, not by yielding to the 
solicitations of present pleasure but by undergoing 
present pain. In the second place, as our acquaint 
ance with nature grows, we discover that there are 


^oods than those that affect the senses, and 
that these goods are higher than sensible goods. 1 
Thus a developed self-love, while still regarding 
personal happiness as the summum bonum, requires 
a strict scrutiny of present pleasure. For such 
pleasure may in two ways actually impair our own 
happiness. It may be positively evil, i.e. pregnant 
with evil consequences. It may be negatively evil, 
i.e. not so high a good as might have been attained 
under the circumstances. 

Our knowledge of nature, carried a step further, 
shows us that the summum bonum cannot be mere 
temporal happiness. The summum bonum cannot 
be confined within the conditions of time. It con 
sists in eternal happiness. Now eternal happiness 
can be guaranteed only by God. Hence self-love 
lays down the rule that we act always in accordance 
with the will of God. The existence of God is re 
quired by morality as it is by knowledge. Berkeley s 
general metaphysical position implies that, apart 
from the_Xjstence of God to guarantee the regularity 
and inva,ria,bj1ity_of_our sense-impressions, no know 
ledge woulcVbepossible. In ethics, though concrete 
moral actions are not existentially dependent on 
God, the natural-rational principles on which they 
are judged are the volitions of God. But Berkeley 
does not, as Kant does, attempt to base a practical 
proof of God s existence on his indispensability for 

This process of the gradual definition of the 
content of happiness may be illustrated by the 
stages through which Berkeley himself went in 

1 Alciphron, ii. 89-97. 


developing his ethical theory. His view of the 
relative value of pleasures of sense and pleasures of 
reason underwent a marked change. In the Common 
place Book (1705-8), he does not recognise pleasures 
of reason at all. " Sensual pleasure," he says, " is 
the summum bonum." l In the essays in the 
Guardian (1713), pleasures of sense and pleasures of 
reason are placed on the same level, so long as they 
are natural. But in Alciphron (1732), pleasures of 
sense are degraded. The view that these constitute 
the summum bonum is strongly attacked. Sense- 
pleasure is natural only to brutes. Reason is the 
highest and most characteristic element in human 
nature, and only rational pleasures are in a strict 
sense natural to man. 

It is strange that at this stage in his philosophical 
development Berkeley did not notice the incon 
sistency of making reason supreme in morality, and 
sense in knowledge. All our knowledge is sense- 
knowledge, but all our moral actions are rational. 
But even when Alciphron was written Berkeley was 
modifying his view of the importance of sense- 
knowledge, and in Siris (1744), sense-knowledge is 
placed far below rational knowledge. Consistently 
with this, the pleasures of sense are depreciated, 
precisely as they were in Alciphron. " The objects 
of sense . . . are too often counted the chief good." 2 
Both in knowledge and morality the same trend is 
evident throughout Berkeley s philosophy the ascent 
from sense to reason. The only difference between 
Berkeley s epistemological and ethical development 
is that his perception of the inadequacy of sense took 

1 Commonplace Book, i. 47. z Siris, iii. 282. 


place earlier in the case of morality than in that of 

Berkeley believes, as we have seen, that each man s 
happiness is for him the summum bonum. This end 
self-love directs him to seek. But at first sight it 
would seem that a universe, in which the only moral 
precept is obedience to the principle of self-love, 
would certainly not display the harmony and 
system of Berkeley s organic moral realm. For 
Berkeley, as for all other British moralists, the 
problem of the relation of egoism and altruism arises. 
But in Berkeley s ethical, as hi his metaphysical 
philosophy, God solves many puzzles. This problem 
like many others would remain unresolved apart 
from God. Self-love remains for Berkeley the 
supreme principle in morality ; but it does not there 
fore follow that the altruism -egoism problem is 
insoluble. It is only at a low stage of moral develop 
ment that self-love bids a man seek his own happiness 
alone. Rational self-love endeavours to consider the 
world sub specie aeternitatis. It finds that true self- 
interest demands that actions be directed not to 
temporal advantage, but to eternal welfare ; and 
thus self-love advocates only that line of action that 
is conceived to be in accordance with the will of God. 
No purely selfish action can be at one with the will 
of God. The Hobbist position of undiluted egoism 
is stated by Berkeley, but only to be refuted by the 
same arguments as Butler used. Man, as Aristotle 
said, is a TTO\ITIKOV "(wov : " there is implanted in 
mankind a natural tendency or disposition to a 
social life." * All that is necessary to keep man 

1 Passive Obedience, iv. 117. 

ETHICS 31 1 

right in this social life is careful attention to the 
dictates of self-love. Self-love will not command 
what is inconsistent with the truest altruism. 

This conception of self-love supplies the key to 
Berkeley s attitude to pleasure. While he agrees 
that the sum/mum bonum is happiness, and that 
happiness consists largely in pleasure, he draws a 
sharp and apparently arbitrary distinction between 
" natural " and " fantastical " pleasures. Under the 
head of natural pleasures he includes " those which 
are suited both to the rational and to the sensual 
parts of our nature." Fantastical pleasures, on the 
other hand, are largely illusory, and, as they are 
not naturally adapted to provide satisfaction for our 
desires, they merely succeed in perpetuating a crav 
ing for more and ever more fantastical pleasures. 

At this point Berkeley introduces God to confirm 
the distinction. God has so arranged the world, he 
believes, that natural pleasures are both easier of 
attainment and more certain to afford satisfaction 
than those that are fantastical. Natural pleasures, 
again, are not purely egoistic : God has decreed that 
these, which form the proper object of desire to a 
rational self-love, should always contribute to the 
general social welfare. And while man is free to 
choose either natural or fantastical pleasures accord 
ing to his own volition, it is the will of God that he 
should seek, not merely the private enjoyment of 
pleasure, but also the promotion of the happiness of 
mankind as a whole. 

It is in connection with the nature of pleasure in 
life that Berkeley s relation to contemporary writers 
on ethical problems is most clearly seen. In 


Alciphron he criticises both Mandeville and Shaftes- 
bury with much asperity and some acumen. 

From Mandeville he differs at the outset with 
regard to the conception of self-love. Self-love for 
Mandeville is always egoistic ; it directs each man to 
seek his own pleasure only, irrespective of what its 
social reference may be. A man s business is with 
himself alone ; if he satisfies his own desires according 
to his own wishes, he should not give a thought to 
the mischief to other individuals or the State as a 
whole which may result from his selfish satisfaction. 
And the burden of Berkeley s criticism of Mandeville 
is that he simply repeats, in an even more pernicious 
form, the undiluted egoism of Hobbes. 

To Berkeley s criticism Mandeville replied in his 
Letter to Dion. 1 In that tract, which is vigorously 
written, he refuses to acknowledge the view attri 
buted to him by Berkeley, and says that the most 
charitable construction to put upon the travesty 
is that Berkeley had not really read The Fable of the 

Now, it is quite clear that Berkeley understands 
Mandeville s fundamental dictum, " Private Vices 
Public Benefits " otherwise than Mandeville himself. 
As Hutcheson pointed out in his Remarks upon the 
Fable of the Bees, Mandeville s dictum may mean any 
one of these five distinct propositions : " Private 
vices are themselves public benefits," " private vices 
naturally tend, as the direct and necessary means, 
to produce public happiness," " private vices, by 
dexterous management of governors, may be made 

1 " Dion " is the character in Alciphron whom Berkeley makes 
the exponent of his own views. 


to tend to public happiness," " private vices naturally 
and necessarily flow from public happiness," " private 
vices will probably flow from public prosperity, 
through the present corruption of man." The 
version of Mandeville which Berkeley puts into the 
mouth of Lysicles adopts the second of these 
meanings. Lysicles argument is precisely that 
" private vices naturally tend, as the direct and 
necessary means, to produce public happiness." l 
Lysicles is even made to regard vice as a positive 
good, " a fine thing with an ugly name." Now 
Mandeville himself both in the Fable of the Bees and 
in the Letter to Dion insists that while private vices 
are inseparable from the material greatness of a 
society, it does not follow that vice is a good. 
" Vice," he says, " is always bad, whatever benefits 
we may receive from it." 2 And he definitely gives 
his imprimatur to the third of Hutcheson s suggested 
meanings. He means that " private vices, by the 
dexterous management of a skilful politician, might 
be turned into public benefits." 3 Hence a good 
deal of Berkeley s criticism, directed against a 
different interpretation of Mandeville, is simply an 
ignoratio elenchi. 

Even less satisfactory is the criticism of Shaftes- 
bury which Berkeley offers in the third dialogue of 
Alciphron. The theory which the character Alci- 
phron is made to defend, and which is attributed to 
Shaftesbury, is a maimed and decrepit version of 
what Shaftesbury really meant. In dealing with 
Shaftesbury, his mind, usually so acute and incisive, 
seems to have lost its cutting edge. He is able 

1 Alciphron, ii. 71-74. 2 Letter to Dion, p. 34. 3 Ibid. p. 36. 


neither to appreciate the value of Shaftesbury s 
views, nor to indicate clearly the grounds of his 
objection to them. No one, in fact, who has written 
about Shaftesbury has written to less purpose than 
Berkeley. He seems to see that Shaftesbury s 
analogy between physical beauty and moral goodness 
is not altogether adequate, but he does not seem to 
see why it is not. He objects that the moral sense 
is not capable of supplying a satisfactory criterion 
of right and wrong, but he does not seem to see why 
it cannot. He attacks Shaftesbury s doctrine of the 
disinterestedness of virtue on grounds that are 
entirely unworthy of a moral philosopher. All in 
all, his attitude to Shaftesbury, as we see it in 
Alciphron, is that of the man whose prejudices make 
him incapable of appreciating whatever truth may 
exist in the opinions of those with whom he does not 
see eye to eye. 

Berkeley s attitude to both Mandeville and Shaftes 
bury is, as we have seen, distinctly hostile. With 
the ethical theory of Butler, on the other hand, his 
own view is in close sympathy. But it is significant 
of Berkeley s methods that the author of the doctrine 
to which his own bears at many points such a striking 
resemblance is not once mentioned in his works. 

The similarities in the views of the two contem 
porary philosopher-bishops, taken in their cumulative 
effect, are so notable as to suggest the possibility that 
one was directly influenced by the other. But such 
a suspicion is really gratuitous. It is, indeed, barely 
possible, so far as the dates of publication of their 
works are concerned, that each was in some measure 
indebted to the other. Butler s Sermons was first 


published in 1726, while Berkeley s Passive Obedience 
appeared in 1712, and Alciphron in 1732. But there 
is no real internal evidence that Passive Obedience 
influenced the Sermons or the Sermons, Alciphron. 
The resemblance may be sufficiently accounted for 
by their philosophical environment. They shared 
a common antipathy to Hobbes, and they adopted 
a similar attitude towards the tendencies of ethical 
thought represented on the one hand by the so-called 
Cambridge Platonists, and on the other by such 
" men of the world " as Mandeville and Shaftesbury. 
To Hobbism they were both fundamentally opposed, 
though both were perhaps influenced by the Hobbist 
doctrine that moral rules are natural laws. From 
the Cambridge Platonists both learned something 
the immutability of moral laws and the rational 
ground of moral obligation. To Mandeville and 
Shaftesbury they were both opposed, though Butler 
was more willing than Berkeley to admit that there 
was something in what Shaftesbury had to say. 

The result of all this is that, though Butler s moral 
philosophy is more systematically developed than 
Berkeley s, almost every element which has contri 
buted to make Butler s work the greatest product of 
British ethical thought is present in Berkeley s 
scattered remarks. For Berkeley, as for Butler, 
reason is ultimately the basis of moral obligation, 
and happiness constitutes the summum bonum. In 
the view of both, moral principles are also laws of 
nature, and action in accordance with nature leads 
to the attainment of the moral ideal, for nature is a 
divinely organised system of ends. Both emphasise, 
in language strangely similar, the moral importance 


of the disposition to social life existing in mankind ; 
and both are animated by the same principles of 
practical social idealism. Only in their view of the 
relation of the " principles of human nature " do they 
diverge. Or it would be truer to say that, while 
Butler s chief originality lies in his moral psychology, 
Berkeley has almost entirely omitted to make any 
psychological analysis of moral experience. 

When we remember the originality of Berkeley s 
metaphysics, it may seem strange that, when all is 
said, his writings on ethics make so small a contri 
bution to that branch of philosophy. But we should 
bear in mind that we have only fragments of 
Berkeley s thought on ethical problems. What 
should we think of his metaphysics, if the Principles 
and the Three Dialogues had been lost ? It might 
be argued that if Berkeley s specifically ethical 
treatise had been preserved, it might have paved the 
way for as great an advance in ethics as his syste 
matic works do in metaphysics. One thing at least 
may be said with certainty. It is clear from the 
scattered remarks which we do have that Berkeley s 
work on ethics would have shown the same two 
characteristics as assured his success in his meta 
physical ventures. As Earl Balfour has pointed out, 
two qualities are essential to the philosopher who is 
going to carry forward his study. He must have 
philosophical aptitude, and be mentally capable of 
speculation on the ultimate problems of life and 
knowledge. But in addition he must possess the 
peculiar gift of being able to locate the exact point 
at which the next philosophical forward movement 
can best be made. It was for want of this special 


acumen that Clarke and Malebranche, in spite of 
their speculative ability, were left in a philosophical 
backwater. But Berkeley had the faculty of noticing 
just where the next advance could best be made. 
Hence his position in the main current of English 

It is evident that he did not at first perceive the 
exact point in ethics at which the next forward 
step could be taken. The reason for this is 
that the main line of ethical thought did not pass 
through Locke. Berkeley s intuition was not at 
fault in believing that the main line of metaphysical 
progress lay through Locke ; and he was able to do 
his own good work by putting his finger unerringly 
on the spot from which that advance might best 
originate. His initial mistake in ethics lay in 
thinking that progress might be made in that 
department of philosophy also by observing and 
correcting Locke s suggestions towards a mathe 
matical system of ethics. But he soon perceived 
that the path marked out by Locke led into a cul-de- 
sac ; and he therefore abandoned the attempt to 
construct a mathematical system of ethics. In his 
later ethical work, as we have seen, he does make 
suggestions which place him right in the centre of 
the line of ethical advance in England. That line 
led through Hume to Utilitarianism. Berkeley 
believes, as we have seen, that the summum bonum 
is not private pleasure, but the happiness and general 
good of all. And he draws a sharp distinction 
between the different kinds of pleasure. He did 
not appreciate the problems v/hich Utilitarianism 
has to face ; and it is an anachronism to style him, 


as Campbell Eraser does, a Theological Utilitarian. 1 
But he was moving in that direction, and if he had 
given to the question the thought necessary to 
produce a systematic work, he might well have been 
the first Utilitarian. 

1 Life and Letters of Berkeley, p. 49. 



BERKELEY himself did not recognise the philosophy 
of religion as a separate branch of philosophy ; and 
it might therefore seem that we have no right to 
devote a chapter to it. But it should be remembered 
that, in the whole course of his works, he makes 
practically no attempt to introduce distinctions 
between the different branches of philosophy, or to 
classify them in any way : he does not even dis 
tinguish metaphysics from theory of knowledge or 
from psychology, for in his eyes all speculation of an 
interpretative and critical kind is alike philosophy, 
irrespective of the particular subject-matter with 
which it happens to deal. His disinclination to 
distinguish the various branches of philosophy was 
probably due, not to any congenital affection for 
blurred outlines or indistinct margins (for his mind 
was naturally clear, sincere, and anti-obscurantist), 
but partly to his antipathy to the artificial and 
superfluous distinctions introduced by the Schoolmen 
for whom he had little love, and partly to the fact 
that the New Philosophy had hardly yet begun to 
admit that our knowledge of the human under 
standing might conceivably make greater progress, 



if it were recognised that within the one body of 
philosophy are comprised different disciplines, having 
each a characteristic aim and subject-matter. But 
for the purposes of exposition and criticism, it is 
convenient to deal with Berkeley s views under such 
rubrics as Psychology, Metaphysics, and Ethics ; 
and if that is permissible, there would seem to be no 
reason why the chapter in which we gather together 
what he has to say on the problems of religion should 
not be called " The Philosophy of Religion." 

Yet it cannot be denied that there is an argument 
against the use of the term Philosophy of Religion 
which does not hold in the other cases. Although 
Berkeley himself was not concerned to distinguish 
such branches of philosophy as psychology and 
metaphysics from one another, no anachronism is 
involved in ascribing them to him, for they had been 
distinguished before his time. But in strictness it is 
an anachronism to speak of Berkeley s philosophy 
of religion. For the discipline which we commonly 
call by that name, dealing as it does with the critical 
examination and interpretation of actual religious 
experience, differs from what has been traditionally 
known as theology ; and it did not really originate 
till the time of Kant. Both the term and the 
discipline were suggested by Kant, and under his 
influence the study has assumed from the beginning 
the subjective tinge with which he coloured all 
philosophy. Kant enumerated the problems of 
philosophy in a way that was at least apparently 
subjective ; and, regarding religion as the subject- 
matter of the third and final department of pure 
philosophy, he enunciated its problem not as What 


is God ? (that may be the problem of theology), but 
What may I hope ? The questions of which the 
religious philosopher treats are not abstract and 
independent of the religious subject : they depend 
on the human consciousness with all its interests and 
needs, all its hopes and fears, all its emotions and 

While, then, it is impossible to deny that, as the 
philosophy of religion was first developed by German 
post-Kantian Idealism, it is strictly an anachronism 
to attribute the discipline to Berkeley, yet in his 
treatment of the problems of religion there is so 
notable an approximation to the standpoint and 
attitude characteristic of the philosophy of religion 
that the chronological inaccuracy seems pardon 
able. Many of the features of the philosophy of 
religion are anticipated by Berkeley. Thus he insists 
that the study of religion must not merely describe 
the contents of sacred writings, and recapitulate the 
dogmas of theology, but should also exercise its in 
terpretative and critical functions on the actual facts 
of religious experience ; and in the strongest terms 
he emphasises that its conclusions must be judged 
at the bar of human reason, and that its solutions 
must satisfy human needs and aspirations. 

The philosophical attitude which Berkeley adopted 
towards the problems of religion was determined 
very largely by the deist controversy that was 
raging when he was beginning to think. It is not 
very easy to decide whether or not this circumstance 
was favourable to the development of Berkeley s 
philosophy of religion. 

That his views would have been stated very much 


more clearly and systematically if he had not been 
involved in so much discussion and dispute admits 
of no question whatever. His earlier works, e.g. the 
Principles and Three Dialogues, in which there is 
hardly any controversy except with imaginary 
disputants, are clearer and more systematic than 
Alciphron, in which his views on religion are chiefly 
contained. But while it is universally admitted that 
for style and literary craftsmanship Alciphron is the 
finest thing he ever wrote, it is rarely read to-day, 
partly because the controversy to which it is a 
contribution now excites hardly any interest, and 
partly because it is rather difficult to sift his views 
from those which he criticises, and so to obtain from 
the book, in spite of its elegance and clarity of 
diction, any clear-cut conception of what, in the last 
resort, Berkeley s own theory of religion really is. 
The possible extent of Berkeley s achievements may 
be gauged by what Butler, a man of less philosophical 
acumen and literary skill, succeeded in accom 
plishing. Butler, writing at the same time as 
Berkeley, avoided entering into details in connection 
with the controversy, and produced, in the Analogy 
of Religion, a work of permanent value. Almost 
certainly, if Berkeley had been able to keep his hands 
free of the deist controversy, he would have produced 
more ultimately valuable work in the theory of re 
ligion than he did. 

For Berkeley, like Butler, possessed in a marked 
degree the qualities essential to the writer on the 
philosophy of religion. 

(i) In the first place, they are both convinced of 
the fundamental importance of religion. Very 


different views are possible as to the meaning and 
value of religious experience. But Berkeley believes 
that there can be no diversity of opinion on the 
question of the importance of the part played by 
religion in human history. All may admit that 
religion has in the past filled a notable role in human 
experience. But it may be held that the day of 
religion is past, and that if religion were now utterly 
to disappear no real value-for-life would be lost to 
the world. As against any such supposition as this, 
it was the intense conviction of Berkeley that the 
extinction of religion is either an unthinkable im 
possibility, or, if it were possible, it would be a 
universal disaster from which humanity would never 

(ii) But the mere appreciation of the importance 
of the role which religion has played in human 
history is not enough to constitute the philosopher 
of religion. He must also himself enjoy and value 
religious experience. This is clearly a different 
matter. A man may be impressed with the import 
ance of religious experience, and yet be incapable of 
it himself, just as he may agree that aesthetic 
experience is of great value, though he himself is 
incapable of appreciating it. It is essential that the 
philosopher of religion should not only be convinced 
of the general importance of religion, but should also 
himself know by immediate and personal experience 
what religion is. Now the whole career of Berkeley, 
especially after his twenty-fifth year, shows that more 
perhaps than any of his contemporaries he was a 
man in whose life religion exerted a commanding 
influence. Renan s well-known remark that the best 


historian of religion is the man who has once believed 
in it, but no longer does so, has little application to 
the philosophy of religion. 

(iii) But, even for the philosopher of religion, there 
is a grain of truth in Kenan s saying. For the 
philosopher of religion must constantly be on his 
guard against parti pris. He must, indeed, be 
impressed with the general importance of religion, 
and must know by personal experience what religion 
is ; but he must not be so interested in some one 
type of religion as to be incapable of dealing im 
partially with religion as a whole. To a certain 
degree, Berkeley possessed this quality also. He 
showed himself able to treat with impartiality 
members of other communions than his own. He 
certainly believed that they erred, the Roman 
Catholics through excess of superstition, the dis 
senters through excess of enthusiasm ; but he was 
inclined to look upon these errors, and especially the 
latter, with indulgence. 1 Berkeley was certainly not 
a bigoted Churchman. But he was a bigoted 
Christian, and he had not the slightest sympathy 
with the free-thinkers. This dulled his mind in the 

1 One or two examples of this may be mentioned. In Rhode 
Island he did his best to placate the dissenters, and in preaching 
at Newport he " treated only those general points agreed by all 
Christians " (Letter to Percival, Aug. 30, 1729). He also advised 
the missionaries of the Society for the Propagation of the Gospel 
to try to conciliate the nonconformists in Rhode Island (Works, 
iv. 370). And he gave his house in Rhode Island to the 
" College at New Haven," now Yale University, for the provision 
of scholarships to be awarded irrespective of denominational 
considerations. Berkeley s attitude to Roman Catholicism is 
rather more complex. But it is certainly not bigoted. See 
A Word to the Wise, iv. 541, and the Letter to Sir John James, 
iv, 519, 


deist controversy, and rendered him incapable of 
appreciating some of the points which they tried to 
make. In respect of this quality of impartiality 
Berkeley certainly suffers by comparison with the 
calm, impartial, and judicial Butler. 

(iv) But one obvious quality of the philosopher 
of religion still remains to be mentioned. He must 
be able to philosophise, and he must believe in the 
possibility of a philosophical interpretation and 
formulation of religion. With regard to the former 
point, it would be impertinent to say anything of 
Berkeley, naturally the keenest mind in the history 
of English philosophy. And the latter half of the 
qualification is also possessed by Berkeley ; he 
believed that a rational formulation of religious 
truth is perfectly attainable. 

On all these grounds, then, it is clear that Berkeley 
was well qualified to write on the philosophy of 
religion ; and in the circumstances in which he lived 
it is not strange that his philosophical activity was 
not only influenced by the deist controversy, but 
was almost dominated by it. For in his religious 
views, as in all else, Berkeley was very much the child 
of his time. It would, indeed, be difficult to name a 
thinker who was more influenced by contemporary 
life and thought than he was. And it is natural that 
the religious tendencies of the day should have 
exercised an especially profound influence upon 
him. For religion, more than any other fruit of 
the spirit, draws its substance from the soil in 
which it grows. 

In order to understand the progress of the deist 
controversy, and the place which Berkeley took in it, 


it is necessary to uncover its roots in the latitudi- 
narianism of the Church of England. 

In the late seventeenth and early eighteenth 
centuries the moderation and toleration of the 
Church of England were specially marked, and 
it came to be officially held that the standard of 
the truth of religion is not the authority of the Church 
nor the authority of Scripture, but natural reason, 
which is common to all men. 

This view was emphasised and popularised by 
two prominent Anglican divines, Chillingworth * 
and Tillotson, both of whom asserted in the most 
uncompromising terms the prerogative of reason 
to investigate and determine the truth of religious 
experience. " Nothing," says the latter, " ought to 
be received as a revelation from God, which plainly 
contradicts the principles of natural religion." " And 
nothing," he adds, " ought to be received as a divine 
doctrine or revelation, without good proof that it is 
so." 2 Tillotson claimed the right of examining 
religious experience rationally, whether it purported 
to be guaranteed by Scripture or immediate experi 
ence. Towards the end of the seventeenth century 
the English theologians were all bent on constructing 
a rational or philosophical system of religion. The 
Cambridge Platonists rationalised and allegorised 
with a view to the interpretation of the true universal 
meaning of religious beliefs as actually experienced. 

1 Berkeley had a high opinion of Chillingworth. (Cf. Letter to 
Johnson, March 24, 1730.) 

2 Tillotson s Sermons, i. 225, quoted in Leslie Stephen s English 
Thought in the Eighteenth Century, i. 78. This paragraph and 
the next owe much to this book and to Lechler s Geschichte des 
Englischen Deismus. 


And other theologians tried to formulate theoretical 
proofs of such religious fundamentals as the existence 
of God and the immortality of the soul. 

Such was the religious position in the English 
Church when Berkeley was born. But before he 
reached manhood the rationalising tendencies of the 
Church were being developed and turned against 
Christianity. The consequent growth of scepticism 
in one way advanced, and in another retarded, the 
progress of a genuine philosophy of religion. It 
certainly gave rise to a keener and more extensive 
examination of the basis of religion than would 
otherwise have been the case. On the other hand, 
a philosophy of religion requires for its development 
an atmosphere free of controversy and parti pris ; 
and the heated disputes which raged for the next 
fifty years, though they stimulated interest in re 
ligion, undoubtedly had an unfortunate effect on its 
philosophical interpretation. 

The germs of scepticism had thus been sown 
within the Church long before the deist controversy 
actually broke out ; and it did not escape the leading 
deists that their views had nearly all been suggested 
by professedly orthodox Churchmen. Collins, for 
example, declared that nobody doubted the existence 
of God till the Boyle lecturers undertook to demon 
strate it, and he referred to Tillotson as the man 
" whom all English free-thinkers own as their head." 
The men who actually started the controversy 
and the immediate questions which they raised 
were alike mean and small. Although the greatest 
problems were involved, hardly any question of the 
first importance was explicitly raised at first. The 


disputants on both sides engaged in tremendous 
battles over matters which to us now seem of very 
little consequence. But more was at stake than 
appeared on the surface, or even than the combatants 
themselves were aware of. The free-thinkers them 
selves made no contribution at all to the philosophy 
of religion, but their activity forced the defenders of 
Christianity to bestir themselves to formulate a 
systematic rationale of religion. 

The deists may, indeed, be regarded as the 
Sophists of the philosophy of religion. As the 
Sophists deserve credit for compelling by their doubts 
and denials the formulation of a more adequate 
philosophy of knowledge and conduct, the deists by 
their scepticism forced the orthodox to examine and 
re-interpret the facts of religion which were being 
so openly and so vigorously questioned. Thus the 
existence of the deist controversy and the emergence 
of a philosophy of religion in England in the eighteenth 
century were complementary and closely-related 
facts, and it is interesting to note that as the free- 
thinking conflagration died down the philosophical 
study of religion languished. 

We must now proceed to indicate in some detail 
Berkeley s attitude to the deist controversy, whose 
genesis we have just sketched. 

Berkeley early adopted towards all free-thinkers 
a position of uncompromising hostility. This 
critical attitude was never abandoned, and it is 
revealed in some form or other in almost everything 
he wrote. 

In the Commonplace Boole (1705-8) the free 
thinkers come in for much criticism ; and the New 


Theory of Vision (1709), while not ostensibly directed 
against scepticism, was certainly regarded by its 
author as a useful weapon with which to attack it. 1 
The Principles (1710) has as one of its chief objects 
an enquiry into " the grounds of scepticism, atheism, 
and ir religion " ; and the Three Dialogues (1713) 
brings the practical religious aim into even greater 
prominence, stating on the title-page that its design 
is " plainly to demonstrate the reality and perfection 
of human knowledge, the incorporeal nature of the 
soul, and the immediate providence of a deity, in 
opposition to sceptics and atheists." In the same 
year he entered the lists in a more popular way with 
the essays which he contributed to the Guardian. 
The first of these is a review of Collins s Discourse of 
Free-thinking, which had been published early that 
year ; and nearly all the others are written in 
criticism of deism and in defence of Christianity. 
After 1713 a period of twenty years of almost 
complete literary barrenness elapsed, 2 during which 
he was occupied in travel and in endeavours to stamp 
out practical atheism, but when in 1732 he again 
appeared in print it was once more to attack his old 

1 The application to religion is made explicit in the Theory of 
Vision Vindicated (1733). With regard to the New Theory of 
Vision Berkeley writes to Percival as follows : (March 1, 1710.) 
" In a little time I hope to make what is there laid down appear 
subservient to the ends of morality and religion in a treatise 
I have now in the press [The Principles ], the design of which is, ... 
by showing the emptiness and falseness of several parts of the 
speculative sciences, to reduce men to the study of religion and 
things useful." 

2 Berkeley s only publications in the twenty years from 1713 
till 1732 were the small tracts De Motu (1721), An Essay towards 
preventing the Ruin of Great Britain (1721), and A Proposal for 
the better supplying of Churches in our Foreign Plantations (1725). 


enemies. The book that was published in that year 
was Alciphron, his most careful and most pretentious 
work, which is described not inadequately on the 
title-page as "an apology for the Christian Religion 
against those who are called free-thinkers." It was 
directed chiefly against Collins, Mandeville, and 
Shaftesbury, and gave rise to a good deal of con 
troversy. Mandeville produced his Letter to Dion, 
in which he complained of misrepresentation, Browne 
defended his theory of analogical knowledge in 
Divine Analogy, and one or two other criticisms 
appeared. All were ignored by Berkeley except an 
anonymous letter printed in the Daily Post-boy of 
September 9, 1732, which he thought important 
enough to answer in the Theory of Vision Vindicated 
(1733). And he continued to attack various aspects 
of free-thinking in the Analyst ("A Discourse 
Addressed to an Infidel Mathematician," 1734), A 
Defence of Free-thinking in Mathematics (1735), and 
A Discourse Addressed to Magistrates and Men in 
Authority (1736). Last of all, in Siris (1744) his 
work reached its culmination in the attempt to give, 
for the final confusion of sceptics, a perfectly adequate 
philosophical interpretation of religion and things 
in general. In every one of these works Berkeley 
had in view the refutation of the deists. 

It has not been noticed, so far as I am aware, that 
the most remarkable thing about Berkeley s partici 
pation in the deist controversy is just the fact that 
he did take part in it against the deists. Berkeley 
early developed, as we have seen, a precocious hetero 
doxy in philosophy, and it is not without interest 
that this heterodoxy did not, ostensibly at least, 


extend to religion. And it seems worth while, at the 
cost of a slight digression, to make clear Berkeley s 
motives in adopting his critical attitude to the deists. 
His mind was naturally sceptical, and he always 
refused to rest content with anything less than 
experimental evidence. One or two amusing anec 
dotes of his student-days illustrate his aversion to 
taking anything on trust. 1 And in philosophy his 
regular line of argument is, Do not believe anything 
which you cannot prove for yourself. Refuse to 
believe in abstract ideas simply because authoritative 
philosophers proclaim their existence. Try yourself 
if you can frame an abstract idea, and if you cannot, 
do not believe in the doctrine. Now, if this attitude 
be applied to religion, it becomes that of the typical 
free-thinker. Berkeley tells us himself that he " was 
distrustful at eight years old ; and consequently by 
nature disposed for these new doctrines." 2 He is 
referring here to philosophy ; but if a man is by 
nature disposed for new doctrines in philosophy, it 
seems strange that he should not be similarly disposed 
for new doctrines in religion. Berkeley was a free 
thinker in philosophy and mathematics, but he did 
not extend his free-thinking to religion. Why this 
distinction ? 

At one time he was inclined to draw an absolute 
distinction between philosophy and religion, between 
reason and revelation. Revealed religion is the 
preserve of implicit faith, and therefore reason with 
its brood of doubts has no right to trespass upon it. 
When I say," he writes, " I will reject all proposi 
tions wherein I know not fully and adequately and 
1 Life and Letters, p. 22. - Commonplace Book, i. 79. 


clearly, so far as knowable, the thing meant thereby, 
this is not to be extended to propositions in the 
Scripture. I speak of matters of Reason and 
Philosophy not Revelation. In this I think an 
humble, implicit faith becomes us (when we cannot 
comprehend or understand the proposition), such as 
a popish peasant gives to propositions he hears at 
mass in Latin." x This view Berkeley later aban 
doned : the important point about the passage is its 
emphasis, which shows, of course, that he did have 
doubts in religion, and that he came to the deliberate 
conclusion that it was necessary to suppress them. 
What motives can he have had for stifling the 
enquiries of his spirit in religion ? 

(1) Shrewd enough in practical matters, Berkeley 
saw that it would not be to his interest to incur any 
suspicion of " infidelity." Preferment, both academic 
and ecclesiastical, depended on his orthodoxy ; and 
therefore orthodox he was. There is some evidence 
that such motives may have induced him to suppress 
his doubts in religion. 

Thus he says vigorously in the Commonplace Book 
" I d never blame a man for acting upon interest. 
He s a fool that acts on any other principles." 2 He 
knew well that his interest demanded perfect con 
formity to the Church, and accordingly he makes the 
following memorandum : " N.B. To use utmost 
caution not to give the least handle of offence to the 
Church or Churchmen." 3 This certainly seems to 
show that he had reached the deliberate decision not 
to annoy the Church, in order to avoid the possibility 
of prejudice to his own chance of advancement. He 

1 Commonplace Book, i. 42. 2 i. 24. 3 i. 41. 


always took pains to put his views in such a way 
that they would " go down with " people ; 1 and 
when he was developing his philosophical principles 
he was scrupulously careful not to bring them into 
conflict, at any point, with the dogmas of the 
Church. 2 It is perfectly clear that, at least previous 
to the Bermuda project, he had an eye to what he 
himself calls " the main chance." He was very 
eager for ecclesiastical preferment, and lost no chance 

1 Commonplace Book, i. 69. Cf. i. 92. 

2 When he is writing the Commonplace Book the arriere pensee 
of religion is constantly at the back of his mind. He is careful 
to see whether his New Principle is consistent with the dogmas 
of the Church, e.g. the Creation and the Trinity (pp. 62, 86, 10, 42). 
He sees that there is difficulty in applying his view to the Trinity ; 
but contents himself with the observation that the danger to the 
Trinity is as great on the materialist doctrine, concluding that, 
though on some points of revealed theology demonstrative know 
ledge is possible, " to pretend to demonstrate or reason anything 
about the Trinity is absurd. Here an implicit faith becomes 
us " (pp. 28, 84). (It is interesting to remember that the denial 
of the Trinity was at this time a punishable offence. Only six 
or seven years before Berkeley made these entries in 1699, to be 
exact a statute of King William decreed that the punishment 
for denying the Trinity should be (for the first offence) incapacity 
to hold any office of trust, and (for the second) three years 
imprisonment with other penalties. This Act relaxed the law 
that was previously in force. In 1696 a man was hanged for 
denying the Trinity.) But Berkeley is anxious not merely to 
show that his views are consistent with the dogmas of the Church, 
but also to prove that they confirm these doctrines. If the New 
Principle be adopted, he says, the immortality of the soul may be 
easily understood and defended (p. 59), and it is possible to give 
a brief and direct demonstration of the existence of God (p. 60). 
He argues that many of the theories of Locke are dangerous to 
religion, in particular the doctrine of the eternity and infinity 
of space, which would either make God extended, or set up, in 
addition to God, a second eternal infinite being (pp. 39, 81, 82). 
And, in general, he regards Locke and his followers as the patrons 
of scepticism, and virtually sets himself up as a " simple Christian" 
in opposition to these " higher critics." 


of improving his prospects by soliciting the favour 
of those in power. 1 

1 As the view of Berkeley s motives and character which has 
just been suggested is very different from the traditional one, it 
is necessary to confirm it. The evidence on which we draw is 
almost all contained in the collection of letters between Berkeley 
and Percival (Berkeley and Percival, edited by B. Rand). 

Berkeley s prospects of ecclesiastical preferment were at first 
seriously affected by the suspicion that he was a Jacobite. This 
was based on the sermons which he preached in the College Chapel, 
and though he attempted to dissipate it by publishing a rechauffe 
of them in the Discourse on Passive Obedience, he did not succeed 
in dispelling the cloud under which he rested. In 1716 he was 
presented to the Prince and Princess of Wales by Molyneux, and 
the Prince recommended him to the living of St. Paul s, Dublin. 
But the authorities still believed that he was disaffected, and, 
though his friends did all they could for him, he and they were 
unable to secure his advancement. Before the end of the year 
Berkeley left for Italy. 

In 1721 he was again in Dublin, as eager as before for ecclesi 
astical preferment. He wrote to Percival, afterwards first Earl 
of Egmont, informing him that the Deanery of Dromore was 
vacant, and begging him to use his influence on his behalf. 
" I had no sooner set foot on shore," he says in the letter of 
October 12, 1721, " but I heard that the Deanery of Dromore was 
become vacant. ... I instantly applied to His Grace, and put 
him in mind of his promises." He also mentions that he had 
written in the matter to the Earl of Burlington, and had sought 
the favour of the Duchess of Grafton and of Fairfax, who, he 
thotight, were both well-disposed to him. The letter of January 
9, 1722, reveals something of his remarkable persistence in seeking 
his own advancement. 

As the result of this, the Deanery was granted to him ; but the 
right of appointment was claimed by Lambert, Bishop of Dro 
more, who nominated Lesley, his clerk. In the lawsuit which 
ensued Berkeley spared no pains in his efforts to win the case, 
employing eight lawyers and using all the influence he could bring 
to bear. In order to help him to meet the expenses of the suit, 
he asked Percival to try to get for him the Chantership of Christ 
Church, which happened to be vacant at the time. Percival did 
his best, but the Duke of Grafton would not hear of giving it to 
Berkeley, even for the duration of the suit. Berkeley s next 
letters are all concerned with the lawsuit, which progressed very 
slowly, and made him very impatient of lawyers and the world 
in general. He was annoyed, too, he says, that it detained him 


Now, he was aware that it was an essential con 
dition of his success in the Church that he should 
either keep clear of the deist controversy altogether, 
or, preferably, adopt a hostile attitude towards free- 
thinking. Now, there is one thing that Berkeley 
never did. He never " hedged " in any matter, 
either speculative or practical. Thus it was 

in Ireland, and prevented his prosecuting his interest in England. 
He began to despair of success, and devised an ingenious scheme 
for securing the deanery without fighting the case to the bitter 
end. According to this plan, Lesley was to be made a bishop. 
If that were done, the Bishop of Dromore would probably not 
press his right to appoint to the deanery, and Berkeley s entry 
would accordingly be unopposed. But as the scheme did not 
meet with the approval of those in power Berkeley was forced to 
abandon the hope it offered of attaining his end. In October, 
however, he wrote to Percival to suggest a new solution of the 

The Dean of Derry was seriously ill, and Berkeley thought that, 
if the proper means were used, he might obtain that deanery on 
the death of the dean. Percival thought the suggestion a good 
one, and expressed his best wishes ; but as he was not willing to 
interview the Lord Lieutenant on Berkeley s behalf, this project 
also had to be laid aside. Meanwhile the deanery of Down had 
become vacant, and again Berkeley was an applicant. Again he 
was doomed to disappointment. But at last, on May 5, 1724, 
he was able to tell Percival that he had received the deanery of 
Derry. The lawsuit with regard to the deanery of Dromore was 
still dragging on, and Berkeley was thoroughly glad to be rid of 
it, though so long as his interest demanded, he carried it on with 
remarkable persistence. 

So far, Berkeley seems to have been a decidedly calculating 
man, with a fixed determination to do the best he could for him 
self. But suddenly, in 1723, he intimated to Percival his 
dramatic decision to go as a missionary to the New World. And 
thenceforth his motto was non sibi sed toti mundo. (For his 
motives in this project, see Berkeley and Percival, pp. 203-236 ; 
his " Essay towards preventing the Ruin of Great Britain," 
Works, iv. 319; his "Proposal for the better supplying of 
Churches in our Foreign Plantations," Works, iv. 341 ; and 
my review of Berkeley and Percival in Mind, N.S. no. 94, p. 


necessary for him, under the circumstances, to be 
uncompromisingly opposed to free-thinking. 

(2) The second reason for Berkeley s active inter 
vention in opposition to the free-thinkers is more 
problematical. Possibly he criticised deism because 
it was popular and because it was easy to criticise. 
The man who wished to attract attention (and it is 
indubitable that inter alia this was Berkeley s 
intention) could not do better than take part in the 
controversies to which free-thinking had given rise. 
" The dissection of a deist was a recognised title to 
obtaining preferment." x Now, Berkeley saw very 
clearly the weak points in the arguments of such men 
as Toland and Collins. He perceived that it would 
be relatively easy to establish a position from which 
they might be criticised. It needed a great deal less 
acuteness than he possessed to recognise that they 
are essentially dull and ineffective. None of the 
English deists have the wit and incisiveness of 
Voltaire, and they do not make nearly as much of 
their case as really penetrating critics would have 
done. To criticise the deists was thus a relatively 
easy task, and one, moreover, from which a good deal 
of credit might be expected. 2 

1 Leslie Stephen, English Thought in the Eighteenth Century, 
i. 86. 

2 Berkeley s general philosophical attitude is so similar to that 
of the deists that it is difficult to avoid believing (though the 
supposition does not admit of serious argument) that he may have 
been seriously tempted during his student-days to throw in his 
lot with them. Had he done so, he would certainly have been 
much more formidable than any of them. To the deists his acute 
dialectic and subtle satire would have been invaluable weapons. 
And he would have enjoyed himself hugely if he had been in a 
position to bait Clarke and Whiston, Browne and King, and the 
.other prominejit hepl9.gians of the day, not on philosophical 


That such considerations as these may have 
contributed to the formation of Berkeley s attitude 
to deism will, no doubt, appear startling to those 
who have been accustomed to picture an angelic 
Berkeley so transparently disinterested as to win the 
support of State and Church for his impracticable 
and Utopian missionary scheme, and so wonderfully 
good that Pope ascribed to him every virtue under 
heaven. 1 No one, of course, would dream of denying 
the real strain of deep piety in Berkeley s character, 
and there is no doubt that that supplies one motive 
for his opposition to deism. But it has seemed 
necessary to insist that it is not the only one. 

In any case, whether for the reasons we have 
mentioned or not, Berkeley decided to range himself 
against the free-thinkers ; and nearly all his books, 
as we have seen, have them in view. 

In the mass of Berkeley s controversial writings 
on deism there is naturally a good deal of repetition ; 
and his contribution to the philosophy of religion 

points where, since few took any interest in obscure metaphysics, 
these men might safely refuse to answer him, but on the funda 
mentals of Christianity, where they would be bound, for the sake 
of the Church, to reply to his attacks. 

And, if one may carry the merest speculation a step further, 
it seems not improbable that, if Toland had never lived, Berkeley 
might have been the leader of free -thinking in the eighteenth 
century. For Toland s personality may have had something to 
do with Berkeley s aversion from the cause of which he was the 
early leader. The polished scholar in Berkeley had an intuitive 
antipathy to such a literary swashbuckler as Toland, and possibly 
this natural incompatibility may have had a good deal to do with 
his opposition to the deists. But Berkeley s incjenium was 
naturally sceptical, and he can hardly have avoided seeing how 
easy it would have been to apply his theory to criticise not free- 
thinking but Christianity. 

1 Epilogue to the Satires, ii. 70. 


may best be estimated, if we consider first his 
attitude to the immediate questions raised by the 
deists, and then proceed to state his general views 
on the universal problems of religion. 

The main contention of the deists was simply 
an extension of the argument of Chilling worth, 
Tillotson, and Locke. Locke and the theologians 
endeavoured to found a " reasonable Christianity " 
by welding into a system those beliefs in which both 
reason and Christianity agree. The deists went 
further, and maintained that, as Christianity is only 
a particular religion, it is necessary, in order to 
establish an ultimately credible natural religion, to 
find those beliefs in which reason and religion-in- 
general agree. The deists believed that in this 
process of constructing a true natural religion many 
of the doctrines of Christianity, including all its 
" mysteries," would have to be abandoned. 

Berkeley, Butler, and other Christian apologists 
met this contention by attempting to prove that 
every religious belief conformable to reason is a 
Christian belief. Berkeley accepted the deists 
premiss that religion is wider than Christianity, but 
he pointed out that religion includes both reasonable 
beliefs and fantastic superstitions. Fantastic super 
stitions, he argued, are to be found, not in Chris 
tianity, but in non-Christian religions ; and religion 
so far forth as it is rational religion may be identified 
with Christianity. Thus the system of beliefs in 
which reason and religion agree is Christianity. 

From the standpoint of the philosophy of religion, 
the importance of the advance made by Berkeley 
beyond the general position of the seventeenth and 


early eighteenth centuries lay in his recognition that 
he was giving a philosophical treatment to religion 
in general, and not merely to Christianity. The 
seventeenth century had contented itself with, at 
the most, a philosophy of the Christian religion ; but 
Berkeley and Butler were forced by the arguments 
of the deists to take account of " natural religion," 
and, though they maintained that this " natural 
religion " adds no truth to Christianity, their real 
significance consists in advancing beyond a mere 
interpretation of Christianity, and attempting a 
genuine philosophy of religion. 

Of all the deists the most important were Toland, 
Tindal, Woolston and Collins. Toland, following 
Locke, maintains that reason is the only foundation 
of certainty. But he goes beyond Locke in holding 
that no beliefs are justifiable unless there are rational 
grounds for them ; l and he restricts the validity of 
the principle of probability to practical matters alone. 
" I banish all hypotheses from my philosophy," 2 
he says, adapting a famous phrase of Newton s ; and 
he declares that probability provides no adequate 
basis for religious beliefs. 

Now, when this theory is applied to Christianity, 
one of two conclusions must result. It follows either 
that Christianity, basing itself on probabilities, is 
false ; or that, because it is true, it must be wholly 
rational and contain no mysteries. The former con 
clusion is almost certainly the one that Toland really 
believed, but the latter is what he professed. The 
ostensible burden of his argument is that Chris 
tianity contains nothing either contrary to reason or 

1 Christianity not Mysterious, p 22. 2 Ibid. p. 15. 


above reason. The so-called Christian mysteries 
involve no ultimate inexplicabilities ; and, if they 
seem mysterious to us, it is only because their 
meaning has not yet been fully revealed, for there is 
nothing ultimately foreign to reason in them. Hence 
there is no such thing as faith, or, if we retain the 
word faith, we should remember that " it is entirely 
built upon ratiocination." 1 

The arguments of Toland were taken up and 
developed by Tindal, who reduced Christianity to a 
body of ethical maxims that had been formulated 
even better by Confucius. Like Toland, he pro 
fessed to be anxious to purge Christianity of its 
mysteries ; and in Christianity as Old as the Creation 
he vigorously attacked the miracles of Christianity, 
finding both in sacred history and theological dogma 
abundant examples of the two Mies noires of the 
age " enthusiasm " and " superstition." 

Beside these arguments we may set, though on a 
much lower level, Woolston s attempts, in his Six 
Discourses, 2 to allegorise the miracles of the Bible. 
When he wrote these tracts, he was almost certainly 
mad. Though he regarded himself as "at bottom 
as sound as a rock," 3 he tried to prove that practi 
cally the whole Bible is " a fraud and a cheat." 
But in spite of his mental alienation, he retained 
enough of his study of Origen to be able to apply, in 
an extreme form, that thinker s method of allegorical 
interpretation to the miracles of the New Testament. 

1 Christianity not Mysterious, p. 127. 

2 These tracts had an immense circulation. Voltaire estimated 
the total sale at 30,000. 

3 Six Discourses, p. 68. 


This series of arguments against the miracles and 
mysteries of Christianity was answered by Berkeley 
in the second and sixth dialogues in Alciphron. With 
an abundance of learning he defends the historical 
accuracy of Scripture, and the rationality of the 
articles of the Christian faith ; and examines care 
fully the difficulties, emphasised by Tindal and 
Woolston, in the form and matter of the Christian 
revelation. So far as this part of the controversy 
is concerned, the progress of Biblical Criticism has 
cut away the ground from under the feet of the 
participants, and it would hardly have even historical 
interest to recount in detail the arguments advanced 
on both sides. 

But Berkeley s general philosophical conclusion 
is still of interest and even of importance. He 
insists that, if we admit that the essence of Chris 
tianity is the same as " natural religion," we must 
not define " natural religion " in so narrow a way 
as to render it unsatisfying to the religious conscious 
ness. The religious consciousness, with its complex 
needs and aspirations, will not rest content with a 
religion which is purged of the miraculous and the 
mysterious. The element of mystery and miracle 
cannot be banished from Christianity without doing 
violence to its spirit. And if it could be expunged 
from religion in general, one of life s spiritual values 
would be destroyed. The ultimate determination of 
what is or is not valuable in religion must be made 
by the religious consciousness. The religious con 
sciousness decides what is and what is not true 
religion, just as the knowing consciousness decides 
what is and what is not true knowledge. And, as the 


esse of the external world is per dpi, the esse of religion 
may be said to be credi. Belief or faith is the 
characteristic attitude of religion, and Berkeley 
insists, against the deists, (a) that faith is necessary 
to religion, and (6) that probable arguments form an 
adequate basis for faith. " Knowledge, I grant, in 
a strict sense, cannot be had without evidence or 
demonstration : but probable arguments are a suffi 
cient ground of faith. Whoever supposed that scien- 
tifical proofs were necessary to make a Christian ? 
Faith alone is required ; and, provided that, in the 
main and upon the whole, men are persuaded, this 
saving faith may consist with some degrees of 
obscurity, scruple, and error." 1 Thus on the 
whole we may say that, while Berkeley s detailed 
arguments are chiefly directed against Tindal and 
Woolston, his general philosophical position is 
intended to be, in the main, a criticism of Toland. 

Now, Toland had also been criticised by Browne, 
who was Provost of Trinity College when Berkeley 
was a student, and was subsequently made a bishop ; 
and it is interesting to note that Berkeley, in develop 
ing his criticism of Toland, came into conflict with 
the arguments which Browne had used in his 
attempt to pulverise the notorious free-thinker. 

At the outset there is a certain similarity between 
the theory of Berkeley and that of his brother - 
bishop. Both maintain that probable arguments 
are sufficient to justify faith ; both admit that, in 
strictness, knowledge of the mysteries of Christianity 
is impossible ; but both believe that we may have 
an " analogical " acquaintance with these mysteries. 

1 Alciphron, ii. 311. 


But though, so far, the two bishops seem to be in 
perfect agreement, a radical difference between them 
soon emerges, 

Browne s reason for maintaining the impossibility 
of real knowledge of God lies in a positivist distrust 
of the knowing-consciousness. Of God s real nature 
and attributes, he says, " we can have no ideas or 
conceptions at all, either in whole or in part, distinct 
or confused, clear or obscure, determinate or inde 
terminate." l " The true nature and manner of all 
the divine operations of goodness is utterly incom 
prehensible." 2 Any knowledge we have of God 
must be analogical, and if God has knowledge of us, 
that also is analogical. Our analogical knowledge is 
below the level of ordinary knowledge, but God s 
analogical knowledge is above that level. 

With any such sceptical distrust of ordinary 
knowledge Berkeley has no sympathy, for he 
believes firmly in the power and adequacy of the 
knowing-consciousness, and cherishes a sturdy con 
viction that knowledge does not fail. 

This general difference of attitude affects the 
meaning which Berkeley and Browne attach to the 
term " analogical." Browne developed his theory 
out of hints in Archbishop King s Sermon on Pre 
destination, 3 in which it was shown that our know 
ledge of God s attributes is merely " metaphorical." 
For the term " metaphorical " Browne substituted 

1 Things Divine and Supernatural, p. 237. 

2 Op. cit. p. 333. Cf. Alciphron, ii. 179. 

3 Berkeley wrote a few words of criticism of this sermon in a 
letter to Percival, March 1, 1710. And it is interesting to note 
that Collins criticised it from the deist standpoint, in a tract 
published in 1710, on precisely the same grounds. 


" analogical," and maintained that we have an 
analogical knowledge of God s attributes. In other 
words, while the wisdom and goodness we attribute 
to God are not the same as the corresponding 
qualities which we ascribe to man, they are very 

This view Berkeley criticised on the ground that 
it involves a fallacy of four terms. He insists that, 
if we ascribe any attributes at all to God, we must 
mean by them essentially the same as we do when we 
apply them to man. " Otherwise," he says, " it is 
evident that every syllogism brought to prove those 
attributes, or, what is the same thing, to prove the 
being of a God, will be found to consist of four terms, 
and consequently can conclude nothing." * For 
himself, he maintains that our knowledge of God, so 
far as it goes, is real ; or, if we say that it is analogical, 
all we mean by that is that such knowledge is not 
perfect or complete. 

Now, it might conceivably be suggested that the 
only difference, after all, between these views is 
that, whereas Browne holds that the goodness we 
attribute to God is like the goodness we attribute 
to man, Berkeley maintains that the goodness we 
attribute to God is very like the goodness we attribute 
to man. In other words, the difference between the 
two theories is merely one of degree. But this 
criticism cannot be upheld. There is more than this 
between Berkeley and Browne. The former em 
phasises the difference by drawing a sharp distinction 
between analogical as meaning (i) metaphorical, 
and (ii) proportional. He denies that we have 

1 Alciphron, ii. 188-189. 


analogical knowledge of God, or that God s know 
ledge is analogical, in the former sense. But he 
admits that, if we restrict " analogical " to its proper 
mathematical sense, such qualities as wisdom and 
knowledge, which per se involve no defect, may be 
analogically predicated of God. Analogy, as used in 
mathematics, i.e. in its strict and proper sense, 
signifies, he says, " a similitude of proportions." 1 
Thus, the goodness of God is analogical in the sense 
that it preserves " a proportion to the infinite nature 
of God." 2 

It must be admitted, I think, that in this case 
Berkeley s application of mathematical conceptions 
is not very successful. It does not help us to know 
God s goodness if we know that it is proportionate 
to his nature, for we do not know his nature. From 
such a proportion it is possible under certain con 
ditions to determine the values of an unknown term, 
but only if one of the terms is already known. If 
we merely start with two unknowns, e.g. God s 
nature and God s goodness, then the supposition 
that there is a proportion between them does not 
enable us to determine either. 

So far, in our account of Berkeley s participation 
in the deist controversy, we have not dealt with the 
most important of all the deists. This is Anthony 
Collins, the friend and disciple of Locke, who touched 
the controversy at more points than any other, and 
had, besides, the additional distinction, from our 
point of view, of attracting Berkeley s most persistent 

He attacked Collins first in the essays against free- 

1 Ibid. ii. 186. 2 Ibid. ii. 187. 


thinking in the Guardian, the first of which purports 
to be a criticism of Collins Discourse of Free-thinking. 
It is really an argumentum ad hominem of the most 
shameless kind : 1 in general, in the Guardian, 
Berkeley simply rules the contentions of the deists 
out of court on the ground that, in spite of all their 
pretensions to breadth of mind and largeness of 
outlook, they are really the narrowest of men, veri 
table " minute philosophers " ; and he compares the 
free-thinker to a fly on the pillar of a great cathedral, 
so engrossed with the slight inequalities on the 
surface of the stone as to be incapable of appreciating 
the beauty of the building as a whole. 2 

Shortly after the appearance of these critical 
essays in the Guardian, Collins published his Enquiry 
concerning Human Liberty, which gave rise to a 
heated controversy with Clarke, and is criticised by 
Berkeley in Alciphron. Berkeley s motive in main 
taining, in opposition to Collins, that man is free, is, 
of course, a religious one. To defend the reality and 
value of religion he finds it necessary to maintain 
human freedom. Now, Collins had pointed out 
clearly the sense in which he denies freedom to man. 
He admits that in Locke s sense of the term man is 
free, i.e. " man has a power to do as he wills or 
pleases " ; but he declares that such freedom is 
neither adequate nor ultimately real, for it means 
nothing but " freedom or liberty from outward 
impediments of action " ; and he holds that, if we 
are free, our freedom must be " liberty from neces 
sity." 3 Now, this freedom, Collins holds, is an 
impossibility. Man is " a necessary agent," or in 

1 Works, iv. 139. 2 Works, iv. 170. 3 Enquiry, p. 20. 


other words, " all his actions are so determined by 
the causes preceding each action that not one past 
action could possibly not have come to pass, or been 
otherwise than it hath been ; nor one future action 
can possibly not come to pass, or be otherwise than 
it will be." * He advances six arguments why 
freedom is impossible, (i) the argument from experi 
ence, (ii) the argument from " the impossibility of 
liberty," (iii) the argument from " the imperfection 
of liberty," (iv) the argument from " divine pre 
science," (v) the argument from reward and punish 
ment, and (vi) the argument from morality. 

Berkeley considers most of these arguments, but 
he points out that his dissatisfaction with the con 
clusions of Collins and the other free-thinkers arises 
chiefly from disagreement with their assumptions. 
The problem has seemed to be insoluble, Berkeley 
says, only because it is unreal. Its difficulties have 
been artificially introduced by minute philosophers. 
And he maintains that, in reality, in order to be 
assured of freedom, we need only appeal to " the 
Common Sense of mankind," 2 or " ask any plain 
unlettered man." 3 And this, says he, is the only 
proof we need. Yet, in the second edition, Berkeley 
does introduce a formal proof. It is this. Whatever 
does not imply a contradiction is possible. Whatever 
is possible may be supposed to be real. As freedom 
implies no contradiction it is possible, and may 

1 Op. cit. pp. 16-17. 2 Alciphron, ii. 352. 

3 Although Berkeley makes use of this argument from common 
sense he is aware of its weakness. And he objects to its employ 
ment by the minute philosophers, on the ground that when they 
appeal to common sense they mean only the sense of their own 
party " (ii. 269). 


therefore be supposed to be real. Man s freedom may 
be regarded as real. Now any plausibility that this 
" proof " possesses springs from its similarity to the 
ontological argument from conception to reality, an 
argument which Berkeley rejects. Berkeley has 
inferred the reality of freedom from the fact that it 
can be supposed. Now if the ontological argument 
is valid, its validity depends on the fact that it is 
directed to prove the existence of a God, who is 
assumed to be the whole of reality. If God be con 
ceived in any other way than this, the ontological 
argument cannot be defended. In the case of any 
thing partial, such as freedom, the ontological proof 
proves nothing. You no more prove that freedom 
is real from the fact that it is supposed than you 
prove that there is a shilling in my pocket by suppos 
ing that it is there. 

For Berkeley freedom has a great religious signifi 
cance. It is the religious consciousness that demands 
freedom for itself. It demands practical freedom in 
the relations between man and man, it demands 
freedom for man from the necessity of nature, and 
it demands freedom for man in his dealings with God. 
Berkeley regards the denial of freedom as one of the 
most pernicious errors of the deists. 

Berkeley s outlook is not bounded by the some 
what narrow limits of the deist controversy. 1 He 

1 Berkeley s attacks on the deists represent them all alike as 
atheists and infidels. But, of course, the deists differed much 
among themselves. Samuel Clarke distinguished four kinds, 
(i) those who " pretend to believe the existence of an eternal, 
infinite, independent, intelligent Being ; and . . . teach also that 
the Supreme Being made the world : though at the same time . . . 
they fancy that God does not at all concern himself in the govern 
ment of the world, nor has any regard to, or care of, what is done 


sees, less clearly indeed than Butler, but more clearly 
than anybody else, that the whole controversy is 
based on assumptions that are highly doubtful. He 
charges the deists with almost every logical fallacy ; * 
and most of his criticisms are just. But Berkeley 
had enough practical wisdom to know that the mere 
refutation of deist arguments was not enough either 
to secure the historicity of Christianity or to supply an 
adequate philosophy of religion. In the same spirit 
and on the same lines as Butler, he endeavoured to 
suggest the outlines of a philosophy of religion. 
Butler s Analogy continues to be read, while Alci- 
phron and Siris are not, because, whereas Berkeley s 
suggestions are interspersed with much controversial 
matter, Butler brought together all his positive 
arguments into one systematic whole. 

Berkeley s own views on religion are stated in so 
many different places, and are so intricately involved 
with the theories which he is engaged in criticising, 
that it is far from easy to get the gist of what he has 
to say on the chief problems of religion. But an 
attempt must now be made to state his most im 
portant positive tenets. The great problems which 
he raises are the existence of God, the immortality 
of the soul, and the meaning of faith. 

On the first question he vacillates. But on one 
point he remains consistent throughout : he confi- 

therein " ; (ii) those who in addition admit divine providence 
in nature ; (iii) those who also allow moral perfection to God ; 
and (iv) those who go further and acknowledge that man has 
duties towards God, and must look forward to a future state of 
reward or punishment ..." but only so far as tis discoverable by 
the light of nature." (The Being and Attributes of God, 159 ff.) 

1 Cf. Alciphron, ii. 357. 


dently and persistently rejects the ontological proof. 
" Absurd," he says, " to argue the existence of 
God from his idea." 1 It is absurd because we can 
have no idea of God, i.e. we cannot perceive God by 
sense. Thus, it is not strictly the argument that is 
absurd, but the presupposition on which it rests. 
// we could have an idea of God, this would certainly 
guarantee his existence ; nay, it would be his exist 
ence. Of God it would be as true as it is of any other 
idea that esse is percipi. But we have, in fact, no 
idea of God, and^from wlwLt is/Aoprexistent nothing 
can be inferred. 

But with the traditional cosmological and teleo- 
logical arguments for the existence of God he shows 
some sympathy. He points out that it is " repug 
nant " that finite things should subsist of themselves. 
In themselves they are contingent, and need some 
infinite and necessary Ground. He also makes use 
of the teleological proof, arguing to the existence of a 
perfect God, from the " constant regularity, order, 
and concatenation of natural things, the surprising 
magnificence, beauty, and perfection of the larger, 
and the exquisite contrivance of the smaller parts 
of the creation, together with the exact harmony and 
correspondence of the whole." 2 

Berkeley restates these proofs in terms of his own 
metaphysics. Ideas depend for their existence on 
being perceived by human beings, i.e. spirits. But 
these are finite spirits, and finite spirits can cause 
only images. Finite spirits cannot cause ideas, and 
they cannot cause other spirits. Human beings 
cannot be the cause of other human beings. Hence 

1 Commonplace Book, i. 48. Cf. i. 51. 2 Principles, 146. 


the existence of an ultimate cause is required to 
account for (a) the existence of ideas, and (6) the 
existence of spirits. This ultimate cause is God, the 
infinite Spirit. 1 To this general line of argument 
Berkeley gives two somewhat different forms of 
expression. In each case the existence of God is 
an inference from experience ; but at one time he 
considers that the inference is made directly from 
the existence of ideas, and at another that it involves 
the middle term " spirits." In the latter case he 
argues that ideas presuppose finite spirits, and finite 
spirits presuppose Spirit. 2 In the former case, 
" sensible things do really exist ; and, if they really 
exist, they are necessarily perceived by an infinite 
Mind ; therefore there is an infinite Mind, or God." 3 
The same proof is expressed rather differently in 
Alciphron. Berkeley proves that as our certainty of 
the existence of the soul is based, not on immediate 
perception of it, but on the perception of certain 
motions and actions which suggest it, so the existence 
of God is suggested or signified by the harmony of 
action and reaction in the world as a whole. 4 Thus 
Berkeley brings his proof of the existence of God into 
connection with his psychological doctrine of per 
ception. 5 In the Theory of Vision or Visual Language 
he makes the relation perfectly clear. The perma 
nence of the world, and the self-identity of things 
and spirits depend on the fact that they are con 
stantly being perceived by God. God s existence, 
then, may be inferred from the permanence and 
regularity of the world, of which we are assured by 

1 Ibid. 146. 2 Ibid. 146, and Three Dialogues, i. 448. 

3 Three Dialogues, i. 425. 4 Alciphron. ii. 160. 5 Ibid. ii. 174. 


Common Sense. Berkeley may give different ex 
pressions to the proof of the existence of God, but 
he never wavers in his belief in the fact. " Nothing 
can be more evident to anyone that is capable of the 
least reflection than the existence of God." 1 

Granted, then, that God exists, how can we know 
him, or what sort of knowledge can we have of him ? 
In the Commonplace Book Berkeley said that we 
have no idea of God, i.e. God is neither perceptible 
nor imaginable. In the Commonplace Boole per 
ception and imagination are the only kinds of know 
ledge. But since in the Commonplace Book Berkeley 
had asserted his firm conviction that God exists, 2 
it was necessary for him to discover some way of 
knowledge by which God might be known. In the 
Commonplace Book he had not discovered that way 
of knowledge, but in the second edition of the 
Principles he suggests that, though we can have no 
ideas of spirits, we can and do have notions of 
spirits. And this notional knowledge extends also 
to the Infinite Spirit. From first to last he insists 
that we cannot know God by sense. Yet he once 
says that we may have " an image or likeness of God, 
though," he adds, " though indeed extremely inade 
quate." 3 On the same page he identifies our notional 
knowledge of God with reflection or intuition or reason, 
indicating by all these words the difference of such 
knowledge from sense-perception. Whatever pre 
cisely may be the character of notional knowledge, 
it is at least direct. Knowledge by notions is always 
distinguished from indirect and representative know 
ledge by signs. The only characteristic we can 

1 Principles, i. 342. 2 i. 51. 3 Three Dialogues, i. 448. 


with safety ascribe to notional knowledge is its 

Side by side with this theory of a direct notional 
knowledge of God Berkeley gives us, as we have seen, 
his doctrine of indirect analogical knowledge. He 
was content to leave these two views unreconciled ; 
and all we can say is that this is yet another instance 
of the lack of finish which is so characteristic of all 
his work. 

Berkeley s attitude towards the problem of the 
immortality of the soul is closely similar to that 
which he adopts towards the existence of God. He 
believes in the existence of God, and he believes in 
the immortality of the soul. He thinks that both 
beliefs can be defended on his metaphysical theory, ; 
but in addition he adduces other arguments in their 
favour. He holds that the soul is naturally immortal. 
The existence of the soul " consists in perceiving 
ideas and thinking." x It might be supposed that 
Berkeley would admit that sense-perception at least 
is impossible without a body. But he refuses to 
allow this. " It is even very possible," he says, " to 
apprehend how the soul may have ideas of colour 
without an eye, or of sounds without an ear." 2 Even 
if the sense organs were to be annihilated in death, 
the soul might still exist, and not only think, but 
perceive ideas. Thus, existence after death differs 
neither in kind nor in degree from existence in the 
flesh. In both cases existence essentially means 
perceiving ideas and thinking. The existence of the 
body makes no difference to the existence of the soul. 
Immortality is perfectly natural. So far as our 
1 Principles, 139. * Letter to Johnson, June 25, 1729, 
P.P, 7, 


actual experience goes, perception always takes place 
through sense organs, but there -may be " other ways 
of perception," l and in any case there is no proof that 
sense organs are essential to the perception of ideas. 
On this basis the impossibility of disproof Berke 
ley rests the assertion that the soul is necessarily 
and naturally immortal, i.e. is a necessarily and 
eternally percipient being. 

But in addition to this proof, based on his own 
metaphysical doctrine, Berkeley uses traditional argu 
ments to confirm belief in the immortality of the soul. 
Like Clarke, he maintains that the soul is " indivis 
ible, incorporeal, unextended," and consequently, by 
a traditional argument, is indissoluble and incorrupt 
ible. 2 Like Butler, he insists on the separateness of 
the soul from the body, and argues that, since it is 
isolated and impervious, it is not affected by the 
dissolution of the body. He also mentions with 
approval a teleological argument (Man would not 
have been created with such infinite capacities and 
desires, did he not have eternity in which to realize 
and satisfy them), and an ethical argument (Inequal 
ity and injustice in this life point to a future existence 
in which they will be redressed), with both of which 
the belief in immortality may be buttressed. 3 And 
he even finds some satisfaction in referring, for con 
firmation of " this comfortable truth," to the in 
stinctive beliefs of Common Sense, the opinions of 
the Pythagoreans and the Greek mythologists, and 
supernatural revelation as vouchsafed to Christ and 
Mohammed. 4 

1 Essays in the " Guardian," iv. 146. 2 Principles, 141. 
8 Essays in the " Guardian," iv. 143-147. * Ibid. iv. 184. 


But these arguments are only auxiliary. Berke 
ley s real proof is that which is based on his own 
metaphysical system. The soul is, in its very nature, 
immortal. There is no dualism between the present 
life and eternal life, for time and eternity are relative 
distinctions within a wider whole. The soul is 
essentially existent. Within its existence it includes 
the moments of past existence and future existence, 
and neither its past nor its future are bounded by 
what we call birth and death. 1 

In spite of Berkeley s claim that the two great 
religious beliefs are capable of proof, he admits, nay 
asserts, that there is such a thing as religious faith, 
distinct at once from opinion and knowledge. It is 
unfortunate that Berkeley does not make clear the 
differentia of faith. Still, it is possible to gather from 
Alciphron the outlines of his view. It is plain, in the 
first place, that faith is not sense-knowledge. Nor is 
it notional knowledge. Now for Berkeley all know 
ledge is either sense-knowledge (which includes 
imagination) or notional knowledge. Thus faith, 
being neither sense-knowledge nor notional know 
ledge, is not strictly knowledge at all. 

Faith differs from sense -knowledge in three 
respects. (1) Faith is only probable : "Knowledge, 
I grant, in a strict sense, cannot be had without 
evidence or demonstration : but probable arguments 
are a sufficient ground of faith." 2 Religious faith is a 
type of assent. The religious consciousness does not 

1 The Revelation of Life and Immortality (a sermon preached in 
Trinity College), simply takes for granted the immortality of 
the soul as a revealed truth. 

2 Alciphron, ii. 311. 


demand scientifically rigorous proofs. It is satisfied 
with faith, which may " consist with some degree of 
obscurity, scruple, and error." l (2) Faith differs 
from sense-knowledge also inasmuch as it involves 
no ideas. The attitude of faith is possible, " although 
his understanding may not be furnished with those 
abstract, precise, distinct ideas." 2 Faith assures us 
of the reality of things of which we have no ideas. 
(3) Faith is active and practical. " Faith is not an 
indolent perception, but an operative persuasion of 
mind, which ever worketh some suitable action, 
disposition, or emotion in those who have it." 3 

Faith differs also from notional knowledge, but 
only in respect of the first and third points above- 
mentioned. Unlike faith, notional knowledge is both 
theoretical and demonstrable, though the kind of 
demonstration of which it admits is different from 
that of sense-knowledge. But notional knowledge 
is like faith in dispensing with ideas. Thus the 
ultimate differentia of faith is its practical nature and 
the fact that it is based on probable arguments. 

Berkeley illustrates his conception of faith by 
examples. We have faith in such doctrines as Grace 
and Original Sin, (i) though they cannot be rigorously 
demonstrated, and (ii) though we can have no idea of 
them, because (iii) they are beliefs which have a 
" practically efficacious " influence on life. But 
faith is not an isolated phenomenon, confined to the 
realm of religion. Faith is involved also in the 
special sciences. We have no demonstrative know 
ledge by way of ideas of " force " or " number." 
Mechanics and arithmetic alike are based on faith : 

1 Alciphron, ii. 311. 2 Ibid, ii, 335. 3 Ibid. ii. 337-8. 


we give practical assent to the " efficacy " of the con 
ceptions which they employ. Thus, we may say that 
the existence of " force " or " number," like that of 
the data of religion, is not percipi but credi. Their 
existence consists in being believed in, or practically 
assented to. 

Now, it is, of course, evident that we may be 
mistaken in our beliefs. Those religious beliefs 
which Berkeley calls fantastic superstitions are 
held by some people, but that does not guarantee 
their truth. In view of this, can we still maintain 
that the esse of the facts of religion is credi ? 

To this query Berkeley would reply that the pro 
position esse is credi is in precisely the same position, 
with regard to its validity, as esse is percipi. When 
we say that the existence of a thing consists in being 
perceived, we do not forget that some things which do 
not really exist may be perceived or imaged in dreams 
or hallucinations. The mere fact that a thing is 
perceived in a dream or hallucination does not 
guarantee its real existence. Thus, in order to guard 
our proposition from misinterpretation, we should 
have to formulate certain conditions under which it 
is true. And, in general, we may say that esse is 
percipi, provided the particular perception agrees 
with the system of the rest of our perceptions and 
with what we take to be the systems of other people s 
perceptions. If it does not readily find a place 
within the system of experience, it should be looked 
upon with suspicion. It may, indeed, turn out in 
the long run that the single perception is true, and the 
rest of our perceptions are false ; but, as a general 
principle, the presumption is in favour of the system 


and against the particular exception. It is only 
under such conditions as these that we are entitled 
to say that the proposition esse is per dpi is valid. 

And the case of esse is credi is precisely similar. 
The mere fact that a belief is held by one man or by 
a group of men does not necessarily guarantee its 
religious truth. For the belief may be a " fantastic 
superstition." Such a belief is on exactly the same 
level as the perception of the man or group of men 
who are subject to an hallucination. Hence it 
follows that the proposition esse is credi is true onty 
under certain conditions. And the conditions which 
it implies are very similar to those that determine the 
validity of the other proposition. A belief, we may 
say, is valid and valuable if it conforms to the system 
of beliefs held by the wisest and best men of the time. 
If a new belief suggests itself to some particular man, 
which contradicts not only the system of his beliefs 
but also the systems of his neighbours, it may turn 
out to be true, the previous systems being, in reality, 
false, but the presumption, under such circumstances, 
must always be against its truth. We conclude, 
then, that the essential attitude of religion is one of 
faith ; and that, under certain general conditions, the 
fact that a religious belief actually is held guarantees 
its value and validity. 

To sum up, we find that in religion as in theory of 
knowledge Berkeley, starting with isolated partic 
ulars, is forced in the end to assume the conception 
of system in order to justify these particular beliefs. 
While, in exceptional cases, a particular belief may be 
true against a system of beliefs, the general rule is 
that it is confirmed as a valid and valuable belief only 


because it is not an isolated particular but is a 
member of a system. Thus, in the theory of religion, 
as in every other department of philosophy, Berkeley 
is driven by the inner logic of his thought to abandon 
his early particularism in favour of a conception of 
life based on organic system. 



THE general resemblance of the Berkeleian theory 
to that stated by Arthur Collier in his Clavis Uni- 
versalis, which was published in 1713, gives rise to 
some interesting and important historical questions 
which will be examined in this appendix. I shall 
first mention briefly, what is known of Collier, and 
then consider whether his work was influenced in any 
way by Berkeley. 

Clavis Universalis is not, in itself, any more re 
markable than many other English philosophical 
tracts published about the beginning of the eighteenth 
century, which attracted little or no attention when 
they originally appeared and which have been per 
sistently neglected by succeeding generations. Such 
rare treatises as Richard Burthogge s Essay upon 
Reason and the Nature of Spirits, 1694, John Ser 
geant s Solid Philosophy, 1696, and John Norris s 
Essay towards the Theory of the Ideal or Intelligible 
World, 1701-4, may be specially mentioned. In 
themselves these works are quite as interesting and 
important as Collier s book ; but to the English 
student of philosophy they are very little known, and 
no effort seems to have been made to reprint them. 



And it is safe to say that Clavis Universalis would 
have remained in as great obscurity as these and 
many others had it not been for the coincidence that 
it contains a theory strangely similar to that of 
Berkeley, whose Principles appeared three years 
before it. The modicum of attention that Collier has 
received has been due to this interesting coincidence, 
if coincidence it be. 

For a hundred years after his death Collier re 
mained, in Britain, at least, in almost complete 
oblivion. 1 He was forgotten in the parish of which 
he had been hereditary rector, and in an elaborate 
catalogue of the authors of Wiltshire, in which he was 
born and bred and lived and died, his name does not 
appear at all. But one day Thomas Reid chanced on 
a copy of Clavis in the Glasgow University Library, 
and gave a brief account of it in his Essays on the 
Intellectual Powers of Man. 2 He cannot have read 
the book very carefully, however, for he says that 
Collier s arguments are the same in essence as Berke 
ley s ; and this is, in fact, far from being the case. 
Reid s notice brought Clavis to the attention of 
Dugald Stewart, who devoted a note to its author 
in his Dissertation on the History of Metaphysical 
Science, 3 in which he praised the book with more 
enthusiasm than discrimination. " When compared 
with the writings of Berkeley himself," he says, " it 
yields to them less in force of argument than in com 
position and variety of illustration." Stewart refers 

1 He is referred to in Grub Street Journal, cvii., and in Corry a 
Reflections on Liberty and Necessity, 1761. 

2 Essay, ii. chap. 10. 

3 Hamilton s edition, vol. i. p. 349. 


also to its " logical closeness and precision " 
qualities which, in reality, it decidedly lacks. These 
and other references roused, at about the same time, 
the interest of Dr. Parr, and of an Edinburgh literary 
society, and the result was the almost simultaneous 
publication of Clams by the Edinburgh society in 
1836, and in Metaphysical Tracts by English Philo 
sophers of the Eighteenth Century in 1837. In 1837 
also appeared Memoirs of the Life and Writings of the 
Rev. Arthur Collier, by Robert Benson, who was a 
descendant of Collier s sister, and possessed a quan 
tity of Collier s unpublished manuscripts. A notice 
of the last two volumes was written in the Edinburgh 
Review in 1839 by Sir William Hamilton. But 
after this Collier s work again relapsed into ob 
scurity. 1 

In Germany Collier has attracted more attention. 
In 1717 a careful abstract of Clavis was printed in the 
Acta Eruditorum. 2 This abstract runs to only 5^ 
pages, but it is so good that many Continental philo 
sophers were probably content to take their know 
ledge of Collier s views entirely from it. There is, at 
least, no doubt that the book itself became very rare 
in Germany, and when Bulffinger refers to it in his 
interesting Dilucidationes Philosophicae de Deo, 
Anima Humana, Mundo et Generalibus Rerum 
Affectionibus, 1746, his exact references are always to 

1 Collier receives some attention in G. Lyon, L Idealisme en 
Angleterre, pp. 241-293 ; R. Blakey, History of the Philosophy of 
Mind ; W. R. Sorley in the Cambridge History of English Litera 
ture, ix. 287 ; A. C. Fraser, Works of Berkeley, iii. 384 ; and in the 
Dictionary of National Biography. A reprint of Clavis has been 
issued by the Open Court Publishing Company. 

2 Supplementary volume, vi. 244. 


the abstract in Ada Eruditorum 1 and never to Claws 

itself, which suggests that he did not have access to 

the book itself. Bulfnnger introduces Collier as one 

of the protagonists of Idealism. " Mundum visi- 

bilem non esse externum prolixe contendit ; tamen 

ad argumentum quod tactus demonstret extra- 

existentiam corporum respondere id non contra se, 

quoniam de visibili mundo quaerat non de tangi- 

bili." 2 He also suggests that Christian Wolff refers 

to Collier in one of his writings on the relation of 

Idealism and Orthodoxy. " Puto ilium (i.e. Wolff) 

intendere digitum ad Arthurum Collierium, de quo 

ex Actis Lips, notum est, ilium vel theologica ex 

idealismo suo corollaria v.g. adversus transubstan- 

tiationem intulisse manentibus enim speciebus nihil 

immutatum esse contendit." 3 The fact that the 

reference here is to Acta Eruditorum and not to Claris 

would again seem to indicate that Collier s book was 

not known to Bulffinger, for the view referred to is 

quite definitely stated in Claris. " So that if these 

(i.e. the sensible species of bodies) are supposed to 

remain as before, there is no possible room for the 

supposal of any change." The argument is that if 

a thing is nothing but the secondary qualities, then 

so long as the secondary qualities remain unchanged 

1 At the end of this abstract the writer puts the relation of 
Collier and Berkeley very tersely. " Haec sunt paradoxa 
autoris nostri qxiae procul dubio non maiori plausu excipientur 
quam ilia quae in eandem sententiam, aliis tamen argumentis, 
conterraneus eius Georgius Berkeley . . . defendere conatus est. 
(Op. cit., Supp., vol. vi. p. 249.) 

2 Dilucidationes Philosophicae, 115. 

3 Op. cit. 118. Immutatum is an error for mutatum. Acta 
Lips, i.e. Acta Eruditorum quae TApsiae publicantur. 


no change can have taken place in the thing, and 
transubstantiation is therefore impossible. 

Clavis was translated into German by Professor 
Eschenbach of Rostock in 1756. Together with 
Berkeley s Three Dialogues it forms the Samlung der 
vornehmsten Schriftsteller die die Wuerklichkeit ihres 
eignenKoerpers und der ganzen Koerperwelt laeugnen.^ 
Appreciative accounts of Collier are to be found in the 
chief German histories of philosophy, e.g. Tennemann, 
Geschichte der Philosophie, x. 398-404, Ueberweg, 
Geschichte der Philosophie, ii. 121, Erdmann, Grund- 
riss der Geschichte der Philosophie, ii. 291, Ernst 
Cassirer, Das JErkenntnisproblem, ii. 327, and Erich 
Cassirer, BerJceleys System, p. 162. 

Of Collier s life little is known, and that little is not 
particularly interesting. He was born in 1680, the 
son of Arthur Collier, rector of Langford Magna, 
near Salisbury. Schooled at Winchester, he entered 
Pembroke College, Oxford, in 1697, and removed next 
year to Balliol. He took orders, and in 1704 was 
presented to Langford Magna, of which the advowson 
belonged to the family. He lived all his life in the 
parish, and died in 1732. 

Clavis Universalis is the only book by which 
Collier deserves to be remembered. But he also 
published, in addition to a couple of controversial 
sermons, A Specimen of True Philosophy, 1730, 

1 The spelling of the original is retained. As evidence of the 
rarity of Clavis in Germany, a sentence or two may be quoted 
from Eschenbach s preface. " If ever any book involved trouble 
in obtaining it, Clavis Universalis is that book. At first all my 
attempts to get it were in vain. At last a worthy friend, Herr 
J. Selck, sent me the work after I had given up all hope that I 
should ever be able to procure it." 


and Logology, 1732. These treatises, which are 
reprinted in Parr s Metaphysical Tracts, are theo 
logical rather than philosophical, and may be passed 
over in silence. 

Collier s chief claim on the interest of the philo 
sophical student arises out of the similarity of his 
theory to that of Berkeley. That resemblance gives 
rise to certain problems which have never been 
faced, and it seems worth while to examine them. 

It has always been assumed that Collier is quite 
independent of Berkeley, and that he did not know of 
Berkeley s Theory of Vision or Principles before the 
publication of his own book. But it is difficult to see 
any ground for this assumption. Collier mentions 
Berkeley twice in letters written shortly after the 
publication of Clavis, and in neither case does he 
assert that his work is independent of Berkeley, or 
deny that he had seen Berkeley s Principles. In a 
letter written to Solomon Low, on March 8, 1714, he 
says, " He [i.e. a certain Mr. Balch who had criticised 
Collier] cannot show another in the world, besides Mr. 
Berkeley and myself, who hold the testimony of sense 
to be infallible as to this point " [i.e. the existence of 
visible objects]. Writing to Samuel Clarke on 
February, 14, 1715, he says, " I could almost dare to 
put the whole question upon trial whether you, or 
any man else, ever so much as heard of either of them 
before [i.e. the theories that the visible world is not 
external, but is dependent on mind or soul ; and that 
there is no such thing as matter] ; I mean before Mr. 
Berkeley s book on the same subject, which was 
published a small time before mine." It is certainly 
strange, if Collier had seen Berkeley s books, that he 


does not refer to him in his Introduction. On the 
other hand, Collier does not claim originality. At 
first sight, indeed, there are two sentences in the 
Introduction which seem to claim originality for his 
work. He says that he has decided to publish his 
work, " rather than the world should finish its course, 
without once offering to enquire in what manner it 
exists." But this is simply a rhetorical nourish. 
Collier knew something of the history of philosophy, 
and he therefore knew that philosophy is simply an 
enquiry into the manner of the existence of the world. 
Again, he speaks of the " ten years pause and 
deliberation," after which he had decided to bring 
his views to the notice of the public. But he could 
have said this, even if he had seen Berkeley s Prin 
ciples before the publication of his own work. The 
view of the relationship which I should like to suggest 
is that Collier had for a considerable time been 
reflecting and writing desultorily on the non-existence 
of the external world, and that when Berkeley s books 
appeared he was encouraged to publish his views. 1 
There is support for this theory, both on internal 
and external evidence. 

1 Collier makes a false statement with regard to Berkeley 
in A Specimen of True Philosophy, where he says of Clavis Uni- 
ver sails, " This work is, with the exception of a passage or two 
in the Three Dialogues of Dr. Berkeley, printed in the same year, 
the only book on the subject of which I have ever heard " (p. 114). 
This statement may be disproved out of Collier s own mouth. 
In the letter to Low, referred to above, he mentions, " Mr. 
Berkeley s book on the same subject, which was published a 
small time before mine." Now this must refer to the Principles, 
for the Three Dialogues was published after Clavis Universalis. 
Again, in the preface to the Three Dialogues Berkeley himself 
mentions the Principles ; and therefore, as Collier had read the 
Three Dialogues, he must " have heard of " the Principles. 


We must first examine two arguments which have 
been advanced for the absolute independence of 


(1) It has been held that the concurrent publica 
tion of the two similar theories is a pure coincidence. 
This view is usually simply accepted without ques 
tion. Now a purely fortuitous coincidence is always 
possible, and, qua coincidence, it admits of no expla 
nation. And it is not prima facie strange that two 
men should independently deny the existence of the 
external world. It is indeed remarkable that the 
Berkeleian view should have cropped up so rarely. 
The view is a very natural one for a man who is just 
beginning to think for himself to land in. It is 
perfectly possible that both Berkeley and Collier hit 
upon the same theory Oela TLV\ TV-^U. 

(2) But it is more probable that there is some 
common source of their views. This is suggested by 
Campbell Fraser. " The agreement may be referred 
to the common philosophical point of view at the 
time." x " The intellectual atmosphere of the Lock- 
ian epoch in England contained elements favourable 
to such a result." 2 Let us examine this suggestion. 
In the first place, the early philosophical environ 
ments of the two men were as different as possible. 
Berkeley was educated at Dublin, Collier at Oxford. 
Berkeley s earlier interests were chiefly mathema 
tical, while Collier s were classical. And the philo 
sophers who chiefly influenced them were, with one 
exception, different. It is possible to reconstruct the 
earlier philosophical development of the two thinkers 
with some exactitude, because Berkeley s Common- 

i Life and Letters of Berkeley, p. 62. 2 Works of Berkeley, i. 253. 


place Book gives a good idea of what he was reading 
and thinking between 1705 and 1708 ; and in the case 
of Collier, the manuscripts dated from 1703 onwards 
enable us to measure the forces which played upon 

Collier was influenced chiefly by Norris. Both by 
conversation and by his books Norris affected the 
trend of Collier s thought. When Collier mentions 
Norris, he uses terms of exaggerated veneration, 
though he does not follow him blindly. It is because 
of the greatness of his esteem for " the great and 
excellent Mr. Norris " that he never criticises him 
directly, but when he is forced to differ from him 
always mentions his views in the form of an objection 
to his own, " that I may seem rather to defend myself 
than voluntarily oppose this author." 1 Collier s 
central thought the non-existence of the external 
world is certainly not due to Norris. Norris 
definitely considers the question, and concludes that 
it is arrant scepticism to doubt its existence. 2 And 
Norris is no sceptic. But the general form of the 
exposition of Collier s theory shows the influence of 
Norris, and Collier readily admits this. Collier also 
admits the influence of Malebranche. On the ques 
tion of the existence of the external world, Male 
branche and Norris are in agreement, but Collier 
acutely points out that Malebranche s purely philo 
sophical arguments do not entitle him to assert its 
existence. In the last resort, Malebranche founds 
the existence of the external world on the authority 
of Scripture. Now, Collier suggests that Scripture 
does not really bear him out, 3 and he argues that if 

1 Clams, p. 123,, 2 Ideal World, i. iv. 3 Clams, p. 114. 


Malebranche were only consistent, and remained 
throughout on the strictly philosophical level, he 
would be forced to the same conclusion as Collier 
himself. Collier is anxious to emphasise his agree 
ment with Norris and Malebranche. 

On the other hand, Berkeley denies, even violently, 
that he has been influenced by them, or is in any way 
in agreement with them. Thus he writes to Percival, 
" As to what is said of ranking me with Father Male 
branche and Mr. Norris, whose writings are thought 
too fine-spun to be of any great use to mankind, I 
have this to answer : that I think the notions I 
embrace are not in the least coincident with, or agree- 


ing with theirs, but indeed plainly inconsistent with 
them in the main points, insomuch that I know few 
writers whom I take myself at bottom to differ more 
from than them." So far as his attitude to Norris is 
concerned, this disclaimer is fully justified. In his 
writings he does not mention Norris once, his works 
do not show any sign of influence, and apart from 
this reference in a letter there is no evidence that he 
ever read him. But with Malebranche it is different. 
Berkeley certainly knew his works well, refers to him 
frequently in the Commonplace Book (pp. 9, 24, 38, 
50, 51, 76, 78, 81), and went to see him in Paris. 1 

1 In a letter to Prior (November 25, 1713) Berkeley says, 
" Tomorrow I intend to visit Father Malebranche, and discourse 
him on certain points." The Abbe d Aubigne was to introduce 
him, as he informs Percival in a letter written on November 24, 
1713. Unfortunately Berkeley says nothing further of this visit. 
This is not to be confounded with the interview which Berkeley 
is said to have had with Malebranche two years later, when he 
became the "occasional cause" of his death. This story, an 
amusing version of which is given by De Quincey in Murder 
considered as one of the Fine Arts, appeared probable to Dugald 
B.P. 2 A 


There is no doubt at all, as we have seen in an earlier 
chapter, that Berkeley was influenced by Male- 
branche, though this was probably more by repulsion 
than by attraction. In the Commonplace Book he 
criticises Malebranche with regard to his views on 
divine agency and the existence of the external world. 
The French Father maintained that our belief in an 
external world is grounded on our inclination to 
believe in its existence, and on the Scriptural warrant 
for it. 1 The former ground is obviously unsatis 
factory, and ultimately Malebranche is reduced to 
the latter. But Berkeley points out that this is, as a 
philosophical argument, no better than the other. 
And Berkeley also differs from Malebranche with 
regard to causation. For Malebranche all causation, 


human as well as natural, is divine. 2 Berkeley, 
less consistently, refers natural causation to divine 
power, but reserves human agency to man s will. 
" We move our legs ourselves," he says, " it is we that 
will their movement. Herein I differ from Male 
branche." 3 But, on the whole, as we have seen, 
Berkeley s general view of causation is simply a 
modified version of Malebranche s. In fact, had the 
Frenchman not been anxious to maintain his ecclesi 
astical orthodoxy he might well have anticipated 
Berkeley in his most notable innovations. Male 
branche had a real influence both on Berkeley and on 

Stewart (Works, i. 161), and even to Sir William Hamilton 
(Discussions, p. 198), but, as is shown by the Berkeley-Percival 
correspondence, it is certainly fictitious. 

1 Entretiens sur la mdtaphysique, vi. 8. 

* Meditations Chr&icnnes, v. 54. 

3 Commonplace Book, i. 24, cf. i. 55. 


But no other thinker exercised an influence on both 
men. Locke s influence on Berkeley was so great 
that, as we have seen, had there been no Locke there 
would have been no Berkeley. But there would 
certainly have been a Collier. Not only does Collier 
never mention Locke, but his books do not breathe 
the Lockian atmosphere. It was certainly not the 
influence of Locke that was responsible for the con 
current development of the two theories. But on 
Collier the scholastic philosophy had a great influence 
and he never frees himself from Scholastic termin 
ology. 1 On the other hand, Scholasticism had 
hardly any effect on the formation of Berkeley s 

On the whole, then, the philosophical influences 
which played upon Berkeley and Collier were very 
different, and it seems impossible to maintain that 
there was any really common source of their 
theories. And, indeed, that Berkeley and Collier 
should both have hit on the same doctrine is not at 
all surprising. What is surprising is that it had not 
been suggested long before. The philosophical 
groundwork and premises of the Berkeley-Collier 
theory are to be found in the speculations of the 
Schoolmen. That the Schoolmen produced no 
system akin, in its conclusions, to Berkeley s Idealism 
was due to (1) their physiology, and (2) their theology. 
In the schools a question frequently proposed for 
determination was, " Whether God may not maintain 

1 The first nine chapters of Part II. of Clavis are almost entirely 
on the Scholastic level. Collier seems to have been acquainted 
with Scholasticism mainly through the manuals of Baronius and 
Scheiblerus. He mentions Suarez once (Clavis, p. 42). 


the species 1 before the mind, the eternal reality 
being destroyed ? " or, " Whether God may not 
bring before the senses the species representing an 
external world, though the external world in reality 
does not exist ? " On purely philosophical grounds 
the weight of opinion is in favour of an affirmative 
answer. But the physiological and theological 
presuppositions of the schools proved too strong to 
allow of its being elevated to the rank of " probable " 

(1) The Schoolmen, following Aristotle, held that 
the physiological conditions of sense-perception were 
such as to make all sense-perception impossible apart 
from external material reality. In visual perception 
material things were supposed to give rise to certain 
images. These impinge upon the active intellect, 
which spiritualises them into ideas, and hands them 
over to the passive intellect, which perceives them ; 
and as nihil est in intellectu quod non prius fuerit in 
sensu, no knowledge at all is possible apart from an 
external world. But when the physiological revolu 
tion, with which Descartes had much to do, took 
place, the supposed necessity of the external world 
for sense-perception was removed. It is noticeable 
that Malebranche does not use this argument in 
support of the existence of an external world. 

(2) Theologically also an Idealism such as that of 
Berkeley was an impossibility for the Schoolmen. 
They were well acquainted with idealist premises, 
but on theological grounds they refrained from draw 
ing idealist conclusions. It did not escape their 

1 " Species," i.e. "ideas" in Berkeleian terminology. Collier 
uses " species." 


notice that Subjective Idealism is incompatible with 
the dogma of Transubstantiation. So long as philo 
sophy continued to be ancillary to a theology which 
maintained Transubstantiation, Subjective Idealism 
was impossible. Collier expressly points out that his 
theory disproves Transubstantiation. Berkeley does 
not mention this as a consequence of his doctrine, 
probably because he was acute enough to see that it 
also gave rise to difficulties in connection with the 
Incarnation. It was thus perfectly natural that 
two thinkers, born at the time that Berkeley and 
Collier were, and acquainted, as they were, with 
Scholasticism and the New Philosophy, should have 
reached their conclusions. 

We have thus seen that it is possible that the con 
current formulation of idealist theories by both 
Collier and Berkeley was either a pure coincidence or 
the result of what Lyon has called " the imperious 
power of an inner logic." x But, on the whole, it is 
more probable, I think, that Berkeley exercised a 
direct influence on Collier. For this view there is 
some evidence, both on external and on internal 

The external evidence (which we shall take first) 
is, it must be admitted, of the circumstantial 
variety ; but, at the very least, it seems plausible 
that Collier had seen Berkeley s book before the 
publication of his own. As we have already seen, 
when Collier mentions Berkeley in letters written 
about a year after the appearance of Clavis he does 
not deny prior acquaintance with the Principles. 
And it is really very difficult to believe that Collier 

1 ISIdtalisme en Angleterre, p. 250. 


did not, in fact, know of its argument before the 
printing of his own book. For the Principles, pub 
lished in 1710, created a good deal of stir in London. 
Berkeley s friend Percival did his best to make it 
widely known, and though the reports he sent to 
Berkeley were not altogether encouraging, they 
showed at least that people were talking about his 
book. Thus, in one of his regular bulletins, he writes, 
" A physician of my acquaintance undertook to 
describe your person, and argued you must needs be 
mad. A bishop pitied you. Another told me an 
ingenious man ought not to be discouraged from 
exerting his wit." Again, he writes of the attitude of 
Clarke and Whiston towards Berkeley as follows, " I 
can only report to you at second hand that they think 
you a fair arguer and a clear writer, but they say 
your first principles you lay down are false." And, 
finally, he says that Lord Pembroke thought that 
Berkeley was " an ingenious man, and ought to be 
encouraged, but that he could not be convinced of 
the non-existence of matter." It is clear, then, that 
Berkeley was being talked about, however unintelli- 
gently, in literary and philosophical circles in 
London in 1710. Is it likely that Collier did not hear 
of him ? Langford Magna is not London. But 
Collier was not as isolated as one might think. The 
neighbouring parish is Bemerton, the rector of which, 
John Norris, " the English Malebranche," was still 
alive. And Salisbury, the cathedral town, was at 
that time quite a literary centre. Further, through 
his wife, who was a niece of Sir Stephen Fox, pay 
master of the army, he had a connection with 
London. Lastly, Collier was a friend and correspon- 


dent of Whiston. Now Whiston had received from 
Berkeley a copy of his Principles, and was so much 
interested that he went to see Clarke about the new 
doctrine. 1 It seems exceedingly probable, especi 
ally if he knew that Collier s thoughts were running 
in the same direction, that he informed Collier of 
Berkeley s book. All this evidence amounts, it is 
true, to nothing more than probability ; but the 
probability seems almost convincing. 

But it is certain that Collier had been incubating 
the theory himself long before he could have heard of 
Berkeley. In the first place, we have his explicit 
statement, already quoted, that he entertained his 
doctrine for ten years before publishing it. He must, 
therefore, have adopted it in 1703, a year before he 
became rector of Langford Magna. Further, Benson 
had in his possession, when he wrote the Memoir of 
Collier, three of Collier s manuscripts, which contain 
drafts and sketches of the theory which was finally 
promulgated in Clavis. The first of these is dated 
1708, and is entitled Sketch of a Metaphysical Essay on 

1 [Berkeley] " was pleased to send to Mr. Clarke and myself 
each of us a book. After we had both perused it, I went to Dr. 
Clarke and discoursed with him about it, to this effect, that I 
being not a metaphysician was not able to answer Mr. Berkeley s 
subtle premises, though I did not at all believe Mi absurd con 
clusion. I therefore desired that he, who was deep in such 
subtleties, but did not appear to believe Mr. Berkeley s con 
clusion, would answer him, which task he declined." (Whiston s 
Historical Memoirs of the Life of Dr. S. Clarke, pp. 133-4. ) Collier 
is not mentioned in Whiston s Memoirs of the Life and Writings 
of Mr. William Whiston, containing Memoirs of Several of his 
Friends also. But in this strange autobiography Whiston makes 
a system of mentioning only those of his friends who were well 
known or connected in some way with the controversies in which 
he engaged. And Collier was not well known, nor did he concern 
himself with Whiston s conflicts with his Church and University. 


the Subject of the Visible World being without Us or 

On the whole, the external evidence seems to show 
that (a) Collier had seen Berkeley s book before he 
published his own ; but (6) he had hit upon the 
theory independently, 

The internal evidence is, from the philosophical 
standpoint, more interesting. Here again, however, 
we must be concerned with arguments which are 
merely probable. It must be admitted that there is 
nothing whatever in Clavis which makes it certain 
that Collier had seen Berkeley s book ; but on the 
whole, internal evidence seems to support our theory. 

In Clavis Collier s question is, " Is there an external 
world ? " While Berkeley denies mainly the materi 
ality of the world, Collier denies its externality. In 
the end the two arguments reach the same con 
clusion ; but the arguments are different, and their 
tendency is different. Collier defines his terms very 
broadly. By " world " he understands " body, 
extension, space, matter, quantity, etc." * And 
when he speaks of the world as " not external," he 
means that it " exists in, or in dependence on, 
mind, thought, or perception." 2 He gives three 
examples of what exactly he means by saying 
that a thing exists in, or in dependence on 
mind. It may exist in mind, first, as an accident 
exists in substance (Thus there is only one substance 
mind : matter is only an accident. Hence the 
Cartesian two-substance doctrine is by implication 
denied) ; second, as a body exists in a place (A most 
unfortunate example, for it suggests that the mind, 

1 Clavis, p. 2. 2 Ibid. p. 3. 


in which all things exist, is a place, and that " inside 
the mind " and " outside the mind " are spatial 
relations. And to do Collier justice, he really does 
not mean that) ; thirdly, as an object of perception 
exists in its respective faculty. Collier prefers the 
last way of stating the relation. As objects seen in 
hallucinations or dreams are admitted to exist in, or 
in dependence on, mind, so, Collier maintains, all the 
world exists. These definitions and explanations 
are made in the Introduction. In Part I. he endea 
vours to show that the visible world is not external. 
First, in Chapter I. section i. he holds that what is 
visible need not be external, and then in Chapter I. 
section ii., that what is visible cannot be external. 

(1) Collier s first thesis is that what is visible is 
not necessarily external, or that a thing may seem to 
be external without being really so. The first argu 
ment he adduces is fallacious. He maintains that an 
object of imagination seems as much external as an 
object of perception. An object of imagination, for 
example a centaur, need not have external existence. 
Therefore what seems to be external need not be so. 
But it is psychologically false that an imagined 
object seems as much external as a perceived object. 
The imagined object is recognised as being dependent 
on the mind in a way in which the perceived object 
is not. Collier s next arguments, however, are 
better. Secondary qualities, though seemingly ex 
ternal and independent, are now admitted, he says, 
thanks to the proofs of "Mr Des Cartes, Mr Male- 
branche, and Mr Norris," not to be really so, but to 
be dependent on mind. Thus what is visible is not 
necessarily external. 


Collier then adduces a series of arguments to 
show that men in hallucinations, visions, dreams, 
etc., see objects which seem to be external. But 
these objects are normally admitted not to be really 
external. Thus, on this count also, what is visible 
is not necessarily external. 

(2) Having, as he thinks, shown that what is 
visible need not be external, Collier proceeds to prove 
that it cannot be external. In this he entirely fails. 
He rests his argument chiefly on an experiment which 
he requests each of his readers to make. Press or 
distort the eye, and look at the moon. Two moons 
will be seen. These moons cannot both be external. 
Therefore neither can be external. The fallacy, of 
course, is the very simple one of inferring that because 
both cannot be external therefore neither can be 
external. Collier says that one cannot be external 
without the other s being external also, because in 
that case it ought to be possible to distinguish 
between the percepts, and this cannot be done. But 
note what the experiment involves. It implies 
interference with the normal conditions of sense- 
perception. Collier s argument, indeed, is this. 
Because under certain abnormal conditions, e.g. 
when you press your eye or labour under hallucina 
tion, you seem to see something which is external, 
but which is really not, therefore always under normal 
conditions what is seen to be external is not really 
so. From a proposition which is true sometimes 
in abnormal conditions Collier attempts to deduce 
one which is true universally under normal conditions. 

Part II. of Clams extends the arguments of Part I. 
to the whole world. Part I. was to prove that the 

visible world is not external. Part II. sets out to show 
that there is no external world at all. But the nine 
arguments which Collier brings forward, and the 
three objections to which he replies, really make no 
further contribution to the problem. These pages 
are cast in a Scholastic mould, bristle with technical 
terminology, and are both in matter and style as 
different as possible from Berkeley s work. 

All in all, we have so far seen little real similarity 
between Berkeley and Collier. Collier s Introduction 
is written with the Cartesians in view, Berkeley s is 
directed largely against Locke. And in the main 
body of his work, Collier uses a great many argu 
ments which Berkeley was far too acute to employ. 
In the general tendency of their doctrines there is 
a real and most significant difference. Collier is 
mainly negative, while Berkeley, though employing 
destructive criticism, is positive in method, intention 
and result. Collier s thesis is, What is visible is not 
external, or, more generally, The external world does 
not exist. Berkeley s, on the other hand, is Esse is 
percipi, or, more generally, The world does exist as a 
world of ideas. So far, Collier s work has revealed 
absolutely no trace of the influence of Berkeley. 

But there are two passages in Clavis, one at least 
introduced as an afterthought, which bear a much 
closer resemblance to Berkeley s attitude and stand 
point than to Collier s ; and it is, I think, neither 
fanciful nor uncharitable to suggest that we may, in 
these pages, detect the influence of Berkeley. In 
these passages, which occur on pp. 5-10 and 36-37, 
we find the following specifically Berkeleian views 
which appear nowhere else in the treatise. 


(1) The positive doctrine is affirmed that what is 
visible does really exist. "It is with me a first 
principle that whatsoever is seen is." l " The objects 
we speak about are supposed to be visible ; and that 
they are visible or seen is supposed to be all that we 
know of them or their existence. If so, they exist 
as visible, or, in other words, their visibility is their 
existence." 2 Now, all this is clearly very similar to 
Berkeley s esse is percipi. And it may be noted that 
Collier has very little corresponding to Berkeley s 
aut percipere. The theory of spirit, which hardly 
appears at all in those of Berkeley s works which 
Collier could have seen, is practically non-existent in 
Collier s own writings. 

(2) Collier " makes no doubt or question of the 
existence of bodies, or whether the bodies which are 
seen exist or not." 3 Bodies that are seen certainly 
exist, for their existence is constituted by their 
visibility. It is noteworthy that on this point 
Collier agrees with Berkeley against Malebranche, 
whom, as we have seen, he usually follows. 

(3) He attributes " the seeming or quasi externeity 
of visible objects " to the will of God. In granting 
to objects this quasi-externality God does not act 
capriciously, for it is "a natural and necessary con 
dition of their visibility." 4 With this may be com 
pared Berkeley s theory of God as the cause of the 
reality of the world, and of God s volitions as the 
arbitrary but not capricious laws of nature. 

(4) Collier holds that the mind does not cause its 
own ideas or objects of perception, though it is 

1 Claws, p. 5. z Ibid. pp. 36-37. 

s Ibid. p. 5. * Ibid. p. 7. 


responsible for its own imaginative experience. He 
sharply distinguishes mind from will, and maintains 
that though man is free to will as he pleases, the mind 
must perceive objects as they are presented to it by 
God, according to natural and necessary conditions. 
All this is precisely Berkeley s doctrine. And again, 
it should be noted, Collier has joined with Berkeley 
against Malebranche, who maintained that all human 
as well as all natural causation is due to God. 

(5) Collier points out, finally, that when he argues 
that all matter necessarily exists in some mind or 
other, he does not restrict the conception of mind to 
created mind. It is in the mind of God that matter 
exists permanently. 1 Collier is not so fully aware as 
Berkeley of the indispensability of God to guarantee 
the permanent existence of the world. But the view 

is there. 

We have, then, half-a-dozen most important points 
in which Collier agrees with Berkeley stated in two 
short passages of half-a-dozen pages, and nowhere 
else in the book. In the rest of the treatise the 
resemblance between the two " Idealists " is really 
very slight. Thus there seems to be some ground 
for supposing that in these six or seven pages, pos 
sibly introduced after the rest was in manuscript, 
Collier was directly indebted to Berkeley. It must, 
however, be repeated that nothing more than pro 
bability is claimed for these arguments. 

It may be mentioned, in conclusion, that it is not 
difficult to account for the difference in the fortunes 
enjoyed by Berkeley s and Collier s books, both 
among their contemporaries and in the estimation 

1 Cf. Claris, pp. 9-10. 


of history. On their intrinsic philosophical merits, 
the Principles and Dialogues are in a different class 
altogether from Clavis. And while Berkeley s 
literary style is the most delightful in the history of 
English philosophy, Collier s is gnarled and technical, 
and even in his own day must have sounded anti 
quated. Further, Berkeley made himself known to 
his own generation by plunging vigorously into 
nearly all the public debates of the time, while 
Collier s nearest approach to controversy was a mild 
indulgence in the Arian heresy. And finally, while 
Berkeley always tried to enlist people on his side by 
gradually " insinuating " his views, Collier s book 
breathes the very spirit of odi profanum, and he takes 
as his motto the dictum of Malebranche : " Vulgi 
assensus et approbatio circa materiam difficilem est 
certum argumentum falsitatis istius opinionis cui 
assentitur." Nothing could be more different than 
this from Berkeley s endeavour to base his theory on 
principles approved by common sense. 



JOHN SERGEANT, critic of Locke and precursor of 
Berkeley, was born in 1622. He was admitted a 
sub-sizar of St. John s College, Cambridge, in 1639, 
and soon after leaving the University he was con 
verted to Roman Catholicism. Thenceforth he 
employed his gifts, which were considerable, in the 
defence and propagation of his Faith. He took part 
in most of the controversies of the time in religious, 
philosophical, and political matters ; and, as a 
vigorous defender of the Roman Catholic Church, he 
encountered almost every great Protestant thinker 
and writer of his day. In 1707 he died, as he had 
lived, " with a pen in his hand." 

He produced in all 36 works, the great majority of 
which are controversial pamphlets on theological 
questions. Only three of his books are of philo 
sophical importance, and they were all written near 
the end of his life. They are : 

1. The Method to Science. London, 1696. 

2. Solid Philosophy Asserted, Against the Fancies 
of the Ideists : or, The Method to Science Farther 
Illustrated. With Reflexions on Mr. Locke s 



Essay concerning Human Understanding. London, 
1697. 1 

3. Transnatural Philosophy, or Metaphy sicks : 
Demonstrating the Essences and Operations of all 
Beings whatever, which gives the Principles to all other 
Sciences. And shewing the perfect Conformity of 
Christian Faith to Right Reason, and the Unreason 
ableness of Atheists, Deists, Anti-trinitarians, and 
other Sectaries. London, 1700. 

Very little attention has been paid by historians 
of philosophy to Sergeant s work. In this Appendix 
I propose to give a short account of Sergeant s 
general attitude to the problems of philosophy in 
view of the interest it possesses for the student of 
Locke and Berkeley. 

Sergeant believes that the failure of philosophy is 
due to its faulty methods, and that for its renaissance 
the first requisite is an adequate method. A survey 
of the history of philosophy, with its differences and 
controversies, its false beginnings and inept conclu 
sions, fills him with despair, especially when its lack 
of progress is compared with the advances made in 
mathematics. 2 Sergeant accordingly suggests, pre- 

1 The two copies of this book which I have seen have slightly 
different title-pages. One gives the author s name in the form 
which Sergeant generally uses, viz. " By J. S.", the other has 
no indication who the author is. 

2 He expresses his philosophical aim in very vigorous language 
in the Epistle Dedicatory of his Solid Philosophy. " Wherefore, 
seeing philosophy reduced to this lamentable condition, .... 
I thought it became me to reinstate Reason in his soveraignty 
over Fancy ; and to assert to her the rightful dominion Nature 
had given her over all our judgments and discourses. I resolved 
therefore to disintricate Truth (which lay too deep for Fancy to 
fathom) from all those labyrinths of errour. I observ d that philo 
sophy labour d and languish d under many complicated dis- 


cisely as Kant subsequently did, that philosophy 
might do well to study the method of mathematics 
with a view to improving its own. And he sets 
himself to consider " whether the same clear way has 
been taken in other parts of philosophy as has been 
in that science (i.e. mathematics)." J The great 
advantage of the method of mathematics is, in his 
view, that it is definitive and demonstrative. " Tis 
evident," he says, " that geometricians do lay for 
their axioms self-evident propositions and clear 
definitions ; and their postulatums are not such as 
are merely begg d or supposed, and so need our 
favour to let them pass for truths ; but they claim 
our assent to them as their due ; and the conse 
quences they draw are all of them immediate ; which 
makes the contexture of the whole work close and 
compacted." 2 These advantages are not enjoyed 
by philosophy, because its votaries do not follow the 
rigorous way of mathematics. " I have not ob 
served," he continues, " that any other sort of philo 
sophers have taken that clear method. 3 Whence we 

tempers (all springing from this way of ideas) and that they were 
grown epidemical ; nor could they be cur d by the application 
of remedies to this or that particular part, or by confuting this 
or that particular errour. Hereupon, having found out the true 
cause of all these maladies of human understanding, I saw it was 
necessary to stub up by the roots that way itself ; and, by close 
and solid reasons, (the most decisive weapons in Truth s armory) 
to break in pieces the brittle glassy essences of those fantastick 
apparitions ; which, if a right way of reasoning be settled, and 
understood, will disappear and vanish out of the world, as their 
elder sisters the Fairies have done in this last half century." 
(Solid Philosophy, Epistle Dedicatory, pp. 8-9). 

1 Method to Science, Preface, p. 6. 2 Op. cit. Preface, p. 6. 

8 Sergeant later admits that suggestions towards the mathe 
matical method are to be found in Descartes (op. cit. Preface, 
B.P. 2 B 


have good reason to suspect that the want of observ 
ing this method, or something equivalent to it, has 
been the sole occasion of all those deviations from 
truth and disagreements among philosophers in their 
tenets and conclusions, which we find in the world." l 

Like Kant, also, Sergeant develops his method by 
criticism of the two methods previously employed by 
Descartes and Locke respectively, which he calls the 
Speculative and the Experimental. It is character 
istic of the former method to proceed by what Ser 
geant calls " Reason and Principles," while the latter 
is the method of Induction. 2 

Sergeant considers and examines each of these 
methods in turn. The Cartesian method, in the first 
place, is based on a first principle which claims to be 
self-evident. He criticises this first principle on 
several counts, of which the most important are the 

Descartes procedure for the discovery of the 
principle " Cogito ergo sum " is unnecessary, for he 
could have reached the certainty of his own existence 
equally well, at the very beginning of his method of 
doubt, in the proposition " Dubito ergo sum." And, 
since in each case the existence of a mental process is 
conceived to prove the existence of a thinking being, 
if " Cogito ergo sum " is conclusive of his own exist- 

p. 86). The mathematical method was also adopted, at least to 
some extent, by Spinoza and Cumberland. Sergeant knew 
Spinoza, but he does not seem to have known Cumberland s work. 
He was well acquainted with the writings of the Cartesians, 
mentioning Malebranche frequently, and also Regis, Rohault, 
Regius and Le Grand, with the latter of whom he engaged in 

1 Op. cit. Preface, p. 6 f. * Method to Science, Preface, p. 27. 


ence, so is " Dubito ergo sum." " Nor can any 
reason be given," he says, " why Ego sum dubi- 
tans does not include in it Ego sum as well as 
Ego sum cogitans does. And Cartesius himself 
(Medit. 3d) confesses the same expressly. To what 
end, then, did he run on in a long ramble of doubting, 
whenas the very first act of doubting would have done 
his whole business, and have prov d that he is ? " x 

Sergeant objects, in the second place, that Des 
cartes first principle is methodologically self-contra 
dictory. It is the nature of a genuine first principle 
to be self-evident ; that is, it is incapable of being 
reached by inference or validated by proof, for there 
is nothing more evident than it from which it may 
be inferred or by which it may be proved. But 
" Cogito ergo sum " involves, as the illative particle 
ergo indicates, a process of inference ; and it is 
therefore not a true first principle. And, Sergeant 
points out, it is impossible to defend Descartes, as 
Spinoza had attempted to do, by denying that he 
meant an inference, and reading as his first principle 
one positive proposition, viz. " Ego sum cogitans." 
For Descartes himself uses terms compatible only 
with the assumption that an inference is implied, 
when he says expressly in the third Meditation, 
" Ex eo quod dubito sequitur me esse." 

But though Descartes is not pinned down to his 
own words, and though we agree with Spinoza that 
the principle may be stated " Ego sum cogitans," it 
is clear that the whole first principle has been reached 
by a process of inference. Descartes whole method 
of doubt is ultimately a method of inference, and his 

1 Ibid. Preface, p. 32. 


principle, which is reached at the end of the process of 
doubt, is therefore not self-evident. " For, if this 
was evident of itself, and not needed to be proved, he 
might have proposed it at first, without making all 
that a-do." l Since, then, the principle is not self- 
evident, it cannot be a genuine first principle. 

For these and other reasons, Sergeant concludes 
that the Cartesian method is, as method, inade 
quate. 2 

Equally inadequate, in his judgment, is the 
inductive experimental method. He does not at 
tempt any detailed criticism of it, as method, in the 
Method to Science, but simply asserts that it is utterly 
incompetent to beget science. 3 He takes the position 
that no universal truths can be demonstrated on a 

1 Method to Science, Preface, p. 34. 

* It may be mentioned that Sergeant criticises Descartes 
ontological proof of the existence of God on lines closely similar 
to those on which Kant subsequently based his destructive 
criticism. The essence of his argument, which is not expressed 
nearly so clearly as Kant s, is that it is impossible to conclude 
from conception to existence, and therefore that my conception 
of God does not warrant the conclusion that he actually exists. 
" We may consider the notion of existence, or (which is all one), 
know the meaning of that word, and yet abstract whether it does 
actually put ita formal effect, that is, whether that existence is 
exercis d or not exercis d in the thing ; which consideration alone 
spoils his whole argument. Let us put a parallel. I have a 
complex idea of these words " My debtor will pay me a hundred 
pounds tomorrow at ten o clock at his goldsmith s " ; that is, 
I have in my mind the meaning of all the words ; and existence 
is necessarily involv d in the meaning of those words, for they 
signifie determinate persons, time, place, and action, all which 
involve existence ; will it therefore follow that that action of 
paying me money will be, because my idea includes the existence 
of that action, so determinately circumstanc d ? (Method to 
Science, Preface, p. 46 f.). 

8 Method to Science, Preface, p. 57. Cf. Solid Philosophy, Pre 
face, 2, 3, 6. 


basis of actual data obtained by experiment, for no 
mere enumeration of particular facts can lead logic 
ally to the enunciation of a universal proposition ; 
and he even declares that " when an experiment, or 
(which is the same) a matter of fact in nature is dis 
covered, we are never the nearer knowing what is the 
proper cause of such an effect, into which we may 
certainly refund it ; which, and onely which, is the 
work of science." l His point is that those who 
pretend that their principles are derived by induction 
from particulars really interpret these particulars 
according to principles which they assume on grounds 
other than those supplied by the particulars them 

The method that Sergeant himself adopts is a 
mathematico-logical one, in which emphasis is laid on 
system as exemplified in logical concatenation and 
mathematical proof. 2 System in philosophy is 
recognised by him to be of the very first importance. 
He professes that his method is a new one, and 
expects much of it ; but, in reality, it is largely a 
rechauffe of Aristotelian logic. He points out that 
Aristotle has been misrepresented by the Schoolmen, 
and he regards it as part of his task to reinstate the 
philosophy of Aristotle by re -interpreting his works. 
Sergeant s ideal is a " solid " philosophy, and he takes 
care to state that " those who followed Aristotle s 
principles (as the great Aquinas constantly endea 
voured) did generally discourse, even in such subjects, 
when they had occasion, very solidly." 3 

1 Method to Science, Preface, p. 59. 

2 Method to Science, p. 60 f. 

3 Solid Philosophy, Epistle Dedicatory, p. 3. 


Sergeant believes that it is impossible to demon 
strate philosophy solidly unless our notions are 
clearly defined. " The proper and effectual way to 
gain a clear and distinct knowledge of our simple 
notions is to make definitions of them." * Hence he 
advocates, as one of the first and most important 
pre-requisites of philosophical progress, the compila 
tion of a standard dictionary. " They (sc. defini 
tions) are such necessary instruments to true and 
solid science, that I could wish for the improvement 
of knowledge that our Universities would appoint a 
Committee of Learned Men to compile a Dictionary 
of Definitions for the notions we use in all parts of 
philosophy whatever." 2 

Though Sergeant criticises Locke and Descartes 
severely, he agrees with them in the initial assump 
tions of their two-substance doctrine. 3 Man, he says, 
is one thing, compounded of a corporeal and a spiritual 
nature. Each of these two natures gives rise to a 
mental operation proper and peculiar to it. The 
bodily faculty is that called Imagination or Fancy, 
the spiritual faculty is Mind or Understanding. 
There are some beings, e.g. brutes, which possess in 
strictness no souls but only bodies, and consequently 
their mental operations are limited to such perception 
as the faculty of Fancy enables them to have. On 
the other hand, purely spiritual beings, such as 
angels, have no faculty of Fancy (for that is essen- 

1 Method to Science, Preface, p. 51. 

2 Method to Science, Preface, p. 53. Cf. Berkeley s conception 
of the necessity of a Dictionary of Definitions for a demon 
strative science of ethics. 

\Solid Philosophy, Preface, 18. Cf. p. 65 ff. 


tially dependent on body) but only Mind or Under 
standing. Man, however, as a complex being, 
possessing both body and soul, and consequently both 
Fancy and Understanding, knows by means of both 
spiritual notions and material ideas or phantasms. 
Sergeant points out that, in the history of philo 
sophy, notions and ideas have very commonly been 
confused, and he maintains that one of the most 
necessary tasks for the reformer in philosophy is to 
explain carefully the differences between them. 1 

His account of sense-perception is largely based on 
Scholastic and Cartesian theories. All bodies, he 
holds, emit " effluviums," i.e. minute and impercep 
tible particles, which pass through the " pores " of the 
senses, and are thus carried to the brain. Now, the 
particles and the motions they cause in the sense- 
organs are material, but the notions which they 
produce in the soul are not material. How, then, 
are we to explain this interaction and intercausation 
of body and mind ? Sergeant accounts for it by a 
supposition that was then very generally made. 
" There must be some chief corporeal part in man," 
he says, " which is immediately united with the soul, 
as the matter with its form, and therefore is primarily 
corporeo-spiritual, and includes both natures." 2 
This part of the body is, in the view of Descartes, the 
pineal gland. And Sergeant agrees that between 
body and soul, in the pineal gland, there is a close 
interaction. " When that part is affected, after its 

1 Some account of Sergeant s conception of the relation between 
ideas and notions has been given above, in connection with our 
investigation of Berkeley s theory of notions. 

2 Solid Philosophy, p. 66. 


peculiar nature, corporeally, the soul is affected after 
its nature, that is spiritually or knowingly." x The 
body is regarded as the matter of the human being, 
the mind as the form ; and in the pineal gland there 
occurs what Sergeant calls " the immediate identi 
fication of matter and form." He does not, however, 
mean that they are completely identical. They still 
remain as matter and form respectively ; and each 
is affected in a way peculiar to itself and therefore 
different from the other. It is essential that the soul 
or the seat of knowledge, though identified in the 
pineal gland with the corporeal nature of the body, 
should yet be independent of it, for it must be so 
distinct from the body as to be able to abstract from 
the actual concrete effluviums supplied to it, and thus 
form universal notions. It is this fact of abstraction 
that explains why it is that the effluviums do not 
always cause in the mind the notion of the object as 
a whole from which they come. The effluviums enter 
consciousness through different sense-organs, and 
are " imprinted diversely " according to the partic 
ular sense-organ through which they come. And it 
is possible to consider the effluviums abstractly 
according to the sense-organs through which they 
come, and in this way to form notions not of the 
object as a whole, but of some one aspect of it. And 
it is in this way that abstract notions are produced. 

Sergeant admits that the word " notion " is 
ambiguous, for it may mean either what he himself 
calls an act of knowing, or the object known. 2 Now, 

1 Solid Philosophy, p. 66. 

2 Cf. the distinction made in recent psychology and episte- 
mology between act and object (Akt and Objckt). 


he admits that in philosophy both act and object are 
of importance, for " there are two considerations in 
knowledge, viz. the act of my knowing power and the 
object of that act, which as a kind of form actuates 
and determines the indifferency of my power, and 
thence specifies my act." l He explains, however, 
that he does not take notion in the subjective sense of 
an act of simple apprehension, but in its objective 
meaning ; and he accordingly gives the following 
definition. " A notion is the very thing itself exist 
ing in my understanding." 2 Yet, though he insists 
that notion and thing are identical, he admits that 
their manners of existing differ. The notion of a 
thing, e.g. a stone, qua " in the mind," has a spiritual 
manner of existing, whereas the thing itself has a 
corporeal manner of existing. He maintains, how 
ever, that this difference of manner of existing has 
no effect on what he believes to be the essential 
identity of " thing " and " notion." 3 

He illustrates this conception of identity through 
difference by the relations between notions in human 
minds and in the mind of God. Things, he believes, 
were in the divine understanding prior to their crea 
tion ; and they still exist there as divine archetypes. 
But, as created things, they exist also as notions in 
human minds. It is essentially the same thing that 
thus exists both in God s mind and in human minds. 4 

This doctrine of notions is expounded, with many 
applications and in great detail, in the Method to 
Science and Solid Philosophy. In the former book 
Sergeant classifies the " common heads of notions >r 

1 Solid Philosophy, p. 26. * Op. cit. p. 27. Op. cit. p. 38. 
4 Op. cit. p. 40. 


according to the Aristotelian table of categories. 
The whole book is, in fact, Aristotelian in tendency 
and execution, and it professes to lay down the 
principles of all scientific knowledge. He maintains, 
as we have seen when considering his criticism of 
Cartesianism, that all genuine first principles are 
self-evident propositions. 1 Self-evidence in a propo 
sition he understands in a very strict sense to require 
the formal identity of its terms. The terms need 
not, indeed, be verbally or grammatically identical, 
but they must be capable of reduction to verbal and 
grammatical identity. He attempts to show in 
detail that the first principles which form the basis 
of all philosophical sciences are self-evident proposi 
tions of this sort. 

Thus, as the first principles of metaphysics he 
mentions various forms of the Law of Identity, e.g. 
" Self-existence is self -existence," " What is is," 
" Ens is ens." Different expressions for the Law of 
Contradiction are also given, e.g. " Existence is not 
non-existence," and " Tis impossible the same thing 
should both be and not be at once." 

The first principles of other sciences are also 
identical propositions. The science of physics is 
grounded, he maintains, on the principle " Corpus 
est quantum " or " Corpus est extensum." Now, 
these formulations of the first principles of physics 
are not verbally self-evident, but, "if we rifle the 
words to get out the inward sense," 2 we shall find 
that they are really self -identical. " Corpus est 
extensum " really means, if we examine it carefully, 
" Ens extensum est ens extensum " or " Corpus est 

1 Method to Science, p. 130 ff. * Ibid. p. 151. 


corpus," propositions which are obviously formally 

The first principles of mathematics also are self- 
evident. They are reducible to formally self- 
identical propositions. Sergeant merely mentions 
two such propositions : " A whole is greater than 
part of itself " is not verbally identical ; but it may 
be reduced to a verbally identical proposition ; and 
the axioms about equals in Euclid s Elements may 
all be reduced to the identical proposition, " Aequale 
est aequale sibi." 

These are examples of some of the identical 
propositions involved in some of the most important 
philosophical sciences. Sergeant believes that the 
arguments which he has used in connection with these 
first principles apply equally to all others ; and 
consequently he affirms, as a universal proposition, 
that all the first principles of science are ultimately 
self-evident propositions. 

Solid Philosophy is intended, as the Preface shows, 
to apply the principles developed in the Method to 
Science to criticism of Locke, or rather, to criticise 
Locke from the standpoint of the Method to Science. 
It examines Locke s Essay chapter by chapter and 
verse for verse in much the same way as Leibniz did 
in his Nouveaux Essais, and its total of 534 closely- 
printed pages contains many acute and searching 
criticisms of the theory of Locke. The general lines 
of his criticism of Locke s theory of ideas have already 
been indicated in connection with our account of the 
very similar criticisms of Locke developed by Berke 
ley in the Commonplace Book. For our purpose, at 
least, that is the most interesting of his criticisms ; 


but the book is packed with passages, often indeed 
prolix and inept, but frequently terse, incisive and 
suggestive, which deserve the close attention of all 
students of Locke and Berkeley. To give an ade 
quate account of these criticisms within the limits 
of this Appendix would be an impossible task, and 
it will not be attempted. But enough has perhaps 
been said to show that Sergeant merits study by 
all who are interested in the philosophy of Locke 
and Berkeley. 


Abbott, 106, 133 n.^ 
Abstract ideas, j&59, 64-65, 

167. S / 

Berkeley s criticism of, 

118 ff. 
Algebra, in the Commonplace 

Book, 80. 
of Ethics, 289fl. 
of Nature, 219ff. 
Altruism, 310. 
Analytic philosophy, 294. 
Appearance and Reality, 1 91 ff . 
Aristotle, 7, 232, 235, 310, 372, 

Avenarius, 203. 

Bacon, 1. 
Bailey, 105, 109. 
Balfour, 316. 
Baronius, 371. 
Barrow, 83 n., 87. 
Bentley, 79. 
Blakey, 362 n. 
Browne, 15, 330, 342-3. 
Biilffinger, 363. 
Burthogge, 166 n., 360. 
Butler, 314 ff., 322, 338, 349, 

Cantor, 212n. 

Cartesianism, geometrical 

optics of, 95 ff. 

Cartesianism, influence of, on 
Berkeley, 67-73. 

Cassirer, 138n., 364. 
Causality, Berkeley s theory of, 

57, 205 ff., 250 ff. 
Locke s theory of, 56 ff. 
Cavalieri, 76, 82, 279. 
Certainty, 58 ff. 
Cheselden s case, 113n. 
Cheyne, 87. 

Chillingworth, 326, 338. 
Christianity, 338 ff. 
Clarke, 317, 346, 348 n., 354, 

365, 374. 
Collier, 360 ff. 
Collins, 327, 329, 330, 336, 339, 

345 ff. 

Colours, perception of, 104, 108- 
Common Sense, 57, 61, 347, 

352, 355. 
Confucius, 340. 
Cumberland, 289 n. 
Cudworth, 73, 74. 

Deists, 15 ff., 321 ff. 
De Moivre, 272. 
Demonstration, 60. 
Descartes, 7, 31, 68, 75, 150, 

179, 211, 215, 222, 250, 

290 n., 372, 386. 
Distance, perception of , 97, 103. 

Egoism, 310. 

Environment, Berkeley s philo 
sophical and religious, 
12 ff. 




Epicurus, 75. 
Erdmann, 364. 
Error, 60. 

Ethics, application of mathe 
matics to, 288 ff. 

Berkeley s theory of, 291 ff. 

Locke s theory of, 284 ff. 
Evil, 307 ff. 
Extension, HOff. 
Externality, 181 ff. 

Collier s theory of, 376 ff. 

Faith, 342. 

difference from sense-know 
ledge, 355. 

difference from notional 
knowledge, 356. 

Ferrier, 98 n., 106. 

Fluxions, 267 ff. 

Fraser, Campbell, 20 n., 229 n., 
318, 367. 

Freedom, 305-306, 310, 346. 

Free-thinkers, 327 ff. 

Galileo, 91. 

Geometry, Berkeley s relation 

to Euclidean, 83 ff. 
Berkeley s conception of, 

261 ff. 

Geulincx, 68, 289 n. 
Glanvill, 290 n. 

God, Berkeley s theory of, as 
cause, 57, 184, 194, 206, 
226, 250 ff. 
Berkeley s theory of, in 

morality, 308, 310. 
Collier s theory of, 380. 
Locke s theory of, 57 
Malebranche s theory of, 

70 ff. 
ontological proof of, 69, 348, 


Good, 307 ff. 
Green, T. H., 4. 

Halley, 87, 272. 

Hamilton, 113n., 157 n. 

Happiness, 307 ff., 315. 

Harris, 87. 

Hayes, 87, 272. 

Helmholtz, 102 n. 

Hobbes, 1, 13, 31, 61, 74, 75, 

312, 315. 
Hume, 2, 5, 47, 148, 196, 198, 

202, 317. 

Husserl, 138 n., 153, 168. 
Hutcheson, 312. 

Idea, archetypal, 256. 

Berkeley s theory of, 147 ff., 

181 ff. 
Locke s theory of, 36 ff., 

42 ff., 54 ff. 
Sergeant s criticism of 

Locke s theory of, 62-66. 
Identity, 49 ff., 198 ff. 
Imagination, 128, 148 ff., 160, 


Immediacy, 148 ff., 193 ff. 
Immortality, 301, 353. 
Indivisibles, 83. 
Infinite, see God. 
Infinitesimals, 86, 88, 265 ff. 
Introspection, 33, 107, 109 , 

121, 123. 
Intuition, 53, 58 ff. 

James, 105. 
Jurin, 265-6. 
Judgment, 255. 

Kant, 5, 13, 117, 294 n., 301, 

306, 320, 385, 386. 
Keill, 87. 
King, 343. 
Knowledge, analogical, 343. 

notional, 161 ff. 

theory of, 117ff. 

of ideas, 147 ff. 

of spirits, 159 ff. 



Laws of Nature, 221 ff., 224 f., 

248 ff. 

as moral rules, 301. 
Leibniz, 76, 87, 88, 211, 212, 
228-230, 251, 272, 275, 
279, 289 n. 

Locke, general character of 
philosophy of, 1, 13, 14, 
17, 19. 

influence on Berkeley, 32-67. 
method of, 9, 32. 
theory of abstract ideas, 

causality, 56. 
ethics, 284 ff., 317. 
ideas, 36 ff., 168. 
mind, 46 ff. 
modes, 54. 
psychology, 7. 
reality, 41 ff. 
relations, 56. 
representative perception, 

150 ff. 
qualities, primary and 

secondary, 40 ff., 179ff. 
space and time, 239ff. 
sobstance, 41 ff. 
Lyon, Georges, 167, 373. 

Magnitude, 98, 104 ff. 
Malebranche, 31, 38, 57, 68, 
98 ff., 102 n., 187 n., 215, 
317, 368, 369. 
Mandeville, 312, 315, 330. 
Mathematics, Berkeley s 

theory of, 261 ff. 
in application to ethics, 

263 ff., 289 ff. 
in the Commonplace Book, 

75 ff. 

theory of signs, 209 ff. 
Matter, Berkeley s criticism of, 

170 ff. 

Cartesian view of, 68. 
Collier s view of, 376. 
Meanings, 130-131, 159. 
Meinong, 153. 

Memory, 148. 
Metaphysics, 117ff. 
Method, 8. 
Mill, 6, 103. 

Mind, Berkeley s theory of, 
51 ff., 193 ff. 

Locke s theory of, 46, 52. 
Miracles, 302 n. 
Modes, Berkeley s theory of, 55- 

Locke s theory of, 54. 
Molyneux, 15, 100. 
Moral rules, 310 ff. 
More, Henry, 73. 
Motion, 226 ff. 

Names as universals, 129-130. 
Nature, 208, 221, 301. 
Newton, 14, 17, 31, 75 ff., 87, 

212, 222, 227-230, 235, 

239, 243, 267. 
Nieuwentijt, 88. 
Norris, 361, 368, 369. 
Notion, Berkeley s theory of, 

67, 143, 144, 161 ff., 254. 


Burthogge s theory of, 166 n. 
Sergeant s theory of, 163 ff., 


Obligation, moral, 300, 315. 
Occam s Razor, 39, 176. 
Occasionalism, 68, 175, 196. 
Ontological proof, 69, 348, 350. 

Pampsychism, 205. 
Perception, 142 ff., 253, 255. 

representative, 150 ff. 

See also Vision. 
Permanence, 49ff., 185 ff., 

193 ff., 198 ff. 
Personality, 198 ff. 
Phaenomena, 254. 
Philosophy, general char 
acteristics of English, 1-9. 
Plato, 232, 233, 256. 
Pleasure, 307. 
Presentations, 153. 



Psychology, method of, 3 ft. ! 
of Vision, 94-116. 

Qualities, primary and secon 
dary, Berkeley s theory of, 
180 f. 

primary and secondary, Col 
lier s reference to, 377. 

primary and secondary, 
Locke s theory of, 40 ff . , 

Raphson, 87. 

Reality, Berkeley s theory of, 
178ff., 193ff., 204-5. 

Locke s theory of, 42 ff. 
Reason, 257. 

and religion, 326. 

pleasures of, 309. 
Reid, 152 n., 156 n., 361. 
Relations, Berkeley s theory 
of, 6, 159. 

Locke s theory of, 55. 
Religion, philosophy of, 319 ff. 
Revelation, 232. 
Robins, 265-6, 271. 

Sameness, 154 ff., 186 f. 
Scepticism, 53, 57 ff., 70. 
Scheiblerus, 371 n. 
Scholasticism, 16, 95, 118, 187, 

235, 371. 

Self, 56 ff., and see Spirit. 
Self-love, 307, 310. 
Sensations, pleasure -aspect of, 


tactual, 99 ff. 
visual, 100 ff. 
Sergeant, 61-67, 162 ff., 290 n., 

292 n., 383 ff. 

Shaftesbury, 313, 315, 330. 
Signs, theory of, 102, 110, 

131 ff., 209 ff., 250. 
Solipsism, 205. 
Sorley, 362 n. 

Soul, immortality of, see Im 

Space, 90, 226 ff., 242 ff. 
Spinoza, 31, 74, 75, 289 n. 
Spirit, existence of, 193 ff. 

ground of reality, 1 78 ff. 
Stewart, 361. 
Stout, 114n., 148 n., 153. 
Suarez, 371 n. 

Substance, Berkeley s criticism 
of Locke, 177 ff. 

Locke s theory of, 42 ff., 390. 
Summum Bonum, 307 ff., 315. 
Swift, 16. 

Taylor, 203 n. 
Tennemann, 364. 
Theology, 320. 
Tillotson, 326, 338. 
Time. 89. 226 ff., 239ff. 
Tindul, 339, 340, 341. 
Toland. 15, 336, 337 n., 339, 

Ueberweg, 364. meanings, 1 30- \ 3 1 

as names, 129-130. 

as particular images, 128-1 

as particular things, 127- 

as signs, 131 ff. 

possibility of, 123 ff., ~G3. 

relation to abstract ideas, 1 22. 
Utilitarianism, 317-8. 

Vision, psychology of, 94-116. 
Volition, see Will. 

Wallis, 76, 87, 212. 

Walton, 265. 

Ward, 7, 8, 156 n. 

Whiston, 374, 375. 

Will, Berkeley s theory of, 

200 ff., 252. 
freedom of, 305, 370. 

Woolston, 339-341. 



/OU < r f( * 



Johnston, George Alexander 

The development of Berkeley s 
J6 philosophy 
COD. 3 



\ririr-i * ..*.*._