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M C M I I 







THEY who have presumed to dogmatize on nature, as 
on some well investigated subject, either from self-conceit 
or arrogance, and in the professorial style, have inflicted 
the greatest injury on philosophy and learning. For they 
have tended to stifle and interrupt inquiry exactly in pro 
portion as they have prevailed in bringing others to their 
opinion: and their own activity has not counterbalanced 
the mischief they have occasioned by corrupting and de 
stroying that of others. They again who have entered upon 
a contrary course, and asserted that nothing whatever can 
be known, whether they have fallen into this opinion from 
their hatred of the ancient sophists, or from the hesitation 
of their minds, or from an exuberance of learning, have 
certainly adduced reasons for it which are by no means 
contemptible. They have not, however, derived their 
opinion from true sources, and, hurried on by their zeal 
and some affectation, have certainly exceeded due modera 
tion. But the more ancient Greeks (whose writings have 
perished), held a more prudent mean, between the arro 
gance of dogmatism, and the despair of scepticism; and 
though too frequently intermingling complaints and indig- 



nation at the difficulty of inquiry, and the obscurity of 
things, and champing, as it were, the bit, have still per 
sisted in pressing their point, and pursuing their inter 
course with nature; thinking, as it seems, that the better 
method was not to dispute upon the very point of the pos 
sibility of anything being known, but to put it to the test 
of experience. Yet they themselves, by only employing 
the power of the understanding, have not adopted a fixed 
rule, but have laid their whole stress upon intense medita 
tion, and a continual exercise and perpetual agitation of 
the mind. 

Our method, though difficult in its operation, is easily 
explained. It consists in determining the degrees of cer 
tainty, while we, as it were, restore the senses to their 
former rank, but generally reject that operation of the 
mind which follows close upon the senses, and open and 
establish a new and certain course for the mind from the 
first actual perceptions of the senses themselves. This, no 
doubt, was the view taken by those who have assigned so 
much to logic; showing clearly thereby that they sought 
some support for the mind, and suspected its natural and 
spontaneous mode of action. But this is now employed 
too late as a remedy, when all is clearly lost, and after the 
mind, by the daily habit and intercourse of life, has come 
prepossessed with corrupted doctrines, and filled with the 
vainest idols. The art of logic therefore being (as we have 
mentioned), too late a precaution, 1 and in no way remedy- 

1 Because it was idle to draw a logical conclusion from false principles, error 

i being propagated as much by false premises, which logic does not -pretend to 

j examine, as by illegitimate inference. Hence, us Bacon says further on, men 

being easily led lo confound legitimate inference with truth, were confirmed 

V in their errors by the very subtilty of their genius. Ed. 


ing the matter, has tended more to confirm errors, than to 
disclose truth. Our only remaining hope and salvation is 
to begin the whole labor of the mind again; not leaving 
it to itself, but directing it perpetually from the very first, 
and attaining our end as it were by mechanical aid. If 
men, for instance, had attempted mechanical labors with 
their hands alone, and without the power and aid of instru 
ments, as they have not hesitated to carry on the labors 
of their understanding with the unaided efforts of their 
mind, they would have been able to move and overcome 
but little, though they had exerted their utmost and united 
powers. And just to pause awhile on this comparison, 
and look into it as a mirror; let us ask, if any obelisk of 
a remarkable size were perchance required to be moved, 
for the purpose of gracing a triumph or any similar pag 
eant, and men were to attempt it with their bare hands, 
would not any sober spectator avow it to be an act of the 
greatest madness? And if they should increase the num 
ber of workmen, and imagine that they could thus succeed, 
would he not think so still more ? But if they chose to make 
a selection, and to remove the weak, and only employ the 
strong and vigorous, thinking by this means, at any rate, 
to achieve their object, would he not say that they were 
more fondly deranged? Nay, if not content with this, they 
were to determine on consulting the athletic art, and were 
to give orders for all to appear with their hands, arms, and 
muscles regularly oiled and prepared, would he not exclaim 
that they were taking pains to rave by method and design ? 
Yet men are hurried on with the same senseless energy and 
useless combination in intellectual matters, as long as they 
expect great results either from the number and agreement, 
or the excellence and acuteness of their wits; or even 


strengthen their minds with logic, which may be con 
sidered as an athletic preparation, but yet do not desist 
(if we rightly consider the matter) from applying their own 
understandings merely with all this zeal and effort. While 
nothing is more clear, than that in every great work exe 
cuted by the hand of man without machines or implements, 
it is impossible for the strength of individuals to be in 
creased, or for that of the multitude to combine. 

Having premised so much, we lay down two points on 
which we would admonish mankind, lest they should fail 
to see or to observe them. The first of these is, that it is 
our good fortune (as we consider it), for the sake of extin 
guishing and removing contradiction and irritation of mind, 
to leave the honor and reverence due to the ancients un 
touched and undiminished, so that we can perform our 
intended work, and yet enjoy the benefit of our respectful 
moderation. For if we should profess to offer something 
better than the ancients, and yet should pursue the same 
course as they have done, we could never, by any artifice, 
contrive to avoid the imputation of having engaged in a 
contest or rivalry as to our respective wits, excellences, 
or talents; which, though neither inadmissible nor new (for 
why should we not blame and point out anything that is 
imperfectly discovered or laid down by them, of our own 
right, a right common to all?), yet however just and allow 
able, would perhaps be scarcely an equal match, on account 
of the disproportion of our strength. But since our present 
plan leads up to open an entirely different course to the 
understanding, and one unattempted and unknown to them, 
the case is altered. There is an end to party zeal, and we 
only take upon ourselves the character of a guide, which 
requires a moderate share of authority and good fortune, 


rather than talents and excellence. The first admonition 
relates to persons, the next to things. 

We make no attempt to disturb the system of philosophy 
that now prevails, or any other which may or will exist, 
either more correct or more complete. For we deny not 
that the received system of philosophy, and others of a 
similar nature, encourage discussion, embellish harangues, 
are employed, and are of service in the duties of the pro 
fessor, and the affairs of civil life. Nay, we openly express 
and declare that the philosophy we offer will not be very 
useful in such respects. It is not obvious, nor to be under 
stood in a cursory view, nor does it flatter the mind in its 
preconceived notions, nor will it descend to the level of the 
generality of mankind unless by its advantages and effects. 

Let there exist then (and may it be of advantage to 
both), two sources, and two distributions of learning, and 
in like manner two tribes, and as it were kindred families 
of contemplators or philosophers, without any hostility or 
alienation between them; but rather allied and united by 
mutual assistance. Let there be in short one method 
of cultivating the sciences, and another of discovering 
them. And as for those who prefer and more readily re 
ceive the former, on account of their haste or from motives 
arising from their ordinary life, or because they are unable 
from weakness of mind to comprehend and embrace the 
other (which must necessarily be the case with by far the 
greater number), let us wish that they may prosper as they 
desire in their undertaking, and attain what they pursue. 
But if any individual desire, and is anxious not merely to 
adhere to, and make use of present discoveries, but to pene 
trate still further, and not to overcome his adversaries in 
disputes, but nature by labor, not in short to give elegant 


and specious opinions, but to know to a certainty and dem 
onstration, let him, as a true son of science (if such be his 
wish), join with us; that when he has left the antechambers 
of nature trodden by the multitude, an entrance may at last 
be discovered to her inner apartments. And in order to be 
better understood, and to render our meaning more familiar 
by assigning determinate names, we have accustomed our 
selves to call the one method the anticipation of the mind, 
and the other the interpretation of nature. 

We have still one request left. We have at least re 
flected and taken pains in order to render our propositions 
not only true, but of easy and familiar access to men s 
minds, however wonderfully prepossessed and limited. 
Yet it is but just that we should obtain this favor from 
mankind (especially in so great a restoration of learning 
and the sciences), that whosoever may be desirous of form 
ing any determination upon an opinion of this our work 
either from his own perceptions, or the crowd of authori 
ties, or the forms of demonstrations, he will not expect to 
be able to do so in a cursory manner, and while attending 
to other matters; but in order to have a thorough knowledge 
of the subject, will himself by degrees attempt the course 
which we describe and maintain; will be accustomed to the 
subtilty of things which is manifested by experience; and 
will correct the depraved and deeply rooted habits of his 
mind by a seasonable, and, as it were, just hesitation: 
and then, finally (if he will), use his judgment when he 
has be^un to be master of himself. 



I. MAN, as the minister and interpreter of nature, does 
and understands as much as his observations on the order 
of nature, either with regard to things or the mind, permit 
him, and neither knows nor is capable of more. 

II. The unassisted hand and the understanding left to 
itself possess but little power. Effects are produced by the 
means of instruments and helps, which the understanding 
requires no less than the hand; and as instruments either 
promote or regulate the motion of the hand, so those that 
are applied to the mind prompt or protect the understanding. 

III. Knowledge and human power are synonymous, since 
the ignorance of the cause frustrates the effect; for nature is 
only subdued by submission, and that which in contem--, 
plative philosophy corresponds with the cause in practical 
science becomes the rule. 

IV. Man while operating can only apply or withdraw 
natural bodies; nature internally performs the rest. 

Y. Those who become practically versed in nature are, 
the mechanic, the mathematician, the physician, the al 
chemist, and the magician, 1 but all (as matters now stand) 
with faint efforts and meagre success. 

1 Bacon uses the term in its ancient sense, and means one who, knowing 
the occult properties of bodies, is able to startle the ignorant by drawing out of 
them wonderful and unforeseen changes. See the 85th aphorism of this book, 
and the 5th cap. book iii. of the De Augmentis Bcientiarum, where he speaks 
more clearly Ed. 



VI. It would be madness and inconsistency to suppose 
that things which have never yet been performed can be 
performed without employing some hitherto untried means. 

VII. The creations of the mind and hand appear very 
numerous, if we judge by books and manufactures; but all 
that variety consists of an excessive refinement, and of de 
ductions from a few well known matters not of a number 
of axioms.* 

VIII. Even the effects already discovered are due to 
chance and experiment rather than to the sciences; for our 
present sciences are nothing more than peculiar arrange 
ments of matters already discovered, and not methods for 
discovery or plans for new operations. 

IX. The sole cause and root of almost every defect in 
the sciences is this, that while we falsely admire and extol 
the powers of the human mind, we do not search for its 
real helps. 

X. The subtilty of nature is far beyond that of sense 
or of the understanding: so that the specious meditations, 
speculations, and theories of mankind are but a kind of 
insanity, only there is no one to stand by and observe it. 

XI. As the present sciences are useless for the discovery 
of effects, so the present system of logic 3 is useless for the 
discovery of the sciences. 

} By this term axiomata, Bacon here speaks of general principles, or univer 
sal laws. lu the 19th aphorism he employs the term to express any proposition 
collected from facts by induction, and thus fitted to become the starting-point 
of deductive reasoning. In the last and more rigorous sense of the term, Bacon 
held they arose from experience. See "Whewell s "Philosophy of the Inductive 
Sciences," vol. i. p. 74; and Mill s "Logic," vol. i. p. 311; and the June 
"Quarterly," 1841, for the modern phase of the discussion. Ed. 

3 Bacon here attributes to the Aristotelian logic the erroneous consequences 
which sprung out of its abuse. The demonstrative forms it exhibits, whether 
verbally or mathematically expressed, are necessary to the support, verification, 


XII. The present system of logic rather assists in con 
firming and rendering inveterate the errors founded on 
vulgar notions than in searching after truth, and is there 
fore more hurtful than useful. 

/^ XIII. The syllogism is not applied to the principles of 
I the sciences, and is of no avail in intermediate axioms, 4 as 

and extension of induction, and when the propositions they embrace are founded 
on an accurate and close observation of facts, the conclusions to which they 
lead, even in moral science, may be regarded as certain as the facts wrested out 
of nature by direct experiment. In physics such forms are absolutely required 
to generalize the results of experience, and to connect intermediate axioms with, 
laws still more general, as is sufficiently attested by the fact, that no science 
since Bacon s day has ceased to be experimental by the mere method of induc 
tion, and that all become exact only so far as they rise above experience, and 
connect their isolated phenomena with general laws by the principles of deduc 
tive reasoning. So far, then, are these forms from being useless, that they are 
absolutely essential to the advancement of the sciences, and in no case can be 
looked on as detrimental, except when obtruded in the place of direct experi 
ment, or employed as a means of deducing conclusions about nature from im 
aginary hypotheses and abstract conceptions. This had been unfortunately the 
practice of the Greeks. From the rapid development geometry received in their 
hands, they imagined the same method would lead to results equally brilliant in 
natural science, and snatching up some abstract principle, which they carefully 
removed from the test of experiment, imagined they could reason out from it all 
the laws and external appearances of the universe. The scholastics were im 
pelled along the same path, not only by precedent, but by profession. Theology 
was the only science which received from them a consistent development, and 
the d priori grounds on which it rested prevented them from employing any 
other method in the pursuit of natural phenomena. Thus, forms of demonstra 
tion, in themselves accurate, and of momentous value in their proper sphere, 
became confounded with fable, and led men into the idea they were exploring 
truth when they were only accurately deducing error from error. One principle 
ever so slightly deflected, like a false quantity in an equation, could be sufficient 
to infect the whole series of conclusions of which it was the base ; and though 
the philosopher might subsequently deduce a thousand consecutive inferences 
with the utmost accuracy or precision, he would only succeed in drawing out 
very methodically nine hundred and ninety-nine errors. Ed. 

4 It would appear from this and the two preceding aphorisms, that Bacon 
fell into the error of denying the utility of the syllogism in the very part of 
inductive science where it is essentially required. Logic, like mathematics, ia 


being very unequal to the subtilty of nature, it forces 
assent, therefore, and not things. 

XIV. The syllogism consists of propositions; proposi 
tions of words; words are the signs of notions. If, there 
fore, the notions (which form the basis of the whole) be 
confused and carelessly abstracted from things, there is no 
solidity in the superstructure. Our only hope, then, is in 
genuine induction. 

XV. We have no sound notions either in logic or phys 
ics; substancej quality, action, passion, and existence are 
not clear notions; much less weight, levity, density, tenu 
ity, moisture, dryness, generation, corruption, attraction, 

purely a formal process, and must, as the scaffolding to the building, be em 
ployed to arrange facts in the structure of a science, and not to form any por 
tion of its groundwork, or to supply the materials of which the system is to 
be composed. The word syllogism, like most other pyschological terms, has 
no fixed or original signification, but is sometimes employed, as it was by the 
Greeks, to denote general reasoning, arid at others to point out the formal 
method of deducing a particular inference from two or more general proposi 
tions. Bacon does not confine the term within the boundaries of express defi 
nition, but leaves us to infer that he took it in the latter sense, from his custom 
of associating the term with the wranglings of the schools. The scholastics, it 
is true, abused the deductive syllogism, by employing it in its naked, skeleton- 
like form, and confounding it with the whole breadth of logical theory; but 
their errors are not to be visited on Aristotle, who never dreamed of playing 
with formal syllogisms, and, least of all, mistook the descending for the ascend 
ing series of inference. In our mind wo are of accord with the Stagyrite, who 
propounds, as far as we can interpret him, two modes of investigating truth 
the one by which we ascend from particular and singular facts to general laws 
and axioms, and the other by which we descend from universal propositions to 
the individual cases which they virtually include. Logic, therefore, must equally 
vindicate the formal purity of the synthetic illation by which it ascends to the 
whole, as the analytic process by which it descends to the parts. The deductive 
and inductive syllogism are of equal significance in building up any body of 
truth, and whoever restricts logic to either process, mistakes one-half of its 
province for the whole; and if he acts upon his error, will paralyze his meth 
ods, and strike the noblest part of science with sterility. Ed. 


repulsion, element, matter, form, and the like. They are 
all fantastical and ill-defined. 

XVI. The notions of less abstract natures, as man, doer, 

* / O7 

dove, and the immediate perceptions of sense, as heat, cold, 
white, black, do not deceive us materially, yet even these 
are sometimes confused by the mutability of matter and 
the intermixture of things. All the rest which men have 
hitherto employed are errors, and improperly abstracted 
and deduced from things. 

XVII. There is the same degree of licentiousness and 
error in forming axioms as in abstracting notions, and that 
in the first principles, which depend on common induction; 
still more is this the case in axioms and inferior proposi 
tions derived from syllogisms. 

XVIII. The present discoveries in science are such as 
lie immediately beneath the surface of common notions. It 
is necessary, however, to penetrate the more secret and re 
mote parts of nature, in order to abstract both notions and 
axioms from things by a more certain and guarded method. 

XIX. There are and can exist but two ways of investi 
gating and discovering truth. The one hurries on rapidly 
from the senses and particulars to the most general axioms, 
and from them, as principles and their supposed indisput 
able truth, derives and discovers the intermediate axioms. 
This is the way now in use. The other constructs its axioms 
from the senses and particulars, by ascending continually 
and gradually, till it finally arrives at the most general 
axioms, which is the true but unattempted way. 

XX. The understanding when left to itself proceeds by 
the same way as that which it would have adopted under 
the guidance of logic, namely, the first; for the mind is fond 
of starting off to generalities, that it may avoid labor, and 


after dwelling a little on a subject is fatigued by experiment. 
But those evils are augmented by logic, for the sake of the 
ostentation of dispute. 

XXI. The understanding, when left to itself in a man of 
a steady, patient, and reflecting disposition (especially when 
unimpeded by received doctrines), makes some attempt in 
the right way, but with little effect, since the understanding, 
undirected and unassisted, is unequal to and unfit for the 
task of vanquishing the obscurity of things. 

XXII. Each of these two ways begins from the senses 
and particulars, and ends in the greatest generalities. But 
they are immeasurably different; for the one merely touches 
cursorily the limits of experiment and particulars, while the 
other runs duly and regularly through them the one from 
the very outset lays down some abstract and useless general 
ities, the other gradually rises to those principles which are 
really the most common in nature. 5 

XXIII. There is no small difference between the idols 
of the human mind and the ideas of the Divine mind that 
is to say, between certain idle dogmas and the real stamp 
and impression of created objects, as they are found in 

XXIV. Axioms determined upon in argument can never 
assist in the discovery of new effects; for the subtilty of 
nature is vastly superior to that of argument. But axioms 
properly and regularly abstracted from particulars easily 

5 The Lalin is, ad ea qua revera sunt nature notiora. This expression, 
natune notiora, nature nolior, is so frequently employed by Bacon, that, \vo 
may conclude it to point to some distinguishing feature in the Baconian physics. 
It properly refers to the most evident principles and laws of nature, and springs 
from that system which regards the material universe as endowed with intelli 
gence, and acting according to rules either fashioned or clearly understood by 
itself. Ed. 


point out and define new particulars, and therefore impart 
activity to the sciences. 

XXY. The axioms now in use are derived from a scanty 
handful, as it were, of experience, and a few particulars of 
frequent occurrence, whence they are of much the same 
dimensions or extent as their origin. And if any neglected 
or unknown instance occurs, the axiom is saved by some 
frivolous distinction, when it would be more consistent with 
truth to amend it. 

XXVI. We are wont, for the sake of distinction, to call 
that human reasoning which we apply to nature the antici 
pation of nature (as being rash and premature), and that 
which is properly deduced from things the interpretation of 

XXVII. Anticipations are sufficiently powerful in pro 
ducing unanimity, for if men were all to become even uni 
formly mad, they might agree tolerably well with each 

XXVIII. Anticipations again, will be assented to much 
more readily than interpretations, because being deduced 
from a few instances, and these principally of familiar oc 
currence., they immediately hit the understanding and sat 
isfy th imagination; while, on the contrary, interpretations, 

>eing deduced from various subjects, and these widely dis 
persed, cannot suddenly strike the understanding, so that in 
common estimation they must appear difficult and discord 
ant, and almost like the mysteries of faith. 

XXIX. In sciences founded on opinions and dogmas, it 
is right to make use of anticipations and logic if you wish to 
force assent rather than things. 

XXX. If all the capacities of all ages should unite and 
combine and transmit their labors, no great progress will be 


made in learning by anticipations, because the radical errors, 
and those which occur in the first process of the mind, are 
not cured by the excellence of subsequent means and reme 

XXXI. It is in vain to expect any great progress in the 
sciences by the superinducing or ingrafting new matters 
upon old. An instauration must be made from the very 
foundations, if we do not wish to revolve forever in a cir 
cle, making only some slight and contemptible progress. 

XXXII. The ancient authors and all others are left in 
undisputed possession of their honors; for we enter into no 
comparison of capacity or talent, but of method, and assume 
the part of a guide rather than of a critic. 

XXXIII. To speak plainly, no correct judgment can be 
formed either of our method or its discoveries by those an 
ticipations which are now in common use; for it is not to be 
required of us to submit ourselves to the judgment of the 
very method we ourselves arraign. 

XXXIY. Nor is it an easy matter to deliver and explain 
our sentiments; for those things which are in themselves 
new can yet be only understood from some analogy to what 
is old. 

XXXV. Alexander Borgia 8 said of the expedition of the 
French into Italy that they came with chalk in their hands 
to mark up their lodgings, and not with weapons to force 
their passage. Even so do we wish our philosophy to make 
its way quietly into those minds that are fit for it, and of 
good capacity; for we have no need of contention where we 

6 This Borgia was Alexander VI., and tho expedition alluded to that in 
which Charles VIII. overran the Italian peninsula in five months. Bacon uses 
the same illustration in concluding his survey of natural philosophy, in the sec 
ond book of tho "De Augmcntid. " Ed. 


differ in first principles, and in our very notions, and even 
in our forms of demonstration. 

XXXVI. We have but one simple method of delivering 
our sentiments, namely, we must bring men to particulars 
and their regular series and order, and they must for a while 
renounce their notions, and begin to form an acquaintance 
with things. 

XXXVII. Our method and that of the sceptics 7 agree 
in some respects at first setting out, but differ most widely, 
and are completely opposed to each other in their conclu 
sion; for they roundly assert that nothing can be known; 
we, that but a small part of nature can be known, by the 
present method; their next step, however, is to destroy the 
authority of the senses and understanding, while we invent 
and supply them with assistance. 

XXXV1IL The idols and false notions which have al 
ready preoccupied the human understanding, and are deeply 
rooted in it, not only so beset men s minds that they become 
difficult of access, but even when access is obtained will again 
meet and trouble us in the instauration of the sciences, un 
less mankind when forewarned guard themselves with all 
possible care against them. 

XXXIX. Four species of idols beset the human mind, 8 

7 Ratio eorum qui acatalepsiam tenuerunt. Bacon alludes to the members 
of the later academy, who held the aicaraAijijfia, or the impossibility of compre 
hending anything. His translator, however, makes him refer to the sceptics, 
who neither dogmatized about the known or the unknown, but simply held, 
that as all knowledge was relative, *?<> aa.vra. ] man could never arrive at 
absolute truth, and therefore could not with certainty affirm or deny any 
thing. Ed. 

8 It is argued by Hallam, with some appearance of truth, that idols is not 
the correct translation of etSwAa ) from which the original idola is manifestly de 
rived ; but that Bacon used it in the literal sense attached to it by the Greeks, 
as a species of illusion, or false appearance, and not as a species of divinity be- 


to which (for distinction s sake) we have assigned names, 
calling the first Idols of the Tribe, the second Idols of the 
Den, the third Idols of the Market, the fourth Idols of the 

XL. The formation of notions and axioms on the foun 
dation of true induction is the only fitting remedy by which 
we can ward off and expel these idols. It is, however, of 
great service to point them out; for the doctrine of idols 
bears the same relation to the interpretation of nature as 
that of the confutation of sophisms does to common 
logic. 9 

XLI. The idols of the tribe are inherent in human nature 
and the very tribe or race of man; for man s sense is falsely 
asserted to be the standard of things; on the contrary, all 
the perceptions both of the senses and the mind bear refer 
ence to man and not to the universe, and the human mind 
resembles those uneven mirrors which impart their own 

fore which the mind bows down. If Hallam be right, Bacon is saved from the 
odium of an analogy which his foreign commentators are not far wrong in de 
nouncing as barbarous; but this service is rendered at the expense of the men 
who have attached an opposite meaning to the word, among whom are Brown, 
Playfair and Dugald Stewart. Ed. 

9 We cannot see how these idols have less to do witli sophistical paralogisms 
than with natural philosophy. The process of scientific induction involves only 
the first elements of reasoning, and presents such a clear and tangible surface, 
as to allow no lurking-place for prejudice; while questions of politics and 
morals, to which the deductive method, or common logic, as Bacon calls it, is 
peculiarly applicable, are ever liable to be swayed or perverted by the preju 
dices he enumerates. After mathematics, physical science is the least amenable 
to the illusions of feeling; each portion having been already tested by experi 
ment and observation, is fitted into its place in the system, with all the rigor 
of the geometrical method; affection or prejudice cannot, as in matters of taste, 
history or religion, select fragmentary pieces, and form a system of their own. 
The whole must be admitted, or the structure of authoritative reason razed to 
the ground. It is needless to say that the idols enumerated present only 
another interpretation of the substance of logical fallacies. -Ed. 


properties to different objects, from which rays are emitted 
and distort and disfigure them. 10 

XLII. The idols of the den are those of each individual; 
for everybody (in addition to the errors common to the race 
of man) has his own individual den or cavern, which inter 
cepts and corrupts the light of nature, either from his own 
peculiar and singular disposition, or from his education and 
intercourse with others, or from his reading, and the author 
ity acquired by those whom he reverences and admires, or 
from the different impressions produced on the mind, as it 
happens to be preoccupied and predisposed, or equable and 
tranquil, and the like; so that the spirit of man (according 
to its several dispositions), is variable, confused, and as it 
were actuated by chance; and Heraclitus said well that men 
search for knowledge in lesser worlds, and not in the greater 
or common world. 

XLIII. There are also idols formed by the reciprocal in 
tercourse and society of man with man, which we call idols 
of the market, from the commerce and association of men 
with each other; for men converse by means of language, 
but words are formed at the will of the generality, and there 
arises from a bad and unapt formation of words a wonderful 
obstruction to the mind. Nor can the definitions and ex 
planations with which learned men are wont to guard and 
protect themselves in some instances afford a complete rem 
edy words still manifestly force the understanding, throw 
everything into confusion, and lead mankind into vain and 
innumerable controversies and fallacies. 

XLIV. Lastly, there are idols which have crept into 

10 The propensity to this illusion may be viewed in the spirit of system, 
or hasty generalization, which is still one of the chief obstacles in the path 
of modern science. Ed. 


men s minds from the various dogmas of peculiar systems 
of philosophy, and also from the perverted rules of demon 
stration, and these we denominate idols of the theatre: for 
we regard all the systems of philosophy hitherto received 
or imagined, as so many plays brought out and performed, 
creating fictitious and theatrical worlds. Nor do we speak 
only of the present systems, or of the philosophy and sects 
of the ancients, since numerous other plays of a similar 
nature can be still composed and made to agree with each 
other, the causes of the most opposite errors being generally 
the same. Nor. again, do we allude merely to general sys 
tems, but also to many elements and axioms of sciences 
which have become inveterate by tradition, implicit cre 
dence, and neglect. We must, however, discuss each spe 
cies of idols more fully and distinctly in order to guard the 
human understanding against them. 

XLV. The human understanding, from its peculiar na 
ture, easily supposes a greater degree of order and equality 
in things than it really finds; and although many things in 
nature be sui generis and most irregular, will yet invent 
parallels and conjugates and relatives, where no such thing 
is. Hence the fiction, that all celestial bodies move in per 
fect circles, thus rejecting entirely spiral and serpentine 
lines (except as explanatory terms). 11 Hence also the ele- 

11 Though Kepler had, when Bacon wrote this, already demonstrated his 
throe great laws concerning the elliptical path of the planets, neither Bucon 
nor Descartes seems to have known or assented to his discoveries. Onr author 
deemed the startling astronomical announcements of his time to bo mere theo 
retic solutions of the phenomena of the heavens, not so perfect as those ad 
vanced by antiquity, but still deserving a praise for the ingenuity displayed in 
their contrivance. Bacon believed a hundred such systems might exist, and 
though true iu their explanation of phenomena, yet might all more or less 
differ, according to the preconceived notions which their framers brought to 
the survey of the heavens, lie even thought he might put in hia claim to the 


ment of fire is introduced with its peculiar orbit," to keep 
square with those other three which are objects of our 
senses. The relative rarity of the elements (as they are 
called) is arbitrarily made to vary in tenfold progression, 
with many other dreams of the like nature. 13 Nor is this 
folly confined to theories, but it is to be met with even in 
simple notions. 

XLVL The human understanding, when any proposi 
tion has been once laid down (either from general admission 
and belief, or from the pleasure it affords), forces everything 
else to add fresh support and confirmation; and although 
most cogent and abundant instances may exist to the con 
trary, yet either does not observe or despises them, or gets 
rid of and rejects them by some distinction, with violent and 
injurious prejudice, rather than sacrifice the authority of its 
first conclusions. It was well answered by him 14 who was 

notice of posterity for his astronomical ingenuity, and, as Ptolemy had labored 
by means of epicycles and eccentrics, and Kepler with ellipses, to explain the 
laws of planetary motion, Bacon thought the mystery would unfold itself quite 
as philosophically through spiral labyrinths and serpentine lines. What the 
details of his system were, we are left to conjecture, and that from a very 
meagre but naive account of one of his inventions which he has left in his 
Miscellany MSS. Ed. 

12 Hinc elementum ignis cum orbe suo introductum est. Bacon saw in fire 
the mere result of a certain combination of action, and was consequently led 
to deny its elementary character. The ancient physicists attributed an orbit to 
each of the four elements, into which they resolved the universe, and supposed 
their spheres to involve each other. The orbit of the earth was in the centre, 
that of fire at the circumference. For Bacon s inquisition into the nature 
of heat, and its complete failure, see the commencement of the second book 
of the Novum Organum. Ed. 

13 Eobert Fludd is the theorist alluded to, who had supposed the gravity 
of the earth to be ten times heavier than water, that of water ten times heavier 
than air, and that of air ten times heavier than fire. Ed. 

14 Diagoras. The same allusion occurs in the second part of the Advance 
ment of Learning, where Bacon treats of the idols of the mind. 


shown in a temple the votive tablets suspended by such as 
had escaped the peril of shipwreck, and was pressed as to 
whether he would then recognize the power of the gods, by 
an inquiry, But where are the portraits of those who have 
perished in spite of their vows ? All superstition is much 
the same, whether it be that of astrology, dreams, omens, 
retributive judgment, or the like, in all of which the deluded 
believers observe events which are fulfilled, but neglect and 
pass over their failure, though it be much more common. 
But this evil insinuates itself still more craftily in philoso 
phy and the sciences, in which a settled maxim vitiates and 
governs every other circumstance, though the latter be much 
more worthy of confidence. Besides, even in the absence 
of that eagerness and want of thought (which we have men 
tioned), it is the peculiar and perpetual error of the human 
understanding to be more moved and excited by affirmatives 
than negatives, whereas it ought duly and regularly to be 
impartial; nay, in establishing any true axiom the negative 
instance is the most powerful. 

XLVIL The human understanding is most excited by 
that which strikes and enters the mind at once and sud 
denly, and by which the imagination is immediately filled 
and inflated. It then begins almost imperceptibly to con 
ceive and suppose that everything is similar to the few 
objects which have taken possession of the mind, while it 
is very slow and unfit for the transition to the remote and 
heterogeneous instances by which axioms are tried as by 
fire, unless the office be imposed upon it by severe regula 
tions and a powerful authority. 

XLVII1. The human understanding is active and cannot 
halt or rest, but even, though without effect, still presses 
forward. Thus we cannot conceive of any end or external 


boundary of the world, and it seems necessarily to occur 
to us that there must be something beyond. Nor can we 
imagine how eternity has flowed on down to the present 
day, since the usually received distinction of an infinity, 
a parte ante and a parte post, 1 * cannot hold good; for it 
would thence follow that one infinity is greater than an 
other, and also that infinity is wasting away and tending 
to an end. There is the same difficulty in considering the 
infinite divisibility of lines, arising from the weakness of 
our minds, which weakness interferes to still greater dis 
advantage with the discovery of causes; for although the 
greatest generalities in nature must be positive, just as 
they are found, and in fact not causable, yet the human 
understanding, incapable of resting, seeks for something 
more intelligible. Thus, however, while aiming at further 
progress, it falls back to what is actually less advanced, 
namely, final causes; for they are clearly more allied to 
man s own nature, than the system of the universe, and 
from this source they have wonderfully corrupted philoso 
phy. But he would be an unskilful and shallow philoso 
pher who should seek for causes in the greatest generalities, 

18 A scholastic term, to signify the two eternities of past and future dura 
tion, that stretch out on both sides of the narrow isthmus (time) occupied by 
man. It must be remembered that Bacon lived before the doctrine of limits 
gave rise to the higher calculus, and therefore could have no conception of dif 
ferent denominations of infinities : on the other hand he would have thought 
the man insane who should have talked to him about lines infinitely great, in- 
doaing angles infinitely little ; that a right line, which is a right line so long as 
it ia finite, by changing infinitely little its direction, becomes an infinite curve, 
and that a curve may become infinitely less than another curve ; that there are 
infinite squares and infinite cubes, and infinites of infinites, all greater than one 
another, and the last but one of which is nothing in comparison with the last. 
Yet hall a century sufficed from Bacon s time, to make this nomenclature, 
which would have appeared to him the excess of frenzy, not only reasonabla 
bat necessary, to grasp the higher demonstrations of physical science. Ed. 


and not be anxious to discover them in subordinate 

XLIX. The human understanding resembles not a dry- 
light, but admits a tincture of the will I9 and passions, which 
generate their own system accordingly; for man always be 
lieves more readily that which he prefers. He, therefore, 
rejects difficulties for want of patience in investigation; 
sobriety, because it limits his hope; the depths of nature, 
from superstition; the light of experiment, from arrogance 
and pride, lest his mind should appear to be occupied with 
common and varying objects; paradoxes, from a fear of the 
opinion of the vulgar; in short, his feelings imbue and 
corrupt his understanding in innumerable and sometimes 
imperceptible ways. 

L. But by far the greatest impediment and aberration 
of the human understanding proceeds from the dulness, 
incompetence, and errors of the senses; since whatever 
strikes the senses preponderates over everything, however 
superior, which does not immediately strike them. Hence 
^ contemplation mostly ceases with sight, and a very scanty, 
or perhaps no regard is paid to invisible objects. The entire 
operation, therefore, of spirits inclosed in tangible bodies 17 
is concealed, and escapes us. All that more delicate change 
of formation in the parts of coarser substances (vulgarly 

18 Spinoza, in his letter to Oldcnberg (Op. Posth. p. 398), considers this 
aphorism based on a wrong conception of the origin of error, and, believing it 
to be fundamental, was led to reject Bacon s method altogether. Spinoza re 
fused to acknowledge in man any such thing as a will, and resolved all hia 
volitions into particular acts, which he considered to be as fatally determined 
by a chain of physical causes as any effects in nature. Ed. 

11 Operatio spirituum in corporilus tangibilibus. Bacon distinguished with 
the schools the gross and tangible parts of bodies, from such as wore volatile 
and intangible. Those, in conformity with the scholastic language, he terms 
spirits, and frequently returns to their operations in the 2d book. Ed. 


called alteration, but in fact a change of position in the 
smallest particles) is equally unknown ; and yet, unless the 
two matters we have mentioned be explored and brought 
to light, no great effect can be produced in nature. Again, 
the very nature of common air, and all bodies of less den 
sity (of which there are many) is almost unknown; for the 
senses are weak and erring, nor can instruments be of great 
use in extending their sphere or acuteness all the better 
interpretations of nature are worked out by instances, and 
fit and apt experiments, where the senses only judge of the 
experiment, the experiment of nature and the thing itself. 

LI. The human understanding is, by its own nature, 
prone to abstraction, and supposes that which is fluctuating 
to be fixed. But it is better to dissect than abstract _nature: 
such was the method employed by the school of Democ 
ritus, 18 which made greater progress in penetrating nature 
than the rest. It is best to consider matter, its conforma- 

l/ <4 

tion,. and the changes of that conformation, its own action," 
and the law of this action or motion; for forms are a mere 
fiction of the human mind, unless you will call the laws of 
action by that name. 80 

18 Democritus, of Abdera, a disciple of Leucippus, born B.C. 470, died 360; 
all his works are destroyed. He is said to be the author of the doctrine of 
atoms: he denied the immortality of the soul, and first taught that the milky 
way was occasioned by a confused light from a multitude of stars. He may 
be considered as the parent of experimental philosophy, in the prosecution of 
which he was so ardent as to declare that he would prefer the discovery of one 
of the causes of natural phenomena, to the possession of the diadem of Persia. 
Democritus imposed on the blind credulity of his contemporaries, and, like 
Roger Bacon, astonished them by his inventions. Ed. 

19 The Latin is actus purus, another scholastic expression to denote the 
action of the substance, which composes the essence of the body apart from ite 
accidental qualities. For an exposition of the various kinds of motions he con 
templates, the reader may refer to the 48lh aphorism of the 2 d book. Ed. 

20 The scholastics after Aristotle distinguished in a subject three modes of 

SCIENCE Vol. 22 2 


LII. Such are the idols of the tribe, which arise either 
from the uniformity of the constitution of man s spirit, or 
its prejudices, or its limited faculties or restless agitation, 
or from the interference of the passions, or the incompetence 
of the senses, or the mode of their impressions. 

LIIL The idols of the den derive their origin from the 
peculiar nature of each individual s mind and body, and 
also from education, habit, and accident; and although they 
be various and manifold, yet we will treat of some that re 
quire the greatest caution, and exert the greatest power in 
polluting the understanding. 

LIV. Some men become attached to particular sciences 
and contemplations, either from supposing themselves the 
authors and inventors of them, or from having bestowed 
the greatest pains upon such subjects, and thus become 
most habituated to them. 91 If men of this description apply 
themselves to philosophy and contemplations of a universal 

beings: viz., the power or faculty, the act, and the habitude, or in other words 
that which is able to exist, what exists actually, and what continues to exist. 
Bacon means that is necessary to fix our attention not on that which can 
or ought to be, but on that which actually is; not on the right, but on the 

Z1 The inference to be drawn from this is to suspect that kind of evidence 
which is most consonant to our inclinations, and not to admit any notion as real 
except we can base it firmly upon that kind of demonstration which is peculiar 
to the subject, not to our impression. Sometimes the mode of proof may bo 
consonant to our inclinations, and to the subject at the same time, as in the 
case of Pythagoras, when he applied his beloved numbers to the solution of 
astronomical phenomena; or in that of Descartes, when he reasoned geomet 
rically concerning the nature of the soul. Such examples cannot be censured 
with justice, inasmuch as the methods pursued were adapted to the end of the 
inquiry. The remark in the text can only apply to those philosophers who at 
tempt to build up a moral or theological system by the instruments of induction 
alone, or who rush, with the geometrical axiom, and the d priori syllogism, to 
the investigation of nature. The means in such cases are totally inadequate 
to the object in view. Ed. 


nature, they wrest and corrupt them by their preconceived 
fancies, of which Aristotle affords us a single instance, who 
made his natural philosophy completely subservient to his 
logicj and thus rendered it little more than useless and dis 
putatious. The chemists, again, have formed a fanciful 
philosophy with the most confined views, from a few ex 
periments of the furnace. Gilbert,** too, having employed 
himself most assiduously in the consideration of the magnet, 
immediately established a system of philosophy to coincide 
with his favorite pursuit. 

LV. The greatest and, perhaps, radical distinction be 
tween different men s dispositions for philosophy and the 
sciences is this, that some are more vigorous and active in 
observing the differences of things, others in observing their 
resemblances ; for a steady and acute disposition can fix its 
thoughts, and dwell upon and adhere to a point, through 
all the refinements of differences, but those that are sub 
lime and discursive recognize and compare even the most 
delicate and general resemblances; each of them readily 
falls into excess, by catching either at nice distinctions or 
shadows of resemblance. 

LYI. Some dispositions evince an unbounded admira 
tion of antiquity, others eagerly embrace novelty, and but 
few can preserve the just medium, so as neither to tear up 

M Gilbert lived toward the close of the sixteenth century, and was court 
physician to both Elizabeth and James. In his work alluded to in the text he 
continually asserts the advantages of the experimental over the a priori method 
in physical inquiry, and succeeded when his censor failed in giving a practical 
example of the utility of his precepts. His "De Magnete" contains all the 
fundamental parts of the science, and these so perfectly treated, tha we have 
nothing to add to them at the present day. 

Gilbert adopted the Copernican system, and even spoke of the contrary 
theory as utterly absurd, grounding his argument on the vast velocities which 
such a supposition requires us to ascribe to the heavenly bodies. Ed. 


what the ancients have correctly laid down, nor to despise 
the just innovations of the moderns. But this is very preju 
dicial to the sciences and philosophy, and instead of a cor 
rect judgment we have but the factions of the ancients and 
moderns. Truth is not to be sought in the good fortune 
of any particular conjuncture of time, which is uncertain, 
but in the light of nature and experience, which is eternal. 
Such factions, therefore, are to be abjured, and the under 
standing must not allow them to hurry it on to assent. 

LVII. The contemplation of nature and of bodies in 
their individual form distracts and weakens the understand 
ing; but the contemplation of nature and of bodies in their 
general composition and formation stupefies and relaxes it. 
We have a good instance of this in the school of Leucippus 
and Democritus compared with others, for they applied 
themselves so much to particulars as almost to neglect the 
general structure of things, while the others were so as 
tounded while gazing on the structure that they did not 
penetrate the simplicity of nature. These two species of 
contemplation must, therefore, be interchanged, and each 
employed in its turn, in order to render the understanding 
at once penetrating and capacious, and to avoid the incon 
veniences we have mentioned, and the idols that result 
from them. 

LVIII. Let such, therefore, be our precautions in con 
templation, that we may ward off and expel the idols of 
the den, which mostly owe their birth either to some pre 
dominant pursuit, or, secondly, to an excess in synthesis 
and analysis, or, thirdly, to a party zeal in favor of certain 
ages, or, fourthly, to the extent or narrowness of the sub 
ject. In general, he who contemplates nature should sus 
pect whatever particularly takes and lixes his understand- 


ing, and should use so much the more caution to preserve 
it ecjuable and unprejudiced. 

QjIX. The idols of the market are the most troublesome 
of alTpfcliose namely which have entwined themselves round 
the understanding from the associations of words and names. 
For men imagine that their reason governs words, while, in 
fact, words react upon the understanding; and this has ren- / 
dered philosophy and the sciences sophistical and inactive. I 
Words are generally formed in a popular sense, and define j 
things by those broad lines which are most obvious to the 
vulgar mind; but when a more acute understanding or 
more diligent observation is anxious to vary those lines, 
and to adapt them more accurately to nature, words oppose 
it. Hence the great and solemn disputes of learned men 
often terminate in controversies about words and names, in 
regard to which it would be better (imitating the caution 
of mathematicians) to proceed more advisedly in the first 
instance, and to bring such disputes to a regular issue by 
definitions. Such definitions, however, cannot remedy the 
evil in natural and material objects, because they consist 
themselves of words, and these words produce others;" 
so that we must necessarily have recourse to particular 
instances, and their regular series and arrangement, as we 

28 The Latin text adds "without end" ; but Bacon is scarcely right in sup 
posing that the descent from complex ideas and propositions to those of simple 
nature, involve the analyst in a series of continuous and interminable defini 
tions. For in the gradual and analytical scale, there is a bar beyond which we 
cannot go, as there is a summit bounded by the limited variations of our con 
ceptions. Logical definitions, to fulfil their conditions, or indeed to be of any 
avail, must be given in simpler terms than the object which is sought to be 
defined ; now this, in the case of primordial notions and objects of sense, ia im 
possible; therefore we are obliged to rest satisfied with the mere names of our 
perceptions. Ed. 


shall mention when we come to the mode and scheme of 
determining notions and axioms. 

LX. The idols imposed upon the understanding by words 
are of two kinds. They are either the names of things which 
have no existence (for as some objects are from inattention 
left without a name, so names are formed by fanciful imagi 
nations which are without an object), or they are the names 
of actual objects, but confused, badly defined, and hastily 
and irregularly abstracted from things. Fortune, the pri- 
vnum mobile, the planetary orbits, 84 the element of fire, and 
the like fictions, which owe their birth to futile and false 
theories, are instances of the first kind. And this species 
of idols is removed with greater facility, because it can be 
exterminated by the constant refutation or the desuetude of 
the theories themselves. The others, which are created by 
vicious and unskilful abstraction, are intricate and deeply 
rooted. Take some word, for instance, as moist, and let us 
examine how far the different significations of this word are 
consistent. It will be found that the word moist is nothing 
but a confused sign of different actions admitted of no set 
tled and defined uniformity. For it means that which easily 
diffuses itself over another body; that which is indetermi 
nable and cannot be brought to a consistency; that which 

24 The ancients supposed the planets to describe an exact circle round the 
south. As observations increased and facts were disclosed, which were irrec 
oncilable with this supposition, the earth was removed from the centre to some 
other point in the circle, and the planets were supposed to revolve in a smaller 
circle (epicycle) round an imaginary point, which in its turn described a circle 
of which the earth waa the centre. In proportion as observation elicited fresh 
facts, contradictory to these representations, other epicycles and eccentrics 
were added, involving additional confusion. Though Kepler had swept away all 
these complicated theories in the preceding century, by the demonstration of his 
three laws, which established the elliptical course of the planets, Bacon re 
garded him and Copernicus in the same light as Ptolemy and Xcuophanes. Ed. 


yields easily in every direction ; that which is easily divided 
and dispersed; that which is easily united and collected; 
that which easily flows and is put in motion; that which 
easily adheres to, and wets another body; that which is 
easily reduced to a liquid state though previously solid. 
When, therefore, you come to predicate or impose this 
name, in one sense flame is moist, in another air is not 
moist, in another fine powder is moist, in another glass is 
moist; so that it is quite clear that this notion is hastily ab 
stracted from water only, and common ordinary liquors, 
without any due. verification of it. 

There are, however, different degrees of distortion and 
mistake in words. One of the least faulty classes is that of 
the names of substances, particularly of the less abstract and 
more defined species (those then of chalk and mud are good, 
of earth bad); words signifying actions are more faulty, as 
to generate, to corrupt, to change; but the most faulty are 
those denoting qualities (except the immediate objects of 
sense), as heavy, light, rare, dense. Yet in all of these 
there must be some notions a little better than others, in 
proportion as a greater or less number of things come be 
fore the senses. 

LXI. The idols of the theatre are not innate, nor do 
they introduce themselves secretly into the understanding, 
but they are manifestly instilled and cherished by the fic 
tions of theories and depraved rules of demonstration. To 
attempt, however, or undertake their confutation would not 
be consistent with our declarations. For since we neither 
agree in our principles nor our demonstrations, all argument 
is out of the question. And it is fortunate that the ancients 
are left in possession of their honors. We detract nothing 
from them, seeing our whole doctrine relates only to the 


path to be pursued. The lame (as they say) m the path 
outstrip the swift who wander from it, and it is clear that 
the very skill and swiftness of him who runs not in the right 
direction must increase his aberration. 

Our method of discovering the sciences is such as to leave 
little to the acuteness and strength of wit, and indeed rather 
to level wit and intellect. For as in the drawing of a straight 
line, or accurate circle by the hand, much depends on its 
steadiness and practice, but if a ruler or compass be em 
ployed there is little occasion for either; so it is with our 
method. Although, however, we enter into no individual 
confutations, yet a little must be said, first, of the sects and 
general divisions of these species of theories; secondly, 
something further to show that there are external signs of 
their weakness; and, lastly, we must consider the causes of 
so great a misfortune, and so -long and general a unanimity 
in error, that we may thus render the access to truth less 
difficult, and that the human understanding may the more 
readily be purified, and brought to dismiss its idols. 

LXII. The idols of the theatre, or of theories, are numer 
ous, and may, and perhaps will, be still more so. For un 
less men s minds had been now occupied for many ages in 
religious and theological considerations, and civil govern 
ments (especially monarchies), had been averse to novelties 
of that nature even in theory (so that men must apply to 
them with some risk and injury to their own fortunes, and 
not only without reward, but subject to contumely and 
envy), there is no doubt that many other sects of philoso 
phers and theorists would have been introduced, like those 
which formerly flourished in such diversified abundance 
among the Greeks. For as many imaginary theories of the 
heavens can be deduced from the phenomena of the sky, so 


it is even more easy to found many dogmas upon the phe 
nomena of philosophy and the plot of this our theatre 
resembles those of the poetical, where the plots which are 
invented for the stage are more consistent, elegant, and 
pleasurable than those taken from real history. 

In general, men take for the groundwork of their phi 
losophy either too much fromr a few topics, or too little from 
many; in either case their philosophy is founded on too nar 
row a basis of experiment and natural history, and decides 
on too scanty grounds. For the theoretic philosopher seizes 
various common circumstances by experiment, without re 
ducing them to certainty or examining and frequently con 
sidering them, and relies for the rest upon meditation and 
the activity of his wit. 

There are other philosophers who have diligently and 
accurately attended to a few experiments, and have thence 
presumed to deduce and invent systems of philosophy, form 
ing everything to conformity with them. 

A third set, from their faith and religious veneration, 
introduce theology and traditions; the absurdity of some 
among them having proceeded so far as to seek and derive 
the sciences from spirits and genii. There are, therefore, 
three sources of error and three species of false philosophy; 
the^p^Khistic, empiric, and superstitious. 

>^P* LXIII. Aristotle affords the most eminent instance of 
tmT~ first ;""for he corrupted natural philosophy by logic 
thus he formed the world of categories, assigned to the 
human soul, the noblest of substances, a genus determined 
by words of secondary operation, treated of density and rar 
ity (by which bodies occupy a greater or lesser space), by 
the frigid distinctions of action and power, asserted that 
there was a peculiar and proper motion in all bodies, and 


that if they shared in any other motion, it was owing to an 
external moving cause, and imposed innumerable arbitrary 
distinctions upon the nature of things; being everywhere 
more anxious as to definitions in teaching and the accuracy 
of the wording of his propositions, than the internal truth 
of things. And this is best shown by a comparison of his 
philosophy with the others of greatest repute among the 
Greeks. For the similar parts of Anaxagoras, the atoms 
of Leacippus and Democritus, the heaven and earth of Par- 
menides, the discord and concord of Empedocles, 86 the reso 
lution of bodies into the common nature of fire, and their 
condensation according to Heraclitus, exhibit some sprink 
ling of natural philosophy, the nature of things, and experi 
ment; while Aristotle s physics are mere logical terms, and 
he remodelled the same subject in his metaphysics under a 
more imposing title, and more as a realist than a nominalist. 
Nor is much stress to be laid on his frequent recourse to ex 
periment in his books on animals, his problems, and other 
treatises; for he had already decided, without having prop 
erly consulted experience as the basis of his decisions and 
axioms, and after having so decided, he drags experiment 
along as a captive constrained to accommodate herself to his 
decisions: so that he is even more to be blamed than his 
modern followers (of the scholastic school) who have de 
serted her altogether. 

18 Empedocles, of Agrigentum, flourished 414 B.C. He was the disciple of 
Telangca the Pythagorean, and warmly adopted the doctrine of transmigration. 
He resolved the universe into the four ordinary elements, the principles of 
whose composition were life and happiness, or concord and amity, but whose 
decomposition brought forth death and evil, or discord and hatred. Heniclitus 
held matter to be indifferent to any peculiar form, but as it became rarer or 
more dense, it took the appearance of fire, air, earth and water. Fire, how 
ever, he believed to be the elementary principle out of which the others were 
evolved. This was also the belief of Lucretius. See book i. 783, etc. 


LXIY. The empiric school produces dogmas of a more 
deformed and monstrous nature than the sophistic or theo 
retic school; not being founded in the light of common no 
tions (which, however poor and superstitious, is yet in a 
manner universal, and of a general tendency), but in the 
confined obscurity of a few experiments. Hence this spe 
cies of philosophy appears probable, and almost certain to 
those who are daily practiced in such experiments, and have 
thus corrupted their imagination, but incredible and futile 
to others. We have a strong instance of this in the alche 
mists and their dogmas; it would be difficult to find another 
in this age, unless perhaps in the philosophy of Gilbert.* 9 
We could not, however, neglect to caution others against 
this school, because we already foresee and augur, that if 
men be hereafter induced by our exhortations to apply seri 
ously to experiments (bidding farewell to the sophistic doc 
trines), there will then be imminent danger from empirics, 
owing to the premature and forward haste of the under 
standing, and its jumping or flying to generalities and the 
principles of things. We ought, therefore, already to meet 
the evil. 
/^JLX"v). The corruption of philosophy by the mixing of it 

up with superstition and theology, is of a much wider ex 
tent, and is most injurious to it both as a whole and in parts. 
For the human understanding is no less exposed to the im 
pressions of fancy, than to those of vulgar notions. The 
disputatious and sophistic school entraps the understand 
ing, while the fanciful, bombastic, and, as it were, poetical 
school, rather flatters it. There is a clear example of this 

56 Tt is thus the Vulcanists and Neptunians have framed their opposite 
theories in geology. Phrenology is a modern instance of hasty generaliza 
tion. Ed. 


among the Greeks, especially in Pythagoras, where, how 
ever, the superstition is coarse and overcharged, but it is 
more dangerous and refined in Plato and his school. This 
evil is found also in some branches of other systems of phi 
losophy, where it introduces abstracted forms, final and first 
causes, omitting frequently the intermediate and the like. 
Against it we must use the greatest caution; for the apothe 
osis of error is the greatest evil of all, and when folly is 
worshipped, it is, as it were, a plague spot upon the under 
standing. Yet some of the moderns have indulged this folly 
with such consummate inconsiderateness, that they have en 
deavored to build a system of natural philosophy on the first 
chapter of Genesis, the book of Job, and other parts of 
Scripture; seeking thus the dead among the living." And 
tins folly is the more to be prevented and restrained, be 
cause not only fantastical philosophy, but heretical religion 
spring from the absurd mixture of matters divine and 
human. It is therefore most wise soberly to render unto 
fuith the things that are faith s. 

LXYI. Having spoken of the vicious authority of the 
systems founded either on vulgar notions, or on a few ex 
periments, or on superstition, we must now consider the 
faulty subjects for contemplation, especially in natural phi 
losophy. The human understanding is perverted by observ 
ing the power of mechanical arts, in which bodies are very 
materially changed by composition or separation, and is in 
duced to suppose that something similar takes place in the 
universal nature of things. Hence the fiction of elements, 

n In Scripture everything which concerns the passing interests of the body 
Is called de;id; the only living knowledge having regard to the eternal interest 
of tho soul. Ed. 


and their co-operation in forming natural bodies.* 8 Again, 
when man reflects upon the entire liberty of nature, he meets 
with particular species of things, as animals, plants, min 
erals, and is thence easily led to imagine that there exist in 
nature certain primary forms which she strives to produce, 
and that all variation from them arises from some impedi 
ment or error which she is exposed to in completing her 
work, or from the collision or metamorphosis of different 
species. The first hypothesis has produced the doctrine of 
elementary properties, the second that of occult properties 
and specific powers; and both lead to trifling courses of re 
flection, in which the mind acquiesces, and is thus diverted 
from more important subjects. But physicians exercise a 
much more useful labor in the consideration of the second 
ary qualities of things, and the operations of attraction, re 
pulsion, attenuation, inspissation, dilatation, astringency, 
separation, maturation, and the like; and would do still 
more if they would not corrupt these proper observations 
by the two systems I have alluded to, of elementary quali 
ties and specific powers, by which they either reduce the 
secondary to first qualities, and their subtile and immeas- 

28 In mechanics and the general sciences, causes compound their effects, or 
in other words, it is generally possible to deduce a priori the consequence of 
introducing complex agencies into any experiment, by allowing for the effect 
of each of the simple causes which enter into their composition. In chemistry 
and physiology a contrary law holds ; the causes which they embody generally 
uniting to form distinct substances, and to introduce unforeseen laws and com 
binations. The deductive method here is consequently inapplicable, and we are 
forced back upon experiment. 

Bacon in the text is hardly consistent with himself, as he admits in the 
second book the doctrine, to which modern discovery points, of the reciprocal 
transmutation of the elements. What seemed poetic fiction in the theories of 
Pythagoras and Seneca, assumes the appearance of scientific fact in the handa 
of Baron Caynard. Ed. 


urable composition, or at any rate neglect to advance 
by greater and more diligent observation to the third 
and fourth qualities, thus terminating their contemplation 
prematurely. Nor are these powers (or the like) to be in 
vestigated only among. the medicines for the human body, 
but also in all changes of other natural bodies. 

A greater evil arises from the contemplation and inves 
tigation rather of the stationary principles of things from 
which, than of the active by which things themselves are 
created. For the former only serve for discussion, the lat 
ter for practice. Nor is any value to be set on those com 
mon differences of motion which are observed in the received 
system of natural philosophy, as generation, corruption, aug 
mentation, diminution, alteration, and translation. For this 
is their meaning: if a body, unchanged in other respects, is 
moved from its place, this is translation; if the place and 
species be given, but the quantity changed, it is alteration; 
but if, from such a change, the mass and quantity of the 
body do not continue the same, this is the motion of aug 
mentation and diminution; if the change be continued so as 
to vary the species and substance, and transfuse them to 
others, this is generation and corruption. All this is merely 
popular, and by no means penetrates into nature; and these 
are but the measures and bounds of motion, and not differ 
ent species of it; they merely suggest how far, and not how 
or whence. For they exhibit neither the affections of bodies 
nor the process of their parts, but merely establish a divi 
sion of that motion, which coarsely exhibits to the senses 
matter in its varied form. Even when they wish to point 
out something relative to the causes of motion, and to estab 
lish a division of them, they most absurdly introduce nat 
ural and violent motion, which is also a popular notion, 


since every violent motion is also in fact natural, that is to 
say, the external efficient puts nature in action in a different 
manner to that which she had previously employed. 

But if, neglecting these, any one were, for instance, to 
observe that there is in bodies a tendency of adhesion, so as 
not to suffer the unity of nature to be completely separated 
or broken, and a vacuum? 9 to be formed, or that they have a 
tendency to return to their natural dimensions or tension, so 
that, if compressed or extended within or beyond it, they 
immediately strive to recover themselves, and resume their 
former volume and extent; or that they have a tendency to 
congregate into masses with similar bodies the dense, for 
instance, toward the circumference of the earth, the thin 
and rare toward that of the heavens. These and the like 
are true physical genera of motions, but the others are 
clearly logical and scholastic, as appears plainly from a 
comparison of the two. 

Another considerable evil is, that men in their systems 
and contemplations bestow their labor upon the investiga 
tion and discussion of the principles of things and the ex 
treme limits of nature, although all utility and means of 
action consist in the intermediate objects. Hence men 
cease not to abstract nature till they arrive at potential and 
shapeless matter, 30 and still persist in their dissection, till 

89 Galileo had recently adopted the notion that nature abhorred a vacuum 
for an axiomatic principle, and it was not till Torricelli, his disciple, had given 
practical proof of the utility of Bacon s method, by the discovery of the barom 
eter (1643) that this error, as also that expressed below, and believed by Bacon, 
concerning the homoeopathic tendencies of bodies, was destroyed. Ed. 

30 Donee ad materiam poteniialem et informem ventum fuerit. Nearly all 
the ancient philosophers admitted the existence of a certain primitive and 
Bhapeless matter as the substratum of things which the creative power had 
reduced to fixed proportions, and resolved into specific substances. The ex- 


they arrive at atoms; and yet were all this true, it would 
be of little use to advance man s estate. 

LXVII. The understanding must also be cautioned 
against the intemperance of systems, so far as regards its 
giving or withholding its assent; for such intemperance ap 
pears to fix and perpetuate idols, so as to leave no means 
of removing them. 

These excesses are of two kinds. The first is seen in 
those who decide hastily, and render the sciences positive 
and dictatorial. The other in those who have introduced 
scepticism, and vague unbounded inquiry. The former sub 
dues, the latter enervates the understanding. The Aristo 
telian philosophy, after destroying other systems (as the 
Ottomans 31 do their brethren) by its disputatious confuta 
tions, decided upon everything, and Aristotle himself then 
raises up questions at will, in order to settle them; so that 
everything should be certain and decided, a method now in 
use among his successors. 

The school of Plato introduced scepticism, first, as it 
were in joke and irony, from their dislike to Protagoras, 
Ilippias, 32 and others, who were ashamed of appearing not 

prcssion potential matter refers to that substance forming the basis of the 
Peripatetic system, which virtually contained all the forms that it was in the 
power of the efficient cause to draw out of it. Ed. 

81 An allusion to the humanity of the Sultans, who, in their earlier histories 
are represented as signalizing their accession to the throne by the destruction of 
their family, to remove the danger of rivalry and the terrors of civil war. Ed. 

38 The text is "in odium veterum sophistarum, Protagorse, HippiaJ, et rcli- 
quornm." Those were called sophists, who, ostentationis aut qnestus causa 
philosophabantur. (Acad. Prior, ii. 22.) They had corrupted and degraded 
philosophy before Socrates. Protagoras of Abdera OApSrjpa), the most cele 
brated, taught that man is the measure of all things, by which he meant not 
only that all which can be known is known only as it related to our faculties, 
but also that apart from our faculties nothing can be known. The sceptics 


to doubt upon any subject. But the new academy dog 
matized in their scepticism, and held it as their tenet. 
Although this method be more honest than arbitrary deci 
sion (for its followers allege that they by no means con 
found all inquiry, like Pyrrho and his disciples, but hold 
doctrines which they can follow as probable, though they 
cannot maintain them to be true), yet when the human 
mind has once despaired of discovering truth, everything 
begins to languish. Hence men turn aside into pleasant 
controversies and discussions, and" into a sort of wandering 
over subjects rather than sustain any rigorous investigation. 
But as we observed at first, we are not to deny the authority 
of the human senses and understanding, although weak, but 
rather to furnish them with assistance. 

LXVIII. We have now treated of each kind of idols, 
and their qualities, all of which must be abjured and re 
nounced with firm and solemn resolution, and the under 
standing must be completely freed and cleared of them, so 
that the access to the kingdom of man, which is founded 
on the sciences, may resemble that to the kingdom of 
heaven, where no admission is conceded except to children. 

LXIX. Vicious demonstrations are the muniments and 
support of idols, and those which we possess in logic, merely 
subject and enslave the world to human thoughts, and 
thoughts to words. But demonstrations are in some man 
ner themselves systems of philosophy and science ; for such 
as they are, and accordingly as they are regularly or im- 

equally held that knowledge was probable only as it related to our faculties, 
but they stopped there, and did not, like the sophist, dogmatize about the un 
known. The works of Protagoras were condemned for their impiety, and 
publicly burned by the asdiles of Athens, who appear to have discharged the 
office of common hangmen to the literary blasphemers of their day. Ed. 


properly established, such will be the resulting systems 
of philosophy and contemplation. But those which we 
employ in the whole process leading from the senses and 
things to axioms and conclusions, are fallacious and incom 
petent. This process is fourfold, and the errors are in equal 
number. In the first place the impressions of the senses are 
erroneous, for they fail and deceive us. We must supply 
defects by substitutions, and fallacies by their correction. 
Secondly, notions are improperly abstracted from the senses, 
and indeterminate and cohf used when they ought to be the 
reverse. Thirdly, the induction that is employed is im 
proper, for it determines the principles of sciences by simple 
enumeration," without adopting exclusions and resolutions, 
or just separations of nature. Lastly, The usual method of 
discovery and proof, by first establishing the most general 
propositions, then applying and proving the intermediate 
axioms according to them, is the parent of error and the 
calamity of every science. But we will treat more fully 

33 Bacon is hardly correct in implying that the enumerationem per siinplicem 
was the only light in which the ancients looked upon induction, as they appear 
to have regarded it as only one, and that the least important, of its species. 
Aristotle expressly considers induction in a perfect or dialectic sense, and in 
an imperfect or rhetorical sense. Thus if a genus (G), contains four species 
(A, B, c, P), the syllogism would lead us to infer, that what ia true of G, ia 
true of any one of Hie four. But perfect induction would reason, that what 
we can prove of A, B, c. D, separately, we may properly state as true of o, the 
whole genus. This is evidently a formal argument as demonstrative as the syl 
logism. In necessary matters, however, legitimate induction may claim a wider 
province, and infer of the whole genus what is only apparent in a part of the 
species. Such are those inductive inferences which concern the laws of nature, 
the immutability of forms, by which Bacon strove to erect his new system of 
philosophy. The Stagynte, however, looked upon enumerationem per simpli* 
cem, without any regard to the nature of the matter, or to the completeness 
of the species, with as much reprehensive caution as Bacon, and guarded his 
readei-s against it as the source of innumerable errors. Ed. 


of that which we now slightly touch upon, when we come 
to lay down the true way of interpreting nature, after hav 
ing gone through the above expiatory process and purifica 
tion of the mind. 

LXX. But experience is by far the best demonstration, 
provided it adhere to the experiment actually made, for if 
that experiment be transferred to other subjects apparently 
similar, unless with proper and methodical caution it be 
comes fallacious. The present method of experiment is 
blind and stupid; hence men wandering and roaming with 
out any determined course, and consulting mere chance, 
are hurried about to various points, and advance but little 
at one time they are happy, at another their attention is 
distracted, and they always find that they want something 
further. Men generally make their experiments carelessly, 
and as it were in sport, making some little variation in a 
known experiment, and then if they fail they become dis 
gusted and give up the attempt; nay, if they set to work 
more seriously, steadily, and assiduously, yet they waste 
all their time on probing some solitary matter, as Gilbert 
on the magnet, and the alchemists on gold. But such con 
duct shows their method to be no less unskilful than mean; 
for nobody can successfully investigate the nature of any 
object by considering that object alone; the inquiry must 
be more generally extended. 

Even when men build any science and theory upon ex 
periment, yet they almost always turn with premature and 
hasty zeal to practice, not merely on account of the advan 
tage and benefit to be derived from it, but in order to seize 
upon some security in a new undertaking of their not em 
ploying the remainder of their labor unprofitably, and by 
making themselves conspicuous, to acquire a greater name 


for their pursuit. Hence, like Atalanta, they leave the 
course to pick up the golden apple, interrupting their 
speed, and giving up the victory. But in the true course 
of experiment, and in extending it to new effects, we should 
imitate the Divine foresight and order; for God on the first 
day only created light, and assigned a whole day to that 
work without creating any material substance thereon. In 
like manner we must first, by every kind of experiment, 
elicit the discovery of causes and true axioms, and seek for 
experiments which may afford light rather than profit. 
Axioms, when rightly investigated and established, pre 
pare us not for a limited but abundant practice, and bring 
in their train whole troops of effects. But we will treat 
hereafter of the ways of experience, which are not less 
beset and interrupted than those of judgment; having 
spoken at present of common experience only as a bad 
species of demonstration, the order of our subject now re 
quires some mention of those external signs of the weakness 
in practice of the received systems of philosophy and con 
templation 94 which we referred to above, and of the causes 
of a circumstance at first sight so wonderful and incredible. 
For the knowledge of these external signs prepares the way 
for assent, and the explanation of the causes removes the 
wonder; and these two circumstances are of material use 
in extirpating more easily and gently the idols from the 

LXXI. The sciences we possess have been principally 
derived from the Greeks; for the addition of the Roman, 
Arabic, or more modern writers, are but few and of small 
importance, and such as they are, are founded on the basis 

M See Ax. Ixi. toward the end. This subject extends to Ax. Ixxviii. 


of Greek invention. But the wisdom of the Greeks was 
professional and disputatious, and thus most adverse to the 
investigation of truth. The name, therefore, of sophists, 
which the contemptuous spirit of those who deemed them 
selves philosophers, rejected and transferred to the rhetori 
cians Gorgias," Protagoras, Hippias, Polus might well suit 
the whole tribe, such as Plato, Aristotle, Zeno, Epicurus, 
Theophrastus, and their successors Chrysippus, Carneades, 
and the rest. There was only this difference between them 
the former were mercenary vagabonds, travelling about 
to different states, making a show of their wisdom, and re 
quiring pay; the latter more dignified and noble, in pos 
session of fixed habitations, opening schools, and teaching 
philosophy gratuitously. Both, however (though differing 
in other respects), were professorial, and reduced every sub 
ject to controversy, establishing and defending certain sects 
and dogmas of philosophy, so that their doctrines were 
nearly (what Dionysius not unaptly objected to Plato) the 
talk of idle old men to ignorant youths. But the more 
ancient Greeks, as Empedocles, Anaxagoras, Leucippus, De- 
mocritus, Parmenides, Heraclitus, Xenophanes, Philolaus, 
and the rest 38 (for I omit Pythagoras as being superstitious), 

36 Gorgias of Leontium went to Athena in 424 B.C. He and Polus were 
disciples of Empedocles, whom we have already noticed (Aphorism 63), where he 
sustained the three famous propositions, .that nothing exists, that nothing can be 
known, and that it is out of the power of man to transmit or communicate intel 
ligence. He is reckoned one of the earliest writers on the art of rhetoric, and 
for that reason, Plato called his elegant dialogue on that subject after his name. 

36 Chrysippus, a stoic philosopher of Soli in Cilicia, Campestris, born in 280, 
died in the 143d Olympiad, 208 B.C. He was equally distinguished for natural 
abilities and industry, seldom suffering a day to elapse without writing 500 
lines. He wrote several hundred volumes, of which three hundred were on 
logical subjects ; but in .all, borrowed largely from others. He was very fond 
of the sorites ia argument, which is hence called by Persius the heap of Chry- 


did not (that we are aware) open schools, but betook them 
selves to the investigation of truth with greater silence and 
with more severity and simplicity, that is, with less aft ecta- 
tion and ostentation. Hence in our opinion they acted more 
advisedly, however their works may have been eclipsed in 
course of time by those lighter productions which better 
correspond with and please the apprehensions and passions 
of the vulgar; for time, like a river," bears down to us that 

sippus. He was called the Column of the Portico, a name given to the Stoical 
School from Zono, its founder, who had given his lessons under the portico. 

Carncadcs, born about 215, died in 130. He attached himself to Chrysip- 
pus, and sustained with eclat the scepticism of the academy. The Athenians 
sent him with Critolaus and Diogenes as ambassador to Rome, where he at 
tracted the attention of his new auditory by the subtilty of his reasoning, and 
the fluency and vehemence of his language. Before Galba and Cato the Censor, 
he harangued with great variety of thought and copiousness of diction in praise 
of justice. The next day, to establish his doctrine of the uncertainty of human 
knowledge, lie undertook to refute all his arguments, lie maintained with the 
New Academy, that the senses, the imagination, and the understanding fre 
quently deceive us, and therefore cannot be infallible judges of truth, but that 
from the impressions produced on the mind by means of the senses, we infer 
appearances of truth or probabilities. Nevertheless, with respect to the conduct 
of life, Carueades held that probable opinions are a sufficient guide. 

Xenophanes, a Greek philosopher, of Colophon, born in 556, the founder of 
the Kleatic school, which owes its fame principally to Farrnenides. Wild in his 
opinions about astronomy, he supposed that the stars were extinguished every 
morning, and rekindled at night; that eclipses were occasioned by the tempo 
rary extinction of the sun, and that there were several suns for the convenience 
of the different climates of the earth. Yet this man held the chair of philoso 
phy at Athens for seventy years. 

Philolaus, a Pythagorean philosopher of Crotona, B.C. 374. He first sup 
ported the diurnal motion of the earth round its axis, and its annual motion 
round the sun. Cicero (Acad. iv. 39) has ascribed this opinion to the Syracu- 
san philosopher Nicetas, and likewise to Plato. From this passage, it is most 
probable that Copernicus got the idea of the system he afterward established. 
Bacon, in the Advancement of Human Learning, charges Gilbert with restoring 
the doctrines of Philolaus, because he ventured to support the Copornican 
theory. Ed. 

31 Bacon is equally conspicuous for the use and abuse of analogical illustra 
tions. The levity, as Stuart Mill very properly observes, by which substances 


which is light and inflated, and sinks that which is heavy 
and solid. Nor were even these more ancient philosophers 
free from the national defect, but inclined too much to the 
ambition and vanity of forming a sect, and captivating 
public opinion, and we must despair of any inquiry after 
truth when it condescends to such trifles. Nor must we 
omit the opinion, or rather prophecy, of an Egyptian priest 
with regard to the Greeks, that they would forever remain 
children, without any antiquity of knowledge or knowledge 
of antiquity; for they certainly have this in common with 
children, that they are prone to talking, and incapable of 
generation, their wisdom being loquacious and unproduc 
tive of effects. Hence the external signs derived from the 
origin and birthplace of our present philosophy are not 

LXXII. Nor are those much better which can be de 
duced from the character of the time and age, than the 
former from that of the country and nation ; for in that age 
the knowledge both of time and of the world was confined 
and meagre, which is one of the worst evils for those who 
rely entirely on experience they had not a thousand years 
of history worthy of that name, but mere fables and ancient 
traditions; they were acquainted with but a small portion 
of the regions and countries of the world, for they indis 
criminately called all nations situated far toward the north 
Scythians, all those to the west Celts; they knew nothing 
of Africa but the nearest part of Ethiopia, or of Asia be- 

float on a stream, and the levity which is synonymous with worthlessness, have 
nothing beside the name in common ; and to show how little value there is in 
the figure, we need only change the word into buoyancy, to turn the semblance 
of Bacon s argument against himself Ed. 


yond the Ganges, and had not even heard any sure and 
clear tradition of the regions of the New World. Besides, 
a vast number of climates and zones, in which innumerable 
nations live and breathe, were pronounced by them to be 
uninhabitable; nay, the travels of Democritus, Plato, and 
Pythagoras, which were not extensive, but rather mere 
excursions from home, were considered as something vast. 
But in our times many parts of the New World, and every 
extremity of the Old, are well known, and the mass of 
experiments has been infinitely increased; wherefore, if ex 
ternal signs were to be taken from the time of the nativity 
or procreation (as in astrology), nothing extraordinary could 
be predicted of these early systems of philosophy. 

LXXIII. Of all signs there is none more certain or 
worthy than that of the fruits produced, for the fruits and 
effects are the sureties and vouchers, as it were, for the 
truth of philosophy. Now, from the systems of the Greeks, 
and their subordinate divisions in particular branches of the 
sciences during so long a period, scarcely one single experi 
ment can be culled that has a tendency to elevate or assist 
mankind, and can be fairly set down to the speculations 
and doctrines of their philosophy. Celsus candidly and 
wisely confesses as much, when he observes thac experi 
ments were first discovered in medicine, and that men after 
ward built their philosophical systems upon them, and 
searched for and assigned causes, instead of the inverse 
method of discovering and deriving experiments from phi 
losophy and the knowledge of causes; it is not, therefore, 
wonderful that the Egyptians (who bestowed divinity and 
sacred honors on the authors of new inventions) should 
have consecrated more images of brutes than of men, for 
the brutes by their natural instinct made many discoveries, 


while men derived but few from discussion and the con 
clusions of reason. 

The industry of the alchemists has produced some effect, 
by chance, however, and casualty, or from varying their ex 
periments (as mechanics also do), and not from any regular 
art or theory, the theory they have imagined rather tending 
to disturb than to assist experiment. Those, too, who have 
occupied themselves with natural magic (as they term it) 
have made but few discoveries, and those of small import, 
and bordering on imposture; for which reason, in the same 
manner as we are cautioned by religion to show our faith 
by our works, we may very properly apply the principle to 
philosophy, and judge of it by its works, accounting that to 
be futile which is unproductive, and still more so if, instead 
of grapes and olives, it yield but the thistle and thorns of 
dispute and contention. 

LXXIY. Other signs may be selected from the increase 
and progress of particular systems of philosophy and the 
sciences; for those which are founded on nature grow and 
increase, while those which are founded on opinion change 
and increase not. If, therefore, the theories we have men 
tioned were not like plants, torn up by the roots, but grew 
in the womb of nature, and were nourished by her, that 
which for the last two thousand years has taken place would 
never have happened, namely, that the sciences still con 
tinue in their beaten track, and nearly stationary, without 
having received any important increase, nay, having, on 
the contrary, rather bloomed under the hands of their first 
author, and then faded away. But we see that the case is 
reversed in the mechanical arts, which are founded on na 
ture and the light of experience, for they (as long as they 
are popular) seem full of life, and uninterruptedly thrive and 

SCIENCE Vol. 22 3 


grow, being at first rude, then convenient, lastly polished, 
and perpetually improved. 

LXXY. There is yet another sign (if such it may be 
termed, being rather an evidence, and one of the strongest 
nature), namely, the actual confession of those very authori 
ties whom men now follow; for even they who decide on 
things so daringly, yet at times, when they reflect, betake 
themselves to complaints about the subtilty of nature, the 
obscurity of things, and the weakness of man s wit. If they 
would merely do this, they might perhaps deter those who 
are of a timid disposition from further inquiry, but would 
excite and stimulate those of a more active and confident 
turn to further advances. They are not, however, satisfied 
with confessing so much of themselves, but consider every 
thing which has been either unknown or unattempted by 
themselves or their teachers, as beyond the limits of possi 
bility, and thus, with most consummate pride and envy, 
convert the defects of their own discoveries into a calumny 
on nature and a source of despair to every one else. Hence" 
arose the New Academy, which openly professed scepti 
cism, 38 and consigned mankind to eternal darkness; hence 
the notion that forms, or the true differences of things (which 
are in fact the laws of simple action), are beyond man s 

38 We have before observed, that the New Academy did not profess skep 
ticism, but the aicaTdArj^ia, or incomprehensibility of the absolute essences of 
things. Even modern physicists are not wanting, to assert with this school 
that the utmost knowledge we can obtain is relative, and necessarily short of 
absolute certainty. It is not without an appearance of truth that these philoso 
phers maintain that our ideas and perceptions do not express the nature of the 
things which they represent, but only the effects of the peculiar organs by 
which they are conveyed to the understanding, so that were these organs 
changed, we should have different conceptions of their nature. That constitu 
tion of air which is dark to man is luminous to bats and owls. 


reach, and cannot possibly be discovered; hence those no 
tions in the active and operative branches, that the heat of 
the sun and of fire are totally different, so as to prevent men 
from supposing that they can elicit or form, by means of 
fire, anything similar to the operations of nature; and again, 
that composition only is the work of man and mixture of 
nature, so as to prevent men from expecting the generation 
or transformation of natural bodies by art. Men will, there 
fore, easily allow themselves to be persuaded by this sign 
not to engage their fortunes and labor in speculations, 
which are not only desperate, but actually devoted to des 

LXXVI. Nor should we omit the sign afforded by the 
great dissension formerly prevalent among philosophers, and 
the variety of schools, which sufficiently show that the way 
was not well prepared that leads from the senses to the 
understanding, since the same groundwork of philosophy 
(namely, the nature of things), was torn and divided into 
such widely differing and multifarious errors. And al 
though in these days the dissensions and differences of 
opinions with regard to first principles and entire systems 
are nearly extinct, 89 yet there remain innumerable questions 
and controversies with regard to particular branches of phi 
losophy. So that it is manifest that there is nothing sure or 
sound either in the systems themselves or in the methods of 
demonstration. 40 

LXXYII. With regard to the supposition that there is a 
general unanimity as to the philosophy of Aristotle, because 

39 Owing to the universal prevalence of Aris totelism. 

40 It must be remembered, that when Bacon wrote, algebra was in its 
infancy, and the doctrine of units and infinitesimals undiscovered. 


the other systems of the ancients ceased and became obso 
lete on its promulgation, and nothing better has been since 
discovered; whence it appears that it is so well determined 
and founded, as to have united the suff rages of both ages; 
we will observe 1st. That the notion of other ancient sys 
tems having ceased after the publication of the works of 
Aristotle is false, for the works of the ancient philosophers 
subsisted long after that event, even to the time of Cicero, 
and the subsequent ages. But at a later period, when 
human learning had, as it were, been wrecked in the inun 
dation of barbarians into the Roman empire, then the sys 
tems of Aristotle and Plato were preserved in the waves of 
ages, like planks of a lighter and less solid nature. 2d. The 
notion of unanimity, on a clear inspection, is found to be 
fallacious. For true unanimity is that which proceeds from 
a free judgment, arriving at the same conclusion, after an 
investigation of the fact. Now, by far the greater number 
of those who have assented to the philosophy of Aristotle, 
have bound themselves down to it from prejudice and the 
authority of others, so that it is rather obsequiousness and 
concurrence than unanimity. But even if it were real and 
extensive unanimity, so far from being esteemed a true 
and solid confirmation, it should even lead to a violent pre 
sumption to the contrary. For there is no worse augury in 
intellectual matters than that derived from unanimity, with 
the exception of divinity and politics, where suffrages are 
allowed to decide. For nothing pleases the multitude, un 
less it strike the imagination or bind down the understand 
ing, as we have observed above, with the shackles of vulgar 
notions. Hence we may well transfer Phocion s remark 
from morals to the intellect: "That men should immediately 
examine what error or fault they have committed, when the 


multitude concurs with, and applauds them." 41 This then 
is one of the most unfavorable signs. All the signs, there 
fore, of the truth and soundness of the received systems of 
philosophy and the sciences are unpropitious, whether taken 
from their origin, theirfruits, their progress, the confessions 
of their authors, or from unanimity. 

LXXYIII. We now come to the causes of errors," and 
of such perseverance in them for ages. These are suffi 
ciently numerous and powerful to remove all wonder, that 
what we now offer should have so long been concealed from, 
and have escaped the notice of mankind, and to render it 
more worthy of astonishment, that it should even now have 
entered any one s mind, or become the subject of his 
thoughts; and that it should have done so, we consider 
rather the gift of fortune than of any extraordinary talent, 
and as the offspring of time rather than wit. But, in the 
first place, the number of ages is reduced to very narrow 
limits, on a proper consideration of the matter. For out of 
twenty-five 48 centuries, with which the memory and learn- 

41 Because the vulgar make up the overwhelming majority in such decisions, 
and generally allow their judgments to be swayed by passion or prejudice. 

42 See end of Axiom Ixi. The subject extends to Axiom xc. 

43 If we adopt the statement of Herodotus, who pjaces the Homeric era 400 
years back from his time, Homer lived about 900 years before Christ. On add 
ing this number to the sixteen centuries of the Christian era which had elapsed 
tip to Bacon s lime, we get the twenty -five centuries he mentions. The Homeric 
epoch is the furthest point in antiquity from which Bacon could reckon with 
any degree of certainty. Hesiod, if he were not contemporary, immediately 
preceded him. 

The epoch of Greek philosophy may be included between Thalos and Plato, 
that is, from the 35th to the 88th Olympiad; that of the Roman, between 
Terence and Pliny. The modern revolution, in which Bacon is one of the 
central figures, took its rise from the time of Dante and Petrarch, who lived 
at the commencement of the fourteenth century ; and to which, on account oi 
the invention of printing, and the universal spread of literature, which has ren- 


ing of man are conversant, scarcely six can be set apart and 
selected as fertile in science and favorable to its progress. 
For there are deserts and wastes in times as in countries, 
and we can only reckon up three revolutions and epochs of 
philosophy. 1. The Greek. 2. The Roman. 3. Our own, 
that is the philosophy of the western nations of Europe: 
and scarcely two centuries can with justice be assigned to 
each. The intermediate ages of the world were unfortunate 
both in the quantity and richness of the sciences produced. 
Nor need we mention the Arabs, or the scholastic philoso 
phy, which, in those ages, ground down the sciences by 
their numerous treatises, more than they increased their 
weight. The first cause, then, of such insignificant prog 
ress in the sciences, is rightly referred to the small propor 
tion of time which has been favorable thereto. 

LXXIX. A second cause offers itself, which is certainly 
of the greatest importance; namely, that in those very ages 
in which men s wit and literature flourished considerably, 
or even moderately, but a small part of their industry was 
bestowed on natural philosophy, the great mother of the 
sciences. For every art and science torn from this root 
may, perhaps, be polished, and put into a serviceable shape, 
but can admit of little growth. It is well known, that after 
the Christian religion had been acknowledged, and arrived 
at maturity, by far the best wits were busied upon theology, 
where the highest rewards offered themselves, and every 
species of assistance was abundantly supplied, and the study 
of which was the principal occupation of the western Euro 
pean nations during the third epoch; the rather because 

derod a second destruction of learning impossible, it is difficult to foresee anj 
other end than the extinction of the race of man. Ed. 


literature flourished about the very time when controver 
sies concerning religion first began to bud forth. 2. la the 
preceding ages, during the second epoch (that of the Ko- 
mans), philosophical meditation and labor was chiefly occu 
pied and wasted in moral philosophy (the theology of the 
heathens): besides, the greatest minds in these times applied 
themselves to civil affairs, on account of the magnitude of 
the Roman empire, which required the labor of many. 
3. The age during which natural philosophy appeared 
principally to flourish among the Greeks, was but a short 
period, since in the more ancient times the seven sages 
(with the exception of Thales), applied themselves to moral 
philosophy and politics, and at a later period, after Socrates 
had brought down philosophy from heaven to earth, moral 
philosophy became more prevalent, and diverted men s 
attention from natural. Nay, the very period during which 
physical inquiries flourished, was corrupted and rendered 
useless by contradictions, and the ambition of new opinions. 
Since, therefore, during these three epochs, natural philoso 
phy has been materially neglected or impeded, it is not at 
all surprising that men should have made but little progress 
in it, seeing they were attending to an entirely different 

LXXX. Add to this that natural philosophy, especially 
of late, has seldom gained exclusive possession of an indi 
vidual free from all other pursuits, even among those who 
have applied themselves to it, unless there may be an ex 
ample or two of some monk studying in his cell, or some 
nobleman in his villa. 44 She has rather been made a pas 
sage and bridge to other pursuits. 

44 The allusion is evidently to Roger Bacon and Rene Descartes. Ed. 


Thus has this great mother of the sciences been degraded 
most unworthily to the situation of a handmaid, and made 
to wait upon medicine or mathematical operations, and to 
wash the immature minds of youth, and imbue them with a 
first dye, that they may afterward be more ready to receive 
and retain another. In the meantime, let no one expect any 
great progress in the sciences (especially their operative part), 
unless natural philosophy be applied to particular sciences, 
and particular sciences again referred back to natural phi 
losophy. For want of this, astronomy, optics, music, many 
mechanical arts, medicine itself, and (what perhaps is more 
wonderful), moral and political philosophy, and the logical 
sciences have no depth, but only glide over the surface and 
variety of things; because these sciences, when they have 
been once partitioned out and established, arc no longer 
nourished by natural philosophy, which would have im 
parted fresh vigor and growth to them from the sources and 
genuine contemplation of motion, rays, sounds, texture, and 
conformation of bodies, and the affections and capacity of 
the understanding. But we can little wonder that the sci 
ences grow not when separated from their roots. 

LXXXI. There is another powerful and great cause of j 
the little advancement of the sciences, which is this; it is j 
impossible to advance properly in the course when the goal 
is not properly fixed. But the real and legitimate goal of 
the sciences is the endowment of human life with new in 
ventions and riches. The great crowd of teachers know 
nothing of this, but consist of dictatorial hirelings; unless 
it so happen that some artisan of an acute genius, and am 
bitious of fame, gives up his time to a new discovery, which 
is generally attended with a loss of property. The major 
ity, so far from proposing to themselves the augmentation 


of the mass of arts and sciences, make no other use of an in 
quiry into the mass already before them, than is afforded by 
the conversion of it to some use in their lectures, or to gain, 
or to the acquirement of a name, and the like. But if one 
out of the multitude be found, who courts science from real 
zeal, and on his own account, even he will be seen rather to 
follow contemplation, and the variety of theories, than a 
severe and strict investigation of truth. Again, if there 
even be an unusually strict investigator of truth, yet will 
he propose to himself, as the test of truth, the satisfaction 
of his mind and understanding, as to the causes of things 
long since known, and not such a test as to lead to some 
new earnest of effects, and a new light in axioms. If, there 
fore, no one have laid down the real end of science, we can 
not wonder that there should be error in points subordinate 
to that end. 

LXXXIL But, in like manner, as the end and goal of 
science is ill denned, so, even were the case otherwise, men 
have chosen an erroneous and impassable direction. For it 
is sufficient to astonish any reflecting mind, that nobody 
should have cared or wished to open and complete a way for 
the understanding, setting off from the senses, and regular, 
well-conducted experiment; but that everything has been 
abandoned either to the mists of tradition, the whirl and con 
fusion of argument, or the waves and mazes of chance, and 
desultory, ill-combined experiment. Now, let any one but 
consider soberly and diligently the nature of the path men 
have been accustomed to pursue in the investigation and 
discovery of any matter, and he will doubtless first observe 
the rude and inartificial manner of discovery most familiar 
to mankind: which is no other than this. When any one 
prepares himself for discovery, he first inquires and obtains 


a full account of all that has been said on the subject by 
others, then adds his own reflections, and stirs up and, as it 
were, invokes his own spirit, after much mental labor, to 
disclose its oracles. All which is a method without founda 
tion, and merely turns on opinion. 

Another, perhaps, calls in logic to assist him in discov 
ery, which bears only a nominal relation to his purpose. 
For the discoveries of logic are not discoveries of principles 
and leading axioms, but only of what appears to accord with 
them." And when men become curious and importunate, 
and give trouble, interrupting her about her proofs, and the 
discovery of principles or first axioms, she puts them off 
with her usual answer, referring them to faith, and ordering 
them to swear allegiance to each art in its own department. 

There remains but mere experience, which, when it offers 
itself, is called chance; when it is sought after, experiment. 4 
But this kind of experience is nothing but a loose fagot; 
and mere groping in the dark, as men at night try all means 
of discovering the right road, while it would be better and 
more prudent either to wait for day, or procure a light, and 
then proceed. On the contrary, the real order of experience 
begins by setting up a light, and then shows the road by it, 
commencing with a regulated and digested, not a misplaced 
and vague course of experiment, and thence deducing 
axioms, and from those axioms new experiments: for not 
even the Divine Word proceeded to operate on the general 
mass of things without due order. 

Let men, therefore, cease to wonder if the whole course 

44 From the abuse of the scholastics, who mistook the d priori method, the 
deductive syllogism, for the entire province of logic. Ed. 
48 riee Aphorism xcv. 


of science be not run, when all have wandered from the 
path; quitting it entirely, and deserting experience, or in 
volving themselves in its mazes, and wandering about, while 
a regularly combined system would lead them in a sure track 
through its wilds to the open day of axioms. 

LXXXIII. The evil, however, has been wonderfully in- 
creased by an opinion, or inveterate conceit, which is both 
vainglorious and prejudicial, namely, that the dignity of the 
human mind is lowered by long and frequent intercourse 
with experiments and particulars, which are the objects of 
sense, and confined to matter; especially since such matters 
generally require labor in investigation, are mean subjects 
for meditation, harsh in discourse, unproductive in practice, 
infinite in number, and delicate in their subtilty. Hence 
we have seen the true path not only deserted, but inter 
cepted and blocked up, experience being rejected with dis 
gust, and not merely neglected or improperly applied. 

LXXXIV. Again, the reverence for antiquity, 47 and the 
authority of men who have been esteemed great in philoso 
phy, and general unanimity, have retarded men from ad 
vancing in science, and almost enchanted them. As to 
unanimity, we have spoken of it above. 

The opinion which men cherish of antiquity is altogether 
idle, and scarcely accords with the term. For the old age 
and increasing years of the world should in reality be con 
sidered as antiquity, and this is rather the character of our 
own times than of the less advanced age of the world in 
those of the ancients; for the latter, with respect to our- 

41 The incongruity to which Bacon alludes appears to spring from confound 
ing two things, which are not only distinct, b ut affect human knowledge in 
inverse proportion, viz., the experience which terminates with life, with that 
experience which one century transmits to another. Ed. 


selves, are ancient and elder, with respect to the world mod 
ern and younger. And as we expect a greater knowledge 
of human affairs, and more mature judgment from an old 
man than from a youth, on account of his experience, and 
the variety and number of things he has seen, heard, and 
meditated upon, so we have reason to expect much greater 
things of our own age (if it knew but its strength and would 
essay and exert it) than from antiquity, since the world has 
grown older, and its stock has been increased and accumu 
lated with an infinite number of experiments and observa 

We must also take into our consideration that many ob 
jects in nature fit to throw light upon philosophy have been 
exposed to our view, and discovered by means of long voy 
ages and travels, in which our times have abounded. It 
would, indeed, be dishonorable to mankind, if the regions 
of the material globe, the earth, the sea, and stars, should 
be so prodigiously developed and illustrated in our age, and 
yet the boundaries of the intellectual globe should be con 
fined to the narrow discoveries of the ancients. 

"With regard to authority, it is the greatest weakness to 
attribute infinite credit to particular authors, and to refuse 
his own prerogative to time, the author of all authors, and, 
therefore, of all authority. For truth is rightly named the 
daughter of time, not of authority. It is not wonderful, 
therefore, if the bonds of antiquity, authority, and unanim 
ity, have so enchained the power of man, that he is unable 
(as if bewitched) to become familiar with things themselves. 

LXXXV. Nor is it only the admiration of antiquity, 
authority, and unanimity, that has forced man s industry 
to rest satisfied with present discoveries, but, also, the ad 
miration of the effects already placed within his power. For 


whoever passes in review the variety of subjects, and the 
beautiful apparatus collected and introduced by the me 
chanical arts for the service of mankind, will certainly be 
rather inclined to admire our wealth than to perceive our 
poverty: not considering that the observations of man and 
operations of nature (which are the souls and first movers of 
that variety) are few, and not of deep research; the rest 
must be attributed merely to man s patience, and the deli 
cate and well-regulated motion of the hand or of instru 
ments. To take an instance, the manufacture of clocks is 
delicate and accurate, and appears to imitate the heavenly 
bodies in its wheels, and the pulse of animals in its regular 
oscillation, yet it only depends upon one or two axioms of 

Again, if one consider the refinement of the liberal arts, 
or even that exhibited in the preparation of natural bodies 
in mechanical arts and the like, as the discovery of the 
heavenly motions in astronomy, of harmony in music, of 
the letters of the alphabet 48 (still unadopted by the Chinese) 
in grammar; or, again, in mechanical operations, the pro 
ductions of Bacchus and Ceres, that is, the preparation of 
wine and beer, the making of bread, or even the luxuries of 
the table, distillation, and the like; if one reflect also, and 
consider for how long a period of ages (for all the above, ex 
cept distillation, are ancient) these things have been brought 
to their present state of perfection, and (as we instanced in 
clocks) to how few observations and axioms of nature they 
may be referred, and how easily, and as it were, by obvious 
chance or contemplation, they might be discovered, one 

48 The Chinese characters resemble, in many respects, the hieroglyphics 
of the Egyptians, being adapted to represent ideas, not sounds. 


would soon cease to admire and rather pity the human lot 
on account of its vast want and dearth of things and discov 
eries for so many ages. Yet even the discoveries we have 
mentioned were more ancient than philosophy and the intel 
lectual arts; so that (to say the truth) when contemplation 
and doctrinal science began, the discovery of useful works 

But if any one turn from the manufactories to libraries, 
and be inclined to admire the immense variety of books 
offered to our view, let him but examine and diligently in 
spect the matter and contents of these books, and his aston 
ishment will certainly change its object: for when he finds 
no end of repetitions, and how much men do and speak the 
same thing over again, he will pass from admiration of this 
variety to astonishment at the poverty and scarcity of mat 
ter, which has hitherto possessed and filled men s minds. 

But if any one should condescend to consider such sci 
ences as are deemed rather curious than sound, and take a 
full view of the operations of the alchemists or magii, he 
will perhaps hesitate whether he ought rather to laugh or 
to weep. For the alchemist cherishes eternal hope, and 
when his labors succeed not, accuses his own mistakes, 
deeming, in his self-accusation, that he has not properly 
understood the words of art or of his authors; upon which 
he listens to tradition and vague whispers, or imagines there 
is some slight unsteadiness in the minute details of hia 
practice, and then has recourse to an endless repetition of 
experiments: and in the meantime, when, in his casual ex 
periments, he falls upon something in appearance new, or 
of some degree of utility, he consoles himself with such an 
earnest, and ostentatiously publishes them, keeping up his 
hope of the final result. Nor can it be denied that the alche- 

NOVUM OR&tftKMi^^ 65 

mists have made_fifiiera]^discoveries, and presentetkmankind 
with useful inventions. But vfe may well apply to theft^the 
fable of the old man, who bequeathed to his sons some gol 
buried in his garden, pretending not to know the exact spot, 
whereupon they worked diligently in digging me~i4neyard, 
and though they found no gold, the vintage was rendei 
more abundant by their labor. 

The followers of natural magic, who explain everything 
by sympathy and antipathy, have assigned false powers and 
marvellous operations to things by gratuitous and idle con 
jectures: and if they have ever produced any effects, they 
are rather wonderful and novel than of any real benefit or 

In superstitious magic (if we say anything at all about 
it) we must chiefly observe, that there are only some pecul 
iar and definite objects with which the curious and supersti 
tious arts have, in every nation and age, and even under 
every religion, been able to exercise and amuse themselves. 
Let us, therefore, pass them over. In the meantime we 
cannot wonder that the false notion of plenty should have 
occasioned want. 

LXXXVL The admiration of mankind with regard to 
the arts and sciences, which is of itself sufficiently simple 
and almost puerile, has been increased by the craft and ar 
tifices of those who have treated the sciences, and delivered 
them down to posterity. For they propose and produce 
them to our view so fashioned, and as it were masked, as 
to make them pass for perfect and complete. For if you 
consider their method and divisions, they appear to em 
brace and comprise everything which can relate to the 
subject. And although this frame be badly filled up and 
resemble an empty bladder, yet it presents to the vul- 


gar understanding the form and appearance of a perfect 

The first and most ancient investigators of truth were 
wont, on the contrary, with more honesty and success, to 
throw all the knowledge they wished to gather from con 
templation, and to lay up for use, into aphorisms, or short 
scattered sentences unconnected by any method, and with 
out pretending or professing to comprehend any entire art. 
But according to the present system, we cannot wonder 
that men seek nothing beyond that which is handed down 
to them as perfect, and already extended to its full com 

LXXXVII. The ancient theories have received addi 
tional support and credit from the absurdity and levity of 
those who have promoted the new, especially in the active 
and practical part of natural philosophy. For there have 
been many silly and fantastical fellows who, from credulity 
or imposture, have loaded mankind with promises, announc 
ing and boasting of the prolongation of life, the retarding 
of old age, the alleviation of pains, the remedying of nat 
ural defects, the deception of the senses, the restraint and 
excitement of the passions, the illumination and exaltation 
of the intellectual faculties, the transmutation of substances, 
the unlimited intensity and multiplication of motion, the 
impressions and changes of the air, the bringing into our 
power the management of celestial influences, the divina 
tion of future events, the representation of distant objects, 
the revelation of hidden objects, and the like. One would 
not be very wrong in observing with regard to such pre 
tenders, that there is as much difference in philosophy, 
between their absurdity and real science, as there is in his 
tory between the exploits of Csesar or Alexander, and those 


of Amadis de Gaul and Arthur of Britain. JTor those illus 
trious generals are found to have actually performed greater 
exploits than such fictitious heroes are- even pretended to 
have accomplished, by the means, however, of real action, 
and not by any fabulous and portentous power. Yet it is 
not right to suffer our belief in true history to be dimin 
ished, because it is sometimes injured and violated by 
fables. In the meantime we cannot wonder that great 
prejudice has been excited against any new propositions 
(especially when coupled with any mention of effects to be 
produced), by the conduct of impostors who have made a 
similar attempt; for their extreme absurdity, and the dis 
gust occasioned by it, has even to this day overpowered 
every spirited attempt of the kind. 

LXXXVI1I. Want of energy, and the littleness and 
futility of the tasks that human industry has undertaken, 
have produced much greater injury to the sciences: and 
yet (to make it still worse) that very want of energy mani 
fests itself in conjunction with arrogance and disdain. 

For, in the first place, one excuse, now from its repeti 
tion become familiar, is to be observed in every art, namely, 
that its promoters convert the weakness of the art itself into 
a calumny upon nature: and whatever it in their hands fails 
to effect, they pronounce to be physically impossible. But 
how can the art ever be condemned while it acts as judge in 
its own cause ? Even the present system of philosophy cher- *~ 
ishes in its bosom certain positions or dogmas, which (it 
will be found on diligent inquiry) are calculated to produce 
a full conviction that no difficult, commanding, and power 
ful operation upon nature ought to be anticipated through 

the means of art; we instanced 49 above the alleged different 


49 See Axiom 76. 


quality of heat in the sun and fire, and Composition and 
mixture. Upon an accurate observation the whole ten 
dency of such positions is wilfully to circumscribe man s 
power, and to produce a despair of the means of invention 
and contrivance, which would not only confound the prom 
ises of hope, but cut the very springs and sinews of indus 
try, and throw aside even the chances of experience. The 
only object of such philosophers is to acquire the reputation 
of perfection for their own art, and they arc anxious to ob 
tain the most silly and abandoned renown, by causing a be 
lief that whatever hasjiot yet been invented and understood 
can never be so hereafter. But if any one attempt to give 
himself up to things, and to discover something new; yet 
he will only propose and destine for his object the investiga 
tion and discovery of some one invention, and nothing more; 
as the nature of the magnet, the tides, the heavenly system, 
and the like, which appear enveloped in some degree of 
mystery, and have hitherto been treated with but little suc 
cess. Now it is the greatest proof of want of skill, to inves 
tigate the nature of any object in itself alone; for that same 
nature, which seems concealed and hidden in some instances, 
is manifest and almost palpable in others, and excites wonder 
in the former, while it hardly attracts attention in the lat 
ter. 59 Thus the nature of consistency is scarcely observed 
in wood or stone, but passed over by the term solid without 
any further inquiry about the repulsion of separation or the 

50 The methods by which Newton carried the rule and compass to the boun 
daries of creation is a sufficient comment on the sagacity of the text. The same 
cause which globalizes a bubble, has rounded the earth, and the same law which 
draws a stone to its surface, keeps the moon in her orbit. It was by calculating 
and ascertaining these principles upon substances entirely at his disposal that 
this great philosopher was enabled to give us a key to unlock the mysteries 
of the universe. Ed. 


solution of continuity. But in water-bubbles the same cir 
cumstance appears matter of delicate and ingenious research, 
for they form themselves into thin pellicles, curiously shaped 
into hemispheres, so as for an instant to avoid the solution 
of continuity. 

In general those very things which are considered as 
secret are manifest and common in other objects, but will 
never be clearly seen if the experiments and contemplation 
of man be directed to themselves only. Yet it commonly 
happens, that if, in the mechanical arts, any one bring old 
discoveries to a finer polish, or more elegant height of orna 
ment, or unite and compound them, or apply them more 
readily to practice, or exhibit them on a less heavy and 
voluminous scale, and the like, they will pass off as new. 

We cannot, therefore, wonder that no magnificent dis 
coveries, worthy of mankind, have been brought to light, 
while men are satisfied and delighted with such scanty and 
puerile tasks, nay, even think that they have pursued or 
attained some great object in their accomplishment. 

LXXXIX. Nor should we neglect to observe that nat 
ural philosophy has, in every age, met with a troublesome 
and difficult opponent: I mean superstition, and a blind and 
immoderate zeal for religion. For we see that, among the 
Greeks, those who first disclosed the natural causes of 
thunder and storms to the yet untrained ears of man were 
condemned as guilty of impiety toward the gods." Nor 
did some of the old fathers of Christianity treat those much 
better who showed by the most positive proofs (such as no 

61 See the "Clouds" of Aristophanes, where Socrates is represented as chas 
ing Jupiter out of the sky, by resolving thunderstorms into aerial concussions 
and whirlwinds. Ed. 


one now disputes) that the earth is spherical, and thence 
asserted that there were antipodes." 

Even in the present state of things the condition of dis 
cussions on natural philosophy is rendered more difficult 
and dangerous by the summaries and methods of divines, 
who, after reducing divinity into such order as they could, 
and brought it into a scientific form, have proceeded to 
mingle an undue proportion of the contentious and thorny 
philosophy of Aristotle with the substance of religion. 63 

The fictions of those who have not feared to deduce and 
confirm the truth of the Christian religion by the principles 
and authority of philosophers, tend to the same end, though 
in a different manner." They celebrate the union of faith 
and the senses as though it were legitimate, with great pomp 
and solemnity, and gratify men s pleasing minds with a 
variety, but in the meantime confound most improperly 
things divine and human. Moreover, in these mixtures of 
divinity and philosophy the received doctrines of the lat 
ter are alone included, and any novelty, even though it 

62 Robespierre was the latest victim of this bigotry. In his younger days 
he attempted to introduce Franklin s lightning conductor into France, but was 
persecuted by those whose lives he sought to protect, as one audaciously striving 
to avert the designs of Providence. Ed. 

63 "We can hardly agree with the text. The scholastics, in building np a 
system of divinity, certainly had recourse to the deductive syllogism, because 
the inductive was totally inapplicable, except as a veriticatory process. With 
regard to the technical form in which they marshalled their arguments, which 
is what our author aims at in his censure, they owed nothing at all to Aristotle, 
the conducting a dispute in naked syllogistic fashion having originated entirely 
with themselves. Ed. 

64 Bacon cannot be supposed to allude to those divines who have attempted 
to show that the progress of physical science is confirmatory of revelation, but 
only to such as have built up a system of faith out of their own refinements 
on nature and revelation, as Patricius and Kinauiiel S\vedenborg. Ed. 


be an improvement, scarcely escapes banishment and ex 

In short, you may find all access to any species of phi 
losophy, however pure, intercepted by the ignorance of 
divines. Some in their simplicity are apprehensive that 
a too deep inquiry into nature may penetrate beyond the 
proper bounds of decorum, transferring and absurdly apply - 
,ing what is said of sacred mysteries in Holy Writ against 
those who pry into divine secrets, to the mysteries of nature, 
which are not forbidden by any prohibition. Others with 
more cunning imagine and consider, that if secondary causes 
be unknown, everything may more easily be referred to the 
Divine hand and wand, a matter, as they think, of the great 
est consequence to religion, but which can only really mean 
that God wishes to be gratified by means of falsehood. 
Others fear, from past example, lest motion and change in 
philosophy should terminate in an attack upon religion. 
Lastly, there are others who appear anxious lest there 
should be something discovered in the investigation of 
nature to overthrow, or at least shake, religion, particularly 
among the unlearned. The last two apprehensions appear 
to resemble animal instinct, as if men were diffident, in the 
bottom of their minds and secret meditations, of the strength 
of religion and the empire of faith over the senses, and there 
fore feared that some danger awaited them from an inquiry 
into nature. But any one who properly considers the sub 
ject will find natural philosophy to be, after the Word of 
God, the surest remedy against superstition, and the most 
approved support of faith. She is, therefore, rightly be 
stowed upon religion as a most faithful attendant, for the 
one exhibits the will and the other the power of God. Nor 
was he wrong who observed, "Ye err, not knowing the 


Scriptures and the power of God," thus uniting in one 
bond the revelation of his will and the contemplation of 
his power. In the meanwhile, it is not wonderful that the 
progress of natural philosophy has been restrained, since 
religion, which has so much influence on men s minds, has 
been led and hurried to oppose her through the ignorance 
of some and the imprudent zeal of others. 

XC. Again, in the habits and regulations of schools, 
universities, and the like assemblies, destined for the abode 
of learned men and the improvement of learning, everything 
is found to be opposed to the progress of the sciences; for 
the lectures and exercises are so ordered, that anything out 
of the common track can scarcely enter the thoughts and 
contemplations of the mind. If, however, one or two have 
perhaps dared to use their liberty, they can only impose 
the labor on themselves, without deriving any advantage 
from the association of others; and if they put up with this, 
they will find their industry and spirit of no slight disad 
vantage to them in making their fortune; for the pursuits 
of men in such situations are, as it were, chained down to 
the writings of particular authors, and if any one dare to 
dissent from them he is immediately attacked as a turbulent 
and revolutionary spirit. Yet how great is the difference 
between civil matters and the arts, for there is not the same 
danger from new activity and new light. In civil matters 
even a change for the better is suspected on account of the 
commotion it occasions, for civil government is supported 
by authority, unanimity, fame, and public opinion, and not 
by demonstration. In the arts and sciences, on the con 
trary, every department should resound, as in mines, with, 
new works and advances. And this is the rational, though 
not the actual view of the case, for that administration and 


government of science we have spoken of is wont too rigor 
ously to repress its growth. 

XCI. And even should the odium I have alluded to be 
avoided, yet it is sufficient to repress the increase of science 
that such attempts and industry pass unrewarded; for the 
cultivation of science and its reward belong not to the same 
individual. The advancement of science is the work of 
a powerful genius, the prize and reward belong to the vul 
gar or to princes, who (with a few exceptions) are scarcely 
moderately well informed. Nay, such progress is not only 
deprived of the rewards and beneficence of individuals, but 
even of popular praise; for it is above the reach of the 
generality, and easily overwhelmed and extinguished by 
the winds of common opinions. It is not wonderful, there 
fore, that little success has attended that which has been 
little honored. 

XC1I. But by far the greatest obstacle to the advance 
ment of the sciences, and the undertaking of any new at 
tempt or department, is to be found in men s despair and 
the idea of impossibility ; for men of a prudent and exact 
turn of thought are altogether diffident in matters of this 
nature, considering the obscurity of nature, the shortness 
of life, the deception of the senses, and weakness of the 
judgment. They think, therefore, that in the revolutions 
of ages and of the world there are certain floods and ebbs 
of the sciences, and that they grow and flourish at one time, 
and wither and fall off at another, that when they have 
attained a certain degree and condition they can proceed 
no further. 

If, therefore, any one believe or promise greater things, 
they impute it to an uncurbed and immature mind, and 
imagine that such efforts begin pleasantly, then become 


laborious, and end in confusion. And since such thoughts 
easily enter the minds of men of dignity and excellent judg 
ment, we must really take heed lest we should be captivated 
by our affection for an excellent and most beautiful object, 
and relax or diminish the severity of our judgment; and we 
must diligently examine what gleam of hope shines upon 
us, and in what direction it manifests itself, so that, banish 
ing her lighter dreams, we may discuss and weigh whatever 
appears of more sound importance. We must consult the 
prudence of ordinary life, too, which is diffident upon prin 
ciple, and in all human matters augurs the worst. Let us, 
then, speak of hope, especially as we are not vain promisers, 
nor are willing to enforce or insnare men s judgment, but 
would rather lead them willingly forward. And although 
we shall employ the most cogent means of enforcing hope 
when we bring them to particulars, and especially those 
which are digested and arranged in our Tables of Invention 
(the subject partly of the second, but principally of the 
fourth part of the Instauration), which are, indeed, rather 
the very object of our hopes than hope itself; yet to proceed 
more leniently we must treat of the preparation of men s 
minds, of which the manifestation of hope forms no slight 
part; for without it all that we have said tends rather to 
produce a gloom than to encourage activity or quicken the 
industry of experiment, by causing them to have a worse 
and more contemptuous opinion of things as they are than 
they now entertain, and to perceive and feel more thoroughly 
their unfortunate condition. We must, therefore, disclose 
and prefix our reasons for not thinking the hope of success 
improbable, as Columbus, before his wonderful voyage over 
the Atlantic, gave the reasons of his conviction that new 
lands and continents might be discovered besides those 


already known ; and these reasons, though at first rejected, 
were yet proved by subsequent experience, and were the 
causes and beginnings of the greatest events. 

XCIII. Let us begin from God, and show that our pur 
suit from its exceeding goodness clearly proceeds from him, 
the author of good and father of light. Now, in all divine 
works the smallest beginnings lead assuredly to some result, 
and the remark in spiritual matters that "the kingdom of 
God cometh without observation," is also found to be true 
in every great work of Divine Providence, so that every 
thing glides quietly on without confusion or noise, and the 
matter is achieved before men either think or perceive that 
it is commenced. Nor should we neglect to mention the 
prophecy of Daniel, of the last days of the world, "Many 
shall run to and fro, and knowledge shall be increased/ 66 
thus plainly hinting and suggesting that fate (which is 
Providence) would cause the complete circuit of the globe 
(now accomplished, or at least going forward by means of 
so many distant voyages), and the increase of learning to 
happen at the same epoch. 

XC1Y. We will next give a most potent reason for hope 
deduced from the errors of the past, and the ways still un- 
attempted; for well was an ill-governed state thus reproved, 
"That which is worst with regard to the past should appear 
most consolatory for the future; for if you had done all 
that your duty commanded, and your affairs proceeded no 
better, you could not even hope for their improvement; 
but since their present unhappy situation is not owing to 
the force of circumstances, but to your own errors, you have 
reason to hope that by banishing or correcting the latter 

65 Daniel xii. 4. 

SCIENCE Vol. 22 i 


you can produce a great change for the better in the 
former." So if men had, during the many years that have 
elapsed, adhered to the right way of discovering and culti 
vating the sciences without being able to advance, it would 
be assuredly bold and presumptuous to imagine it possible 
to improve; but if they have mistaken the way and wasted 
their labor on improper objects, it follows that the difficulty 
does not arise from things themselves, which are not in our 
power, but from the human understanding, its practice and 
application, which is susceptible of remedy and correction. 
Our best plan, therefore, is to expose these errors; for in 
proportion as they impeded the past, so do they afford 
reason to hope for the future. And although we have 
touched upon them above, yet we think it right to give a 
brief, bare, and simple enumeration of them in this place. 
XCY. Those who have treated of the sciences have been 
either empirics or dogmatical. 68 The former like ants only 
heap up and use their store, the latter like spiders spin out 
their own webs. The bee, a mean between both, extracts 
matter from the flowers of the garden and the field, but 
works and fashions it by its own efforts. The true labor 
of philosophy resembles hers, for it neither relies entirely 
or principally on the powers of the mind, nor yet lays up 
in the memory the matter afforded by the experiments of 
natural history and mechanics in its raw state, but changes 
and works it in the understanding. We have good reason, 

58 Bacon, in this Aphorism, appears to have entertained a fair idea of the 
use of the inductive and deductive methods in scientific inquiry, though his 
want of geometrical knowledge must have hindered him from accurately deter 
mining the precise functions of each, as it certainly led him in other paris of 
the Organon (V. A ph. 82), to undervalue the deductive, and, as ho calls it, the 
dogmatic method, and to rely too much upon empiricism. Ed. 


therefore, to derive hope from a closer and purer alliance 
of these faculties (the experimental and rational) than has 
yet been attempted. 

XCVI. Natural philosophy is not yet to be found un 
adulterated, but is impure and corrupted by logic in the 
school of Aristotle, by natural theology in that of Plato," 
by mathematics in the second school of Plato (that of Proc- 
lus and others) 68 which ought rather to terminate natural 
philosophy than to generate or create it. We may, there- -\ 
fore, hope for better results from pure and unmixed natural 

XCVII. No one has yet been found possessed of suffi 
cient firmness and severity to resolve upon and undertake 
the task of entirely abolishing common theories and notions, 
and applying the mind afresh, when thus cleared and lev 
elled, to particular researches; hence our human reasoning 
is a mere farrago and crude mass made up of a great deal of 
credulity and accident, and the puerile notions it originally 

67 The reader may consult the note of the 23d Aphorism for the fault which 
Bacon censures, and, if he wish to pursue the subject further, may read Plato s 
Timaeus, where that philosopher explains his system in detail. Bacon, how 
ever, is hardly consistent in one part of his censure, for he also talks about the 
spirit and appetites of inanimate substances, and that so frequently, as to pre 
clude the supposition that he is employing metaphor. Ed. 

68 Proclus flourished about the beginning of the fifth century, and was the 
successor of Plotinus, Porphyry and lamblicus, who, in the two preceding cen 
turies, had revived the doctrines of Plato, and assailed the Christian religion. 
The allusion in the text must be assigned to lamblicus, who, in the fourth cen 
tury, had republished the Pythagorean theology of numbers, and endeavored to 
construct the world out of arithmetic, thinking everything could be solved by 
the aid of proportions and geometry. Bacon must not be understood in the text 
to censure the use but the abuse of mathematics and physical investigations, as 
in the "De Augmentis" (lib. iv. c. 6), he enumerates the multiplicity of demon 
stration scientific facts admit of, from this source. Ed. 


But if a man of mature age, unprejudiced senses, and 
clear mind, would betake himself anew to experience and 
particulars, we might hope much more from such a one; in 
which respect we promise ourselves the fortune of Alex 
ander the Great, and let none accuse us of vanity till they 
have heard the tale, which is intended to check vanity. 

For ^Eschines spoke thus of Alexander and his exploits: 
"We live not the life of mortals, but are born at such a 
period that posterity will relate and declare our prodigies"; 
as if he considered the exploits of Alexander to be mirac 

But in succeeding ages 59 Livy took a better view of the 
fact, and has made some such observation as this upon 
Alexander: That he did no more than dare to despise 
insignificance." So in our opinion posterity will judge of 
us, that we have achieved no great matters, but only set 
less account upon what is considered important; for the 
meantime (as we have before observed) our only hope is 
in the regeneration of the sciences, by regularly raising 
them on the foundation of experience and building them, 
anew, which I think none can venture to affirm to have 
been already done or even thought of. 

XCVIII. The foundations of experience (our sole re 
source) have hitherto failed completely or have been very 
weak; nor has a store and collection of particular facts, 
capable of informing the mind or in any way satisfactory, 
been either sought after or amassed. On the contrary, 
learned, but idle and indolent, men have received some 

59 See Livy. lib. x. c. 17, where, in a digression on the probable effect of a 
contest between Rome and Alexander the Great, lie says: "Non cum Dario rem 
esse dixisset: quem mnlierum ac apadonnm aprmen trahentcm inter purpuram 
atqne aurum, oneratnm fortun;e appuratibns, pnedam verius quara hostem, nihil 
aliud quam ausus vaua coutemnere, incruentus devicit. " 


mere reports of experience, traditions as it were of dreams, 
as establishing or confirming their philosophy, and have not 
hesitated to allow them the weight of legitimate evidence. 
So that a system has been pursued in philosophy with re 
gard to experience resembling that of a kingdom or state 
which would direct its councils and affairs according to the 
gossip of city and street politicians, instead of the letters 
and reports of ambassadors and messengers worthy of credit. 
Nothing is rightly inquired into, or verified, noted, weighed, 
or measured, in natural history; indefinite and vague obser 
vation produces fallacious and uncertain information. If 
this appear strange, or our complaint somewhat too unjust 
(because Aristotle himself, so distinguished a man and sup 
ported by the wealth of so great a king, has completed an 
accurate history of animals, to which others with greater 
diligence but less noise have made considerable additions, 
and others again have composed copious histories and notices 
of plants, metals, and fossils), it will arise from a want of 
sufficiently attending to and comprehending our present 
observations; for a natural history compiled on its own 
account, and one collected for the mind s information as 
a foundation for philosophy, are two different things. They 
differ in several respects, but principally in this the former 
contains only the varieties of natural species without the 
experiments of mechanical arts; for as in ordinary life every 
person s disposition, and the concealed feelings of the mind 
and passions are most drawn out when they are disturbed 
so the secrets of nature betray themselves more readily 
when tormented by art than when left to their own course. 
We must begin, therefore, to entertain hopes of natural 
philosophy then only, when we have a better compilation 
of natural history, its real basis and support. 


XCIX. Again, even in the abundance of mechanical 
experiments, there is a very great scarcity of those which 
best inform and assist the understanding. For the mechanic, 
little solicitous about the investigation of truth, neither 
directs his attention, nor applies his hand to anything that 
is not of service to his business. But our hope of further 
progress in the sciences will then only be well founded, 
when numerous experiments shall be received and collected 
into natural history, which, though of no use in themselves, 
assist materially in the discovery of causes and axioms; 
which experiments we have termed enlightening, to distin 
guish them from those which are profitable. They possess 
this wonderful property and nature, that they never deceive 
or fail you; for being used only to discover the natural 
cause of some object, whatever be the result, they equally 
satisfy your aim by deciding the question. 

C. We must not only search for, and procure a greater 
number of experiments, but also introduce a completely 
different method, order, and progress of continuing and 
promoting experience. For vague and arbitrary experience 
is (as we have observed), mere groping in the dark, and 
rather astonishes than instructs. But when experience 
shall proceed regularly and uninterruptedly by a deter 
mined rule, we may entertain better hopes of the sciences. 

CI. But after having collected and prepared an abun 
dance and store of natural history, and of the experience 
required for the operations of the understanding or phi 
losophy, still the understanding is as incapable of acting 
on such materials of itself, with the aid of memory alone, 
as any person would be of retaining and achieving, by 
memory, the computation of an almanac. Yet meditation 
has hitherto done more for discovery than writing, and no 


experiments have been committed to paper. We cannot, 
however, approve of any mode of discovery without writing, 
and when that comes into more general use, we may have 
further hopes. 

GIL Besides this, there is such a multitude and host, 
as it were, of particular objects, and lying so widely dis 
persed, as to distract and confuse the understanding; and 
we can, therefore, hope for no advantage from its skirmish 
ing, and quick movements and incursions, unless we put 
its forces in due order and array, by means of proper and 
well arranged, and, as it were, living tables of discovery of 
these matters, which are the subject of investigation, and the 
mind then apply itself to the ready prepared and digested 
aid which such tables afford. 

GUI. When we have thus properly and regularly placed 
before the eyes a collection of particulars, we must not im 
mediately proceed to the investigation and discovery of new 
particulars or effects, or, at least, if we do so, must not rest 
satisfied therewith. For, though we do not deny that by 
transferring the experiments from one art to another (when 
all the experiments of each have been collected and ar 
ranged, and have been acquired by the knowledge, and 
subjected to the judgment of a single individual), many 
new experiments may be discovered tending to benefit 
society and mankind, by what we term literate experience; 
yet comparatively insignificant results are to be expected 
thence, while the more important are to be derived from 
the new light of axioms, deduced by certain method and 
rule from the above particulars, and pointing out and de 
fining new particulars in their turn. Our road is not a long 
plain, but rises and falls, ascending to axioms, and descend 
ing to effects. 


CIV. Nor can we suffer the understanding to jump and 
fly from particulars to remote and most general axioms (such 
as are termed the principles of arts and things), and thus 
prove and make out their intermediate axioms according to 
the supposed unshaken truth of the former. This, however, 
has always been done to the present time from the natural 
bent of the understanding, educated too, and accustomed to 
this very method, by the syllogistic mode of demonstration. 
But we can then only augur well foi the sciences, when the 
assent shall proceed by a true scale and successive steps, 
without interruption or breach, from particulars to the 
lesser axioms, thence to the intermediate (rising one above 
the other), and lastly, to the most general. For the lowest 
axioms differ but little from bare experiment; 80 the highest 
and most general (as they are esteemed at present), are 
notional, abstract, and of no real weight. The interme 
diate are true, solid, full of life, and upon them depend 
the business and fortune of mankind; beyond these are the 
really general, but not abstract, axioms, which are truly 
limited by the intermediate. 

60 The lowest axioms are such as spring from simple experience such as in 
chemistry, that animal substances yield no fixed salt by calcination; in music, 
that concords intermixed with discords make harmony, etc. Intermediate axi 
oms advance a step further, being the result of rotlection, which, applied to our 
experimental knowledge, deduces laws from them, such as in optics of the first 
degree of generality, that the angle of incidence is equal to the angle of reflec 
tion; and in mechanics, Kepler s three laws of motion, while his general law, 
that all bodies attract each other with forces proportional to their masses, and 
inversely as the squares of their distances, may be taken as one of the highest 
axioms. Yet so far is this principle from being only notional or abstract, it has 
presented us with a key which lits into the intricate wards of the heavens, and 
has laid bare to our gaze the principal mechanism of the universe. But natural 
philosophy in Bacon s day had not advanced beyond intermediate axioms, and 
Die term notional or abstract is applied to those general axioms then current, 
not founded on the solid principles of inductive inquiry, but based upon a priori 
reasoning and airy metaphysics. Ed. 


We must not then add wings, but rather lead and 
ballast to the understanding, to prevent its jumping 
or flying, which has not yet been done; but whenever 
this takes place, we may entertain greater hopes of the 

CV. In forming axioms, we must invent a different form 
of induction from that hitherto in use; not only for the 
proof and discovery of principles (as they are called), but 
also of minor, intermediate, and, in short, every kind of 
axioms. The induction which proceeds by simple enumer 
ation is puerile, leads to uncertain conclusions, and is ex 
posed to danger from one contradictory instance, deciding 
generally from too small a number of facts, and those only 
the most obvious. But a really useful induction for the dis 
covery and demonstration of the arts and sciences, should 
separate nature by proper rejections and exclusions, and 
then conclude for the affirmative, after collecting a sufficient 
number of negatives. Now this has not been done, nor even 
attempted, except perhaps by Plato, who certainly uses this 
form of induction in some measure, to sift definitions and 
ideas. But much of what has never yet entered the thoughts 
of man must necessarily be employed, in order to exhibit a 
good and legitimate mode of induction or demonstration, so 
as even to render it essential for us to bestow more pains 
upon it than have hitherto been bestowed on syllogisms. 
The assistance of induction is to serve us not only in the dis 
covery of axioms, but also in defining our notions. Much 
indeed is to be hoped from such an induction as has been 

CVI. In forming our axioms from induction, we must 
examine and try whether the axiom we derive be only fitted 
and calculated for the particular instances from which it is 


deduced, or whether it be more extensive and general. If 
it be the latter, we must observe, whether it confirm its own 
extent and generality by giving surety, as it were, in point 
ing out new particulars, so that we may neither stop at actual 
discoveries, nor with a careless grasp catch at shadows and 
abstract forms, instead of substances of a determinate na 
ture: and as soon as we act thus, well authorized hope may 
with reason be said to beam upon us. 

CVII. Herei, too, we may again repeat what we have 
said above, concerning the extending of natural philosophy 
and reducing particular sciences to that one, so as to pre 
vent any schism or dismembering of the sciences; without 
which we cannot hope to advance. 

CVIII. Such are the observations we would make in 
order to remove despair and excite hope, by bidding fare 
well to the errors of past ages, or by -their correction. Let 
us examine whether there be other grounds for hope. And, 
first, if many useful discoveries have occurred to mankind 
by chance or opportunity, without investigation or attention 
on their part, it must necessarily be acknowledged that much 
more may be brought to light by investigation and attention, 
if it be regular and orderly, not hasty and interrupted. For 
although it may now and then happen that one falls by 
chance upon something that had before escaped considerable 
elTorts and laborious inquiries, yet undoubtedly the reverse 
is generally the case. We may, therefore, hope for further, 
better, and more frequent results from man s reason, indus 
try, method, and application, than from chance and mere 
animal instinct, and the like, which have hitherto oeen the 
sources of invention. 

CIX. We may also derive some reason for hope from the 
circumstance of several actual inventions being of such a 


nature, that scarcely any one could have formed a conjecture 
about them previously to their discovery, bat would rather 
have ridiculed them as impossible. For men are wont to 
guess about new subjects from those they are already ac 
quainted with, and the hasty and vitiated fancies they have 
thence formed: than which there cannot be a more fallacious 
mode of reasoning, because much of that which is derived 
from the sources of things does not flow in their usual 

If, for instance, before the discovery of cannon, one had 
described its effects in the following manner: There is a new 
invention by which walls and the greatest bulwarks can be 
shaken and overthrown from a considerable distance; men 
would have begun to contrive various means of multiplying 
the force of projectiles and machines by means of weights 
and wheels, and other modes of battering and projecting. 
But it is improbable that any imagination or fancy would 
have hit upon a fiery blast, expanding and developing itself 
so suddenly and violently, because none would have seen an 
instance at all resembling it, except perhaps in earthquakes 
or thunder, which they would have immediately rejected as 
the great operations of nature, not to be imitated by man. 

So, if before the discovery of silk thread, any one had 
observed, That a species of thread had been discovered, fit 
for dresses and furniture, far surpassing the thread of 
worsted or flax in fineness, and at the same time in tenac 
ity, beauty, and softness; men would have begun to im 
agine something about Chinese plants, or the fine hair of 
some animals, or the feathers or down of birds, but certainly 
would never have had an idea of its being spun by a small 
worm, in so copious a manner, and renewed annually. But 
if any one had ventured to suggest the silkworm, he would 


have been laughed at as if dreaming of some new manufac 
ture from spiders. 

So again, if before the discovery of the compass, any one 
had said, That an instrument had been invented, by which 
the quarters and points of the heavens could be exactly 
taken and distinguished, men would have entered into dis 
quisitions on the refinement of astronomical instruments, 
and the like, from the excitement of their imaginations; but 
the thought of anything being discovered, which, not being 
a celestial body, but a mere mineral or metallic substance, 
should yet in its motion agree with that of such bodies, 
would have appeared absolutely incredible. Yet were these 
facts, and the like (unknown for so many ages) not discov 
ered at last either by philosophy or reasoning, but by chance 
and opportunity; and (as we have observed), they are of a 
nature most heterogeneous, and remote from what was 
hitherto known, so that no previous knowledge could lead 
to them. 

We may, therefore, well hope 01 that many excellent and 
useful matters are yet treasured up in the bosom of nature, 
bearing no relation or analogy to our actual discoveries, but 
out of the common track of our imagination, and still undis 
covered, and which will doubtless be brought to light in the 
course and lapse of years, as the others have been before 
them; but in the way we now point out, they may rapidly 
and at once be both represented and anticipated. 

CX. There are, moreover, some inventions which render 

* This hope has been abundantly realized in the discovery of gravity and 
the decomposition of light, mainly by the inductive method. To a better phi 
losophy we may also attribute the discovery of electricity, galvanism and their 
mutual connection with each other, and magnetism, the inventions of the air- 
pump, steam-engine aud the chronometer. 


it probable that men may pass and hurry over the most 
noble disc6veries which lie immediately before them. For 
however the discovery of gunpowder, silk, the compass, 
sugar, paper, or the like, may appear to depend on peculiar 
properties of things and nature, printing at least involves 
no contrivance which is not clear and almost obvious. But 
from want of observing that although the arrangement of the 
types of letters required more trouble than writing with the 
hand, yet these types once arranged serve for innumerable 
impressions, while manuscript only affords one copy; and 
again, from want of observing that ink might be thickened so 
as to stain without running (which was necessary, seeing the 
letters face upward, and the impression is made from above), 
this most beautiful invention (which assists so materially the 
propagation of learning) remained unknown for so many 

The human mind is often so awkward and ill-regulated 
in the career of invention that it is at first diffident, and then 
despises itself. For it appears at first incredible that any 
such discovery should be made, and when it has been made, 
it appears incredible that it should so long have escaped 
men s research. All which affords good reason for the hope 
that a vast mass of inventions yet remains, which may be 
deduced not only from the investigation of new modes of 
operation, but also from transferring, comparing, and apply 
ing these already known, by the method of what we have 
termed literate experience. 

CXI. Nor should we omit another ground of hope. Let 
men only consider (if they will) their infinite expenditure of 
talent, time, and fortune, in matters and studies of far in 
ferior importance and value; a small portion of which ap 
plied to sound and solid learning would be sufficient to over- 


come every difficulty. And we have thought right to add 
this observation, because we candidly own that such a 
collection of natural and experimental history as we have 
traced in our own mind, and as is really necessary, is a 
great and as it were royal work, requiring much labor 
and expense. 

CXII. In the meantime let no one be alarmed at the mul 
titude of particulars, but rather inclined to hope on that very 
account. For the particular phenomena of the arts and na 
ture are in reality but as a handful, when compared with the 
fictions of the imagination removed and separated from the 
evidence of facts. The termination of our method is clear, 
and I had almost said near at hand; the other admits of no 
termination, but only of infinite confusion. For men have 
hitherto dwelt but little, or rather only slightly touched 
upon experience, while they have wasted much time on 
theories and the fictions of the imagination. If we had but 
any one who could actually answer our interrogations of 
nature, the invention of all causes and sciences would be 
the labor of but a few years. 

CXIII. We think some ground of hope is afforded by 
our own example, which is not mentioned for the sake of 
boasting, but as a useful remark. Let those who distrust 
their own powers observe myself, one who have among my 
contemporaries been the most engaged in public business, 
who am not very strong in health (which causes a great loss 
of time), and am the first explorer of this course, following 
the guidance of none, nor even communicating my thoughts 
to a single individual; yet having once firmly entered in the 
right way, and submitting the powers of my mind to things, 
I have somewhat advanced (as I make bold to think) the 
matter 1 now treat of. Then let others consider what may 


be hoped from men who enjoy abundant leisure, from united 
labors, and the succession of ages, after these suggestions on 
our part, especially in a course which is not confined, like 
theories, to individuals, but admits of the best distribution 
and union of labor and effect, particularly in collecting ex 
periments. For men will then only begin to know their own 
power, when each performs a separate part, instead of un 
dertaking in crowds the same work. 

CXIV. Lastly, though a much more faint and uncertain 
breeze of hope were to spring up from our new continent, 
yet we consider it necessary to make the experiment, if we 
would not show a dastard spirit. For the risk attending 
want of success is not to be compared with that of neglect 
ing the attempt; the former is attended with the loss of a lit 
tle human labor, the latter with that of an immense benefit. 
For these and other reasons it appears to us that there ia 
abundant ground to hope, and to induce not only those who 
are sanguine to make experiment, but even those who are 
cautious and sober to give their assent. 

CXV. Such are the grounds for banishing despair, 
hitherto one of the most powerful causes of the delay and 
restraint to which the sciences have been subjected; in treat 
ing of which we have at the same time discussed the signs 
and causes of the grrorSj idleness, and ignorance that have 
prevailed; seeing especially that the more refined causes, 
which are not open to popular judgment and observation, 
may be referred to our remarks on the idols of the human 

Here, too, we should close the demolishing branch of our 
Instauration, which is comprised in three confutations: /LJ 
the confutation of natural human reason left to itself ;V2/tne 

confutation of demonstration ;j the confutation of theories, 


or received systems of philosophy and doctrines. Oar con 
futation has followed such a course as was open to it, 
namely, the exposing of the signs of error, and the pro 
ducing evidence of the causes of it: for we could adopt no 
other, differing as we do both in first principles and demon 
strations from others. 

It is time for us therefore to come to the art itself, and 
the rule for the interpretation of nature: there is, however, 
still something which must not be passed over. For the in 
tent of this first book of aphorisms being to prepare the 
mind for understanding, as well as admitting, what follows, 
we must now, after having cleansed, polished, and levelled 
its surface, place it in a good position, and as it were a 
benevolent aspect toward our propositions; seeing that prej 
udice in new matters may be produced not only by the 
strength of preconceived notions, but also by a false antici 
pation or expectation of the matter proposed. "We shall 
therefore endeavor to induce good and correct opinions of 
what we offer, although this be only necessary for the mo 
ment, and as it were laid out at interest, until the matter 
itself be well understood. 

CXVI. First, then, we must desire men not to suppose 
that we are ambitious of founding any philosophical sect, 
like the ancient Greeks, or some moderns, as Telesius, Pa- 
tricius, and Severinus. For neither is this our intention, 

62 As Bacon very frequently cites these authors, a slight notice of their 
labors may not be unacceptable to the reader. Bernardimis Telesius, born at 
Cosenza, in 1508, combated the Aristotelian system in a work cutitled "De 
Rerum Natura juxta propria principia," i.e., according to principles of his own. 
The proem of the work announces his design was to show that "the construc 
tion of the world, the magnitude and nature of the bodies contained in it, are 
not to be investigated by reasoning, which was done by the ancients, but are to 
be apprehended by the senses, and collected from the things themselves." He 


nor do we think that peculiar abstract opinions on nature 
and the principles of things are of nmclTimportance to men s 
fortunes, since it were easy to revive many ancient theories, 
and to introduce many new ones; as, for instance, many 
hypotheses with regard to the heavens can be formed, differ 
ing in themselves, and yet sufficiently according with the 

We bestow not our labor on such theoretical and, at the 
same time, useless topics. On the contrary, our determina 
tion is that of trying, whether we can lay a firmer founda 
tion, and extend to a greater distance the boundaries of 
human power and dignity. And although here and there, 
upon some particular points, we hold (in our own opinion) 
more true and certain, and I might even say, more advan 
tageous tenets than those in general repute (which we have 
collected in the fifth part of our Installation), yet we offer 

had, however, no sooner laid down this principle than he departed from it in 
practice, and pursued the deductive method he so much condemned in his prede 
cessors. His first step was an assumption of principles as arbitrary as any of 
the empirical notions of antiquity; at the outset of his book he very quietly 
takes it for granted that heat is the principle of motion, cold of immobility, 
matter being assumed as the corporeal substratum, in which these incorporeal 
and active agents carry on their operations. Out of these abstract and ill- 
defined conceptions Telesius builds up a system quite as complete, symmetrical, 
and imaginative as any of the structures of antiquity. 

Francis Patricius, born at Cherso, in Dalmatia, about 1529, was another 
physicist who rose up against Aristotle, and announced the dawn of a new 
philosophy. In 1593 appeared his "Nova de Universis Philosophia." He 
lays down a string of axioms, in which scholastic notions, physical discover 
ies, and theological dogmas, are strangely commingled, and erects upon them 
a system which represents all the grotesque features of theological empiricism. 

Severinus, born in Jutland, in 1529, published au attack on Aristotle s nat 
ural history, but adopted fantasies which the Stagyrite ridiculed in his own day. 
He was a follower of Paracelsus, a Swiss enthusiast of the fifteenth century, 
who ignored the ancient doctrine of the four elements for salt, sulphur and 
mercury, and allied chemistry and medicine with mysticism. Ed. 


no universal or complete theory. The time does not yet 
appear to us to be arrived, and we entertain no hope of our 
life being prolonged to the completion of the sixth part of 
the Instauration (which is destined for philosophy discovered 
by the interpretation of nature), but are content if we pro 
ceed quietly and usefully in our intermediate pursuit, scat 
tering, in the meantime, the seeds of less adulterated truth 
for posterity, and, at least, commence the great work. 

CXVII. And, as we pretend not to found a sect, so do 
we neither offer nor promise particular effects; which may 
occasion some to object to us, that since we so often speak 
of effects, and consider everything in its relation to that end, 
we ought also to give some earnest of producing them. Our 
course and method, however (as we have often said, and 
again repeat), is such as not to deduce effects from effects, 
nor experiments from experiments (as the empirics do), but 
in our capacity of legitimate interpreters of nature, to de 
duce causes and axioms from effects and experiments; and 
new effects and experiments from those causes and axioms. 

And although any one of moderate intelligence and abil 
ity will observe the indications and sketches of many noble 
effects in our tables of inventions (which form the fourth 
part of the Instauration), and also in the examples of par 
ticular instances cited in the second part, as well as in our 
observations on history (which is the subject of the third 
part); yet we candidly confess that our present natural his 
tory, whether compiled from books or our own inquiries, is 
not sufficiently copious and well ascertained to satisfy, or 
even assist, a proper interpretation. 

If, therefore, there be any one who is more disposed and 
prepared for mechanical art, and ingenious in discovering 
effects, than in the mere management of experiment, we 


allow him to employ his industry in gathering many of the 
fruits of our history and tables in this way, and applying 
them to effects, receiving them as interest till he can obtain 
the principal. For our own part, having a greater object in 
view, we condemn all hasty and premature rest in such pur 
suits as we would Atalanta s apple (to use a common allu 
sion of ours); for we are not childishly ambitious of golden 
fruit, but use all our efforts to make the course of art out 
strip nature, and we hasten not to reap moss or the green 
blade, but wait for a ripe harvest. 

CXYI1L There will be some, without doubt, who, on a 
perusal of our history and tables of invention, will meet with 
some uncertainty, or perhaps fallacy, in the experiments 
themselves, and will thence perhaps imagine that our dis 
coveries are built on false foundations and principles. There 
is, however, really nothing in this, since it must needs hap 
pen in beginnings. 83 For it is the same as if in writing or 
printing one or two letters were wrongly turned or mis 
placed, which is no great inconvenience to the reader, who 
can easily by his own eye correct the error; let men in the 
same way conclude, that many experiments in natural his 
tory may be erroneously believed and admitted, which are 
easily expunged and rejected afterward, by the discovery of 
causes and axioms. It is, however, true, that if these errors 
in natural history and experiments become great, frequent, 
and continued, they cannot be corrected and amended by 

63 Bacon s apology is sound, and completely answers those German and 
French critics, who have refused him a niche in the philosophical pantheon. 
One German commentator, too modest to reveal his name, accuses Bacon of 
ignorance of the calculus, though, in his day, Wallia.had not yet stumbled upon 
the laws of continuous fractions ; while Count de Maistre, in a coarse attack 
upon his genius, expresses his astonishment at finding Bacon unacquainted 
with discoveries which were not heard of till a century after his death. Ed. 


any dexterity of wit or art. If then, even in our natural 
history, well examined and compiled with such diligence, 
strictness, and (1 might say) reverential scruples, there be 
now and then something false and erroneous in the details, 
what must we say of the common natural history, which is 
so negligent and careless when compared with ours ? or of 
systems of philosophy and the sciences, based on such loose 
soil (or rather quicksand) ? Let none then be alarmed by 
such observations. 

CXIX. Again, our history and experiments will contain 
much that is light and common, mean and illiberal, too 
refined and merely speculative, and, as it were, of no use, 
and this perhaps may divert and alienate the attention of 

With regard to what is common; let men reflect, that 
they have hitherto been used to do nothing but refer and 
adapt the causes of things of rare occurrence to those of 
things which more frequently happen, without any investi 
gation of the causes of the latter, taking them for granted 
and admitted. 

Hence, they do not inquire into the causes of gravity, 
the rotation of the heavenly bodies, heat, cold, light, hard 
ness, softness, rarity, density, liquidity, solidity, animation, 
inanimation, similitude, difference, organic formation, but 
taking them to be self-evident, manifest, and admitted, they 
dispute and decide upon other matters of less frequent and 
famiHar occurrence. 

But we (who know that no judgment can be formed of 
that which is rare or remarkable, and much less anything 
new brought to light, without a previous regular examina 
tion and discovery of the causes of that which is common, 
and the causes again of those causes) are necessarily com- 


pelled to admit the most common objects into our nistory. 
Besides, we have observed that nothing has been so injuri 
ous to philosophy as this circumstance, namely, that famil 
iar and frequent objects do not arrest and detain men s con 
templation, but are carelessly admitted, and their causes 
never inquired after; so that information on unknown sub 
jects is not more often wanted than attention to those which 
are known. 

CXX. With regard to the meanness, or even the filthi- 
ness of particulars, for which (as Pliny observes), an apology 
is requisite, such subjects are no less worthy of admission 
into natural history than the most magnificent and costly; 
nor do they at all pollute natural history, for the sun enters 
alike the palace and the privy, and is not thereby polluted. 
We neither dedicate nor raise a capitol or pyramid to the 
pride of man, but rear a holy temple in his mind, on the 
model of the universe, which model therefore we imitate. 
For that which is deserving of existence is deserving of 
knowledge, the image of existence. Now the mean and 
splendid alike exist. Nay, as the finest odors are some 
times produced from putrid matter (such as musk and 
civet), so does valuable light and information emanate from 
mean and sordid instances. But we have already said too 
much, for such fastidious feelings are childish and effemi 

CXXI. The next point requires a more accurate consid 
eration, namely, that many parts of our history will appear 
to the vulgar, or even any mind accustomed to the present 
state of things, fantastically and uselessly refined. Hence, 
we have in regard to this matter said from the first, and must 
again repeat, that we look for experiments that shall afford 
light rather than profit, imitating the divine creation, which, 


as we have often observed, only produced light on the first 
day, and assigned that whole day to its creation, without 
adding any material work. 

If any one, then, imagine such matters to be of no use, 
be might equally suppose light to be of no use, because it 
is neither solid nor material. For, in fact, the knowledge 
of simple natures, when sufficiently investigated and de 
nned, resembles light, which, though of no great use in 
itself, affords access to the general mysteries of effects, and 
with a peculiar power comprehends and draws with it whole 
bands and troops of effects, and the sources of the most val 
uable axioms. So also the elements of letters have of them 
selves separately no meaning, and are of no use, yet are they, 
as it were, the original matter in the composition and prepa 
ration of speech. The seeds of substances, whose effect is 
powerful, are of no use except in their growth, and the scat 
tered rays of light itself avail not unless collected. 

But if speculative subtilties give offence, what must we 
say of the scholastic philosophers who indulged in them to 
such excess? And those subtilties were wasted on words, 
or, at least, common notions (which is the same thing), not 
on things or nature, and alike unproductive of benefit in 
their origin and their consequences: in no way resembling 
ours, which are at present useless, but in their consequences 
of infinite benefit. Let men be assured that all subtile dis 
putes and discursive efforts of the mind are late and prepos 
terous, when they are introduced subsequently to the dis 
covery of axioms, and that their true, or, at any rate, chief 
opportunity is, when experiment is to be weighed and axioms 
to be derived from it. They otherwise catch and grasp at 
nature, but never seize or detain her: and we may well 
apply to nature that which has been said of opportunity 


or fortune, that she wears a lock in front, but is bald 

In short, we may reply decisively to those who despise 
any part of natural history as being vulgar, mean, or sub 
tile, and useless in its origin, in the words of a poor woman 
to a haughty prince, 84 who had rejected her petition as un 
worthy, and beneath the dignity of his majesty: "Then 
cease to reign"; for it is quite certain that the empire of 
nature can neither be obtained nor administered by one who 
refuses to pay attention to such matters as being poor and 
too minute. 

CXXII. Again, it may be objected to us as being singu 
lar and harsh, that we should with one stroke and assault, 
as it were, banish all authorities and sciences, and that too 
by our own efforts, without requiring the assistance and 
support of any of the ancients. 

Now we are aware, that had we been ready to act other 
wise than sincerely, it was not difficult to refer our present 
method to remote ages, prior to those of the Greeks (since 
the sciences in all probability flourished more in their nat 
ural state, though silently, than when they were paraded 
with the fifes and trumpets of the Greeks); or even (in 
parts, at least) to some of the Greeks themselves, and to 
derive authority and honor from thence ; as men of no family 
labor to raise and form nobility for themselves in some an 
cient line, by the help of genealogies. Trusting, however, 
to the evidence of facts, we reject every kind of fiction and 
imposture; and think it of no more consequence to our sub 
ject, whether future discoveries were known to the ancients, 
and set or rose according to the vicissitudes of events and 

84 Philip of Macedon. 


lapse of ages, than it would be of importance to mankind 
to know whether the new world be the island of Atlantis, * 
and known to the ancients, or be now discovered for the 
first time. 

With regard to the universal censure we have bestowed, 
it is quite clear, to any one who properly considers the 
matter, that it is both more probable and more modest than 
any partial one could have been. For if the errors had not 
been rooted in the primary notions, some well conducted 
discoveries must have corrected others that were deficient. 
But since the errors were fundamental, and of such a nature, 
that men may be said rather to have neglected or passed 
over things, than to have formed a wrong or false judgment 
of them, it is little to be wondered at, that they did not ob 
tain what they never aimed at, nor arrive at a goal which 
they had not determined, nor perform a course which they 
had neither entered upon nor adhered to. 

With regard to our presumption, we allow that if we were 
to assume a power of drawing a more perfect straight line 
or circle than any one else, by superior steadiness of hand 
or acuteness of eye, it would lead to a comparison of talent: 
but if one merely assert that he can draw a more perfect line 
or circle with a ruler or compasses, than another can by his 
unassisted hand or eye, he surely cannot be said to boast 
of much. Now this applies not only to our first original 
attempt, but also to those who shall hereafter apply them 
selves to the pursuit. For our method of discovering the 
sciences merely levels men s wits, and leaves but little to 
their superiority, since it achieves everything by the most 
certain rules and demonstrations. Whence (as we have 

85 See Plato s Tima:us. 


often observed), our attempt is to be attributed to fortune 
rather than talent, and is the offspring of time rather than 
of wit. For a certain sort of chance has no less effect upon 
our thoughts than on our acts and deeds. 

CXXIII. We may, therefore, apply to ourselves the 
joke of him who said, that water and wine drinkers could 
not think alike," especially as it hits the matter so well. 
For others, both ancients and moderns, have in the sciences 
drank a crude liquor like water, either flowing of itself 
from the understanding, or drawn up by logic as the wheel 
draws up the bucket. But we drink and pledge others with 
a liquor made of many well-ripened grapes, collected and 
plucked from particular branches, squeezed in the press, 
and at last clarified and fermented in a vessel. It is not, 
therefore, wonderful that we should not agree with others. 

CXXIV. Another objection will without doubt be made, 
namely, that we have not ourselves established a correct, or 
the best goal or aim of the sciences (the very defect we 
blame in others). For they will say that the contemplation 
of truth is more dignified and exalted than any utility or 
extent of effects; but that our dwelling so long and anx 
iously on experience and matter, and the fluctuating state 
of particulars, fastens the mind to earth, or rather casts it 
down into an abyss of confusion and disturbance, and sep 
arates and removes it from a much more divine state, the 
quiet and tranquillity of abstract wisdom. "We willingly 
assent to their reasoning, and are most anxious to effect the 
very point they hint at and require. For we are founding 
a real model of the world in the understanding, such as it 
is found to be, not such as man s reason has distorted. 

68 The saying of Philocratea when he differed from Demosthenes. Ed. 

SCIENCE Vol. 22 5 


Now this cannot be done without dissecting and anatomiz 
ing the world most diligently; but we declare it necessary 
to destroy completely the vain, little and, as it were, apish 
imitations of the world, which have been formed in various 
systems of philosophy by men s fancies. Let men learn 
(as we have said above) the difference that exists between 
the idols of the human mind and the ideas of the divine 
mind. The former are mere arbitrary abstractions; the 
latter the true marks of the Creator on his creatures, as 
they are imprinted on, and denned in matter, by true and 
exquisite touches. Truth, therefore, and utility, are here 
perfectly identical, and the effects are of more value as 
pledges of truth than from the benefit they confer on 

CXXV. Others may object that we arc only doing that 
which has already been done, and that the ancients followed 
the same course as ourselves. They may imagine, there 
fore, that, after all this stir and exertion, we shall at last 
arrive at some of those systems that prevailed among the 
ancients: for that they, too, when commencing their medi 
tations, laid up a great store of instances and particulars, 
and digested them under topics and titles in their common 
place books, and so worked out their systems and arts, and 
then decided upon what they discovered, and related now 
and then some examples to confirm and throw light upon 
their doctrine; but thought it superfluous and troublesome 
to publish their notes, minutes, and commonplaces, and 
therefore followed the example of builders who remove 
the scaffolding and ladders when the building is finished. 
Nor can we indeed believe the case to have been otherwise. 
But to any one, not entirely forgetful of our previous obser 
vations, it will be easy to answer this objection or rather 


scruple; for we allow that the ancients had a particular 
form of investigation and discovery, and their writings show 
it. But it was of such a nature, that they immediately flew 
from a few instances and particulars (after adding some 
common notions, and a few generally received opinions 
most in vogue) to the most general conclusions or the prin 
ciples of the sciences, and then by their intermediate propo 
sitions deduced their inferior conclusions, and tried them 
by the test of the immovable and settled truth of the first, 
and so constructed their art. Lastly, if some new particu 
lars and instances were brought forward, which contradicted 
their dogmas, they either with great subtilty reduced them 
to one system, by distinctions or explanations of their own 
rules, or got rid of them clumsily as exceptions, laboring 
most pertinaciously in the meantime to accommodate the 
causes of such as were not contradictory to their own prin 
ciples. Their natural history and their experience were 
both far from being what they ought to have been, and 
their flying off to generalities ruined everything. 

CXXV1. Another objection will be made against us, 
that we prohibit decisions and the laying down of certain 
principles, till we arrive regularly at generalities by the 
intermediate steps, and thus keep the judgment in suspense 
and lead to uncertainty. But our object is not uncertainty 
but fitting certainty, for we derogate not from the senses 
but assist them, and despise not the understanding but 
direct it. It is better to know what is necessary, and not 
to imagine we are fully in possession of it, than to imagine 
that we are fully in possession of it, and yet in reality to 
know nothing which we ought. 

CXXVII. Again, some may raise this question rather 
than objection, whether we talk of perfecting natural phi- 

102 NOVUM 

losophj alone according to our method, or the other sciences 
also, such as logic, ethics, politics. AVe certainly intend to 
comprehend them all. And as common logic, which regu 
lates matters by syllogisms, is applied not only to natural, 
but also to every other science, so our inductive method 
likewise comprehends them all. 67 For we form a history 
and tables of invention for anger, fear, shame, and the 
like, and also for examples in civil life, and the mental 
operations of memory, composition, division, judgment, and 
the rest, as well as for heat and cold, light, vegetation, 
and the like. But since our method of interpretation, after 
preparing and arranging a history, does not content itself 
with examining the operations and disquisitions of the mind 
like common logic, but also inspects the nature of things, 
we so regulate the mind that it may be enabled to apply 
itself in every respect correctly to that nature. On that 
account we deliver numerous and various precepts in our 
doctrine of interpretation, so that they may apply in some 

61 The old error of placing the deductive syllogism in antagonism to the 
inductive, as if they were not both parts of one system or refused to cohere 
together. So far from there being any radical opposition between them, it 
would not be difficult to show that Bacon s method was syllogistic in his sense 
of the term. For the suppressed premise of every Baconian enthymeme, viz., 
the acknowledged uniformity of the laws of nature as stated in the axiom, 
whatever has once occurred will occur again, must be assumed as the basis 
of every conclusion which he draws before we can admit its legitimacy. The 
opposition, therefore, of Bacon s method could not be directed against the old 
logic, for it assumed and exemplified its principles, but rather to the abusive 
application which the ancients made of this science, in turning its powers to 
the development of abstract principles which they imagined to be pregnant 
with the solution of the latent mysteries of the universe. Bacon justly over 
threw these ideal notions, and accepted of no principle as a basis which was 
not guaranteed by actual experiment and observation ; and so far he laid the 
foundations of a sound philosophy by turning the inductive logic to its proper 
account in the interpretation of nature. 


measure to the method of discovering the quality and con 
dition of the subject matter of investigation. 

CXXVIII. Let none even doubt whether we are anxious 
to destroy and demolish the philosophy, arts, and sciences, 
which are now in use. On the contrary, we readily cherish 
their practice, cultivation, and honor; for we by no means 
interfere to prevent the prevalent system from encouraging 
discussion, adorning discourses, or being employed service- 
ably in the chair of the professor or the practice of common 
life, and being taken, in short, by general consent as cur 
rent coin. Nay, we plainly declare, that the system we 
offer will not be very suitable for such purposes, not being 
easily adapted to vulgar apprehensions, except by effects 
and works. To show our sincerity in professing our regard 
and friendly disposition toward the received sciences, we 
can refer to the evidence of our published writings (espe 
cially our books on the Advancement of Learning). We 
will not, therefore, endeavor to evince it any further by 
words; but content ourselves with steadily and professedly 
premising, that no great progress can be made by the 
present methods in the theory or contemplation of science, 
and that they cannot be made to produce any very abun 
dant effects. 

CXXIX. It remains for us to say a few words on the 
excellence of our proposed end. If we had done so before, 
we might have appeared merely to express our wishes, but 
now that we have excited hope and removed prejudices, it 
will perhaps have greater weight. Had we performed and 
completely accomplished the whole, without frequently 
calling in others to assist in our labors, we should then 
have refrained from saying any more, lest we should be 
thought to extol our own deserts. Since, however, the 


industry of others must be quickened, and their courage 
roused and inflamed, it is right to recall some points to 
their memory. 

First, then, the introduction of great inventions appears 
one of the most distinguished of human actions, and the 
ancients so considered it; for they assigned divine honors 
to the authors of inventions, but only heroic honors to those 
who displayed civil merit (such as the founders of cities 
and empire legislators, the deliverers of their country 
from lasting misfortunes, the quellers of tyrants, and the 
like). And if any one rightly compare them, he will find 
the judgment of antiquity to "be correct; for the benefits 
derived from inventions may extend to mankind in general, 
but civil benefits to particular spots alone; the latter, more 
over, last but for a time, the former forever. Civil reforma 
tion seldom is carried on without violence and confusion, 
while inventions are a blessing and a benefit without 
injuring or afflicting any. 

Inventions are also, as it were, new creations and imita 
tions of divine works, as was expressed by the poet: 68 

"Primum frugiferos foetus mortalibus jegria 
Dididerant quondam prsestanti nomine Athense 
Et recreaverunt vitam legesque rogarunt. " 

And it is worthy of remark in Solomon, that while he 
flourished in the possession of his empire, in wealth, in the 

88 This is the opening of the Sixth Book of Lucretius. Bacon probably 
quoted from memory; the lines are 

"Primse frugiferos fo3tus mortalibus EDgris 
Dididerunt quondam prrcclaro nomine Athense 
Et recreaverunt," etc. 

The teeming corn, that feeble mortals crave, 

First, and long since, renowned Athens gave, 

And cheered their life then taught to frame their laws. 


magnificence of his works, in his court, his household, his 
fleet, the splendor of his name, and the most unbounded 
admiration of mankind, he still placed his glory in none of 
these, but declared 89 that it is the glory of God to conceal 
a thing, but the glory of a king to search it out. 

Again, let any one but consider the immense difference 
between men s lives in the most polished countries of Eu 
rope, and in any wild and barbarous region of the new 
Indies, he will think it so great, that man may be said to 
be a god unto man, not only on account of mutual aid and 
benefits, but from their comparative states the result of 
the arts, and not of the soil or climate. 

Again, we should notice the force, effect, and conse 
quences of inventions, which are nowhere more conspicu 
ous than in those three which were unknown to the ancients; 
namely, printing, gunpowder, and the compass. For these 
three have changed the appearance and state of the whole 
world: first in literature, then in warfare, and lastly in 
navigation; and innumerable changes have been thence 
derived, so that no empire, sect, or star, appears to have 
exercised a greater power and influence on human affairs 
than these mechanical discoveries. 

It will, perhaps, be as well to distinguish three species 
and degrees of ambition. First, that of men who are anx 
ious to enlarge their own power in their country, which is 
a vulgar and degenerate kind; next, that of men who strive 
to enlarge the power and empire of their country over man 
kind, which is more dignified but not less covetous; but if 
one were to endeavor to renew and enlarge the power and 
empire of mankind in general over the universe, such ambi- 

" Prov. xxv. 2. 


tion (if it may be so termed) is both more sound and more 
noble than the other two. Now the empire of man over 
things is founded on the arts and sciences alone, for nature 
is only to be commanded by obeying her. 

Besides this, if the benefit of any particular invention has 
had such an effect as to induce men to consider him greater 
than a man, who has thus obliged the whole race, how 
much more exalted will that discovery be, which leads to 
the easy discovery of everything else ! Yet (to speak the 
truth) in the same manner as we are very thankful for light 
which enables us to enter on our way, to practice arts, to 
read, to distinguish each other, and yet sight is more excel 
lent and beautiful than the various uses of light; so is the 
contemplation of things as they are, free from superstition 
or imposture, error or confusion, much more dignified in 
itself than all the advantage to be derived from discoveries. 

Lastly, let none be alarmed at the objection of the arts 
and sciences becoming depraved to malevolent or luxurious 
purposes and the like, for the same can be said of every 
worldly good; talent, courage, strength, beauty, riches, 
light itself, and the rest. Only let mankind regain their 
rights over nature, assigned to them by the gift of God, 
and obtain that power, whose exercise will be governed by 
right reason and true religion. 

CXXX. But it is time for us to lay down the art of 
interpreting nature, to which we attribute no absolute ne 
cessity (as if nothing could be done without it) nor perfec 
tion, although we think that our precepts are most useful 
and correct. For we are of opinion, that if men had at 
their command a proper history of nature and experience, 
and would apply themselves steadily to it, and could 
bind themselves to two things: 1, to lay aside received 


opinions and notions; 2, to restrain themselves, till the 
proper season, from generalization, they might, by the 
proper and genuine exertion of their minds, fall into our 
way of interpretation without the aid of any art. For in 
terpretation is the true and natural act of the mind, when 
all obstacles are removed: certainly, however, everything 
will be more ready and better fixed by our precepts. 

Yet do we not affirm that no addition can be made to 
them; on the contrary, considering the mind in its connec 
tion with things, and not merely relatively to its own 
powers, we ought to be persuaded that the art of inven 
tion can be made to grow with the inventions themselves. 



I. To GENERATE and superinduce a new nature or new 
natures, upon a given body, is the labor and aim of human 
power: while to discover the form or true difference of a 
given nature, or the nature 1 to which such nature is owing, 
or source from which it emanates (for these terms approach 
nearest to an explanation of our meaning), is the labor and 
discovery of human knowledge; and subordinate to these 
primary labors are two others of a secondary nature and 
inferior stamp. Under the first must be ranked the trans 
formation of concrete bodies from one to another, which is 
possible within certain limits; under the second, the dis 
covery, in every species of generation and motion, of the 
latent and uninterrupted process from the manifest efficient 
and manifest subject matter up to the given form: and a 
like discovery of the latent conformation of bodies which 
are at rest instead of being in motion. 

II. The unhappy state of man s actual knowledge is 
manifested even by the common assertions of the vulgar. 
It is rightly laid down that true knowledge is that which 
is deduced from causes. The division of four causes also 
is not amiss: matter, form, the efficient, and end or final 

i TO ri Jtv tlviu, or $" o& of Aristotle. See lib. iii. Mctap. 



cause. 2 Of these, however, the latter is so far from being 
beneficial, that it even corrupts the sciences, except in the 
intercourse of man with man. The discovery of form is 
considered desperate. As for the efficient cause and matter 
(according to the present system of inquiry and the received 
opinions concerning them, by which they are placed remote 
from, and without any latent process toward form), they are 
but desultory and superficial, and of scarcely any avail to 
real and active knowledge. Nor are we unmindful of our 
having pointed out and corrected above the error of the 
human mind, in assigning the first qualities of essence to 
forms. 3 For although nothing exists in nature except indi-"~ 
victual bodies, 4 exhibiting clear individual effects according 
to particular laws, yet in each branch of learning, that very 
law, its investigation, discovery, and development, are the 
foundation both of theory and practice. This law, therefore, 
and its parallel in each science, is what we understand by 
the term form, 6 adopting that word because it has grown 

into common use, and is of familiar occurrence. 


* These divisions are from Aristotle s Metaphysics, where they are termed, 

1 < vXrj r) TO viroKei/j.evov. 2. To T *l v t^vai. 3. O0ev ^ a.p\r) TTJS Kivijcrcto?. 4. TO "5 evtKtv 
feat TO ayaOov. 

3 See Aphorism li. and second paragraph of Aphorism Ixv. in the first book. ) - 

4 Bacon means, that although there exist in nature only individualities, yet 
a certain number of these may have common properties, and be controlled by 
the same laws. Now, these homogeneous qualities which distinguish them 
from other individuals, lead us to class them under one expression, and some 
times under a single term. Yet these classes are only pure conceptions in 
Bacon s opinion, and cannot be taken for distinct substances. He evidently 
here aims a blow at the Realists, who concluded that the essence which united 
individualities in a class was the only real and immutable existence in nature, 
inasmuch as it entered into their ideas of individual substances as a distinct and 
essential property, and continued in the mind as the mold, type or pattern of 
the class, while its individual forms were undergoing perpetual renovation and . 
decay. Ed. 

6 Bacon s definition is obscure. All the idea we have of a law of nature 


III. He who has learned the cause of a particular nature 
(such as whiteness or heat), in particular subjects only, has 
acquired but an imperfect knowledge: as he who can induce 
a certain effect upon particular substances only, among those 
which are susceptible of it, has acquired but an imperfect 
power. But he who has only learned the efficient and 
material cause (which causes are variable and mere vehicles 

consists in invariable sequence between certain classes of phenomena; but this 
cannot be the complete sense attached by Bacon to the term form, as he em 
ploys it in the fourth aphorism as convertible with the nature of any object; 
and again, in the first aphorism, as the natura naturans, or general law or con 
dition in any substance or quality natura naturata which is whatever ita 
form is, or that particular combination of forces which impresses a certain 
nature upon matter subject to its influence. Thus, in the Newtonian sense, 
the form of whiteness would be that combination of the seven primitive rays 
of light which give rise to that color. In combination with this word, and 
affording a still further insight into its meaning, we have the phrases, latens 
ftrocessus ad formarn, et latens scJtematismus corporum. Now, the latens scJie- 
matismus signifies the internal texture, structure, or configuration of bodies, or 
the result of the respective situation of all the parts of a body; while the latens 
processus ad formam points out the gradation of movements which takes place 
among the molecula of bodies when they either conserve or change their figure. 
Hence we may consider the form of any quality in body as something converti 
ble with that quality, i.e., when it exists the quality is present, and vice versd. 
In this sense, the form of a thing differs only from its efficient cause in being 
permanent, whereas we apply cause to that which exists in order of time. The 
latens processus and latens schematismus are subordinate to form, as concrete 
exemplifications of its essence. The former is the secret and invisible process 
by which change is effected, and involves the principle since called the law of 
continuity. Thus, the succession of events between the application of the 
match to the expulsion of the bullet is an instance of latent progress which we 
can now trace with some degree of accuracy. It also more directly refers to 
the operation by which one form or condition of being is induced upon another. 
For example, when the surface of iron becomes rusty, or when water is con 
verted into steam, some change has taken place, or latent process from one 
form to another. Mechanics afford many exemplifications of the first latent 
process we have denoted, and chemistry of the second. The latens schematis~ 
inus is that visible structure of bodies on which so many of their properties 
depend. "When we inquire into the constitution of crystals, and into the inter 
nal structure of plants, we are examining into their latent schematism. Ed. 


conveying form to particular substances) may perhaps arrive 
at some new discoveries in matters of a similar nature, and 
prepared for the purpose, but does not stir the limits of 
things which are much more deeply rooted; while he who 
is acquainted with forms, comprehends the unity of nature 
in substances apparently most distinct from each other. He 
can disclose and bring forward, therefore (though it has 
never yet been done), things which neither the vicissitudes 
of nature, nor the industry of experiment, nor chance itself, 
would ever have brought about, and which would forever 
have escaped man s thoughts; from the discovery of forms, 
therefore, results genuine theory and free practice. 

IV. Although there is a most intimate connection, and 
almost an identity between the ways of human power 
and human knowledge, yet, on account of the pernicious 
and inveterate habit of dwelling upon abstractions, it is 
by far the safest method to commence and build up the 
sciences from those foundations which bear a relation to 
the practical division, and to let them mark out and limit 
the theoretical. We must consider, therefore, what pre 
cepts, or what direction or guide, a person would most 
desire, in order to generate and superinduce any nature 
upon a given body: and this not in abstruse, but in the 
plainest language. 

For instance, if a person should wish to superinduce the 
yellow color of gold upon silver, or an additional weight 
(observing always the laws of matter) or transparency on an 
opaque stone, or tenacity in glass, or vegetation on a sub 
stance which is not vegetable, we must (I say) consider what 
species of precept or guide this person would prefer. And, 
first, he will doubtless be anxious to be shown some method 
that will neither fail in effect, nor deceive him in the trial of 


it; secondly, he will be anxious that the prescribed method 
should not restrict him and tie him down to peculiar means, 
and certain particular methods of acting; for he will, per 
haps, be at loss, and without the power or opportunity of 
collecting and procuring such means. Now if there be other 
means and methods (besides those prescribed) of creating 
such a nature, they will perhaps be of such a kind as are in 
his power, yet by the confined limits of the precept he will 
be deprived of reaping any advantage from them; thirdly, 
he will be anxious to be shown something not so difficult 
as the required effect itself, but approaching more nearly to 

We will lay this down, therefore, as the genuine and per 
fect rule of practice, that it should be certain, free and pre 
paratory, or having relation to practice. And this is the 
same thing as the discovery of a true form; for the form of 
any nature is such, that when it is assigned the particular 
nature infallibly follows. It is, therefore, always present 
when that nature is present, and universally attests such 
presence, and is inherent in the whole of it. The same 
form is of such a character, that if it be removed the par 
ticular nature infallibly vanishes. It is, therefore, absent, 
whenever that nature is absent, and perpetually testifies such 
absence, and exists in no other nature. Lastly, the true 
form is such, that it deduces the particular nature from some 
source of essence existing in many subjects, and more known 
(as they term it) to nature, than the form itself. Such, then, 
is our determination and rule with regard to a genuine and 
perfect theoretical axiom, that a nature be found convertible 
with a given nature, and yet such as to limit the more 
known nature, in the manner of a real genus. But these 
two rules, the practical and theoretical, are in fact the 


same, and that which is most useful in practice is most 
correct in theory. 

V. But the rule or axiom for the transformation of bodies 
is of two kinds. The first regards the body as an aggregate 
or combination of simple natures. Thus, in gold are united 
the following circumstances: it is yellow, heavy, of a cer 
tain weight, malleable and ductile to a certain extent; it is 
not volatile, loses part of its substance by fire, melts in a 
particular manner, is separated and dissolved by particular 
methods, and so of the other natures observable in gold. 
An axiom, therefore, of this kind deduces the subject from 
the forms of simple natures; for he who has acquired the 
forms and methods of superinducing yellowness, weight, 
ductility, stability, deliquescence, solution, and the like, 
and their degrees and modes, will consider and contrive how 
to unite them in any body, so as to transform 8 it into gold. 
And this method of operating belongs to primary action; for 
it is the same thing to produce one or many simple natures, 
except that man is more confined and restricted in his opera 
tions, if many be required, on account of the difficulty of 
uniting many natures together. It must, however, be ob 
served, that this method of operating (which considers na 
tures as simple though in a concrete body) sets out from j 
what is constant, eternal, and universal in nature, and opens / 
such broad paths to human power, as the thoughts" of "man 
can in the present state of things scarcely comprehend or 
figure to itself. 

The second kind of axiom (which depends on the dis 
covery of the latent process) does not proceed by simple na- 

6 By the recent discoveries in electric magnetism, copper wires, or, indeed, 
wires of any metal, may be transformed into magnets; the magnetic law, or 
form, having been to that extent discovered. 


tures, but by concrete bodies, as they are found in nature 
and in its usual course. For instance, suppose the inquiry 
to be, from what beginnings, in what manner, and by what 
process gold or any metal or stone is generated from the 
original menstruum, or its elements, up to the perfect min 
eral: or, in like manner, by what process plants are gener 
ated, from the first concretion of juices in the earth, or from 
seeds, up to the perfect plant, with the whole successive 
motion, and varied and uninterrupted efforts of nature; and 
the same inquiry be made as to a regularly deduced system 
of the generation of animals from coition to birth, and so on 
of other bodies. 

Nor is this species of inquiry confined to the mere gen 
eration of bodies, but it is applicable to other changes and 
labors of nature. For instance, where an inquiry is made 
into the whole series and continued operation of the nutri 
tive process, from the first reception of the food to its com 
plete assimilation to the recipient; 7 or into the voluntary 
motion of animals, from the first impression of the imagina 
tion, and the continuous effects of the spirits, up to the 
bending and motion of the joints; or into the free motion of 
the tongue and lips, and other accessories which give utter 
ance to articulate sounds. For all these investigations relate 
to concrete or associated natures artificially brought together, 
and take into consideration certain particular and special 
habits of nature, and not those fundamental and general 
laws which constitute forms. It must, however, be plainly 
owned, that this method appears more prompt and easy, and 
of greater promise than the primary one. 

7 Haller has pursued this investigation in his "Physiology," and hits left 
his successors little else to do than repeat his discoveries. Ed. 


In like manner the operative branch, which answers to / 
this contemplative branch, extends and advances its opera- j 
tion from that which is usually observed in nature, to other 
subjects immediately connected with it, or not very remote 
from such immediate connection. But the higher and radi 
cal operations upon nature depend entirely on the primary 
axioms. Besides, even where man has not the means of 
acting, but only of acquiring knowledge, as in astronomy 
(for man cannot act upon, change, or transform the heavenly 
bodies), the investigation of facts or truth, as well as the 
knowledge of causes and coincidences, must be referred to 
those primary and universal axioms that regard simple na 
tures; such as the nature of spontaneous rotation, attraction, 
or the magnetic force, and many others which are more com 
mon than the heavenly bodies themselves. For let no one 
hope to determine the question whether the earth or heaven 
revolve in the diurnal motion, unless he have first compre 
hended the nature of spontaneous rotation. 

VI. But the latent process of which we speak, is far 
from being obvious to men s minds, beset as they now are. 
For we mean not the measures, symptoms, or degrees of any 
process which can be exhibited in the bodies themselves, 
but simply a continued process, which, for the most part, 
escapes the observation of the senses. 

For instance, in all generations and transformations of 
bodies, we must inquire, what is in the act of being lost and 
escaping, what remains, what is being added, what is being 
diluted, what is being contracted, what is being united, what 
is being separated, what is continuous, what is broken off, 
what is urging forward, what impedes, what predominates, 
what is subservient, and many other circumstances. 

Nor are these inquiries again to be made in the mere 


generation and transformation of bodies only, but in all 
other alterations and fluctuations we must in like manner 
inquire; what precedes, what succeeds, what is quick, what 
is slow, what produces and what governs motion, and the 
like. All which matters are unknown and unattempted by 
the sciences, in their present heavy and inactive state. For, 
since every natural act is brought about by the smallest 
efforts/ or at least such as are too small to strike our senses, 
let no one hope that he will be able to direct or change na 
ture unless he have properly comprehended and observed 
these efforts. 

VII. In like manner, the investigation and discovery of 
the latent conformation in bodies is no less new, than the 
discovery of the latent process and form. For we as yet are 
doubtless only admitted to the antechamber of nature, and 
do not prepare an entrance into her presence-room. But 
nobody can endue a given body with a new nature, or trans 
form it successfully and appropriately into a new body, 
without possessing a complete knowledge of the body so to 
be changed or transformed. For he will run into vain, or, 
at least, into difficult and perverse methods, ill adapted to 
the nature of the body upon which he operates. A clear 
path, therefore, toward this object also must be thrown 
open, and well supported. 

Labor is well and usefully bestowed upon the anatomy 
of organized bodies, such as those of men and animals, 
which appears to be a subtile matter, and a useful examina 
tion of nature. The species of anatomy, however, is that of 
first sight, open to the senses, and takes place only in organ - 

8 Bacon here first seems pregnant with the important development of the 
higher calculus, which, in the hands of Newton and Descartes, was to effect 
as great u revolution in philosophy aa his method. Ed. 


ized bodies. It is obvious, and of ready access, when com 
pared with the real anatomy of latent conformation in bodies 
which are considered similar, particularly in specific objects 
and their parts; as those of iron, stone, and the similar parts 
of plants and animals, as the root, the leaf, the flower, the 
flesh, the blood, and bones, etc. Yet human industry has 
not completely neglected this species of anatomy; for we 
have an instance of it in the separation of similar bodies by 
distillation, and other solutions, which shows the dissimi 
larity of the compound by the union of the homogeneous 
parts. These methods are useful, and of importance to our 
inquiry, although attended generally with fallacy: for many 
natures are assigned and attributed to the separate bodies, 
as if they had previously existed in the compound, which, 
in reality, are recently bestowed and superinduced by fire 
and heat, and the other modes of separation. Besides, it is, 
after all, but a small part of the labor of discovering the real 
conformation in the compound, which is so subtile and nice, 
that it is rather confused and lost by the operation of the 
fire, than discovered and brought to light. 

A separation and solution of bodies, therefore, is to be 
effected, not by fire indeed, but rather by reasoning and true 
induction, with the assistance of experiment, and by a com 
parison with other bodies, and a reduction to those simple 
natures and their forms which meet, and are combined in 
the compound; and we must assuredly pass from Vulcan to 
Minerva, if we wish to bring to light the real texture and 
conformation of bodies, upon which every occult and (as it 
is sometimes called) specific property and virtue of things 
depends, and whence also every rule of powerful change and 
transformation is deduced. 

For instance, we must examine what spirit is in every 


body, 9 what tangible essence; whether that spirit is copious 
and exuberant, or meagre and scarce, fine or coarse, aeri 
form or igniform, active or sluggish, weak or robust, pro 
gressive or retrograde, abrupt or continuous, agreeing with 
external and surrounding objects, or differing from them, 
etc. In like manner must we treat tangible essence (which 
admits of as many distinctions as the spirit), and its hairs, 
fibres, and varied texture. Again, the situation of the spirit 
in the corporeal mass, its pores, passages, veins, and cells, 
and the rudiments or first essays of the organic body, are 
subject to the same examination. In these, however, as in 
our former inquiries, and therefore in the whole investiga 
tion of latent conformation, the only genuine and clear light 
which completely dispels all darkness and subtile difficul 
ties, is admitted by means of the primary axioms. 

VIII. This method will not bring us to atoms, 10 which 
takes for granted the vacuum, and immutability of matter 
(neither of which hypotheses is correct), but to the real par 
ticles such as we discover them to be. Nor is there any 

9 By spirit, Bacon here plainly implies material fluid too tine to be grasped 
by the unassisted sense, which rather operates than reasons. "We sometimes 
adopt the same mode of expression, as in the words spirits of nitre, spirits of 
wine. Some such agency has been assumed by nearly all the modern physi 
cists, a few of whom, along with Bacon, would leave us to gather from their 
expressions, that they believe such bodies endowed with the sentient powers 
of perception. As another specimen of his sentiment on this subject, we may 
refer to a paragraph ou the decomposition of compounds, in his essay on death, 
beginning "The spirit which exists in all living bodies, keeps all the parts in 
due subjection; when it escapes, the body decomposes, or the similar parts 
unite." Ed. 

10 The theory of the Epicureans and others. The atoms are supposed to be 
invisible, unalterable particles, endued with all the properties of the given body, 
and forming that body by their union. They must bo separated, of course, 
which either takes a vacuum for granted, or introduces a tertium quid into the 
composition of the body. 


ground for alarm at this refinement as if it were inexpli 
cable, for, on the contrary, the more inquiry is directed to 
simple natures, the more will everything be placed in a 
plain and perspicuous light, since we transfer our attention 
from the complicated to the simple, from the incommensur 
able to the commensurable, from surds to rational quantities, 
from the indefinite and vague to the definite and certain; as 
when we arrive at the elements of letters, and the simple 
tones of concords. The investigation of nature is best con 
ducted when mathematics are applied to physics. Again, 
let none be alarmed at vast numbers and fractions, for in 
calculation it is as easy to set down or to reflect upon a thou 
sand as a unit, or the thousandth part of an integer as an 
integer itself. 

IX. 11 From the two kinds of axioms above specified, 
arise the two divisions of philosophy and the sciences, and 
we will use the commonly adopted terms which approach 
the nearest to our meaning, in our own sense. Let the in 
vestigation of forms, which (in reasoning at least, and after 
their own laws), are eternal and immutable, constitute meta 
physics, 18 and let the investigation of the efficient cause of 

11 Compare the three following aphorisms with the last three chapters of the 
third book of the "De Augmentis Scientiarum. " 

12 Bacon gives this unfortunate term its proper signification ; M"a, in com 
position, with the Greeks signifying change or mutation. Most of our readers, 
no doubt, are aware that the obtrusion of this word into technical philosophy 
was purely capricious, and is of no older date than the publication of Aristotle s 
works by Audronicus of Rhodes, one of the learned men into whose hands the 
manuscripts of that philosopher fell, after they were brought by Sylla from 
Athens to Rome. To fourteen books in these MSS. with no distinguishing 
title, Andronicus is said to have prefixed the words utra. TO. Qvauea, to denote 
the place which they ought to hold either in the order of Aristotle s arrange 
ment, or in that of study. These books treat first of those subjects which are 
common to matter and mind; secondly, of things separate from matter, i.e. of 
God, and of the subordinate spirits, which were supposed by the Peripatetics 


matter, latent process, and latent conformation (which all 
relate merely to the ordinary course of nature, and not to 
her fundamental and eternal laws), constitute physics. 
Parallel to these, let there be two practical divisions; to 
physics that of mechanics, and to metaphysics that of magic, 
in the purest sense of the term, as applied to its ample 
means, and its command over nature. 

X. The object of our philosophy being thus laid down, 
we proceed to precepts, in the most clear and regular order. 
The signs for the interpretation of nature comprehend two 
divisions; the first regards the eliciting or creating of axioms 
from experiment, the second the deducing or deriving of 
new experiments from axioms. The first admits of three 
subdivisions into ministrations. 1. To the senses. 2. To 
the memory. 3. To the mind or reason. 

For we must first prepare as a foundation for the whole, 
a complete and accurate natural and experimental history. 
"We must not imagine or invent, but discover the acts and 
properties of nature. 

But natural and experimental history is so varied and 
diffuse, that it confounds and distracts the understanding 
unless it be fixed and exhibited in due order. We must, 
therefore, form tables and co-ordinations of instances, upon 

to watch over particular portions of the universe. The followers of Aristotle 
accepted the whimsical title of Andronicus, and in their usual manner allowed 
a word to unite things into one science which were plainly heterogeneous. 
Their error was adopted by the Peripatetics of the Christian Church. The 
schoolmen added to the notion of ontology, the science of the mind, or pneu- 
matology, and as that genus of being has since become extinct with the schools, 
metaphysics thus in modern parlance comes to bo synonymous with psychology. 
It were to be wished that Bacon s definition of the term had been accepted, and 
mental science delivered from one of the greatest monstrosities in its nomencla 
ture, yet Bacon whimsically enough in his De Augmeiitis includes mathematics 
in metaphysics. Ed. 


such a plan, and in such order that the understanding may 
be enabled to act upon them. 

Even when this is done, the understanding, left to itself 
and to its own operation, is incompetent and unfit to con 
struct its axioms without direction and support. Our third 
ministration, therefore, must be true and legitimate induc 
tion, the very key of interpretation. We must begin, how 
ever, at the end, and go back again to the others. 

XI. The investigation of forms proceeds thus: a nature 
being given, we must first present to the understanding all 
the known instances which agree in the same nature, al 
though the subject matter be considerably diversified. And 
this collection must be made as a mere history, and without 
any premature reflection, or too great degree of refinement. 
For instance; take the investigation of the form of heat. 

Instances agreeing in the Form of Heat 

1. The rays of the sun, particularly in summer, and at 

2. The same reflected and condensed, as between moun 
tains, or along walls, and particularly in burning mirrors. 

3. Ignited meteors. 

4. Burning lightning. 

5. Eruptions of flames from the cavities of mountains, etc. 

6. Flame of every kind. 

7. Ignited solids. 

8. Natural warm baths. 

9. Warm or heated liquids. 

10. Warm vapors and smoke; and the air itself, which 
admits a most powerful and violent heat if confined, as in 
reverberating furnaces. 


11. Damp hot weather, arising from the constitution of 
the air, without any reference to the time of the year. 

12. Confined and subterraneous air in some caverns, par 
ticularly in winter. 

13. All shaggy substances, as wool, the skins of animals, 
and the plumage of birds, contain some heat. 

14. All bodies, both solid and liquid, dense and rare (as 
the air itself), placed near fire for any time. 

15. Sparks arising from the violent percussion of flint 
and steel. 

16. All bodies rubbed violently, as stone, wood, cloth, 
etc., so that rudders, and axles of wheels, sometimes catch 
fire, and the West Indians obtain fire by attrition. 

17. Green and moist vegetable matter confined and 
rubbed together, as roses, peas in baskets; so hay, if it 
be damp when stacked, often catches fire. 

18. Quicklime sprinkled with water. 

19. Iron, when first dissolved by acids in a glass, and 
without any application to fire; the same of tin, but not so 

20. Animals, particularly internally; although the heat 
is not ^erccivable by the touch in insects, on account of 
their small size. 

21. Horse dung, and the like excrement from other ani 
mals, when fresh. 

22. Strong oil of sulphur and of vitriol exhibit the opera 
tion of heat in burning linen. 

23. As does the oil of marjoram, and like substances, in 
burning the bony substance of the teeth. 

24. Strong and well rectified spirits of wine exhibit the 
same effects; so that white of eggs when thrown into it 
grows hard and white, almost in the same manner as 


when boiled, and bread becomes burned and brown as if 

25. Aromatic substances and warm plants, as the dracun- 
culus [arum], old nasturtium, etc., which, though they be 
not warm to the touch (whether whole or pulverized), yet 
are discovered by the tongue and palate to be warm and 
almost burning when slightly masticated. 

26. Strong vinegar and all acids, on any part of the body 
not clothed with the epidermis, as the eye, tongue, or any 
wounded part, or where the skin is removed, excite a pain 
differing but little from that produced by heat. 

27. Even a severe and intense cold produces a sensation 
of burning. 18 

"Nee Boreae penetrabile frigus adurit. * 

28. Other instances. 

We are wont to call this a table of existence and presence. 

XII. We must next present to the understanding in 
stances which do not admit of the given nature, for form (as 
we have observed) ought no less to be absent where the 
given nature is absent, than to be present where it is pres 
ent. If, however, we were to examine every instance, our 
labor would be infinite. 

Negatives, therefore, must be classed under the affirma 
tives, and the want of the given nature must be inquired 
into more particularly in objects which have a very close 
connection with those others in which it is present and mani 
fest. And this we are wont to term a table of deviation or 
of absence in proximity. 

13 "Ne tenues pluvise, rapidive potentia solis 
Acrior, aut Boreae penetrabile frigus adurat. " 

Virg. Georg. i. 92, 93. 

SCIENCE Vol. 236 


Proximate Instances wanting the Nature of Heat 

The rays of the moon, stars, and comets, are not found 
to be warm to the touch, nay, the severest cold has been 
observed to take place at the full of the moon. Yet the 
larger fixed stars are supposed to increase and render more 
intense the heat of the sun, as he approaches them, when 
the sun is in the sign of the Lion, for instance, and in the 
dog-days. 14 

The rays of the sun in what is called the middle region 
of the air give no heat, to account for which the commonly 
assigned reason is satisfactory; namely, that that region is 
neither sufficiently near to the body of the sun whence the 
rays emanate, nor to the earth whence they are reflected. 
And the fact is manifested by snow being perpetual on the 
tops of mountains, unless extremely lofty. But it is ob 
served, on the other hand, by some, that at the Peak of 
Tenerifl c, and also among the Andes of Peru, the tops of 
the mountains are free from snow, which only lies in the 
lower part as you ascend. Besides, the air on the summit 
of these mountains is found to be by no means cold, but 
only thin and sharp; so much so, that in the Andes it pricks 
and hurts the eyes from its extreme sharpness, and even ex 
cites the orifice of the stomach and produces vomiting. The 
ancients also observed, that the rarity of the air on the sum- 

14 This notion, which lie repeats again, and particularizes in the 18th aph. 
of this book, is borrowed from the ancients, and we need not say is as wise 
as their other astronomical conjectures. The sun also approaches stars quite 
as large in other quarters of the /.odiac, when it looks down upon the earth 
through the murky clouds of winter. When that luminary is in Leo, the heat 
of the earth is certainly greater than at any other period, but this arises from 
the accumulation of heat after the solstice, for the same reason that the maxi 
mum heat of the day is at two o clock instead of noon. Ed. 


mit of Olympus was such, that those who ascended it were 
obliged to carry sponges moistened with vinegar and water, 
and to apply them now and then to their nostrils, as the air 
was not dense enough for their respiration; on the summit 
of which mountain it is also related, there reigned so great 
a serenity and calm, free from rain, snow, or wind, that the 
letters traced upon the ashes of the sacrifices on the altar of 
Jupiter, by the fingers of those who had offered them, would 
remain undisturbed till the next year. Those even, who at 
this day go to the top of the Peak of Teneriffe, walk by 
night and not in the daytime, and are advised and pressed 
by their guides, as soon as the sun rises, to make haste in 
tbeir descent, on account of the danger (apparently arising 
from the rarity of the atmosphere), lest their breathing 
should be relaxed and suffocated. 18 

The reflection of the solar rays in the polar regions is 
found to be weak and inefficient in producing heat, so that 
the Dutch, who wintered in Nova Zembla, and expected 
that their vessel would be freed about the beginning of 
July from the obstruction of the mass of ice which had 
blocked it up, were disappointed and obliged to embark in 
their boat. Hence the direct rays of the sun appear to have 
but little power even on the plain, and when reflected, 
unless they are multiplied and condensed, which takes place 
when the sun tends more to the perpendicular; for, then, 
the incidence of the rays occurs at more acute angles, so 
that the reflected rays are nearer to each other, while, on 
the contrary, when the sun is in a very oblique position, 

15 Bouguer, employed by Louis XIV. in philosophical researches, ascended 
the Andes to discover the globular form of the earth, and published an account 
of his passage, which verifies the statement of Bacon. 


the angles of incidence are very obtuse, and the reflected 
rays at a greater distance. In the meantime it must be 
observed, that there may be many operations of the solar 
rays, relating, too, to the nature of heat, which are not pro 
portioned to our touch, so that, with regard to us, they do 
not tend to produce warmth, but, with regard to some 
other bodies, have their due effect in producing it. 

Let the following experiment be made. Take a lens the 
reverse of a burning-glass, and place it between the hand 
and the solar rays, and observe whether it diminish the heat 
of the sun as a burning-glass increases it. For it is clear, 
with regard to the visual rays, that in proportion as the lens 
is made of unequal thickness in the middle and at its sides, 
the images appear either more diffused or contracted. It 
should be seen, therefore, if the same be true with regard 
to heat. 

Let the experiment be well tried, whether the lunar rays 
can be received and collected by the strongest and best 
burning-glasses, so as to produce even the least degree of 
heat. 16 But if that degree be, perhaps, so subtile and weak, 
as not to be perceived or ascertained by the touch, we must 
have recourse to those glasses which indicate the warm or 
cold state of the atmosphere, and let the lunar rays fall 

18 Montanari asserts in his book against the astrologers that he had satisfied 
himself by numerous and oft-repeated experiments, that the lunar rays gathered 
to a focus produced a sensible degree of heat. Muschenbrock, however, adopts 
the opposite opinion, and asserts that himself, De la Hire, Villct, and Tschirn- 
hausen had tried with that view the strongest burning-glasses in vain. (Opera 
do Ignc.) De la Lande makes a similar confession in his Astronomy (vol. ii. vii. 
1413). Bouguer, whom we have just quoted, demonstrated that the light of 
the moon was 300,000 degrees less than that of the sun; it would consequently 
be necesary to invent a glass with an absorbing power 300,000 degrees greater 
than those ordinarily in use, to try the experiment Baoou speaks of. Ed. 


through the burning-glass on the top of this thermometer, 
and then notice if the water be depressed by the heat." 

Let the burning-glass be tried on warm objects which 
emit no luminous rays, as heated but not ignited iron or 
stone, or hot water, or the like; and observe whether the 
heat become increased and condensed, as happens with the 
solar rays. 

Let it be tried on common flame. 

The effect of comets (if we can reckon them among 
meteors 18 ) in augmenting the heat of the season is not found 
to be constant or clear, although droughts have generally 
been observed to follow them. However, luminous lines, 
and pillars, and openings, and the like, appear more often 
in winter than in summer, and especially with the most in 
tense cold but joined with drought. Lightning, and corus 
cations, and thunder, however, rarely happen in winter, and 

11 In this thermometer, mercury was not dilated by heat or contracted by 
cold, as the one now in use, but a mass of air employed instead, which filled 
the cavity of the bulb. This being placed in an inverted position to ours, that 
is to say, with the bulb uppermost, pressed down the liquor when the air be 
came dilated by heat, as ours press it upward; and when the heat diminished, 
the liqour rose to occupy the place vacated by the air, as the one now in use 
descends. It consequently was liable to be affected by a change in the tempera 
ture, as by the weight of air, and could afford only a rude standard of accuracy 
in scientific investigations. This thermometer was not Bacon s own contriv 
ance, as is commonly supposed, but that of Drebbel. Ed. 

18 La Lande is indignant that the Chaldeans should have more correct notions 
of the nature of comets than the modern physicists, and charges Bacon with 
entertaining the idea that they were the mere effects of vapor and heat. This 
passage, with two others more positive, in the "De Aug." (cap. xl.) and the 
"Descript. Globi Intellect." (cap. vi.) certainly afford ground for the assertion; 
but if Bacon erred, he erred with Galileo, and with the foremost spirits of the 
tames. It is true that Pythagoras and Seneca had asserted their belief in the 
solidity of these bodies, but the wide dominion which Aristotle subsequently 
exercised, threw their opinions into the shade, and made the opposite doctrine 
everywhere paramount. Ed. 


generally at the time of the greatest heats. The appearances 
we term falling stars are generally supposed to consist of 
some shining and inflamed viscous substance, rather than 
of violently hot matter; but let this be further investigated. 

Some coruscations emit light without burning, but are 
never accompanied by thunder. 

Eructations and eruptions of flame are to be found in 
cold climates as well as in hot, as in Iceland and Greenland; 
just as the trees of cold countries are sometimes inflammable 
and more pitchy and resinous than in warm, as the fir, pine, 
and the like. But the position and nature of the soil, where 
such eruptions are wont to happen, is not yet sufficiently 
investigated to enable us to subjoin a negative instance to 
the affirmative. 

All flame is constantly more or less warm, and this in 
stance is not altogether negative; yet it is said that the ignis 
fatuus (as it is called), and which sometimes is driven against 
walls, has but little heat; perhaps it resembles that of spirits 
of wine, which is mild and gentle. That flame, however, 
appears yet milder, which in some well authenticated and 
serious histories is said to have appeared round the head 
and hair of boys and virgins, and instead of burning their 
hair, merely to have played about it. And it is most cer 
tain that a sort of flash, without any evident heat, has some 
times been seen about a horse when sweating at night, or in 
damp weather. It is also a well known fact, 19 and it was 
almost considered as a miracle, that a few years since a 
girl s apron sparkled when a little shaken or rubbed, which 
was, perhaps, occasioned by tho alum or salts with which 

19 Was it a silk apron which exhibited electric sparks ? Silk was theu 


the apron was imbued, and which, after having been stuck 
together and incrusted rather strongly, were broken by the 
friction. It is well known that all sugar, whether candied 
or plain, if it be hard, will sparkle when broken or scraped 
in the dark. In like manner sea and salt water is sometimes 
found to shine at night when struck violently by the oar. 
The foam of the sea when agitated by tempests also sparkles 
at night, and the Spaniards call this appearance the sea s 
lungs. It has not been sufficiently ascertained what degree 
of heat attends the flame which the ancient sailors called 
Castor and Pollux, and the moderns call St. Ermus fire. 

Every ignited body that is red-hot is always warm, al 
though without flame, nor is any negative instance sub 
joined to this affirmative. Rotten wood, however, ap 
proaches nearly to it, for it shines at night, and yet is not 
found to be warm; and the putrefying scales of fish which 
shine in the same manner are not warm to the touch, nor 
the body of the glowworm, or of the fly called Lucciola. 20 

The situation and nature of the soil of natural warm 
baths has not been sufficiently investigated, and therefore 
a negative instance is not subjoined. 

To the instances of warm liquids we may subjoin the 
negative one of the peculiar nature of liquids in general; 
for no tangible liquid is known that is at once warm in its 
nature and constantly continues warm; but their heat is 
only superinduced as an adventitious nature for a limited 
time, so that those which are extremely warm in their power 
and effect, as spirits of wine, chemical aromatic oils, the 
oils of vitriol and sulphur, and the like, and which speedily 
burn, are yet cold at first to the touch, -and the water of 
natural baths, poured into any vessel and separated from 

The Italian fire-fly. 


its source, cools down like water lieated by the fire. It is, 
however, true that oily substances are rather less cold to 
the touch than those that are aqueous, oil for instance than 
water, silk than linen; but this belongs to the table of de 
grees of cold. 

In like manner we may subjoin a negative instance to 
that of warm vapor, derived from the nature of vapor itself, 
as far as we are acquainted with it. For exhalations from 
oily substances, though easily inflammable, are yet never 
warm unless recently exhaled from some warm substance. 

The same may be said of the instance of air; for we 
never perceive that air is warm unless confined or pressed, 
or manifestly heated by the sun, by fire, or some other 
warm body. 

A negative instance is exhibited in weather by its cold 
ness with an east or north wind, beyond what the season 
would lead us to expect, just as the contrary takes place 
with the south or west winds. An inclination to rain (espe 
cially in winter) attends warm weather, and to frost cold 

A negative instance as to air confined in caverns may be 
observed in summer. Indeed, we should make a more dili 
gent inquiry into the nature of confined air. For in the first 
place the qualities of air in its own nature with regard to 
heat and cold may reasonably be the subject of doubt; for 
air evidently derives its heat from the effects of celestial 
bodies, and possibly its cold from the exhalation of the 
earth, and in the mid region of air (as it is termed) from 
cold vapors and snow, so that no judgment can be formed 
of the nature of air by that which is out of doors and ex 
posed, but a more correct one might be derived from con 
fined air. It is necessary, however, that the air should be 


inclosed in a vessel of such materials as would not imbue 
it with heat or cold of themselves, nor easily admit the 
influence of the external atmosphere. The experiment 
should be made, therefore, with an earthen jar, covered 
with folds of leather to protect it from the external air, and 
the air should be kept three or four days in this vessel 
well closed. On opening the jar, the degree of heat may 
be ascertained either by the hand or a graduated glass tube. 

There is a similar doubt as to whether the warmth of 
wool, skins, feathers, and the like, is derived from a slight 
inherent heat, since they are animal excretions, or from 
their being of a certain fat and oily nature that accords 
with heat, or merely from the confinement and separation 
of air which we spoke of in the preceding paragraph;* 1 for 
all air appears to possess a certain degree of warmth when 
separated from the external atmosphere. Let an experiment 
be made, therefore, with fibrous substances of linen, and 
not of wool, feathers, or silk, which are animal excretions. 
For it is to be observed that all powders (where air is mani 
festly inclosed) are less cold than the substances when 
whole, just as we imagine froth (which contains air) to be 
less cold than the liquid itself. 

We have here no exactly negative instance, for we are 
not acquainted with any body tangible or spirituous which 
does not admit of heat when exposed to the fire. There is, 
however, this difference, that some admit it more rapidly, 
as air, oil, and water, others more slowly, as stone and 
metals. 88 This, however, belongs to the table of degrees. 

81 This last is found to be the real reason, air not being a good conductor, 
and therefore not allowing the escape of heat. The confined air is disengaged 
when these substances are placed under an exhausted receiver. 

88 This is erroneous. Air, in fact, is one of the worst, and inetals are the 
best conductors of heat. 


No negative is here subjoined, except the remark that 
sparks are not kindled by flint and steel, or any other hard 
substance, unless some small particles of the stone or metal 
are struck off, and that the air never forms them by friction, 
as is commonly supposed; besides, the sparks from the 
weight of the ignited substance have a tendency to descend 
rather than to rise, and when extinguished become a sort 
of dark ash. 

We are of opinion that here again there is no negative; 
for we are not acquainted with any tangible body which does 
not become decidedly warm by friction, so that the ancients 
feigned that the gods had no other means or power of creat 
ing heat than the friction of air, by rapid and violent rota 
tion. On this point, however, further inquiry must be 
made, whether bodies projected by machines (as balls from 
cannon) do not derive some degree of heat from meeting the 
air, which renders them somewhat warm when they fall. 
The air in motion rather cools than heats, as in the winds, 
the bellows, or breath when the mouth is contracted. The 
motion, however, in such instances is not sufficiently rapid 
to excite heat, and is applied to a body of air, and not to 
its component parts, so that it is not surprising that heat 
should not be generated. 

We must make a more diligent inquiry into this in 
stance; for herbs and green and moist vegetables appear 
to possess a latent heat, so small, however, as not to be 
perceived by the touch in single specimens, but when they 
are united and confined, so that their spirit cannot exhale 
into the air, and they rather warm each other, their heat 
is at once manifested, and even flame occasionally in suit 
able substances. 

Here, too, we must make a more diligent inquiry; for 


quicklime, when sprinkled with water, appears to conceive 
heat, either from its being collected into one point (as we 
observed of herbs when confined), or from the irritation and 
exasperation of the fiery spirit by water, which occasions 
a conflict and struggle. The true reason will more readily 
be shown if oil be used instead of water, for oil will equally 
tend to collect the confined spirit, but not to irritate. The 
experiment may be made more general, both by using the 
ashes and calcined products of different bodies and by pour 
ing different liquids upon them. 

A negative instance may be subjoined of other metals 
which are more soft and soluble; for leaf gold dissolved by 
aqua regia, or lead by aqua fortis, are not warm to the touch 
while dissolving, no more is quicksilver (as far as I remem 
ber), but silver excites a slight heat, and so does copper, 
and tin yet more plainly, and most of all iron and steel, 
which excite not only a powerful heat, but a violent bub 
bling. The heat, therefore, appears to be occasioned by 
the struggle which takes place when these strong dissol 
vents penetrate, dig into, and tear asunder the parts of 
those substances, while the substances themselves resist. 
When, however, the substances yield more easily, scarcely 
any heat is excited. 

There is no negative instance with regard to the heat of 
animals, except in insects (as has been observed), owing to 
their small size; for in fishes, as compared with land ani 
mals, a lower degree rather than a deprivation of heat is 
observable. In plants and vegetables, both as to their 
exudations and pith when freshly exposed, there is no sen 
sible degree of heat. But in animals there is a great differ 
ence in the degree, both in particular parts (for the heat 
varies near the heart, the brain, and the extremities) and in 


the circumstances in which they are placed, such as violent 
exercise and fevers. 

Here, again, there is scarcely a negative instance. I 
might add that the excrements of animals, even when they 
are no longer fresh, possess evidently some effective heat, as 
is shown by their enriching the soil. 

Such liquids (whether oily or watery) as are intensely 
acrid exhibit the effects of heat, by the separation and burn 
ing of bodies after some little action upon them, yet they 
are not at first warm to the touch, but they act according to 
their affinity and the pores of the substances to which they 
are applied; for aqua regia dissolves gold but not silver 
on the contrary, aqua fortis dissolves silver but not gold; 
neither of them dissolves glass, and so of the rest. 

Let spirits of wine be tried on wood, or butter, wax, or 
pitch, to see if this will melt them at all by their beat; for 
the twenty-fourth instance shows that they possess proper 
ties resembling those of heat in causing incrustation. Let 
an experiment also be made with a graduated glass or calen 
dar," concave at the top, by pouring well-rectified spirits of 
wine into the cavity, and covering it up in order that they 
may the better retain their heat, then observe whether their 
heat make the water descend. 

Spices and acrid herbs are sensibly warm to the palate, 
and still more so when taken internally; one should see, 
therefore, on what other substances they exhibit the effects 
of heat. Now, sailors tell us that when large quantities of 
spices are suddenly opened, after having been shut up for 
some time, there is some danger of fever and inflammation 
to those who stir them or take them out. An experiment 

J3 See No. 28 in the table of the degrees of heat. 


might, therefore, be made whether such spices and herbs, 
when produced, will, like smoke, dry fish and meat hung 
up over them. 

There is an acrid effect and a degree of penetration in 
cold liquids, such as vinegar and oil of vitriol, as well as 
in warm, such as oil of marjoram and the like; they have, 
therefore, an equal effect in causing animated substances to 
smart, and separating and consuming inanimate parts. 
There is not any negative instance as to this, nor does there 
exist any animal pain unaccompanied by the sensation of 

There are many effects common to cold and heat, how 
ever different in their process; for snowballs appear to burn 
boys hands after a little time, and cold no less than fire 
preserves bodies from putrefaction besides both heat and 
cold contract bodies. But it is better to refer these instances 
and the like to the investigation of cold. 

XIII. In the third place we must exhibit to the under 
standing the instances in which that nature, which is the 
object of our inquiries, is present in a greater or less degree, 
either by comparing its increase and decrease in the same 
object, or its degree in different objects; for since the form 
of a thing is its very essence, and the thing only differs 
from its form as the apparent from the actual object, or the 
exterior from the interior, or that which is considered with 
relation to man from that which is considered with relation 
to the universe; it necessarily follows that no nature can be 
considered a real form which does not uniformly diminish 
and increase with the given nature. We are wont to call 
this our Table of Degrees, or Comparative Instances. 


Table of the Degrees or Comparative Instances of Heat 

We will first speak of those bodies which exhibit no 
degree of heat sensible to the touch, but appear rather to 
possess a potential heat, or disposition and preparation for 
it. We will then go on to others, which are actually warm 
to the touch, and observe the strength and degree of it. 

1. There is no known solid or tangible body which is by 
its own nature originally warm; for neither stone, metal, 
sulphur, fossils, wood, water, nor dead animal carcasses are 
found warm. The warm springs in baths appear to be 
heated accidentally, by flame, subterraneous fire (such as 
is thrown up by Etna and many other mountains), or by the 
contact of certain bodies, as heat is exhibited in the dissolu 
tion of iron and tin. The degree of heat, therefore, in 
inanimate objects is not sensible to our touch; but they 
differ in their degrees of cold, for wood and metal are not 
equally cold. 24 This, however, belongs to the Table of 
Degrees of Cold. 

2. But with regard to potential heat and predisposition 
to flame, we find many inanimate substances wonderfully 
adapted to it, as sulphur, naphtha, and saltpetre. 

3. Bodies which have previously acquired heat, as horse 
dung from the animal, or lime, and perhaps ashes and soot 
from fire, retain some latent portion of it. Hence distilla 
tions and separations of substances are effected by burying 

i4 Bacon here mistakes sensation confined to ourselves for an internal prop 
erty of distinct substances. Metals are denser than wood, and our bodies con 
sequently coming into contact with more particles of matter when we touch 
them, lose a greater quantity of heat than in the case of lighter sub 
stances. Ed. 


them in horse dung, and heat is excited in lime by sprink 
ling it with water (as has been before observed). 

4. In the vegetable world we know of no plant, nor part 
of any plant (as the exudations or pith) that is warm to 
man s touch. Yet (as we have before observed) green 
weeds grow warm when confined, and some vegetables are 
warm and others cold to our internal touch, i.e., the palate 
and stomach, or even after a while to our external skin (as 
is shown in plasters and ointments). 

5. We know of nothing in the various parts of animals, 
when dead or detached from the rest, that is warm to the 
touch ; for horse dung itself does not retain its heat, unless 
it be confined and buried. All dung, however, appears to 
possess a potential heat, as in manuring fields ; so also dead 
bodies are endued with this latent and potential heat to such 
a degree, that in cemeteries where people are interred daily 
the earth acquires a secret heat, which consumes any 
recently deposited body much sooner than pure earth; and 
they tell you that the people of the East are acquainted with 
a fine soft cloth, made of the down of birds, which can melt 
butter wrapped gently up in it by its own warmth. 

6. Manures, such as every kind of dung, chalk, sea-sand, 
salt and the like, have some disposition toward heat. 

7. All putrefaction exhibits some slight degree of heat, 
though not enough to be perceptible by the touch; for 
neither the substances which by putrefaction are converted 
into animalcules," as flesh and cheese, nor rotten wood 
which shines in the dark, are warm to the touch. The heat, 

85 This was the ancient opinion, but the moderns incline to the belief that 
these insects are produced by generation or fecundity from seeds deposited by 
their tribes in bodies on the verge of putrefaction. Ed. 


however, of putrid substances displays itself occasionally in 
a disgusting and strong scent. 

8. The first degree of heat, therefore, in substances 
which are warm to the human touch appears to be that of 
animals, and this admits of a great variety of degrees, for 
the lowest (as in insects) is scarcely perceptible, the highest 
scarcely equals that of the sun s rays in warm climates and 
weather, and is not so acute as to be insufferable to the 
hand. It is said, however, of Constantius, and some others 
of a very dry constitution and habit of body, that when 
attacked with violent fevers, they became so warm as to 
appear almost to burn the hand applied to them. 

9. Animals become more warm by motion and exercise, 
wine and feasting, vcnery, burning fevers, and grief. 

10. In the paroxysm of intermittent fevers the patients 
are at first seized with cold and shivering, but soon after 
ward become more heated than at first in burning and 
pestilential fevers they are hot from the beginning. 

11. Let further inquiry be made into the comparative 
heat of different animals, as fishes, quadrupeds, serpents, 
birds, and also of the different species, as the lion, the kite, 
or man; for, according to the vulgar opinion, fishes are the 
least warm internally, and birds the most, particularly 
doves, hawks, and ostriches. 

12. Let further inquiry be made as to the comparative 
heat in different parts and limbs of the same animal; for 
inilk, blood, seed, and eggs are moderately warm, and less 
hot than the outward flesh of the animal when in motion or 
agitated. The degree of heat of the brain, stomach, heart, 
and the rest, has not yet been equally well investigated. 

13. All animals are externally cold in winter and cold 
weather, but are thought to be internally warmer. 


14. The heat of the heavenly bodies, even in the warmest 
climates and seasons, never reaches such a pitch as to light 
or burn the driest wood or straw, or even tinder without 
the aid of burning-glasses. It can, however, raise vapor 
from moist substances. 

15. Astronomers tell us that some stars are hotter than 
others. Mars is considered the warmest after the Sun, then 
Jupiter, then Yenus. The Moon and, above all, Saturn, 
are considered to be cold. Among the fixed stars Sirius 
is thought the warmest, then Cor Leonis or Regulus, then 
the lesser Dog-star. 

16. The sun gives out more heat as it approaches toward 
the perpendicular or zenith, which may be supposed to be 
the case with the other planets, according to their degree 
of heat; for instance, that Jupiter gives out more heat when 
situated beneath Cancer or Leo than when he is beneath 
Capricorn and Aquarius. 

17. It is to be supposed that the sun and other planets 
give more heat in perigee, from their approximation to the 
earth, than when in apogee. But if in any country the sun 
should be both in its perigee and nearer to the perpendicular 
at the same time, it must necessarily give out more heat than 
in a country where it is also in perigee, but situated more 
obliquely; so that the comparative altitude of the planets 
should be observed, and their approach to or declination 
from the perpendicular in different countries. 

18. The sun and other planets are thought also to give 
out more heat in proportion as they are nearer to the larger 
fixed stars, as when the sun is in Leo he is nearer Cor 
Leonis, Cauda Leonis, Spica Virginis, Sirius, and the lesser 
Dog-star, than when he is in Cancer, where, however, .he 
approaches nearer to the perpendicular. It is probable, 


also, that the quarters of the heavens produce a greater heat 
(though not perceptibly), in proportion as they are adorned 
with a greater number of stars, particularly those of the 
first magnitude. 

19. On the whole, the heat of the heavenly bodies is 
augmented in three ways: 1. The approach to the perpen 
dicular; 2. Proximity or their perigee; 3. The conjunction 
or union of stars. 

20. There is a very considerable difference between the 
degree of heat in animals, and even in the rays of the heav 
enly bodies (as they reach us), and the heat of the most gen 
tle flame, and even of all ignited substances, nay, liquids, 
or the air itself when unusually heated by fire. For the 
flame of spirit of wine, though diffused and uncollected, is 
yet able to set straw, linen, or paper on fire, which animal 
heat, or that of the sun, will never accomplish without a 

21. There are, however, many degrees of strength and 
weakness in flame and ignited bodies: but no diligent in 
quiry has been made in this respect, and we must, therefore, 
pass it hastily over. Of all flames, that of spirits of wine 
appears to be the most gentle, except perhaps the ignis 
fatuus, or the flashes from the perspiration of animals. 
After this we should be inclined to place the flame of light 
and porous vegetables, such as straw, reeds, and dried 
leaves; from which the flame of hair or feathers differs but 
little. Then, perhaps, comes the flame of wood, particu 
larly that which contains but little rosin or pitch; that of 
small wood, however (such as is usually tied up in fagots), 
is milder than that of the trunks or roots of trees. This can 
be easily tried in iron furnaces, where a fire of fagots or 
branches of trees is of little service. Next follows the flame 


of oil, tallow, wax, and the like oily and fat substances, 
which are not very violent. But a most powerful heat is 
found in pitch and rosin, and a still greater in sulphur, cam 
phor, naphtha, saltpetre, and salts (after they have dis 
charged their crude matter), and in their compounds; as in 
gunpowder, Greek fire (vulgarly called wild fire), and its 
varieties, which possess such a stubborn heat as scarcely to 
be extinguished by water. 

22. We consider that the flame which results from some 
imperfect rnetals is very strong and active ; but on all these 
points further inquiry should be made. 

23. The flarne of vivid lightning appears to exceed all 
the above, so as sometimes to have melted even wrought 
iron into drops, which the other flames cannot accomplish. 

24. In ignited bodies there are different degrees of heat, 
concerning which, also, a diligent inquiry has not been 
made. We consider the faintest heat to be that of tinder, 
touchwood, and dry rope match, such as is used for dis 
charging cannon. Next follows that of ignited charcoal or 
cinders, and even bricks, and the like; but the most vio 
lent is that of ignited metals, as iron, copper, and the like. 
Further inquiry, however, must be made into this also. 

25. Some ignited bodies are found to be much warmer 
than some flames ; for instance, red hot iron is much warmer, 
and burns more than tho flame of spirits of wine. 

26. Some bodies even not ignited, but only heated by 
the fire, as boiling water, and the air confined in reverbera- 
tories, surpass in heat many flames and ignited substances. 

27. Motion increases heat, 28 as is shown in the bellows 

* 6 The correct measure of the activity of flame may be obtained by multiply 
ing its natural force into the square of its velocity. On this account the flame 


and the blowpipe; for the harder metals are not dissolved 
or melted by steady quiet fire, without the aid of the blow 

28. Let an experiment be made with burning-glasses; in 
which respect I have observed, that if a glass be placed at 
the distance of ten inches, for instance, from the combustible 
object, it does not kindle or burn it so readily, as if the glass 
be placed at the distance of five inches (for instance), and be 
then gradually and slowly withdrawn to the distance of ten 
inches. The cone and focus of the rays, however, are the 
same, but the mere motion increases the effect of the heat. 

29. Conflagrations, which take place with a high wind, 
are thought to make greater way against than with the wind, 
because when the wind slackens, the flame recoils more 
rapidly than it advances -when the wind is favorable. 

30. Flame docs not burst out or arise unless it have 
some hollow space to move and exert itself in, except in the 
exploding flame of gunpowder, and the like, where the com 
pression and confinement of the flame increase its fury. 

31. The anvil becomes so hot by the hammer, that if it 
Were a thin plate it might probably grow red, like ignited 
iron by repeated strokes. Let the experiment be tried. 

32. But in ignited bodies that are porous, so as to leave 
room for the fire to move itself, if its motion be prevented 
by strong compression, the fire is immediately extinguished; 
thus it is with tinder, or the burning snuff of a candle or 
lamp, or even hot charcoal or cinders; for when they are 
squeezed by snuil ers, or the foot, and the like, the effect of 
the fire instantly ceases. 

of vivid lightning mentioned in No. 23 contains so much vigor, its velocity 
being greater than that arising from other heat. Ed. 


33. The approach toward a hot body increases heat in 
proportion to the approximation; a similar effect to that of 
light, for the nearer any object is placed toward the light, 
the more visible it becomes. 

34. The" union of different heats increases heat, unless 
the substances be mixed; for a large and small fire in the 
same spot tend mutually to increase each other s heat, but 
lukewarm water poured into boiling water cools it. 

35. The continued neighborhood of a warm body in 
creases heat. For the heat, which perpetually passes and 
emanates from it, being mixed with that which preceded it, 
multiplies the whole. A fire, for instance, does not warm 
a room in half an hour as much as the same fire would in 
an hour. This does not apply to light, for a lamp or candle 
placed in a spot gives no more light by remaining there, 
than it did at first. 

36. The irritation of surrounding cold increases heat, as 
may be seen in fires during a sharp frost. We think that 
this is owing not merely to the confinement and compression 
of the heat (which forms a sort of union), but also by the 
exasperation of it, as when the air or a stick are violently 
compressed or bent, they recoil, not only to the point they 
first occupied, but still further back. Let an accurate ex 
periment, therefore, be made with a stick, or something of 
the kind, put into the flame, in order to see whether it be 
not sooner burned at the sides than in the middle of it. 28 

27 The fires supply fresh heat, the water has only a. certain quantity of heat, 
which being diffused over a fresh supply of cooler water, must be on the whole 

28 If condensation were the cause of the greater heat, Bacon concludes the 
centre of the flame would be the hotter part, and vice versd. The fact is, 
neither of the causes assigned by Bacon is the true one; for the fire burns 


37. There are many degrees in the susceptibility of heat. 
And, first, it must be observed how much a low gentle heat 
changes and partially warms even the bodies least suscep 
tible of it. For even the heat of the hand imparts a little 
warmth to a ball of lead or other metal held a short time in 
it; so easily is heat transmitted and excited, without any 
apparent change in the body. 

38. Of all bodies that we are acquainted with, air admits 
and loses heat the most readily, which is admirably seen in 
weather-glasses, wnose construction is as follows: Take a 
glass with a hollow belly, and a thin and long neck; turn 
it upside down, and place it with its mouth downward into 
another glass vessel containing water; the end of the tube 
touching the bottom of the vessel, and the tube itself lean 
ing a little on the edge, so as to be fixed upright. In order 
to do this more readily, let a little wax be applied to the 
edge, not, however, so as to block up the orifice, lest, by 
preventing the air from escaping, the motion, which wo 
shall presently speak of, and which is very gentle and deli 
cate, should be impeded. 

Before the first glass be inserted in the other, its upper 
part (the belly) should be warmed at the fire. Then upon 
placing i* as we have described, the air (which was dilated 
by the heat), after a sufficient time has been allowed for it 
to lose the additional temperature, will restore and contract 
itself to the same dimensions as that of the external or com 
mon atmosphere at the moment of immersion, and the water 
will be attracted upward in the tube to a proportionate ex 
tent. A long narrow slip of paper should be attached to 

rnoro quickly only because tho draught of air is more rapid, the cold dense 
air pressing rapidly ; nto the heated room and toward tho chimney. Ed. 


the tube, divided into as many degrees as you please. You 
will then perceive, as the weather grows warmer or colder, 
that the air contracts itself into a narrower space in cold 
weather and dilates in the warm, which will be exhibited 
by the rising of the water as the air contracts itself, and its 
depression as the air dilates. The sensibility of the air with 
regard to heat or cold is so delicate and exquisite, that it far 
exceeds the human touch, so that a ray of sunshine, the heat 
of the breath, and much more, that of the hand placed on 
the top of the tube, immediately causes an evident depres 
sion of the water. We think, however, that the spirit of 
animals possesses a much more delicate susceptibility of 
heat and cold, only that it is impeded and blunted by the 
grossness of their bodies. 

39. After air, we consider those bodies to be most sen 
sible of heat, which have been recently changed and con 
tracted by cold, as snow and ice; for they begin to be dis 
solved and melt with the first mild weather. Next, perhaps, 
follows quicksilver; then greasy substances, as oil, butter, 
and the like; then wood; then water; lastly, stones and 
metals, which do not easily grow hot, particularly toward 
their centre. 39 When heated, however, they retain their 
temperature for a very long time; so that a brick or stone, 
or hot iron, plunged in a basin of cold water, and kept there 

29 Bacon appears to have confounded combustibility and fusibility with sus 
ceptibility of heat; for though the metals will certainly neither dissolve as soon 
as ice or butter, nor be consumed as soon as wood, that only shows that differ 
ent degrees of heat are required to produce similar effects on different bodies; 
but metala much more readily acquire and transmit the same degree of heat 
than any of the above substances. The rapid transmission renders them gen 
erally cold to the touch. The convenience of fixing wooden handles to vessels 
containing hot water illustrates these observations. 


for a quarter of an hour or thereabout, retains such a heat 
as not to admit of being touched. 

40. The less massive the body is, the more readily it 
grows warm at the approach of a heated body, which shows 
that heat with us is somewhat averse to a tangible mass. 30 

41. Heat with regard to the human senses and touch is 
various and relative, so that lukewarm water appears hot if 
the hand be cold, and cold if the hand be hot. 

XIY. Any one may readily see how poor we are in his 
tory, since in the above tables, besides occasionally insert 
ing traditions and report instead of approved history and 
authentic instances (always, "however, adding some note if 
their credit or authority be doubtful), we are often forced to 
subjoin, Let the experiment be tried Let further inquiry 
be made." 

XY. We are wont to term the office and use of these 
three tables the presenting a review of instances to the 
understanding; and when this has been done, induction 
itself is to be brought into action. For on an individual 
review of all the instances a nature is to be found, such as 
always to be present and absent with the given nature, to 
increase and decrease with it, and, as we have said, to form 
a more common limit of the nature. If the mind attempt 
this affirmatively from the first (which it always will when 
left to itself), there will spring up phantoms, mere theories 
and ill-defined notions, with axioms requiring daily correc 
tion. These will, doubtless, be better or worse, according 
to the power and strength of the understanding which 
creates them. But it is only for God (the bestower and 

30 Another singular error, the truth being, that solid bodies are the best 
conductors; but of course where heat is diffused over a largo mass, it is less 
in each part, thau if that part alouo absorbed the whole quantum of heat. Ed, 


creator of forms), and perhaps for angels and intelligences, 
at once to recognize forms affirmatively at the first glance of 
contemplation: man, at lest, is unable to do so, and is only 
allowed to proceed first by negatives, and then to conclude 
with affirmatives, after every species of exclusion. 

XVI. We must, therefore, effect a complete solution and 
separation of nature; not by fire, but by the mind, that 
divine fire. The first work of legitimate induction, in the 
discovery of forms, is rejection, or the exclusive instances 
of individual natures, which are not found in some one in 
stance where the given nature is present, or are found in 
any one instance where it is absent, or are found to increase 
in any one instance where the given nature decreases, or the 
reverse. After an exclusion correctly effected, an affirma 
tive form will remain as the residuum, solid, true, and well A 
defined, while all volatile opinions go off in smoke. This i 
is readily said; but we must arrive at it by a circuitous 
route. We shall perhaps, however, omit nothing that can 
facilitate our progress. 

XVII. The first and almost perpetual precaution and 
warning which we consider necessary is this; that none 
should suppose from the great part assigned by us to 
forms, that we mean such forms as the meditations and 
thoughts of men have hitherto been accustomed to. In 
the first place, we do not at present mean the concrete 
forms, which (as we have observed) are in the common 
course of things compounded of simple natures, as those of 
a lion, an eagle, a rose, gold, or the like. The moment for 
discussing these will arrive when we come to treat of the 
latent process and latent conformation, and the discovery of 
them as they exist in what are called substances, or concrete 

SCIENCE Vol. 22 7 


Nor again, would we be thought to mean (even when 
treating of simple natures) any abstract forms or ideas, 
either undefined or badly defined in matter. For when we 
speak of forms, we mean nothing else than those laws and 
regulations of simple action which arrange and constitute 
any simple nature, such as heat, light, weight, in every 
species of matter, and in a susceptible subject. The form 
of heat or form of light, therefore, means no more than the 
law of heat or the law of light. Nor do we ever abstract or 
withdraw ourselves from things, and the operative branch 
of philosophy. "When, therefore, we sa} r (for instance) in 
our investigation of the form of heat, Reject rarity, or, Rar 
ity is not of the form of heat, it is the same as if we were to 
say, Man can superinduce heat on a dense body, or the re 
verse, Man can abstract or ward off heat from a rare body. 

But if our forms appear to any one to be somewhat ab 
stracted, from their mingling and uniting heterogeneous 
objects (the heat, for instance, of the heavenly bodies ap 
pears to be very different from that of fire; the fixed red of 
the rose and the like, from that which is apparent in the 
rainbow, or the radiation of opal or the diamond; 31 death 
by drowning, from that by burning, the sword, apoplexy, 
or consumption ; and yet they all agree in the common na 
tures of heat, redness, and death), let him lie assured that 
his understanding is inthralled by habit, by general appear 
ances and hypotheses. For it is most certain that, however 
heterogeneous and distinct, they agree in the form or law 
which regulates heat, redness, or death; and that human 
power cannot be emancipated and freed from the common 

11 This general law or form has been well illustrated by Newton s discovery 
of the decomposition of colors. 


course of nature, and expanded and exalted to new efficients 
and new modes of operation, except by the revelation and 
invention of forms of this nature. But after this 3a union of 
nature, which is the principal point, we will afterward, in 
its proper place, treat of the divisions and ramifications of 
nature, whether ordinary or internal and more real. 

XVIII. We must now offer an example of the exclusion 
or rejection of natures found by the tables of review, not to 
be of the form of heat; first premising that not only each 
table is sufficient for the rejection of any nature, but even 
each single instance contained in them. For it is clear from 
what has been said that every contradictory instance de-. 
stroys a hypothesis as to the form. Still, however, for 
the sake of clearness, and in order to show more plainly the 
use of the tables, we redouble or repeat the exclusive. 

An Example of the Exclusive Table, or of the Rejection 
of Natures from the Form of Heat 

1. On account of the sun s rays, reject elementary (or 
terrestrial) nature. 

2. On account of common fire, and particularly subter 
ranean fires (which are the most remote and secluded from 
the rays of the heavenly bodies), reject celestial nature. 

3. On account of the heat acquired by every description 
of substances (as minerals, vegetables, the external parts of 
animals, water, oil, air, etc.) by mere approximation to the 
fire or any warm body, reject all variety and delicate texture 
of bodies. 

85 I.e., the common link or form which connects the various kinds of natures, 
such as the different hot or red natures enumerated above. See Aphorism Hi. 
part 2. 


4. On account of iron and ignited metals, which warm 
other bodies, and yet neither lose their weight nor sub 
stance, reject the imparting or mixing of the substance of 
the heating body. 

5. On account of boiling water and air, and also those 
metals and other solid bodies which are heated, but not to 
ignition, or red heat, reject flame or light. 

6. On account of the rays of the moon and other heav 
enly bodies (except the sun), again reject flame or light. 

7. On account of the comparison between reel-hot iron 
and the flame of spirits of wine (for the iron is more hot and 
less bright, while the flame of spirits of wine is more bright 
and less hot), again reject flame and light. 

8. On account of gold and other ignited metals, which 
are of the greatest specific density, reject rarity. 

9. On account of air, which is generally found to be cold 
and yet continues rare, reject rarity. , 

10. On account of ignited iron, 33 which does not swell in 
bulk, but retains the same apparent dimension, reject the 
absolute expansive motion of the whole. 

11. On account of the expansion of the air in thermome 
ters and the like, which is absolutely moved and expanded 
to the eye, and yet acquires no manifest increase of heat, 
again reject absolute or expansive motion of the whole. 

12. On account of the ready application of heat to all 
substances without any destruction or remarkable altera 
tion of them, reject destructive nature or the violent com 
munication of any new nature. 

13. On account of the agreement and conformity of the 
effects produced by cold and heat, reject both expansive and 
contracting motion as rejiards the whole. 

83 This is erroneous all metals expand considerably when heated. 


14. On account of the heat excited by friction, reject 
principal nature, by which we mean that which exists posi 
tively, and is not caused by a preceding nature. 

There are other natures to be rejected; but we are merely 
offering examples, and not perfect tables. 

None of the above natures are of the form of heat; and 
man is freed from them all in his operation upon heat. 

XIX. In the exclusive table are laid the foundations of 
true induction, which is not, however, completed until the 
affirmative be attained. Nor is the exclusive table perfect, 
nor can it be so at first. For it is clearly a rejection of sim 
ple natures; but if we have not as yet good and just notions 
of simple natures, how can the exclusive table be made cor 
rect ? Some of the above, as the notion of elementary and 
celestial nature, and rarity, are vague and ill denned. We, 
therefore, who are neither ignorant nor forgetful of the great 
work which we attempt, in rendering the human understand 
ing adequate to things and nature, by no means rest satisfied 
with what we have hitherto enforced, but push the matter 
further, and contrive and prepare more powerful aid for the 
use of the understanding, which we will next subjoin. And, 

mMfMMHHHHWIHiMBMWM Vn tr? "** 1 ""- ~"* 

indeed, in the interpretation of nature the mind is to be so 
prepared and formed, as to rest itself on proper degrees of 
certainty, and yet to remember (especially at first) that what 
is present depends much upon what remains behind. 

XX. Since, however, truth emerges more readily from 
error than confusion, we consider it useful to leave the un 
derstanding at liberty to exert itself and attempt the inter 
pretation of nature in the affirmative, after having con 
structed and weighed the three tables of preparation, such 
as we have laid them down, both from the instances there 
collected, and others occurring elsewhere. Which attempt 


we are wont to call the liberty of the understanding, or the 
commencement of interpretation, or the iirst vintage. 

The First Vintage of the Form of Heat 

It must be observed that the form of anything is inherent 
(as appears clearly from our premises) in each individual in 
stance in which the thing itself is inherent, or it would not 
be a form. No contradictory instance, therefore, can be al 
leged. The form, however, is found to be much more con 
spicuous and evident in some instances than in others; in 
those (for example) where its nature is less restrained and 
embarrassed, and reduced to rule by other natures. Such 
instances we are wont to term coruscations, or conspicuous 
instances. We must proceed, then, to the first vintage of 
the form of heat. 

From the instances taken collectively, as well as singly, 
the nature whose limit is heat appears to be motion. This 
is chiefly exhibited in flame, which is in constant motion, 
and in warm or boiling liquids, which are likewise in con 
stant motion. It is also shown in the excitement or increase 
of heat by motion, as by bellows and draughts: for which 
see Inst. 29, Tab. 3, and by other species of motion, as in 
Inst. 28 and 31, Tab. 3. It is also shown by the extinction 
of fire and heat upon any strong pressure, which restrains 
and puts a stop to motion; for which see Inst. 30 and 32, 
Tab. 3. It is further shown by this circumstance, namely, 
that every substance is destroyed, or at least materially 
changed, by strong and powerful fire and heat: whence it is 
clear that tumult and confusion are occasioned by heat, to 
gether with a violent motion in the internal parts of bodies; 
and this gradually tends to their dissolution. 

What we have said with regard to motion must be thus 


understood, when taken as the genus of heat: it must not 
be thought that heat generates motion, or motion heat 
(though in some respects this be true), but that the very 
essence of heat, or the substantial self 34 of heat, is motion 
and nothing else, limited, however, by certain differences 
which we will presently add, after giving some cautions for^ 
avoiding ambiguity. 

Sensible heat is relative, and regards man, not universe; 
and is rightly held to be merely the effect of heat on animal 
spirit. It is even variable in itself, since the same body (in 
different states of sensation) excites the feeling of heat and 
of cold; this is shown by Inst. 41, Tab. 3. 

Nor should we confound the communication of heat or 
its transitive nature, by which a body grows warm at the 
approach of a heated body, with the form of heat; for heat 
is one thing and heating another. Heat can be excited by 
friction without any previous heating body, and, therefore, 
heating is excluded from the form of heat. Even when heat 
is excited by the approach of a hot body, this depends not 
on the form of heat, but on another more profound and com 
mon nature; namely, that of assimilation and multiplication, 
about which a separate inquiry must be made. 

The notion of fire is vulgar, and of no assistance; it is 
merely compounded of the conjunction of heat and light in 
any body, as in ordinary flame and red-hot substances. 

Laying aside all ambiguity, therefore, we must lastly con 
sider the true differences which limit motion and render it 
the form of heat. 

I. The first difference is, that heat is an expansive 
motion, by which the body strives to dilate itself, and to 

84 "Quid ipsum, " the TO r\ ^v elai of Aristotle. 


occupy a greater space than before. This difference is 
principally seen in flame, where the smoke or thick vapor 
is clearly dilated and bursts into flame. 

It is also shown in all boiling liquids, which swell, rise, 
and boil up to the sight, and the process of expansion is 
urged forward till they are converted into a much more 
extended and dilated body than the liquid itself, such as 
steam, smoke, or air. 

It is also shown in wood and combustibles where exuda 
tion sometimes takes place, and evaporation always. 

It is also shown in the melting of metals, which, being 
very compact, do not easily swell and dilate, but yet their 
spirit, when dilated and desirous of further expansion, forces 
and urges its thicker parts into dissolution, and if the heat 
be pushed still further, reduces a considerable part of them 
into a volatile state. 

It is also shown in iron or stones, which though not 
melted or dissolved, are however softened. The same cir 
cumstance takes place in sticks of wood, which become flexi 
ble when a little heated in warm ashes. 

It is most readily observed in air, which instantly and 
manifestly expands with a small degree of heat, as in Inst. 
38, Tab. 3. 

It is also shown in the contrary nature of cold; for cold 
contracts and narrows every substance; 35 so that inlntense 
frosts nails fall out of the wall and brass cracks, and heated 
glass exposed suddenly to the cold cracks and breaks. So 

88 To show the error of the text, we need only mention the case of water, 
which, when confined in corked vases, and exposed to the action of a freezing 
atmosphere, is sure to swell out and break those vessels which are not suffi 
ciently large to contain its expanded volume. Megalotti narrates a hundred 
other instances of a similar character. Ed. 


the air, by a slight degree of cold, contracts itself, as in 
Inst. 38, Tab. 3. More will be said of this in the inquiry 
into cold. 

Nor is it to be wondered at if cold and heat exhibit many 
common effects (for which see Inst. 32, Tab. 2), since two 
differences, of which we shall presently speak, belong to 
each nature: although in the present difference the effects 
be diametrically opposed to each other. For heat occasions 
an expansive and dilating motion, but cold a contracting and 
condensing motion. 

II. The second difference is a modification of the preced 
ing, namely, that heat is an expansive motion, tending 
toward the exterior, but at the same time bearing the body 
upward. For there is no doubt that there be many com 
pound motions, as an arrow or dart, for instance, has both 
a rotatory and progressive motion. In the same way the 
motion of heat is both expansive and tending upward. 

This difference is shown by putting the tongs or poker 
into the fire. If placed perpendicularly with the hand 
above, they soon burn it, but much less speedily if the 
hand hold them sloping or from below. 

It is also conspicuous in distillations per descensum, which 
men are wont to employ with delicate flowers, whose scent 
easily evaporates. Their industry has devised placing the 
fire above instead of below, that it may scorch less ; for not 
only flame but all heat has an upward tendency. 

Let an experiment be made on the tontrary nature of 
cold, whether its contraction be downward, as the expansion 
of heat is upward. Take, therefore, two iron rods or two 
glass tubes, alike in other respects, and warm them a little, 
and place a sponge, dipped in cold water, or some snow, be 
low the one and above the other. We are of opinion that 


the extremities will grow cold in that rod first where it is 
placed beneath, as the contrary takes place with regard to 

III. The third difference is this; that heat is not a uni 
form expansive motion of the whole, but of the small par 
ticles of the body; and this motion being at the same time 
restrained, repulsed, and reflected, becomes alternating, per 
petually hurrying, striving, struggling, and irritated by the 
repercussion, which is the source of the violence of flame 
and heat. 

But this difference is chiefly shown in flame and boiling 
liquids, which always hurry, swell, and subside again in de 
tached parts. 

It is also shown in bodies of such hard texture as not 
to swell or dilate in bulk, such as red-hot iron, in which 
the heat is most violent. 

It is also shown by the fires burning most briskly in the 
coldest weather. 

It is also shown by this, that when the air is dilated in 
the thermometer uniformly and equably, without any im 
pediment or repulsion, the heat is not perceptible. In con 
fined draughts also, although they break out very violently, 
no remarkable heat is perceived, because the motion affects 
the whole, without any alternating motion in the particles; 
for which reason try whether flame do not burn more at the 
sides than in its centre. 

It is also shown in this, that all burning proceeds by 
the minute pores of bodies undermining, penetrating, 
piercing, and pricking them as if with an infinite number 
of needle-points. Hence all strong acids (if adapted to the 
body on which they act) exhibit the effects of fire, from 
their corroding and pungent nature. 


The difference of which we now speak is common also 
to the nature of cold, in which the contracting motion is 
restrained by the resistance of expansion, as in heat the ex 
pansive motion is restrained by the resistance of contraction. 

Whether, therefore, the particles of matter penetrate 
inward or outward, the reasoning is the same, though the 
power be very different, because we have nothing on earth 
which is intensely cold. 

IV. The fourth difference is a modification of the pre 
ceding, namely, that this stimulating or penetrating motion 
should be rapid and never sluggish, and should take place 
not in the very minutest particles, but rather in those of 
some tolerable dimensions. 

It is shown by comparing the effects of tire with those 
of time. Time dries, consumes, undermines, and reduces to 
ashes as well as fire, and perhaps to a much finer degree; 
but as its motion is very slow, and attacks very minute 
particles, no heat is perceived. 

It is also shown in a comparison of the dissolution of 
iron and gold; for gold is dissolved without the excitement 
of any heat, but iron with a vehement excitement of it, 
although most in the same time, because in the former the 
penetration of the separating acid is mild, and gently in 
sinuates itself, and the particles of gold yield easily, but 
the penetration of iron is violent, and attended with some 
struggle, and its particles are more obstinate. 

It is partially shown, also, in some gangrenes and morti 
fications of flesh, which do not excite great heat or pain, 
from the gentle nature of the putrefaction. 

Let this suffice for a first vintage, or the commencement 
of the interpretation of the form of heat by the liberty of 
the understanding. 


From this first vintage the form or true definition of heat 
(considered relatively to the universe and not to the sense) 
is briefly thus Heat is an expansive motion restrained, and 
striving to exert itself in the smaller particles. 88 The ex 
pansion is modified by its tendency to rise, though expand 
ing toward the exterior; and the effort is modified by its not 
being sluggish, but active and somewhat violent. 

With regard to the operative definition, the matter is the 
same. If you are able to excite a dilating or expansive 
motion in any natural body, and so to repress that motion 
and force it on itself as not to allow the expansion to pro 
ceed equally, but only to be partially exerted and partially 
repressed, you will beyond all doubt produce heat, without 
any consideration as to whether the body be of earth (or 
elementary, as they term it), or imbued with celestial in 
fluence, luminous or opaque, rare or dense, locally expanded 

36 Bacon s inquisition into the nature of heat, as an example of the mode of 
interpreting nature, cannot be looked upon otherwise than as a complete failure. 
Though the exact nature of this phenomenon is still an obscure and contro 
verted matter, the science of thermotics now consists of many important truths, 
and to none of these truths is there so much as an approximation in Bacon s 
process. The steps by which this science really advanced were the discovery 
of a measure of a heat or temperature, the establishment of the laws of con 
duction and radiation, of the laws of specific heat, latent heat, and the like. 
Such advances have led to Ampere s hypothesis, that heat consists in the vibra 
tions of an imponderable fluid ; and to Laplace s theory, that temperature con 
sists in the internal radiation of a similar medium. These hypotheses cannot 
yet be said to be even probable, but at least they are so modified as to include 
some of the preceding laws which are firmly established, whereas Bacon s 
"form," or true definition of beat, as stated in the text, includes no laws of 
phenomena, explains no process, and is indeed itself an example of illicit gen 

In all the details of his example of heat he is unfortunate. lie includes in 
his collection of instances, the hot tastes of aromatic plants, the caustic effects 
of acids, and many other facts which cannot be ascribed to heat without a stu 
dious laxity in the use of the word. Ed. 


or contained within the bounds of its first dimensions, verg 
ing to dissolution or remaining fixed, animal, vegetable, or 
mineral, water, or oil, or air, or any olrher substance what 
ever susceptible of such motion. Sensible heat is the same, 
but considered relatively to the senses. Let us now proceed 
to further helps. 

XXI. After our tables of first review, our rejection or 
exclusive table, and the first vintage derived from them, we 
must advance to the remaining helps of the understanding 
with regard to the interpretation of nature, and a true and 
perfect induction, in offering which we will take the exam 
ples of cold and heat where tables are necessary, but where 
fewer instances are required we will go through a variety 
of others, so as neither to confound investigation nor to 
narrow our doctrine. 

In the first place, therefore, we will treat of prerogative 
instances; 37 2. Of the supports of induction; 3. Of the cor- 

37 By this term Bacon understands general phenomena, taken in order from 
the great mass of indiscriminative facts, which, as they lie in nature, are apt 
to generate confusion by their number, indistinctness and complication. Such 
classes of phenomena, as being peculiarly suggestive of causation, he quaintly 
classes under the title of prerogative inquiries, either seduced by the fanciful 
analogy, which such instances bore to the prerogativa centuria in the Roman 
Comitia, or justly considering them as Herschel supposes to hold a kind of 
prerogative dignity from being peculiarly suggestive of causation. 

Two high authorities in physical science (v. Herschel, Nat. Phil., art. 192; 
"Whowell s Philosophy of the Inductive Sciences, vol. ii. p. 243) pronounce 
these instances of little service in the task of induction, being for the most part 
classed not according to the ideas which they involve, or to any obvious cir 
cumstance in the facts of which they consist, but according to the extent and 
manner of their influence upon the inquiry in which they are employed. Thus 
we have solitary instances, migrating instances, ostensive instances, clandestine 
instances, so termed according to the degree in which they exhibit, or seem to 
exhibit, the property, whose nature we would examine. We have guide-post 
instances, crucial instances, instances of the parted road, of the doorway, of the 
lamp, according to the guidance they supply to our advance. "Whewell remarks 


rection of induction; 4. Of varying the investigation ac 
cording to the nature of the subject; 5. Of the prerogative 
natures with respect to investigation, or of what should be 
the first or last objects of our research; 6. Of the limits of 
investigation, or a synopsis of all natures that exist in the 
universe; 7. Of the application to practical purposes, or of 
what relates to man; 8. Of the preparations for investiga 
tion; 9. And lastly, of the ascending and descending scale 
of axioms. 38 

XXII. Among the prerogative instances we will first 
mention solitary instances. Solitary instances are those 
which exhibit the required nature in subjects that have 
nothing in common with any other subject than the nature 
in question, or which do not exhibit the required nature in 
subjects resembling others in every respect except that 
of the nature in question; for these instances manifestly 
remove prolixity, and accelerate and confirm exclusion, so 
that a few of them are of as much avail as many. 

For instance, let the inquiry be the nature of color. 
Prisms, crystalline gems, which yield colors not only inter 
nally but on the wall, dews, etc., are solitary instances; for 

that such a classification is much of the same nature as if, having to teach the 
art of building, we were to describe tools with reference to the amount and place 
of the work which they must do, instead of pointing: out their construction and 
nse; as if we were to inform the pupil that we must have tools for lifting a 
stone up, tools for moving it sidewise, tools for laying it square, and tools for 
cementing it firmly. The means are thus lost in the end, and we reap the fruits 
of unmethodical arrangement in the confusion of cross division. In addition, 
all the instances are leavened with the error of confounding the laws with the 
causes of phenomena, and we are urged to adopt the fundamental error of 
seeking therein the universal agents, or general causes of phenomena, without 
ascending the gradual steps of intermediate laws. Ed. 

38 Of these nine general heads no more than the first is prosecuted by the 


they have nothing in common with the fixed colors in 
flowers and colored gems, metals, woods, etc., except the 
color itself. Hence we easily deduce that color is nothing 
but a modification of the image of the incident and absorbed 
light, occasioned in the former case by the different degrees 
of incidence, in the latter by the various textures and forms 
of bodies. 89 These are solitary instances as regards simili 

Again, in the same inquiry the distinct veins of white 
and black in marble, and the variegated colors of flowers of 
the same species, are solitary instances; for the black and 
white of marble, and the spots of white and purple in the 
flowers of the stock, agree in every respect but that of color. 
Thence we easily deduce that color has not much to do with 
the intrinsic natures of any body, but depends only on the 
coarser and as it were mechanical arrangement of the parts. 
These are solitary instances as regards difference. We call 
them both solitary or wild, to borrow a word from the 

XXIII. In the second rank of prerogative instances we 
will consider migrating instances. In these the required 
nature passes toward generation, having no previous exist 
ence, or toward corruption, having first existed. In each 
of these divisions, therefore, the instances are always two 
fold, or rather it is one instance, first in motion or on its 
passage, and then brought to the opposite conclusion. 
These instances not only hasten and confirm exclusion, but 
also reduce affirmation, or the form itself, to a narrow com 
pass; for the form must be something conferred by this 

39 This very nearly approaches to Sir I. Newton s discovery of the decom 
position of light by the prism. 


migration, or, on the contrary, removed and destroyed by 
it; and although all exclusion advances affirmation, yet this 
takes place more directly in the same than in different sub 
jects; but if the form (as it is quite clear from what has 
been advanced) exhibit itself in one subject, it lends to all. 
The more simple the migration is, the more valuable is the 
instance. These migrating instances are, moreover, very 
useful in practice, for since they manifest the form, coupled 
with that which causes or destroys it, they point out the 
right practice in some subjects, and thence there is an easy 
transition to those with which they are most allied. There 
is, however, a degree of danger which demands caution, 
namely, lest they should refer the form too much to its 
efficient cause, and imbue, or at least tinge, the understand 
ing with a false notion of the form from the appearance of 
such cause, which is never more than a vehicle or convey 
ance of the form. This may easily be remedied by a proper 
application of exclusion. 

Let us then give an example of a migrating instance. 
Let whiteness be the required nature. An instance which 
passes toward generation is glass in its entire and in its 
powdered state, or water in its natural state, and when 
agitated to froth; for glass when entire, and water in its 
natural state, are transparent and not white, but powdered 
glass and the froth of water are white and not transparent. 
We must inquire, therefore, what has happened to the glass 
or water in the course of this migration; for it is manifest 
that the form of whiteness is conveyed and introduced by 
the bruising of the glass and the agitation of the water; 
but nothing is found to have been introduced but a dimin 
ishing of the parts of the glass and water and the insertion 
of air. Yet this is no slight progress toward discovering 


the form of whiteness, namely, that two bodies, in them 
selves more or less transparent (as air and water, or air and 
glass), when brought into contact in minute portions, ex 
hibit whiteness from the unequal refraction of the rays 
of light. 

But here we must also give an example of the danger 
and caution of which we spoke; for instance, it will readily 
occur to an understanding perverted by efficients, that air is 
always necessary for producing the form of whiteness, or 
that whiteness is only generated by transparent bodies, which 
suppositions are both false, and proved to be so by many 
exclusions; nay, it will rather appear (without any particu 
lar regard to air or the like), that all bodies which are even 
in such of their parts as affect the sight exhibit transparency, 
those which are uneven and of simple texture whiteness, those 
which are uneven and of compound but regular texture all 
the other colors except black, but those which are uneven 
and of a compound irregular and confused texture exhibit 
blackness. An example has been given, therefore, of an in 
stance migrating toward generation in the required nature of 
whiteness. An instance migrating toward corruption in the 
same nature is that of dissolving froth or snow, for they lose 
their whiteness and assume the transparency of water in its 
pure state without air. 

Nor should we by any means omit to state, that under 
migrating instances we must comprehend not only those 
which pass toward generation and destruction, but also those 
which pass toward increase or decrease, for they, too, assist 
in the discovery of the form, as is clear from our definition 
of a form and the Table of Degrees. Hence paper, which is 
white when dry, is less white when moistened (from the ex 
clusion of air and admission of water), and tends more to 


transparency. The reason is the same as in the above in 
stances. 40 

XXIV. In the third rank of prerogative instances we 
will class conspicuous instances, of which we spoke in our 
first vintage of the form of heat, and which we are also wont 
to call coruscations, or free and predominant instances. 
They are such as show the required nature in its bare sub 
stantial shape, and at its height or greatest degree of power, 
emancipated and free from all impediments, or at least over 
coming, suppressing, and restraining them by the strength 
of its qualities; for since every body is susceptible of many 
united forms of natures in the concrete, the consequence is 
that they mutually deaden, depress, break, and confine each 
other, and the individual forms are obscured. But there are 
some subjects in which the required nature exists in its full 
vigor rather than in others, either from the absence of any 
impediment, or the predominance of its quality. Such in 
stances are eminently conspicuous. But even in these care 
must be taken, and the hastiness of the understanding 
checked, for whatever makes a show of the form, and forces 
it forward, is to be suspected, and recourse must be had to 
severe and diligent exclusion. 

For example, let heat be the required nature. The ther 
mometer is a conspicuous instance of the expansive motion, 
which (as has been observed) constitutes the chief part of 
the form of heat; for although flame clearl} r exhibits expan 
sion, yet from its. being extinguished every moment, it does 
not exhibit the progress of expansion. Boiling water again, 

40 The mineral kingdom, as displaying the sumo nature in all its gradations, 
from the shells so perfect in structure in limestone lo the finer marbles in 
which their nature gradually disappears, is the great theatre for instances 
of migration. Ed. 


from its rapid conversion into vapor, does not so well exhibit 
the expansion of water in its own shape, while red-hot iron 
and the like are so far from showing this progress, that, on 
the contrary, the expansion itself is scarcely evident to the 
senses, on account of its spirit being repressed and weakened 
by the compact and coarse particles which subdue and re 
strain it. But the thermometer strikingly exhibits the ex 
pansion of the air as being evident and progressive, durable 
and not transitory. 41 

Take another example. Let the required nature be 
weight. Quicksilver is a conspicuous instance of weight; 
for it is far heavier than any other substance except gold, 
which is not much heavier, and it is a better instance than 
gold for the purpose of indicating the form of weight; for 
gold is solid and consistent, which qualities must be referred 
to density, but quicksilver is liquid and teeming with spirit, 
yet much heavier than the diamond and other substances 
considered to be most solid; whence it is shown that the 
form of gravity or weight predominates only in the quantity 
of matter, and not in the close fitting of it. 42 

XXV. In the fourth rank of prerogative instances we 
will class clandestine instances, which we are also wont to 

41 Bacon was not aware of the fact since brought to light by Romer, that 
down to fourteen fathoms from the earth s mean level the thermometer remains 
fixed at the tenth degree, but that as the thermometer descends below that 
depth the heat increases in a ratio proportionate to the descent, which happens 
with little variation in all climates. Buffon considers this a proof of a central 
fire in our planet. Ed. 

42 All the diversities of bodies depend upon two principles, i.e., the quantity 
and the position of the elements that enter into their composition. The primary 
difference ia not that which depends on the greatest or least quantity of ma 
terial elements, but; that which depends on their position. It was the quick 
perception of this truth that made Leibnitz say that to complete mathematics it 
was necessary to join to the analysis of quantity the analysis of position. Ed. 


call twilight instances; they are as it were opposed to the 
conspicuous instances, for they show the required nature in 
its lowest state of efficacy, and as it were its cradle and first 
rudiments, making an effort and a sort of first attempt, but 
concealed and subdued by a contrary nature. Such in 
stances are, however, of great importance in discovering 
forms, for as the conspicuous tend easily to differences, so 
do the clandestine best lead to genera, that is, to those com 
mon natures of which the required natures are only the 

As an example, let consistency, or that which confines 
itself, be the required nature, the opposite of which is a 
liquid or flowing state. The clandestine instances are such 
as exhibit some weak and low degree of consistency in 
fluids, as a water bubble, which is a sort of consistent and 
bounded pellicle formed out of the substance of the water. 
So eaves droppings, if there be enough water to follow 
them, draw themselves out into a thin thread, not to break 
the continuity of the water, but if there be not enough to 
follow, the water forms itself into a round drop, which is the 
best form to prevent a breach of continuity; and at the mo 
ment the thread ceases, and the water begins to fall in drops, 
the thread of water recoils upward to avoid such a breach. 
Nay, in metals, which when melted arc liquid but more 
tenacious, the melted drops often recoil and are suspended. 
There is something similar in the instance of the child s look 
ing-glass, which little boys will sometimes form of spittle 
between rushes, and where the same pellicle of water is ob 
servable; and still more in that other amusement of children, 
when they take some water rendered a little more tenacious 
by soap, and innate it with a pipe, forming the water into a 
sort of castle of bubbles, which assumes such consistency, 


by the interposition of the air, as to admit of being thrown 
some little distance without bursting. The best example is 
that of froth and snow, which assume such consistency as 
almost to admit of being cut, although composed of air and 
water, both liquids. All these circumstances clearly show 
that the terms liquid and consistent are merely vulgar no 
tions adapted to the sense, and that in reality all bodies have 
a tendency to avoid a breach of continuity, faint and weak 
in bodies composed of homogeneous parts (as is the case with 
liquids), but more vivid and powerful in those composed of 
heterogeneous parts, because the approach of heterogeneous 
matter binds bodies together, while the insinuation of homo 
geneous matter loosens and relaxes them. 

Again, to take another example, let the required nature 
be attraction or the cohesion of bodies. The most remark 
able conspicuous instance with regard to its form is the mag 
net. The contrary nature to attraction is non-attraction, 
though in a similar substance. Thus iron does not attract 
iron, lead lead, wood wood, nor water water. But the clan 
destine instance is that of the magnet armed with iron, or 
rather that of iron in the magnet so armed. For its nature 
is such that the magnet when armed does not attract iron 
more powerfully at any given distance than when unarmed; 
but if the iron be brought in contact with the armed magnet, 
the latter will sustain a much greater weight than the simple 
magnet, from the resemblance of substance in the two por 
tions of iron, a quality altogether clandestine and hidden in 
the iron until the magnet was introduced. It is manifest, 
therefore, that the form of cohesion is something which is 
vivid and robust in the magnet, and hidden and weak in the- 
iron. It is to be observed, also, that small wooden arrows 
without an iron point, when discharged from large mortars, 


penetrate further into wooden substances (such as the ribs of 
ships or the like), than the same arrows pointed with iron, 43 
owing to the similarity of substance, though this quality was 
previously latent in the wood. Again, although in the mass 
air does not appear to attract air, nor water water, yet when 
one bubble is brought near another, they are both more 
readily dissolved, from the tendency to contact of the water 
with the water, and the air with the air. 44 These clandes 
tine instances (which are, as has been observed, of the most 
important service) are principally to be observed in small 
portions of bodies, for the larger masses observe more uni 
versal and general forms, as will be mentioned in its proper 
place. 45 

43 Query? 

44 The real cause of this phenomenon is the attraction of the surface-water 
in the vessel by the sides of the bubbles. When the bubbles approach, the 
sides nearest each other both tend to raise the small space of water between 
them, and consequently less water is raised by each of these nearer sides than 
by the exterior part of the bubble, and the greater weight of the water raised 
on the exterior parts pushes the bubbles together. In the same manner a bub 
ble near the side of a vessel is pushed toward it; the vessel and bubble both 
drawing the water that is between them. The latter phenomenon cannot be 
explained on Bacon s hypothesis. 

45 Modern discoveries appear to bear out the sagacity of Bacon s remark, 
and the experiments of Baron Cagnard may be regarded as a first step toward 
its full demonstration. After the new facts elicited by that philosopher, there 
can be little doubt that the solid, liquid and aeriform state of bodies are merely 
stages in a progress of gradual transition from one extreme to the other, and 
that however strongly marked the distinctions between them may appear, they 
will ultimately turn out to be separated by no sudden or violent line of de 
marcation, but slide into each other by imperceptible gradations. Bacon s 
suggestion, however, is as old as Pythagoras, and perhaps simultaneous with 
the first dawn of philosophic reason. The doctrine of the reciprocal transmuta 
tion of the elements underlies all the physical systems of the ancients, and was 
adopted by the Epicureans as well as the Stoics. Ovid opens his last book of 
the Metamorphoses with the poetry of the subject, where he expressly points 
to the hint of Bacon : 


XXVI. In the fifth rank of prerogative instances we will 
class constitutive instances, which we are wont also to call 
collective instances. They constitute a species or lesser 
form, as it were, of the required nature. For since the real 
forms (which are always convertible with the given nature) 
lie at some depth, and are not easily discovered, the neces 
sity of the case and the infirmity of the human understand 
ing require that the particular forms, which collect certain 
groups of instances (but by no means all) into some common 
notion, should not be neglected, but most diligently ob 
served. For whatever unites nature, even imperfectly, 
opens the way to the discovery <>f the form. The in 
stances, therefore, which are serviceable in this respect 
are of no mean power, but endowed with some degree of 

Here, nevertheless, great care must be taken that, after 
the discovery of several of these particular forms, and the 
establishing of certain partitions or divisions of the required 
nature derived from them, the human understanding do not 
at once rest satisfied, without preparing for the investiga 
tion of the great or leading form, and taking it for granted 
that nature is compound and divided from its very root, de 
spise and reject any further union as a point of superfluous 
refinement, and tending to mere abstraction. 

For instance, let the required nature be memory, or that 

"Tenuatus in auras 

Aeraque humor abit, etc., etc. 

Inde retro redeunt, idemque retexitur ordo. " xv. 246-249. 

and Seneca, in the third book of his Natural Philosophy, quest, iv., states the 
opinion in more precise language than either the ancient bard or the modern 
philosopher. Ed. 


which excites and assists memory. The constitutive in 
stances are order or distribution, which manifestly assists 
memory: topics or commonplaces in artificial memory, 
which may be either places in their literal sense, as a gate, 
a corner, a window, and the like, or familiar persons and 
marks, or anything else (provided it be arranged in a deter 
minate order), as animals, plants, and words, letters, char 
acters, historical persons, and the like, of which, however, 
some are more convenient than others. All these common 
places materially assist memory, and raise it far above its 
natural strength. Verse, too, is recollected and learned 
more easily than prose. From this group of three instances 
order, the commonplaces of artificial memory, and verses 
is constituted one species of aid for the memory/ 8 which 
may be well termed a separation from infinity. For when 
a man strives to recollect or recall anything to memory, 
without a preconceived notion or perception of the object 
of his search, he inquires about, and labors, and turns from 
point to point, as if involved in infinity. But if he have 
any preconceived notion, this infinity is separated ofl , and 
the range of his memory is brought within closer limits. 
In the three instances given above, the preconceived notion 
is clear and determined. In the first, it must be something 
that agrees with order; in the second, an image which has 
some relation or agreement with the fixed commonplaces; 
iu the third, words which fall into a verse: and thus infinity 
is divided of!. Other instances will oiler another species, 
narnelv, that whatever brings the intellect into contact with 

46 The author s own system of Memoria Techniua, may be found in the De 
Augmeutis, chap. xv. We may add that, notwithstanding Bacon s assertion 
that he intended his method to apply to religion, politics, and morals, this is 
the only lengthy illustration he has adduced of any subject out of the domain 
of physical science. Ed. 


something that strikes the sense (the principal point of 
artificial memory), assists the memory. Others again offer 
another species, namely, whatever excites an impression 
by any powerful passion, as fear, shame, wonder, delight, 
assists the memory. Other instances will afford another 
species: thus those impressions remain most fixed in the 
memory which are taken from the mind when clear and 
least occupied by preceding or succeeding notions, such as 
the things we learn in childhood, or imagine before sleep, 
and the first time of any circumstance happening. Other 
instances afford the following species: namely, that a mul 
titude of circumstances or handles assist the memory, such 
as writing in paragraphs, . reading aloud, or recitation. 
Lastly, other instances afford still another species: thus 
the things we anticipate, and which rouse our attention, 
are more easily remembered than transient events; as if 
you read any work twenty times over, you will not learn 
it by heart so readily as if you were to read it but ten 
times, trying each time to repeat it, and when your memory 
fails you looking into the book. There are, therefore, six 
lesser forms, as it were, of things which assist the memory: 
namely 1, the separation of infinity; 2, the connection of 
the mind with the senses; 3, the impression in strong 
passion; 4, the impression on the mind when pure; 5, the 
multitude of handles; 6, anticipation. 

Again, for example s sake, let the required nature be 
taste or the power of tasting. The following instances are 
constitutive: 1. Those who do not smell, but are deprived 
by nature of that sense, do not perceive or distinguish rancid 
or putrid food by their taste, nor garlic from roses, and the 
like. 2. Again, those whose nostrils are obstructed by 

accident (such as a cold) do not distinguish any putrid or 

SCIENCE Vol. iJ2 8 


rancid matter from anything sprinkled with rose-water. 
3. If those who suffer from a cold blow their noses vio 
lently at the very moment in which they have anything 
fetid or perfumed in their mouth, or on their palate, they 
instantly have a clear perception of the fetor or perfume. 
These instances afford and constitute this species or division 
of taste, namely, that it is in part nothing else than an in 
ternal smelling, passing and descending through the upper 
passages of the nostrils to the mouth and palate. But, on 
the other hand, those whose power of smelling is deficient 
or obstructed, perceive what is salt, sweet, pungent, acid, 
rough, and bitter, and the like, as well as any one else: so 
that the taste is clearly something compounded of the in 
ternal smelling, and an exquisite species of touch which 
we will not here discuss. 

Again, as another example, let the required nature be 
the communication of quality, without intermixture of sub 
stance. The instance of light will afford or constitute one 
species of communication, heat and the magnet another. 
For the communication of light is momentary and imme 
diately arrested upon the removal of the original light. 
But heat, and the magnetic force, when once transmitted 
to or excited in another body, remain fixed for a consider 
able time after the removal of the source. 

In fine, the prerogative of constitutive instances is con 
siderable, for they materially assist the definitions (especially 
in detail) and the divisions or partitions of natures, concern 
ing which Plato has well said, "He who can properly define 
and divide is to be considered a god." 

47 The collective instances here meant are no other than general facts or 
laws of some degree of generality, and are themselves the result of induction. 
For example, the system of Jupiter, or Saturti with its satellites, is a collective 


XXVII. In the sixth rank of prerogative instances we 
will place similar or proportionate instances, which we are 
also wont to call physical parallels, or resemblances. They 
are such as exhibit the resemblances and connection of 
things, not in minor forms (as the constitutive do), but at 
once in the concrete. They are, therefore, as it were, the 
first and lowest steps toward the union of nature; nor do 
they immediately establish any axiom, but merely indicate 
and observe a certain relation of bodies to each other. But 

instance, and materially assisted in securing the admission of the Coperniean 
system. We have here in miniature, and displayed at one view, a system anal 
ogous to that of the planets about the sun, of which, from the circumstance of 
our being involved in it, and unfavorably situated for seeing it otherwise than 
in detail, we are incapacitated from forming a general idea, but by slow and 
progressive efforts of reason. 

But there is a species of collective instance which Bacon does not seem to 
have contemplated, in which particular phenomena are presented in such num 
bers at once, as to make the induction of their law a matter of ocular inspec 
tion. For example, the parabolic form assumed by a jet of water spouted out 
of a hole is a collective instance of the velocities and directions of the motions 
of all the particles which compose it seen together, and which thus leads us 
without trouble to recognize the law of the motion of a projectile. Again, the 
beautiful figures exhibited by sand strewed on regular plates of glass or metal 
set in vibration, are collective instances of an infinite number of points which 
remain at rest while the remainder of the plate vibrates, and in consequence 
afford us an insight into the law which regulates their arrangement and se 
quence throughout the whole surface. The richly colored lemniscates seen 
around the optic axis of crystals exposed to polarized light afford a striking 
instance of the same kind, pointing at once to the general mathematical expres 
sion of the law which regulates their production. Such collective instances as 
these lead us to a general law by an induction which offers itself spontaneously, 
and thus furnish advanced posts in philosophical exploration. The laws of 
Kepler, which Bacon ignored on account of his want of mathematical taste, 
may be cited as a collective instance. The first is, that the planets move in 
elliptical orbits, having the sun for their common focus. The second, that 
about this focus the radius vector of each planet describes equal areas in equal 
times. The third, that the squares of the periodic times of the planets are as 
the cubes of their mean distance from the sun. This collective instance "opened 
the way" to the discovery of the Newtonian law of gravitation. Ed. 


although they be not of much assistance in discovering 
forms, yet they are of great advantage in disclosing the 
frame of parts of the universe, upon whose members they 
practice a species of anatomy, and thence occasionally lead 
us gently on to sublime and noble axioms, especially such 
as relate to the construction of the world, rather than to 
simple natures and forms. 

As an example, take the following similar instances: a 
mirror and the eye; the formation of the ear, and places 
which return an echo. From such similarity, besides ob 
serving the resemblance (which is useful for many pur 
poses), it is easy to collect and form this axiom. That 
the organs of the senses, and bodies which produce reflec 
tions to the senses, are of a similar nature. Again, the 
understanding once informed of this, rises easily to a higher 
and nobler axiom; namely, that the only distinction between 
sensitive and inanimate bodies, in those points in which 
they agree and sympathize, is this: in the former, animal 
spirit is added to the arrangement of the body, in the latter 
it is wanting. So that there might be as many senses in 
animals as there are points of agreement with inanimate 
bodies, if the animated body were perforated, so as to allow 
the spirit to have access to the limb properly disposed for 
action, as a fit organ. And, on the other hand, there are, 
without doubt, as many motions in an inanimate as there 
are senses in the animated body, though the animal spirit 
be absent. There must, however, be many more motions 
in inanimate bodies than senses in the animated, from the 
small number of organs of sense. A very plain example 
of this is afforded by pains. For, as animals are liable to 
many kinds and various descriptions of pains (such as those 
of burning, of intense cold, of pricking, squeezing, stretch- 


ing, and the like), so is it most certain, that the same cir 
cumstances, as far as motion is concerned, happen to inani 
mate bodies, such as wood or stone when burned, frozen, 
pricked, cut, bent, bruised, and the like; although there be 
no sensation, owing to the absence of animal spirit. 

Again, wonderful as it may appear, the roots and 
branches of trees are similar instances. For every vege 
table swells and throws out its constituent parts toward 
the circumference, both upward and downward. And there 
is no difference between the roots and branches, except 
that the root is buried in the earth, and the branches are 
exposed to the air and sun. For if one take a young and 
vigorous shoot, and bend it down to a small portion of loose 
earth, although it be not fixed to the ground, yet will it 
immediately produce a root, and not a branch. And, vice 
versa, if earth be placed above, and so forced down with 
a stone or any hard substance, as to confine the plant and 
prevent its branching upward, it will throw out branches 
into the air downward. 

The gums of trees, and most rock gems, are similar in 
stances; for both of them are exudations and filtered juices, 
derived in the former instance from trees, in the latter from 
stones ; the brightness and clearness of both arising from a 
delicate and accurate filtering. For nearly the same reason, 
the hair of animals is less beautiful and vivid in its color 
than the plumage of most birds, because the juices are less 
delicately filtered through the skin than through the quills. 

The scrotum of males and matrix of females are also 
similar instances; so that the noble formation which consti 
tutes the difference of the sexes appears to differ only as 
to the one being internal and the other external ; a greater 
degree of heat causing the genitals to protrude in the male, 


while the heat of the female being too weak to effect this, 
they are retained internally. 

The fms of fishes and the feet of quadrupeds, or the feet 
and wings of birds, are similar instances; to which Aristotle 
adds the four folds in the motion of serpents; 4 * so that in 
the formation of the universe, the motion of animals appears 
to be chiefly effected by four joints or bendings. 

The teeth of land animals, and the beaks of birds, are 
similar instances, whence it is clear, that in all perfect 
animals there is a determination of some hard substance 
toward the mouth. 

Again, the resemblance and conformity of man to an 
inverted plant is not absurd. For the head is the root of 
the nerves and animal faculties, and the seminal parts are 
the lowest, not including the extremities of the legs and 
arms. But in the plant, the root (which resembles the head) 
is regularly placed in the lowest, and the seeds in the high- 

/ j o 

est part. 49 

Lastly, we must particularly recommend and suggest, 
that man s present industry in the investigation and com 
pilation of natural history be entirely changed, and directed 
to the reverse of the present system. For it has hitherto 
been active and curious in noting the variety of things, and 
explaining the accurate differences of animals, vegetables, 
and minerals, most of which are the mere sport of nature, 
rather than of any real utility as concerns the sciences. 

48 Is not this very hasty generalization ? Do serpents move with four folds 
only ? Observe also the motion of centipedes and other insects. 

49 Shaw states another point of difference between the objects cited in the 
text animals having their roots within, while plants have theirs without; for 
their lacteals nearly correspond with the fibres of the roots in plants; so that 
animals seem nourished witniii themselves as plants are without. Ed. 


Pursuits of this nature are certainly agreeable, and some 
times of practical advantage, but contribute little or nothing 
to the thorough investigation of nature. Our labor must 
therefore be directed toward inquiring into and observing 
resemblances and analogies, both in the whole and its parts, 
for they unite nature, and lay the foundation of the sciences. 

Here, however, a severe and rigorous caution must be 
observed, that we only consider as similar and proportionate 
instances, those which (as we first observed) point out 
physical resemblances; that is, real and substantial resem 
blances, deeply founded in nature, and not casual and 
superficial, much less superstitious or curious; such as 
those which are constantly put forward by the writers on 
natural magic (the most idle of men, and who are scarcely 
fit to be named in connection with such serious matters as 
we now treat of), who, with much vanity and folly, describe, 
and sometimes too, invent, unmeaning resemblances and 

But leaving such to themselves, similar instances are 
not to be neglected, in the greater portions of the world s 
conformation; such as Africa and the Peruvian continent, 
which reaches to the Straits of Magellan; both of which 
possess a similar isthmus and similar capes, a circumstance 
not to be attributed to mere accident. 

Again, the New and Old World are both of them broad 
and expanded toward the north, and narrow and pointed 
toward the south. 

Again, we have very remarkable similar instances in the 
intense cold, toward the middle regions (as it is termed) of 
the air, and the violent fires which are often found to burst 
from subterraneous spots, the similarity consisting in both 
being ends and extremes; the extreme of the nature of cold, 


for instance, is toward the boundary of heaven, and that of 
the nature of heat toward the centre of the earth, by a 
similar species of opposition or rejection of the contrary 

Lastly, in the axioms of the sciences, there is a similarity 
of instances worthy of observation. Thus the rhetorical 
trope which is called surprise, is similar to that of music 
termed the declining of a cadence. Again the mathe 
matical postulate, that things which are equal to the same 
are equal to one another, is similar to the form of the syl 
logism in logic, which unites things agreeing in the middle 
term. 50 Lastly, a certain degree of sagacity in collecting 
and searching for physical points of similarity, is very use 
ful in many respects. 61 

XXVIII. In the seventh rank of prerogative instances, 
we will place singular instances, which we are also wont to 
call irregular or heteroclite (to brorrow a term from the 
grammarians). They are such as exhibit bodies in the con- 

50 Bacon falls into an error here in regarding the syllogism as something 
distinct from the reasoning faculty, and only one of its forms. It is not gen 
erally true that the syllogism is only a form of reasoning by which we unite 
ideas which accord with the middle term. This agreement is not even essen 
tial to accurate syllogisms; when .the relation of the two things compared to 
the third is one of equality or similitude, it of course follows that, the two 
things compared may be pronounced equal, or like to each other. But if the 
relation between these terms exist in a different form, then it is not true that 
the two extremes stand in the same relation to each other as to the middle 
term. For instance, if A is double of B, and B double of c, then A is quadruple 
of c. But then the relation of A to c is different from that of A to B and 
of B to c. Ed. 

61 Comparative anatomy is full of analogies of this kind. Those between 
natural and artificial productions are well worthy of attention, and sometimes 
lead to important discoveries. By observing an analogy of this kind between 
the plan used in hydraulic engines for preventing the counter-current of a fluid, 
and a similar contrivance in the blood vessels, Harvey was led to the discovery 
of the circulation of the blood. Ed. 


crete, of an apparently extravagant and separate nature, 
agreeing but little with other things of the same species. 
For, while the similar instances resemble each other, those 
we now speak of are only like themselves. Their use is 
much the same with that of clandestine instances: they 
bring out and unite nature, and discover genera or common 
natures, which must afterward be limited by real differ 
ences. Nor should we desist from inquiry, until the prop 
erties and qualities of those things, which may be deemed 
miracles, as it were, of nature, be reduced to, and compre 
hended in, some form or certain law; so that all irregularity 
or singularity may be found to depend on some common 
form; and the miracle only consists in accurate differences, 
degree, and rare coincidence, not in the species itself. 
Man s meditation proceeds no further at present, than 
just to consider things of this kind as the secrets and vast 
efforts of nature, without an assignable cause, and, as it 
were, exceptions to general rules. 

As examples of singular instances, we have the sun and 
moon among the heavenly bodies; the magnet among min 
erals; quicksilver among metals; the elephant among quad 
rupeds; the venereal sensation among the different kinds 
of touch; the scent of sporting dogs among those of smell. 
The letter S, too, is considered by the grammarians as sui 
generis, from its easily uniting with double or triple con 
sonants, which no other letter will. FThese instances are of . , 
great value, because they excite and keep alive inquiry, 
and correct an understanding depraved by habit and the 
common course of things. 

XXIX. In the eighth rank of prerogative instances, we 
will place deviating instances, such as the errors of nature, 
or strange and monstrous objects, in which nature deviates 


and turns from her ordinary course. For the errors of 
nature differ from singular instances, inasmuch as the lat 
ter are the miracles of species, the former of individuals. 
Their use is much the same, for they rectify the under 
standing in opposition to habit, and reveal common forms. 


For with regard to these, also, we must not desist from in 
quiry, till we discern the cause of the deviation. The cause 

does not, however, in such cases rise to a regular form, but 


only to the latent process toward such a form. For he who 
is acquainted with the paths of nature, will more readily 
observe her deviations; and, vice versa, he who has learned 
her deviations will be able more accurately to describe 
her paths. 

They differ again from singular instances, by being 
much more apt for practice and the. operative branch. 
For it would be very difficult to generate new species, 
but less so to vary known species, and thus produce many 
rare and unusual results. 63 The passage from the miracles 
of nature to those of art is easy; for if nature be once seized 
in her variations, and the cause be manifest, it will be easy 
to lead her by art to such deviation as she was at first led 
to by chance; and not only to that but others, since devia 
tions on the one side lead and open the way to others in 
every direction. Of this we do not require any examples, 
since they are so abundant. For a compilation, or particu 
lar natural history, must be made of all monsters and pro 
digious births of nature; of everything, in short, which is 
new r rare and unusual in nature. This should be done 
with a rigorous selection, so as to be worthy of credit. 

52 This is well illustrated in plants, for the gardener can produce endless 
varieties of any known species, but can never produce a new species itself. 


Those are most to be suspected which depend upon super 
stition, as the prodigies of Livy, and those perhaps, but 
little less, which are found in the works of writers on nat 
ural magic, or even alchemy, and the like; for such men, 
as it were, are the very suitors and lovers of fables; but our 
instances should be derived from some grave and credible 
history, and faithful narration. 

XXX. In the ninth rank of prerogative instances, we 
will place bordering instances, which we are also wont to 
term participants. They are such as exhibit those species 
of bodies which appear to be composed of two species, or 
to be the rudiments between the one and the other. They 
may well be classed with the singular or heteroclite in 
stances; for in the whole system of things, they are rare 
and extraordinary. Yet from their dignity, they must be 
treated of and classed separately, for they point out admir 
ably the order and constitution of things, and suggest the 
causes of the number and quality of the more common 
species in the universe, leading the understanding from 
that which is, to that which is possible. 

We have examples of them in moss, which is something 
between putrescence and a plant; 53 in some comets, which 
hold a place between stars and ignited meteors; in flying 
fishes, between fishes and birds; and in bats, between birds 
and quadrupeds. 64 Again, 

Simia quam similis turpissima bestia nobis. 

63 The discoveries of Tournefort have placed moss in the class of plants. 
The fish alluded to below are to be found only in the tropics. Ed. 

64 There is, however, no real approximation to birds in either the flying fish 
or bat, any more than a man approximates to a fish because he can swim. The 
wings of the flying fish and bat are mere expansions of skin, bearing no resem 
blance whatever to those of birds. Ed. 



We have also biformed foetus, mingled species and 
the like. 

XXXI. In the tenth rank of prerogative instances, we 
will place the instances of power, or the fasces (to borrow 
a term from the insignia of empire), which we are also wont 
to call the wit or hands of man. These are such works as 
are most noble and perfect, and, as it were, the masterpieces 
in every art. For since our principal object is to make na 
ture subservient to the state and wants of man, it becomes 
us well to note and enumerate the works, which have long 
since been in the power of man, especially those which are 
most polished and perfect: because the passage from these 
to new and hitherto undiscovered works, is more easy and 
feasible. For if any one, after an attentive contemplation 
of such works as are extant, be willing to push forward 
in his design with alacrity and vigor, he will undoubtedly 
either advance them, or turn them to something within 
their immediate reach, or even apply and transfer them 
to some more noble purpose. 

Nor is this all: for as the understanding is elevated and 
raised by rare and unusual works of nature, to investigate 
; and discover the forms which include them also, so is the 
same effect frequently produced by the excellent and won 
derful works of art; and even to a greater degree, because 
I the mode of effecting and constructing the miracles of art 
is generally plain, while that of effecting the miracles 
of nature is more obscure. Great care, however, must be 
taken, that they do not depress the understanding, and 
fix it, as it were, to earth. 

For there is some danger, lest the understanding should 
be astonished and chained down, and as it were bewitched, 
by such works of art, as appear to be the very summit and 


pinnacle of human industry, so as not to become familiar 
with them, but rather to suppose that nothing of the kind 
can be accomplished, unless the same means be employed, 
with perhaps a little more diligence, and more accurate 

Now, on the contrary, it may be stated as a fact, that 
the ways and means hitherto discovered and observed, of 
effecting any matter or work, are for the most part of little 
value, and that all really efficient power depends, and is 
really to be deduced from the sources of forms, none 
of which have yet been discovered. 

Thus (as we have before observed), had any one medi 
tated on ballistic machines, and battering rams, as they were 
used by the ancients, whatever application he might have 
exerted, and though he might have consumed a whole life 
in the pursuit, yet would he never have hit upon the in 
vention of flaming engines, acting by means of gunpowder; 
nor would any person, who had made woollen manufacto 
ries and cotton the subject of his observation and reflection, 
have ever discovered thereby the nature of the silkworm 
or of silk. 

Hence all the most noble discoveries have (if you ob 
serve) come to light, not by any gradual improvement and 
extension of the arts, but merely by chance; while nothing 
imitates or anticipates chance (which is wont to act at in 
tervals of ages) but the invention of forms. 

There is no necessity for adducing any particular exam 
ples of these instances, since they are abundant. The plan 
to be pursued is this: all the mechanical, and even the lib 
eral arts (as far as they are practical), should be visited and 
thoroughly examined, and thence there should be formed 
a compilation or particular history of the great master- 


pieces, or most finished works in each, as well as of 
the mode of carrying them into effect. 

Nor do we confine the diligence to be used in such a 
compilation to the leading works and secrets only of every 
art, and such as excite wonder; for wonder is engendered 
by rarity, since that which is rare, although it be com 
pounded of ordinary natures, always begets wonder. 

On the contrary, that which is really wonderful, from 
some specific difference distinguishing it from other species, 
is carelessly observed, if it be but familiar." Yet the singu 
lar instances of art should be observed no less than those of~j 
nature, which we have before spoken of: and as in the lat- , 
ter we have classed the sun, the moon, the magnet, and the 
like, all of them most familiar to us, but yet in their nature j 
singular, so should we proceed with the singular instances/ 
of art. 

For example: paper, a very common substance, is a 
singular instance of art; for if } T OU consider the subject at 
tentively, you will find that artificial substances are either 
woven by straight and transverse lines, as silk, woollen, 
or linen cloth, and the like; or coagulated from concrete 
juices, such as brick, earthenware, glass, enamel, porcelain 
and the like, which admit of a polish if they be compact, 
but if not, become hard without being polished; all which 
latter substances are brittle, and not adherent or tenacious. 
On the contrary, paper is a tenacious substance, which can 
be cut and torn, so as to resemble and almost rival the skin 
of any animal, or the leaf of vegetables, and the like works 
of nature; being neither brittle like glass, nor woven like 
cloth, but having fibres and not distinct threads, just as 
natural substances, so that scarcely anything similar can 
be found among artificial substances, and it is absolutely 


singular. And in artificial works we should certainly pre- I 

fer those which approach the nearest to an imitation of na- I 
ture, or, on the other hand, powerfully govern and change 
her course. 

Again, in these instances which we term the wit and 
hands of man, charms and conjuring should not be alto 
gether despised, for although mere amusements, and of 
little use, yet they may afford considerable information. 

Lastly, superstition and magic (in its common accepta 
tion) are not to be entirely omitted; for although they be 
overwhelmed by a mass of lies and fables, yet some inves 
tigation should be made, to see if there be really any latent 
natural operation in them; as in fascination, and the fortify 
ing of the"Tmagination, the sympathy of distant objects, the 
transmission of impressions from spirit to spirit no less than 
from body to body, and the like. 

XXXII. From the foregoing remarks, it is clear that the 
last five species of instances (the similar, singular, deviating 
and bordering instances, and those of power) should not be 
reserved for the investigation of any given nature, as the 
preceding and many of the succeeding instances must, but 
a collection of them should be made at once, in the style 
of a particular history, so that they may arrange the matter 
which enters the understanding, and correct its depraved 
habit, for it is necessarily imbued, corrupted, perverted 
and distorted by daily and habitual impressions. 

They are to be used, therefore, as a preparative, for the 
purpose of rectifying and purifying the understanding; for 
whatever withdraws it from habit, levels and planes down 
its surface for the reception of the dry and pure light of 
true notions. 

These instances, moreover, level and prepare the way 


for the operative branch, as we will mention in its proper 
place when speaking of the practical deductions. 

XXXIII. In the eleventh rank of prerogative instances 
we will place accompanying and hostile instances. These 
are such as exhibit any body or concrete, where the required 
nature is constantly found, as an inseparable companion, 
or, on the contrary, where the required nature is constantly 
avoided, and excluded from attendance, as an enemy. From 
these instances may be formed certain and universal propo 
sitions, either affirmative or negative; the subject of which 
will be the concrete body, and the predicate the required 
nature. For particular propositions are by no means fixed, 
when the required nature is found to fluctuate and change 
in the concrete, either approaching and acquired, or reced 
ing and laid aside. Hence particular propositions have no 
great prerogative, except in the case of migration, of which 
we have spoken above. Yet such particular propositions 
are of great use, when compared with the universal, as will 
be mentioned in its proper place. Nor do we require abso 
lute affirmation or negation, even in universal propositions, 
for if the exceptions be singular or rare, it is sufficient for 
our purpose. 

The use of accompanying instances is to narrow the 
affirmative of form; for as it is narrowed by the migrating 
instances, where the form must necessarily be something 
communicated or destroyed by the act of migration, so it is 
narrowed by accompanying instances, where the form must 
necessarily be something which enters into the concretion 
of the body, or, on the contrary, is repugnant to it; and 
one who is well acquainted with the constitution or forma 
tion of the body, will not be far from bringing to light the 
form of the required nature. 


For example: let the required nature be heat. Flame 
is an accompanying instance ; for in water, air, stone, metal, 
and many other substances, heat is variable, and can ap 
proach or retire; but all flame is hot, so that heat always 
accompanies the concretion of flame. We have no hostile 
instance of heat; for the senses are unacquainted with the 
interior of the earth, and there is no concretion of any 
known body which is not susceptible of heat. 

Again, let solidity be the required nature. Air is a 
hostile instance; for metals may be liquid or solid, so may 
glass ; even water may become solid by congelation, but air 
cannot become solid or lose its fluidity. 

With regard to these instances of fixed propositions, 
there are two points to be observed, which are of impor 
tance. First, that if there be no universal affirmative or 
negative, it be carefully noted as not existing. Thus, in 
heat, we have observed that there exists no universal nega 
tive, in such substances, at least, as have come to our 
knowledge. Again, if the required nature be eternity or 
incorruptibility, we have no universal affirmative within 
our sphere, for these qualities cannot be predicated of any 
bodies below the heavens, or above the interior of the earth. 
Secondly, to our general propositions as to any concrete, 
whether affirmative or negative, we should subjoin the 
concretes which appear to approach nearest to the non- 
existing substances; such as the most gentle or least- 
burning flames in heat, or gold in incorruptibility, since it 
approaches nearest to it. For they all serve to show the 
limit of existence and non-existence, and circumscribe 
forms, so that they cannot wander beyond the conditions 
of matter. 

XXXIV. In the twelfth rank of prerogative instances, 


.we will class those subjunctive instances, of which we spoke 
in the last aphorism, and which we arc also wont to call 
instances of extremity or limits; for they are not only 
serviceable when subjoined to fixed propositions, but also 
of themselves and from their own nature. They indicate 
with sufficient precision the real divisions of nature, and 
measures of things, and the "how far" nature effects or 
allows of anything, and her passage thence to something 
else. Such are gold in weight, iron in hardness, the whale 
in the size of animals, the dog in smell, the flame of gun 
powder in rapid expansion, and others of a like nature. 
Nor are we to pass over the extremes in defect, as well as 
in abundance, as spirits of wine in weight, the touchstone 
in softness, the worms upon the skin in the size of animals, 
and the like. 

XXXV. In the thirteenth rank of prerogative instances 
we will place those of alliance or union. They are such as 
mingle and unite natures held to be heterogeneous, and 
observed and marked as such in received classifications. 

These instances show that the operation and effect, which 
is considered peculiar to some one of such heterogeneous 
natures, may also be attributed to another nature styled 
heterogeneous, so as to prove that the difference of the 
natures is not real nor essential, but a mere modification 
r of a common nature. They are very serviceable, there 
fore, in elevating and carrying on the mind, from differ 
ences to genera, and in removing those phantoms and 
images of things, which meet it in disguise in concrete 

For example: let the required nature be heat. The 
classification of heat into three kinds, that of the celestial 
bodies, that of animals, and that of fire, appears to be set- 


tied and admitted; and these kinds of heat, especially one 
of them compared with the other two, are supposed to be 
different, and clearly heterogeneous in their essence and 
species, or specific nature, since the heat of the heavenly 
bodies and of animals generates and cherishes, while that 
of fire corrupts and destroys. We have an instance of 
alliance, then, in a very common experiment, that of a 
vine branch admitted into a building where there is a con 
stant fire, by which the grapes ripen a whole month sooner 
than in the air; so that fruit upon the tree can be ripened 
by fire, although this appear the peculiar effect of the 
sun. From this beginning, therefore, the understanding 
rejects all essential difference, and easily ascends to the 
investigation of the real differences between the heat of 
the sun and that of fire, by which their operation is 
rendered dissimilar, although they partake of a common 

These differences will be found to be four in number. 
1. The heat of the sun is much milder and gentler in degree 
than that of fire. 2. It is much more moist in quality, 
especially as it is transmitted to us through the air. 3. 
Which is the chief point, it is very unequal, advancing and 
increased at one time, retiring and diminished at another, 
which mainly contributes to the generation of bodies. For 
Aristotle rightly asserted, that the principal cause of gen 
eration and corruption on the surface of the earth was the 
oblique path of the sun in the zodiac, whence its heat be 
comes very unequal, partly from the alternation of night 
and day, partly from the succession of summer and winter. 
Yet must he immediately corrupt and pervert his discovery, 
by dictating to nature according to his habit, and dogmati 
cally assigning the cause of generation to the approach of 


the sun, and that of corruption to its retreat; while, in fact, 
each circumstance indifferently and not respectively con 
tributes both to generation and corruption; for unequal 
heat tends to generate and corrupt, as equable heat does 
to preserve. 4. The fourth difference between the heat of 
the sun and fire is of great consequence; namely, that the 
sun, gradually, and for a length of time, insinuates its 
effects, while those of fire (urged by the impatience of 
man) are brought to a termination in a shorter space of 
time. But if any one were to pay attention to the temper 
ing of fire, and reducing it to a more moderate and gentle 
degree (which may be done in various ways), and then were 
to sprinkle and mix a degree of humidity with it; and, 
above all, were to imitate the sun in its inequality; and, 
lastly, were patiently to suffer some delay (not such, how 
ever, as is proportioned to the effects of the sun, but more 
than men usually admit of in those of fire), he would soon 
banish the notion of any difference, and would attempt, or 
equal, or perhaps sometimes surpass the effect of the sun, 
by the heat of fire. A like instance of alliance is that of 
reviving butterflies, benumbed and nearly dead from cold, 
by the gentle warmth of fire; so that fire is no less able to 
revive animals than to ripen vegetables. We may also 
mention the celebrated invention of Fracastorius, of apply 
ing a pan considerably heated to the head in desperate cases 
of apoplexy, which clearly expands the animal spirits, when 
compressed and almost extinguished by the humors and 
obstructions of the brain, and excites them to action, as the 
fire would operate on water or air, and in the result pro 
duces life. Eggs are sometimes hatched by the heat of fire, 
an exact imitation of animal heat; and there are many in 
stances of the like nature, so that no one can doubt that the 


heat of fire, in many cases, can be modified till it resemble 
that of the heavenly bodies and of animals. 

Again, let the required natures be motion and rest. 
There appears to be a settled classification, grounded on 
the deepest philosophy, that natural bodies either revolve, 
move in a straight line, or stand still and rest. For there 
is either motion without limit, or continuance within a cer 
tain limit, or a translation toward a certain limit. The eter 
nal motion of revolution appears peculiar to the heavenly 
bodies, rest to this our globe, and the other bodies (heavy 
and light, as they are termed, that is to say, placed out of 
their natural position) are borne in a straight line to masses 
or aggregates which resemble them, the light toward the 
heaven, the heavy toward the earth; and all this is very 
fine language. 

But we have an instance of alliance in low comets, which 
revolve, though far below the heavens; and the fiction of 
Aristotle, of the comet being fixed to, or necessarily fol 
lowing some star, has been long since exploded; not only 
because it is improbable in itself, but from the evident fact 
of the discursive and irregular motion of comets through 
various parts of the heavens." 

Another instance of alliance is that of the motion of air, 
which appears to revolve from east to west within the trop 
ics, where the circles of revolution are the greatest. 

The flow and ebb of the sea would perhaps be another 
instance, if the water were once found to have a motion of 

65 Seneca was a sounder astronomer than Bacon. He ridiculed the idea of 
the motion of any heavenly bodies being irregular, and predicted that the day 
would come, when the laws which guided the revolution of these bodies would 
be proved to be identical with those which controlled the motions of the planets. 
The anticipation was realized by Newton. Ed. 


revolution, though slow and hardly perceptible, from east 
to west, subject, however, to a reaction twice a day. If 
this be so, it is clear that the motion of revolution is not 
confined to the celestial bodies, but is shared, also, by air 

and water. 

Again the supposed peculiar disposition of light bodies 
to rise is rather shaken; and here we may find an instance 
of alliance in a water bubble. For if air be placed under 
water, it rises rapidly toward the surface by that striking 
motion (as Democritus terms it) with which the descending 
water strikes the air and raises it, not by any straggle or 
effort of the air itself; and when it has reached the surface 
of the water, it is prevented from ascending any further, by 
the slight resistance it meets with in the water, which does 
not allow an immediate separation of its parts, so that the 
tendency of the air to rise must be very slight. 

Again, let the required nature be weight. It is certainly 
a received classification, that dense and solid bodies are 
borne toward the centre of the earth, and rare and light 
bodies to the circumference of the heavens, as their appro 
priate places. As far as relates to places (though these 
things have much weight in the schools), the notion of 
there being any determinate place is absurd and puerile. 
Philosophers trifle, therefore, when they tell you, that if 
the earth were perforated, heavy bodies would stop on their 
arrival at the centre. This centre would indeed be an effi 
cacious nothing, or mathematical point, could it aifect 
bodies or be sought by them, for a body is not acted upon 
except by a body. 6 * In fact, this tendency to ascend and 

&6 But see Bacon s own corollary at the end of the Instances of Divorce, 
Aphorism xxxvii. If Bacon s remark be accepted, the censure will fall upon 


descend is either in the conformation of the moving body, 
or in its harmony and sympathy with another body. But 
if any dense and solid body be found, which does not, how 
ever, tend toward the earth, the classification is at an end. 
Now, if we allow of Gilbert s opinion, that the magnetic 
power of the earth, in attracting heavy bodies, is not ex 
tended beyond the limit of its peculiar virtue (which oper 
ates always at a fixed distance and no further), 67 and this 
be proved by some instance, such an instance will be one 
of alliance in our present subject. The nearest approach 
to it is that of waterspouts, frequently seen by persons navi 
gating the Atlantic toward either of the Indies. For the 
force and mass of the water suddenly effused by water 
spouts, appears to be so considerable, that the water must 
have been collected previously, and have remained fixed 
where it was formed, until it was afterward forced down by 
some violent cause, rather than made to fall by the natural 
motion of gravity: so that it may be conjectured that a 
dense and compact mass, at a great distance from the earth, 
may be suspended as the earth itself is, and would not fall, 
unless forced down. We do not, however, affirm this as 
certain. In the meanwhile, both in this respect and many 
others, it will readily be seen how deficient we are in nat- 

Newton and the system so generally received at the present day. It is, how 
ever, unjust, as the centre of which Newton so often speaks is not a point with 
an active inherent force, but only the result of all the particular and reciprocal 
attractions of the different parts of the planet acting upon one spot. It is evi 
dent, that if all these forces were united in this centre, that the sum would 
be equal to all their partial effects. Ed. 

" Since Newton s discovery of the law of gravitation, we find that the at 
tractive force of the earth must extend to an infinite distance. Bacon himself 
alludes to the operation of this attractive force at great distances in the 
Instances of the Bod, Aphorism xlv. 


ural history, since we are forced to have recourse to sup 
positions for examples, instead of ascertained instances. 

Again, let the required nature be the discursive power 
of the mind. The classification of human reason and ani 
mal instinct appears to be perfectly correct. Yet there are 
some instances of the actions of brutes which seem to show 
that they, too, can syllogize. Thus it is related, that a 
crow, which had nearly perished from thirst in a great 
drought, saw some water in the hollow trunk of a tree, but 
as it was too narrow for him to get into it, he continued to 
throw in pebbles, which made the water rise till he could 
drink; and it afterward became a proverb. 

Again, let the required nature be vision. The classifi 
cation appears real and certain, which considers light as that 
which is originally visible, and confers the power of seeing; 
and color, as being secondarily visible, and not capable of 
being seen without light, so as to appear a mere image or 
modification of light. Yet there are instances of alliance in 
each respect; as in snow when in great quantities, and in 
the flame of sulphur; the one being a color originally and 
in itself light, the other a light verging toward color. 68 

XXXVI. In the fourteenth rank of prerogative in 
stances, we will place the instances of the cross, borrowing 
our metaphor from the crosses erected where two roads 
meet, to point out the different directions. We are wont 
also to call them decisive and judicial instances, and in 
some cases instances of the oracle and of command. Their 
nature is as follows: When in investigating any nature the 
understanding is, as it were, balanced, and uncertain to 
which of two or more natures the cause of the required 

68 Snow reflects light, but is not a source of light. 


nature should be assigned, on account of the frequent and 
usual concurrence of several natures, the instances of the 
cross show that the union of one nature with the required 
nature is firm and indissoluble, while that of the other is 
unsteady and separable; by which means the question is 
decided, and the first is received as the cause, while the 
other is dismissed and rejected. Such instances, therefore, 
afford great light, and are of great weight, so that the course 
of interpretation sometimes terminates, and is completed in 
them. Sometimes, however, they are found among the 
instances already observed, but they are generally new, 
being expressly and purposely sought for and applied, and 
brought to light only by attentive and active diligence. 

For example: let the required nature be the flow and 
ebb of the sea, which is repeated twice a day, at intervals 
of six hours between each advance and retreat, with some 
little difference, agreeing with the motion of the moon. We 
have here the following crossways: 

This motion must be occasioned either by the advancing 
and the retiring of the sea, like water shaken in a basin, 
which leaves one side while it washes the other; or by the ris 
ing of the sea from the bottom, and its again subsiding, like 
boiling water. But a doubt arises, to which of these causes 
we should assign the flow and ebb. If the first assertion be 
admitted, it follows, that when there is a flood on one side, 
there must at the same time be an ebb on another, and the 
question therefore is reduced to this. Now Acosta, and 
some others, after a diligent inquiry, have observed that 
the flood tide takes place on the coast of Florida, and the 
opposite coasts of Spain and Africa, at the same time, as 
does also the ebb; and that there is not, on the contrary, a 

flood tide at Florida when there is an ebb on the coasts of 

SCIENCE Vol. 229 


Spain and Africa. Y"et if one consider the subject atten 
tively, this does not prove the necessity of a rising motion, 
nor refute the notion of a progressive motion. For the 
motion may be progressive, and yet inundate the opposite 
shores of a channel at the same time; as if the waters be 
forced and driven together from some other quarter, for 
instance, which takes place in rivers, for they flow and ebb 
toward each bank at the same time, yet their motion is 
clearly progressive, being that of the waters from the sea 
entering their mouths. So it may happen, that the waters 
coming in a vast body from the eastern Indian Ocean are 
driven together, and forced into the channel of the Atlan 
tic, and therefore inundate both coasts at once. We must 
inquire, therefore, if there be any other channel by which 
the waters can at the same time sink and ebb; and the 
Southern Ocean at once suggests itself, which is not less 
than the Atlantic, but rather broader and more extensive 
than is requisite for this effect. 

We at length arrive, then, at an instance of the cross, 
which is this. If it be positively discovered, that when the 
flood sets in toward the opposite coasts of Florida and Spain 
in the Atlantic, there is at the same time a flood tide on the 
coasts of Peru and the back part of China, in the Southern 
Ocean, then assuredly, from this decisive instance, we must 
reject the assertion, that the flood and ebb of the sea, about 
which we inquire, takes place by progressive motion; for 
no other sea or place is left where there can be an ebb. But 
this may most easily be learned, by inquiring of the inhab 
itants of Panama and Lima (where the two oceans are sepa 
rated by a narrow isthmus), whether the ilood and ebb takes 
place on the opposite sides of the isthmus at the same time, 
or the reverse. This decision or rejection appears certain, 


if it be granted that the earth is fixed; bat if the earth 
revolves, it may perhaps happen, that from the unequal 
revolution (as regards velocity) of the earth and the waters 
of the sea, there may be a violent forcing of the waters into 
a mass, forming the flood, and a subsequent relaxation of 
them (when they can no longer bear the accumulation), 
forming the ebb. A separate inquiry must be made into 
this. Even with this hypothesis, however, it remains 
equally true, that there must be an ebb somewhere, at the 
same time that there is a flood in another quarter. 

Again, let the required nature be the latter of the two 
motions we have supposed; namely, that of a rising and 
subsiding motion, if it should happen that upon diligent 
examination the progressive motion be rejected. We have, 
then, three ways before us, with regard to this nature. The 
motion, by which the waters raise themselves, and again 
fall back, in the floods and ebbs, without the addition of 
any other water rolled toward them, must take place in one 
of the three following ways: Either the supply of water 
emanates from the interior of the earth, and returns back 
again; or there is really no greater quantity of water, but 
the same water (without any augmentation of its quantity) 
is extended or rarefied, so as to occupy a greater space and 
dimension, and again contracts itself; or there is neither an 
additional supply nor any extension, but the same waters 
(with regard to quantity, density, or rarity) raise themselves 
and fall from sympathy, by some magnetic power attracting 
and calling them up, as it were, from above. Let us then 
(passing over the first two motions) reduce the investiga 
tion to the last, and inquire if there be any such elevation 
of the water by sympathy or a magnetic force; and it is evi 
dent, in the first place, that the whole mass of water being 


placed in the trench or cavity of the sea, cannot be raised 
at once, because there would not be enough to cover the 
bottom, so that if there be any tendency of this kind in the 
water to raise itself, yet it would be interrupted and checked 
by the cohesion of things, or (as the common expression is) 
that there may be no vacuum. The water, therefore, must 
rise on one side, and for that reason be diminished and ebb 
on another. But it will again necessarily follow that the 
magnetic power not being able to operate on the whole, 
operates most intensely on the centre, so as to raise the 
waters there, which, when thus raised successively, desert 
and abandon the sides. 59 

We at length arrive, then, at an instance of the cross, 
which is this: if it be found that during the ebb the surface 
of the waters at sea is more curved and round, from the 
waters rising in the middle, and sinking at the sides or 
coast, and if, during a flood, it be more even and level, 
from the waters returning to their former position, then 
assuredly, by this decisive instance, the raising of them by 
a magnetic force can be admitted; if otherwise, it must be 
entirely rejected. It is not difficult to make the experi 
ment (by sounding in straits), whether the sea be deeper 
toward the middle in ebbs, than in floods. But it must be 
observed, if this be the case, that (contrary to common 
opinion) the waters rise in ebbs, and only return to their 
former position in floods, so as to bathe and inundate the 

Again, let the required nature be the spontaneous motion 
of revolution, and particularly, whether the diurnal motion, 
by which the sun and stars appear to us to rise and set, be 

69 Bacon s sagacity here foreshadows Newton s theory of the tides. 


a real motion of revolution in the heavenly bodies, or only 
apparent in them, and real in the earth. There may be an 
instance of the cross of the following nature. If there be 
discovered any motion in the ocean from east to west, 
though very languid and weak, and if the same motion be 
discovered rather more swift in the air (particularly within 
the tropics, where it is more perceptible from the circles 
being greater). If it be discovered also in the low comets, 
and be already quick and powerful in them; if it be found 
also in the planets, but so tempered and regulated as to be 
slower in those nearest the earth, and quicker in those at 
the greatest distance, being quickest of all in the heavens, 
then the diurnal motion should, certainly be considered as 
real in the heavens, and that of the earth must be rejected; 
for it will be evident that the motion from east to west is 
part of the system of the world and universal; since it 
is most rapid in the height of the heavens, and gradually 
grows weaker, till it stops and is extinguished in rest at 
the earth. 

Again, let the required nature be that other motion of 
revolution, so celebrated among astronomers, which is con 
trary to the diurnal, namely, from west to east and which 
the ancient astronomers assign to the planets, and even to 
the starry sphere, but Copernicus ^.nd his .followers to the 
earth also and let it be examined whether any such motion 
be found in nature, or it be rather a fiction and hypothesis 
for abridging and facilitating calculation, and for promoting 
that fine notion of effecting the heavenly motions by perfect 
circles; for there is nothing which proves such a motion in 
heavenly objects to be true and real, either in a planet s not 
returning in its diurnal motion to the same point of the 
starry sphere, or in the pole of the zodiac being different 


from that of the world, which two circumstances have occa 
sioned this notion. For the first phenomenon is well ac 
counted for by the spheres overtaking or falling behind 
each other, and the second by spiral lines; so that the in 
accuracy of the return and declination to the tropics may 
be rather modifications of the one. diurnal motion than con 
trary motions, or about different poles. And it is most 
certain, if we consider ourselves for a moment as part of 
the vulgar (setting aside the fictions of astronomers and the 
school, who are wont undeservedly to attack the senses in 
many respects, and to affect obscurity), that the apparent 
motion is such as we have said, a model of which we have 
sometimes caused to be represented by wires in a sort of a 

We may take the following instances of the cross upon 
this subject. If it be found in any history worthy of credit, 
that there has existed any comet, high or low, which has 
not revolved in manifest harmony (however irregularly) with 
the diurnal motion, then we may decide so far as to allow 
such a motion to be possible in nature. But if nothing of 
the sort be found, it must be suspected, and recourse must 
be had to other instances of the cross. 

Again, let the required nature be weight or gravity. 
Heavy and ponderous bodies must, either of their own 
nature, tend toward the centre of the earth by their peculiar 
formation, or must be attracted and hurried by the corporeal 
mass of the earth itself, as being an assemblage of similar 
bodies, and be drawn to it by sympathy. But if the latter 
be the cause, it follows that the nearer bodies approach to 
the earth, the more powerfully and rapidly they must be 
borne toward it, and the further they are distant, the more 
faintly and slowly (as is the case in magnetic attractions), 


and that this must happen within a given distance; so that 
if they be separated at such a distance from the earth that 
the power of the earth cannot act upon them, they will 
remain suspended like the earth, and not fall at all. 60 

The following instance of the cross may be adopted. 
Take a clock moved by leaden weights, 81 and another by 

60 The error in the text arose from Bacon s impression that the earth was 
immovable. It is evident, since gravitation acts at an infinite distance, that no 
such point could be found; and even supposing the impossible point of equilib 
rium discovered, the body could not maintain its position an instant, but would 
be hurried, at the first movement of the heavenly bodies, in the direction of the 
dominant gravitating power. Ed. 

61 Fly clocks are referred to in the text, not pendulum clocks, which were 
not known in England till 1662. The former, though clumsy and rude in their 
construction, still embodied sound mechanical principles. The comparison of 
the effect of a spring with that of a weight in producing certain motions in cer 
tain times on altitudes and in mines, has recently been tried by Professors Airy 
and Whewell in Dalcoath mine, by means of a pendulum, which is only a 
weight moved by gravity, and a chronometer balance moved and regulated 
by a spring. In his thirty-seventh Aphorism, Bacon also speaks of gravity 
as an incorporeal power, acting at a distance, and requiring time for its trans 
mission ; a consideration which occurred at a later period to Laplace in one 
of his most delicate investigations. 

Crucial instances, as Herschel remarks, afford the readiest and securest 
means of eliminating extraneous causes, and deciding between the claims of 
rival hypotheses ; especially when these, running parallel to each other, in the 
explanation of great classes of phenomena, at length come to be placed at issue 
upon a single fact. A curious example is given by M. Fresnel, as decisive in 
his mind of the question between the two great theories on the nature of light, 
which, since the time of Newton and Huyghens, have divided philosophers. 
"When two very clean glasses are laid one on the other, if they be not perfectly 
flat, but one or both, in an almost imperceptible degree, convex or prominent, 
beautiful and vivid colors will be seen between them ; and if these be viewed 
through a red glass, their appearance will be that of alternate dark and bright 
stripes. These stripes are formed between the two surfaces in apparent con 
tact, and being applicable on both theories, are appealed to by their respective 
supporters as strong confirmatory facts; but there is a difference in one circum 
stance, according as one or other theory is employed to explain them. In the 
case of the Huyghenian theory, the intervals between the bright stripes ought 
to appear absolutely black, when a prism is used for the upper glass, in the 
other half bright. This curious case of difference was tried, as soon as the op- 


a spring, and let them be set well together, so that one be 
neither quicker nor slower than the other; then let the clock 
moved by weights be placed on the top of a very high 
church, and the other be kept below, and let it be well 
observed, if the former move slower than it did, from the 
diminished power of the weights. Let the same experiment 
be made at the bottom of mines worked to a considerable 
depth, in order to see whether the clock move more quickly 
from the increased power of the weights. But if this power 
be found to diminish at a height, and to increase in subter 
raneous places, the attraction of the corporeal mass of the 
earth may be taken as the cause of weight. 

Again, let the required nature be the polarity of the 
steel needle when touched with the magnet. We have these 
two ways with regard to this nature Either the touch of 
the magnet must communicate polarity to the steel toward 
the north and south, or else it may only excite and prepare 
it, while the actual motion is occasioned by the presence 
of the earth, which Gilbert considers to be the case, and 
endeavors to prove with so much labor. The particulars 
he has inquired into with such ingenious zeal amount to 
this 1. An iron bolt placed for a long time toward the 
north and south acquires polarity from this habit, without 
the touch of the magnet, as if the earth itself operating but 
weakly from its distance (for the surface or outer crust of 
the earth does not, in Ins opinion, possess the magnetic 
power), yet, by long continued motion, could supply the 
plaee of the magnet, excite the iron, and convert and change 
it when excited. 2. Iron, at a red or white heat, when 

posing consequences of the two theories were noted by M. Fresnel, and the 
result is stated by him to be decisive in favor of that theory which makes light 
to consist in the vibrations of an elastic medium. Ed. 


quenched in a direction parallel to the north and south, 
also acquires polarity without the touch of the magnet, as 
if the parts of iron being put in motion by ignition, and 
afterward recovering themselves, were, at the moment of 
being quenched, more susceptible and sensitive of the power 
emanating from the earth, than at other times, and therefore 
as it were excited. But these points, though well observed, 
do not completely prove his assertion. 

An instance of the cross on this point might be as fol 
lows: Let a small magnetic globe be taken, and its poles 
marked, and placed toward the east and west, not toward 
the north and south, and let it continue thus. Then let an 
untouched needle be placed over it, and suffered to remain 
so for six or seven days. Now, the needle (for this is not 
disputed), while it remains over the magnet, will leave the 
poles of the world and turn to those of the magnet, and 
therefore, as long as it remains in the above position, will 
turn to the east and west. But if the needle, when removed 
from the magnet and placed upon a pivot, be found imme 
diately to turn to the north and south, or even by degrees 
to return thither, then the presence of the earth must be 
considered as the cause, but if it remains turned as at first, 
toward the east and west, or lose its polarity, then that cause 
must be suspected, and further inquiry made. 

Again, let the required nature be the corporeal substance 
of the moon, whether it be rare, fiery, and aerial (as most 
of the ancient philosophers have thought), or solid and 
dense (as Gilbert and many of the moderns, with some of 
the ancients, hold). 63 The reasons for this latter opinion 

68 Bacon plainly, from this passage, was inclined to believe that the moon, 
like the comets, was nothing more than illuminated vapor. The Newtonian 


are grounded chiefly upon this, that the moon reflects the 
sun s rays, and that light does not appear capable of being 
reflected except by solids. The instances of the cross will 
therefore (if any) be such as to exhibit reflection by a rare 
body, such as flame, if it be but sufficietly dense. Now, 
certainly, one of the reasons of twilight is the reflection 89 
of the rays of the sun by the upper part of the atmosphere. 
We see the sun s rays also reflected on fine evenings by 
streaks of moist clouds, with a splendor not less, but per 
haps more bright and glorious than that reflected from the 
body of the moon, and yet it is not clear that those clouds 
have formed into a dense body of water. We see, also, that 
the dark air behind the windows at night reflects the light 
of a candle in the same manner as a dense body would do. 84 
The experiment should also be made of causing the sun s 
rays to fall through a hole upon some dark and bluish 
flame. The unconfined rays of the sun, when falling on 
faint flames, do certainly appear to deaden them, and render 
them more like white smoke than flames. These are the 
only instances which occur at present of the nature of those 
of the cross, and better perhaps can be found. But it must 
always be observed that reflection is not to be expected 
from flame, unless it be of some depth, for otherwise it be- 

l;t\v, however, lias not only established its solidity, but its density and weight. 
A snllicient proof of the former is afforded by the attraction of the sea, and the 
moon s motion round the earth. Ed. 

6X Rather the refraction; the sky or air, however, r<j!is the blue rays 
of litrht. 

64 The polished surface of the frlass causes the reflection in this case, and 
not the air; and a hat or other black surface put behind the window in the 
daytime will enable the elass to rolled distinctly for the same reason, namely, 
that the reflected rays are not mixed and confused with those transmitted from 
the other wide of the window. 


comes nearly transparent. This at least may be considered 
certain, that light is always either received and transmitted 
or reflected by an even surface. 

Again, let the required nature be the motion of projec 
tiles (such as darts, arrows, and balls) through the air. The 
school, in its usual manner, treats this very carelessly, con 
sidering it enough to distinguish it by the name of violent 
motion, from that which they term natural, and as far as 
regards the first percussion or impulse, satisfies itself by its 
axiom, that two bodies cannot exist in one place, or there 
would be a penetration of dimensions. With regard to this 
nature we have these two crossways The motion must 
arise either from the air carrying the projected body, and 
collecting behind it, like a stream behind boats, or the wind 
behind straws; or from the parts of the body itself not sup 
porting the impression, but pushing themselves forward in 
succession to ease it. Fracastorius, and nearly all those 
who have entered into any refined inquiry upon the sub 
ject, adopt the first. Nor can it be doubted that the air 
has some effect, yet the other motion is without doubt real, 
as is clear from a vast number of experiments. Among 
others we may take this instance of the cross, namely, that 
a thin plate or wire of iron rather stiff, or even a reed or 
pen split in two, when drawn up and bent between the 
finger and thumb, will leap forward; for it is clear that 
this cannot be attributed to the air s being collected behind 
the body, because the source of motion is in the centre of 
the plate or pen, and not in its extremities. 

Again, let the required nature be the rapid and power 
ful motion of the explosion of gunpowder, by which such 
vast masses are upheaved, and such weights discharged as 
we observe in large mines and mortars, there are two cross- 


ways before us with regard to this nature. This motion is 
excited either by the mere effort of the body expanding 
itself when inflamed, or by the assisting effort of the crude 
spirit, which escapes rapidly from fire, and bursts violently 
from the surrounding flame as from a prison. The school, 
however, and common opinion only consider the first effort; 
for men think that they are great philosophers when they 
assert that flame, from the form of the element, is endowed 
with a kind of necessity of occupying a greater space than 
the same body had occupied when in the form of powder, 
and that thence proceeds the motion in question. In the 
meantime they do riot observe, that although this may be 
true, on the supposition of flame being generated, yet the 
generation may be impeded by a weight of sufficient force 
to compress and suffocate it, so that no such necessity exists 
as they assert. They are right, indeed, in imagining that 
the expansion and the consequent emission or removal of 
the opposing body, is necessary if flame be once generated, 
but such a necessity is avoided if the solid opposing mass 
suppress the flame before it be generated; and we in fact 
see that flame, especially at the moment of its generation, 
is rnild and gentle, and requires a hollow space where it 
can play and try its force. The great violence of the effect, 
therefore, cannot be attributed to this cause; but the truth 
is, that the generation of these exploding flames and fiery 
blasts arises from the conflict of two bodies of a decidedly 
opposite nature the one very inflammable, as is the sul 
phur, the other having an antipathy to flame, namely, the 
crude spirit of the nitre; so that an extraordinary conflict 
takes place while the sulphur is becoming inflamed as far 
as it can (for the third body, the willow charcoal, merely 
incorporates and conveniently unites the two others), and 


the spirit of nitre is escaping, as far also as it can, and at 
the same time expanding itself (for air, and all crude sub 
stances, and water are expanded by heat), fanning thus, 
in every direction, the flame of the sulphur by its escape 
and violence, just as if by invisible bellows. 

Two kinds of instances of the cross might here be used 
the one of very inflammable substances, such as sulphur 
and camphor, naphtha and the like, and their compounds, 
which take fire more readily and easily than gunpowder if 
left to themselves (and this shows that the effort to catch 
fire does not of itself produce such a prodigious effect); the 
other of substances which avoid and repel flame, such as all 
salts; for we see that when they are cast into the fire, the 
aqueous spirit escapes with a crackling noise before flame 
is produced, which also happens in a less degree in stiff 
ler.ves, from the escape of the aqueous part Before the oily 
part has caught fire. This is more particularly observed in 
quicksilver, which is not improperly called mineral water, 
and which, without any inflammation, nearly equals the 
force of gunpowder by simple explosion and expansion, 
and is said, when mixed with gunpowder, to increase its 

Again, let the required nature be the transitory nature 
of flame and its momentaneous extinction; for to us the 
nature of flame does not appear to be fixed or settled, but 
to be generated from moment to moment, and to be every 
instant extinguished; it being clear that those flames which 
continue and last, do not owe their continuance to the same 
mass of flame, but to a continued succession of new flame 
regularly generated, and that the same identical flame does 
not continue. This is easily shown by removing the food 
or source of the flame, when it at once goes out. We 


have the two following cross ways with regard to this 
nature : 

This momentary nature either arises from the cessation 
of the cause which first produced it, as in light, sounds, and 
violent motions, as they are termed, or flame may be capa 
ble, by its own nature, of duration, but is subjected to some 
violence from the contrary natures which surround it, and 
is destroyed. 

AVe may therefore adopt the following instance of the 
cross. We see to what a height the flames rise in great 
conflagrations; for as the base of the flame becomes more 
extensive, its vertex is more lofty. It appears, then, that 
the commencement of the extinction takes place at the 
sides, where the flame is compressed by the air, and is ill 
at ease; but the centre of the flame, which is untouched by 
the air and surrounded by flame, continues the same, and 
is not extinguished until compressed by degrees by the air 
attacking it from the sides. All flame, therefore, is pyra 
midal, having its base near the source, and its vertex 
pointed from its being resisted by the air, and not sup 
plied from the source. On the contrary, the smoke, which 
is narrow at the base, expands in its ascent, and resembles 
an inverted pyramid, because the air admits the smoke, but 
compresses the flame; for let no one dream that the lighted 
flame is air, since they are clearly heterogeneous. 

The instance of the cross will be more accurate, if the 
experiment can be made by flames of different colors. 
Take, therefore, a small metal sconce, and place a lighted 
taper in it, then put it in a basin, and pour a small quantity 
of spirits oi wine round the sconce, so as not to reach its 
edge, and light the spirit. Now the flame of the spirit will 
be blue, and that of the taper yellow; observe, therefore, 


whether the latter (which can easily be distinguished from 
the former by its color, for flames do not mix immediately, 
as liquids do) continue pyramidal, or tend more to a globu 
lar figure, since there is nothing to destroy or compress it. 
If the latter result be observed, it must be considered as 
settled, that flame continues positively the same, while in 
closed within another flame, and not exposed to the resist 
ing force of the air. 

Let this suffice for the instances of the cross. We have 
dwelt the longer upon them in order gradually to teach and 
accustom mankind to judge of nature by these instances, and 
enlightening experiments, and not by probable reasons." 

65 These instances, which Bacon seems to consider as a great discovery, 
are nothing more than disjunctive propositions combined with dilemmas. In 
proposing to explain an effect, we commence with the enumeration of the dif 
ferent causes which seem connected with its production ; then with the aid of 
one or more dilemmas, we eliminate each of the phenomena accidental to its 
composition, and conclude with attributing the effect to the residue. For in 
stance, a certain phenomenon (a) is produced either by phenomenon (B) or phe 
nomenon (c); but c cannot be the cause of a, for it is found in D, E, p, neither 
of which are connected with a. Then the true cause of phenomenon (a) must 
be phenomenon (B). 

This species of reasoning is liable to several paralogisms, against which 
Bacon has not guarded his readers, from the very fact that he stumbled into 
them unwittingly himself. The two principal ones are false exclusions and 
defective enumerations. Bacon, in his survey of the causes which are able 
to concur in producing the phenomena of the tides, takes no account of the 
periodic melting of the Polar ice, or the expansion of water by the solar heat; 
nor does he fare better in his exclusions. For the attraction of the planets and 
the progression and retrograde motion communicated by the earth s diurnal revo 
lution, can plainly affect the sea together, and have a simultaneous influence 
on its surface. 

Bacon is hardly just or consistent in his censure of Ramus; the end of 
whose dichotomy was only to render reasoning by dilemma, and crucial 
instances, more certain in their results, by reducing the divisions which 
composed their parts to two sets of contradictory propositions. The affirm 
ative or negative of one would then necessarily have led to the acceptance 
or rejection of the other. Ed. 


XXXVII. We will treat of the instances of divorce as 

the fifteenth of our prerogative instances. They indicate 
the separation of natures of the most common occurrence. 
They diil er, however, from those subjoined to the accom 
panying instances; for the instances of divorce point out 
the separation of a particular nature from some concrete 
substance with which it is usually found in conjunction, 
while the hostile instances point out the total separation of 
one nature from another. They diiler, also, from the in 
stances of the cross, because they decide nothing, but only 
inform us that the one nature is capable of being separated 
from the other. They are of use in exposing false forms, 
and dissipating hasty theories derived from obvious facts; 
so that they add ballast and weight, as it were, to the 

For instance, let the acquired natures be those four 
which Telesius terms associates, and of the same family, 
namely, heat, light, rarity, and mobility, or promptitude 
to motion ; yet many instances of divorce can be discovered 
between them. Air is rare and easily moved, but neither 
hot nor light; the moon is light but not hot; boiling water 
is warm but not light; the motion of the needle in the com 
pass is swift and active, and yet its substance is cold, dense, 
and opaque; and there are many similar examples. 

Again, let the required natures be corporeal nature and 
natural action. The latter appears incapable of subsisting 
without some body, yet may we, perhaps, even here find an 
instance of divorce, as in the magnetic motion, which draws 
the iron to the magnet, and heavy bodies to the globe of the 
earth ; to which we may add other actions which operate at 
a distance. For such action takes place in time, by distinct 
moments, not in an instant; and in space, by regular de- 


grees and distances. There is, therefore, some one moment 
of time and some interval of space, in which the power or 
action is suspended between the two bodies creating the mo 
tion. Our consideration, then, is reduced to this, whether 
the bodies which are the extremes of motion prepare or alter 
the intermediate bodies, so that the power advances from 
one extreme to the other by succession and actual contact, 
and in the meantime exists in some intermediate body; or 
whether there exists in reality nothing but the bodies, the 
power, and the space? In the case of the rays of light, 
sounds, and heat, and some other objects which operate at 
a distance, it is indeed probable that the intermediate 
bodies are prepared and altered, the more so because a 
qualified medium is required for their operation. But the 
magnetic or attractive power admits of an indifferent me 
dium, and it is not impeded in any. But if that power or 
action is independent of the intermediate body, it follows 
that it is a natural power or action existing in a certain time 
and space without any body, since it exists neither in the 
extreme nor in the intermediate bodies. Hence the mag 
netic action may be taken as an instance of divorce of cor 
poreal nature and natural action; to which we may add, as 
a corollary and an advantage not to be neglected, that it 
may be taken as a proof of essence and substance being 
separate and incorporeal, even by those who philosophize 
according to the senses. For if natural power and action 
emanating from a body can exist at any time and place 
entirely without any body, it is nearly a proof that it can 
also emanate originally from an incorporeal substance; for 
a corporeal nature appears to be no less necessary for sup 
porting and conveying, than for exciting or generating nat 
ural action. 


XXXVIII. Next follow five classes of instances which 
we are wont to call by the general term of instances of the 
lamp, or of immediate information. They are such as assist 
the senses; for since every interpretation of nature sets out 
from the senses, and leads, by a regular fixed and well- 
established road, from the perceptions of the senses to those 
of the understanding (which are true notions and axioms), 
it necessarily follows, that in proportion as the representa 
tives or mimsterings of the senses are more abundant and 
accurate, everything else must be more easy and successful. 

The first of these five sets of instances of the lamp, 
strengthen, enlarge, and correct the immediate operations 
of the senses; the second reduce to the sphere of the senses 
such matters as are beyond it; the third indicate the con 
tinued process or series of such things and motions, as for 
the most part are only observed in their termination, or in 
periods; the fourth supply the absolute wants of the senses; 
the fifth excite their attention and observation, and at the 
same time limit the subtilty of things. We will now pro 
ceed to speak of them singly. 

XXXIX. In the sixteenth rank, then, of prerogative 
instances, we will place the instances of the door or gate, 
by which name we designate such as assist the immediate 
action of the senses. It is obvious, that sight holds the 
first rank among the senses, with regard to information, 
for which reason we must seek principally helps for that 
sense. These helps appear to be threefold, either to enable 
it to perceive objects not naturally seen, or to see them from 
a greater distance, or to see them more accurately and dis 

We have an example of the first (not to speak of spec 
tacles and the like, which only correct and remove the in- 


firmity of a deficient sight, and therefore give no further 
information) in the lately invented microscopes, which ex 
hibit the latent and invisible minutiae of substances, and 
their hidden formation and motion, by wonderfully in 
creasing their apparent magnitude. By their assistance we 
behold with astonishment the accurate form and outline 
of a flea, moss, and animalcule, as well as their previously 
invisible color and motion. It is said, also, that an ap 
parently straight line, drawn with a pen or pencil, is dis 
covered by such a microscope to be very uneven and curved, 
because neither the motion of the hand, when assisted by 
a ruler, nor the impression of ink or color, are really regu 
lar, although the irregularities are so minute as not to be 
perceptible without the assistance of the microscope. Men 
have (as is usual in new and wonderful discoveries) added 
a superstitious remark, that the microscope sheds a lustre 
on the works of nature, and dishonor on those of art, which 
only means that the tissue of nature is much more delicate 
than that of art. For the microscope is only of use for 
minute objects, and Democritus, perhaps, if he had seen 
it, would have exulted in the thought of a means being 
discovered for seeing his atom, which he affirmed to be 
entirely invisible. But the inadequacy of these micro 
scopes, for the observation of any but the most minute 
bodies, and even of those if parts of a larger body, destroys 
their utility; for if the invention could be extended to 
greater bodies, or the minute parts of greater bodies, so 
that a piece of cloth would appear like a net, and the 
latent minutiae and irregularities of gems, liquids, urine, 
blood, wounds, and many other things could be rendered 
visible, the greatest advantage would, without doubt, be 


We have an instance of the second kind in the telescope, 
discovered by the wonderful exertions of Galileo; by the 
assistance of which a nearer intercourse may be opened (as 
by boats or vessels) between ourselves and the heavenly 
objects. For by its aid we are assured that the Milky Way 
is but a knot or constellation of small stars, clearly denned 
and separate, which the ancients only conjectured to be the 
case; whence it appears to be capable of demonstration, that 
the spaces of the planetary orbits (as they are termed) are 
not quite destitute of other stars, but that the heaven begins 
to glitter with stars before we arrive at the starry sphere, 
although they may be too small to be visible without the 
telescope. By the telescope, also, we can behold the revolu 
tions of smaller stars round Jupiter, whence it may be con 
jectured that there are several centres of motion among the 
stars. By its assistance, also, the irregularity of light and 
shade on the moon s surface is more clearly observed and 
determined, so as to allow of a sort of selenography. 66 By 
the telescope we see the spots in the sun, and other similar 
phenomena; all of which are most noble discoveries, as far 
as credit can be safely given to demonstrations of this 
nature, which are on this account very suspicious, namely, 
that experiment stops at these few, and nothing further has 
yet been discovered by the same method, among objects 
equally worthy of consideration. 

We have instances of the third kind in measuring-rods, 
astrolabes, and the like, which do not enlarge, but correct 
and jruide the sight. If there be other instances which assist 

66 Pere Slienicr first, pointed out the spots on the sun s disk, and by the 
marks which they afforded him, computed its revolution to be performed in 
twenty-five days and some hours. Ed. 


the other senses in their immediate and individual action, 
yet if they add nothing further to their information they 
are not apposite to our present purpose, and we have there 
fore said nothing of them. 

XL. In the seventeenth rank of prerogative instances 
we will place citing instances (to borrow a term from the 
tribunals), because they cite those things to appear, which 
have not yet appeared. We are wont also to call them in 
voking instances, and their property is that of reducing to 
the sphere of the senses objects which do not immediately 
fall within it. 

Objects escape the senses either from their distance, or 
the intervention of other bodies, or because they are not 
calculated to make an impression upon the senses, or be 
cause they are not in sufficient quantity to strike the senses, 
or because there is not sufficient time for their acting upon 
the senses, or because the impression is too violent, or 
because the senses are previously filled and possessed by 
the object, so as to leave no room for any new motion. 
These remarks apply principally to sight, and next to 
touch, which two senses act extensively in giving informa 
tion, and that too upon general objects, while the remaining 
three inform us only, as it were, by their immediate action, 
and as to specific objects. 

There can be no reduction to the sphere of the senses 
in the first case, unless in the place of the object, which 
cannot be perceived on account of the distance, there be 
added or substituted some other object, which can excite 
and strike the sense from a greater distance, as in the com 
munication of intelligence by fires, bells, and the like. 

In the second case we effect this reduction by rendering 
those things which are concealed by the interposition of 


other bodies, and which cannot easily be laid open, evident 
to the senses by means of that which lies at the surface, 
or proceeds from the interior; thus the state of the body 
is judged of by the pulse, urine, etc. 

The third and fourth cases rpply to many subjects, and 
the reduction to the sphere of the senses must be obtained 
from every quarter in the investigation of things. There 
are many examples. It is obvious that air, and spirit, and 
the like, whose whole substance is extremely rare and deli 
cate, can neither be seen nor touched a reduction, there 
fore, to the senses becomes necessary in every investigation 
relating to such bodies. 

Let the required nature, therefore, be the action and 
motion of the spirit inclosed in tangible bodies; for every 
tangible body with which we are acquainted contains an 
invisible and intangible spirit, over which it is drawn, and 
which it seems to clothe. This spirit being emitted from 
a tangible substance, leaves the body contracted and dry; 
when retained, it softens and melts it; when neither wholly 
emitted nor retained, it models it, endows it with limbs, 
assimilates, manifests, organizes it, and the like. All these 
points are reduced to the sphere of the senses by manifest 

For in every tangible and inanimate body the inclosed 
spirit at first increases, and as it were feeds on the tangible 
parts which are most open and prepared for it; and when 
it has digested and modified them, and turned them into 
spirit, it escapes with them. This formation and increase 
of spirit is rendered sensible by the diminution of weight; 
for in every desiccation something is lost in quantity, not 
only of the spirit previously existing in the body, but of 
the body itself, which was previously tangible, and has 


been recently changed, for the spirit itself has no weight. 
The departure or emission of spirit is rendered sensible in 
the rust of metals, and other putrefactions of a like nature, 
which stop before they arrive at the rudiments of life, which 
belong to the third species of process." In compact bodies 
the spirit does not find pores and passages for its escape, 
and is therefore obliged to force out, and drive before it, 
the tangible parts also, which consequently protrude, whence 
arises rust and the like. The contraction of the tangible 
parts, occasioned by the emission of part of the spirit 
(whence arises desiccation), is rendered sensible by the in 
creased hardness of the substance, and still more by the 
fissures, contractions, shrivelling, and folds of the bodies 
thus produced. For the parts of wood split and contract, 
skins become shrivelled, and not only that, but, if the 
spirit be emitted suddenly by the heat of the fire, be 
come so hastily contracted as to twist and roll them 
selves up. 

On the contrary, when the spirit is retained, and yet ex 
panded and excited by heat or the like (which happens in 
solid and tenacious bodies), then the bodies are softened, 
as in hot iron; or flow, as in metals; or melt, as in gums, 
wax, and the like. The contrary effects of heat, therefore 
(hardening some substances and melting others), are easily 
reconciled, 68 because the spirit is emitted in the former, and 

67 Rust is now well known to be a chemical combination of oxygen with 
the metal, and the metal when rusty acquires additional weight. His theory 
as to the generation of animals, is deduced from the erroneous notion of the 
possibility of spontaneous generation (as it was termed). See the next para 
graph but one. 

68 "Limus ut hie durescit, et haec ut cera liquescit 
Uno eodemque igni." Virg. Eel. yiii. 


agitated and retained in the latter; the latter action is that 
of heat and the spirit, the former that of the tangible parts 
themselves, after the spirit s emission. 

But when the spirit is neither entirely retained nor 
emitted, but only strives and exercises itself, within its 
limits, and meets with tangible parts, which obey and 
readily follow it wherever it leads them, then follows the 
formation of an organic body, and of limbs, and the other 
vital actions of vegetables and animals. These are rendered 
sensible chiefly by diligent observation of the first begin 
nings, and rudiments or effects of life in animalculte sprung 
from putrefaction, as in the eggs of ants, worms, mosses, 
frogs after rain, etc. Both a mild heat and a pliant sub 
stance, however, are necessary for the production of life, 
in order that the spirit may neither hastily escape, nor be 
restrained by the obstinacy of the parts, so as not to be able 
to bend and model them like wax. 

Again, the difference of spirit which is important and 
of effect in many points (as unconnected spirit, branching 
spirit, branching and cellular spirit, the first of which is 
that of all inanimate substances, the second of vegetables, 
and the third of animals), is placed, as it were, before the 
eyes by many reducing instances. 

Again, it is clear that the more refined tissue and con 
formation of things (though forming the whole body of 
visible or tangible objects) arc neither visible nor tangible. 
Our information, therefore, must here also be derived from 
reduction to the sphere of the senses. But the most radical 
and primary difference of formation depends on the abun 
dance or scarcity of matter within the same space or dimen 
sions. For the other formations which regard the dissimi 
larity of the parts contained in the same body, and their 


collocation and position, are secondary in comparison with 
the former. 

Let the required nature then be the expansion or cohe 
rence of matter in different bodies, or the quantity of matter 
relative to the dimensions of each. For there is nothing in 
nature more true than the twofold proposition that nothing 
proceeds from nothing and that nothing is reduced to noth 
ing, but that the quantum, or sum total of matter, is con 
stant, and is neither increased nor diminished. Nor is it 
less true, that out of this given quantity of matter, there 
is a greater or less quantity, contained within the same 
space or dimensions according to the difference of bodies; 
as, for instance, water contains more than air. So that if 
any one were to assert that a given content of water can 
be changed into an equal content of air, it is the same as 
if he were to assert that something can be reduced into 
nothing. On the contrary, if any one were to assert that 
a given content of air can be changed into an equal content 
of water, it is the same as if he were to assert that some 
thing can proceed from nothing. From this abundance or 
scarcity of matter are properly derived the notions of 
density and rarity, which are taken in various and pro 
miscuous senses. 

This third assertion may be considered as being also 
sufficiently certain; namely, that the greater or less quan 
tity of matter in this or that body, may, by comparison, be 
reduced to calculation, and exact, or nearly exact, propor 
tion. Thus, if one should say that there is such an accumu 
lation of matter in a given quanity of gold, that it would 
require twenty-one times the quantity in dimension of spir 
its of wine, to make up the same quantity of matter, it 

would not be far from the truth. 

SCIENCE Vol. 22 10 


The accumulation of matter, however, and its relative 
quantity, are rendered sensible by weight; for weight is 
proportionate to the quantity of matter, as regards the parts 
of a tangible substance, but spirit and its quantity of mat 
ter are not to be computed by weight, which spirit rather 
diminishes than augments. 

We have made a tolerably accurate table of weight, in 
which we have selected the weights and size of all the 
metals, the principal minerals, stones, liquids, oils, and 
many other natural and artificial bodies: a very useful pro 
ceeding both as regards theory and practice, and which is 
capable of revealing many unexpected results. Nor is this 
of little consequence, that it serves to demonstrate that the 
whole range of the variety of tangible bodies with which 
we are acquainted (we mean tolerably close, and not 
spongy, hollow bodies, which are for a considerable part 
filled with air), does not exceed the ratio of one to twenty v 
one. So limited is nature, or at least that part of it to 
which we arc most habituated. 

We have also thought it deserving our industry, to try 
if we could arrive at the ratio of intangible or pneumatic 
bodies to tangible bodies, which we attempted by the fol 
lowing contrivance. We took a vial capable of containing 
about an ounce, using a small vessel in order to effect the 
subsequent evaporation with less heat. We filled this vial, 
almost to the neck, with spirits of wine, selecting it as the 
tangible body which, by our table, was the rarest, and con 
tained a less quantity of matter in a given space than all 
other tangible bodies which arc compact and not hollow. 
Then we noted exactly the weight of the liquid and vial. 
We next took a bladder, containing about two pints, and 
squeezed all the air out of it, as completely as possible, and 


until the sides of the bladder met. We first, however, 
rubbed the bladder gently with oil, so as to make it air 
tight, by closing its pores with the oil. We tied the blad 
der tightly round the mouth of the vial, which we had in 
serted in it, and with a piece of waxed thread to make it 
fit better and more tightly, and then placed the vial on 
some hot coals in a brazier. The vapor or steam of the 
spirit, dilated and become aeriform by the heat, gradually 
swelled out the bladder, and stretched it in every direction 
like a sail. As soon as that was accomplished, we removed 
the vial from the fire and placed it on a carpet, that it 
might not be cracked by the cold; we also pricked the 
bladder immediately, that the steam might not return to a 
liquid state by the cessation of heat, and confound the pro 
portions. We then removed the bladder, and again took 
the weight of the spirit which remained; and so calculated 
the quantity which had been converted into vapor, or an 
aeriform shape, and then examined how much space had 
been occupied by the body in its form of spirits of wine in 
the vial, and how much, on the other hand, had been occu 
pied by it in its aeriform shape in the bladder, and sub 
tracted the results; from which it was clear that the 
body, thus converted and changed, acquired an expansion 
of one hundred times beyond its former bulk. 

Again, let the required nature be heat or cold, of such 
a degree as not to be sensible from its weakness. They are 
rendered sensible by the thermometer, as we described it 
above; 89 for the cold and heat are not actually perceived 
by the touch, but heat expands and cold contracts the air. 
Nor, again, is that expansion or contraction of the air in 

89 See Table of Degrees, No. 38. 


itself visible, but the air when expanded depresses the 
water, and when contracted raises it, which is the first 
reduction to sight. 

Again, let the required nature be the mixture of bodies; 
namely, how much aqueous, oleaginous or spirituous, ashy 
or salt parts they contain; or, as a particular example, how 
much butter, cheese, and whey there is in milk, and the 
like. These things are rendered sensible by artificial and 
skilful separations in tangible substances; and the nature 
of the spirit in them, though not immediately perceptible, 
is nevertheless discovered by the various motions and 
efforts of bodies. And, indeed, in this branch men have 
labored hard in distillations and artiiicial separations, but 
with little more success than in their other experiments 
now in use; their methods being mere guesses and blind 
attempts, and more industrious than intelligent; and what 
is worst of all, without any imitation or rivalry of nature, 
but rather by violent heats and too energetic agents, to the 
destruction of any delicate conformation, in which princi 
pally consist the hidden virtues and sympathies. Nor do 
men in these separations ever attend to or observe what we 
have before pointed out; namely, that in attacking bodies 
by fire, or other methods, many qualities are superinduced 
by the lire itself, and the other bodies used to effect the 
separation, which were not originally in the compound. 
Hence arise most extraordinary fallacies; for the mass of 
vapor which is emitted from water by fire, for instance, did 
not exist as vapor or air in the water, but is chiefly created 
by the expansion of the water by the heat of the fire. 

So, in general, all delicate experiments on natural or 
artificial bodies, by which the genuine are distinguished 
from the adulterated, and the better from the more com- 


mon, should be referred to this division; for they bring that 
which is not the object of the senses within their sphere. 
They are therefore to be everywhere diligently sought after. 

With regard to the fifth cause of objects escaping our 
senses, it is clear that the action of the sense takes place by 
motion, and this motion is time. If, therefore, the motion 
of any body be either so slow or so swift as not to be pro* 
portioned to the necessary momentum which operates on the 
senses, the object is not perceived at all; as in the motion of 
the hour hand, and that, again, of a musket-ball. The mo 
tion which is imperceptible by the senses from its slowness, 
is readily and usually rendered sensible by the accumula 
tion of motion; that which is imperceptible from its veloc 
ity, has not as yet been well measured; it is necessary, how 
ever, that this should be done in some cases, with a view to 
a proper investigation of nature. 

The sixth case, where the sense is impeded by the power 
of the object, admits of a reduction to the sensible sphere, 
either by removing the object to a greater distance, or by 
deadening its effects by the interposition of a medium, 
which may weaken and not destroy the object; or by the 
admission of its reflection where the direct impression is too 
strong, as that of the sun in a basin of water. 

The seventh case, where the senses are so overcharged 
with the object as to leave no further room, scarcely occurs 
except in the smell or taste, and is not of much consequence 
as regards our present subject. Let what we have said, 
therefore, suffice with regard to the reduction to the sensi 
ble sphere of objects not naturally within its compass. 

Sometimes, however, this reduction is not extended to 
the senses of man, but to those of some other animal, whose 
senses, in some points, exceed those of man; as (with regard 


to some scents) to that of the dog, and with regard to light 
existing imperceptibly in the air, when not illuminated from 
any extraneous source, to the sense of the cat, the owl, and 
other animals which see by night. For Telesius has well 
observed, that there appears to be an original portion of 
light even in the air itself, 70 although but slight and meagre, 
and of no use for the most part to the eyes of men, and 
those of the generality of animals; because those animals 
to whose senses this light is proportioned can see by night, 
which does not, in all probability, proceed from their see 
ing either without light or by any internal light. 

Here, too, we would observe, that we at present discuss 
only the wants of the senses, and their remedies; for their 
deceptions must be referred to the inquiries appropriated 
to the senses, and sensible objects; except that important 
deception, which makes them define objects in their rela 
tion to man, and not in their relation to the universe, and 
which is only corrected by universal reasoning and phi 
losophy. 71 

XLI. In the eighteenth rank of prerogative instances we 
will class the instances of the road, which we are also wont 
to call itinerant and jointed instances. They are such as 
indicate the gradually continued motions of nature. This 

10 Riccati, and all modern physicists, discover some portion of light in 
every body, which seems to confirm the passage in Genesis that assigns to this 
substance priority in creation. Ed. 

71 As instances of this kind, which the progress of science since the time 
of Bacon affords, we may cite the air-pump and the barometer, for manifesting 
the weight and elasticity of air: the measurement of the velocity of light, by 
means of the occupation of Jupiter s satellites and the aberration of the fixed 
stars: the experiments in electricity and galvanism, and in the greater part 
of pneumatic chemistry. In all these cases scientific facts are elicited, which 
sense could never have revealed to us. Ed, 


species of instances escapes rather our observation than our 
senses; for men are wonderfully indolent upon this subject, 
consulting nature in a desultory manner, and at periodic 
intervals, when bodies have been regularly finished and 
completed, and not during her work. But if any one were 
desirous of examining and contemplating the talents and 
industry of an artificer, he would not merely wish to see 
the rude materials of his art, and then his work when fin 
ished, but rather to be present while he is at labor, and 
proceeding with his work. Something of the same kind 
should be done with regard to nature. For instance, if any 
one investigate the vegetation of plants, he should observe 
from the first sowing of any seed (which can easily be done, 
by pulling up every day. seeds which have been two, three, 
or four days in the ground, and examining them diligently), 
how and when the seed begins to swell and break, and be 
filled, as it were, with spirit; then how it begins to burst 
the bark and push out fibres, raising itself a little at the 
same time, unless the ground be very stiff; then how it 
pushes out these fibres, some downward for roots, others 
upward for the stem, sometimes also creeping laterally, if 
it find the earth open and more yielding on one side, and 
the like. The same should be done in observing the hatch 
ing of eggs, where we may easily see the process of anima 
tion and organization, and what parts are formed of the 
yolk, and what of the white of the egg, and the like. The 
same may be said of the inquiry into the formation of ani 
mals from putrefaction; for it would not be so humane to 
inquire into perfect and terrestrial animals, by cutting the 
foetus from the womb; but opportunities may perhaps be 
offered of abortions, animals killed in hunting, and the like. 
Nature, therefore, must, as it were, be watched, as being 


more easily observed by night than by day : for contempla 
tions of this kind may be considered as carried on by 
night, from the minuteness and perpetual burning of our 

The same must be attempted with inanimate objects, 
which we have ourselves done by inquiring into the open 
ing of liquids by fire. For the mode in which water ex 
pands is different from that observed in wine, vinegar, or 
verjuice, and very different, again, from that observed in 
milk and oil, and the like; and this was easily seen by boil 
ing them with slow heat, in a glass vessel, through which 
the whole may be clearly perceived. But we merely men 
tion this, intending to treat of it more at large and more 
closely when we come to the discovery of the latent process; 
for it should always be remembered that we do not here 
treat of things themselves, but merely propose examples. 78 

XLII. In the nineteenth rank of prerogative instances 
we will class supplementary or substitutive instances, which 
we are also wont to call instances of refuge. They are such 
as supply information, where the senses are entirely defi 
cient, and we therefore have recourse to them when appro 
priate instances cannot be obtained. This substitution is 

12 The itinerant instances, as well as frontier instances, are cases in which 
we are enabled to trace the general law of continuity which seems to pervade 
all nature, and which has been aptly embodied in the sentence, "natura non 
agit per saltum." The pursuit of this law into phenomena where its applica 
tion is not at lirst sight obvious, has opened a mine of physical discovery, and 
led us to perceive an intimate connection between facts which at first seemed 
hostile to each other. For example, the transparency of gold-leaf, which per 
mits a bluish-green light to pass through it, is a frontier instance between 
transparent and opaque bodies, by exhibiting a body of the glass generally 
regarded the most opaque in nature, as still possessed of some slight degree 
of transparency. It thus proves that the quality of opacity is not a contrary 
or antagonistic quality to that of transparency, but only its extreme lowest 


twofold, either by approximation or by analogy. For in 
stance, there is no known medium which entirely prevents 
the effect of the magnet in attracting iron neither gold, 
nor silver, nor stone, nor glass, wood, water, oil, cloth, 
or fibrous bodies, air, flame, or the like. Yet by accurate 
experiment, a medium may perhaps be found which would 
deaden its effect, more than another comparatively and in 
degree; as, for instance, the magnet would not perhaps 
attract iron through the same thickness of gold as of air, 
or the same quantity of ignited as of cold silver, and so on ; 
for we have not ourselves made the experiment, but it will 
suffice as an example. Again, there is no known body 
which is not susceptible of heat, when brought near the 
fire; yet air becomes warm much sooner than stone. These 
are examples of substitution by approximation. 

Substitution by analogy is useful, but less sure, and 
therefore to be adopted with some judgment. It serves to 
reduce that which is not the object of the senses to their 
sphere, not by the perceptible operations of the impercep 
tible body, but by the consideration of some similar per 
ceptible body. For instance, let the subject for inquiry be 
the mixture of spirits, which are invisible bodies. There 
appears to be some relation between bodies and their sources 
or support. Now, the source of flame seems to be oil and 
fat; that of air, ^ water, and watery substances; for flame 
increases over the exhalation of oil, and air over that of 
water. One must therefore consider the mixture of oil and 
water, which is manifest to the senses, since that of air and 
flame in general escapes the senses. But oil and water mix 
very imperfectly by composition or stirring, while they are 
exactly and nicely mixed in herbs, blood, and the parts of 
animals. Something similar, therefore, may take place in 


the mixture of flame and air in spirituous substances, not 
bearing mixture very well by simple collision, while they 
appear, however, to be well mixed in the spirits of plants 
and animals. 

Again, if the inquiry do not relate to perfect mixtures of 
spirits, but merely to their composition, as whether they 
easily incorporate with each other, or there be rather (as an 
example) certain winds and exhalations, or other spiritual 
bodies, which do not mix with common air, but only adhere 
to and float in it in globules and drops, and are rather 
broken and pounded by the air, than received into, and 
incorporated with it; this cannot be perceived in common 
air, and other aeriform substances, on account of the rarity 
of the bodies, but an image, as it were, of this process may 
be conceived in such liquids as quicksilver, oil, water, and 
even air, when broken and dissipated it ascends in small 
portions through water, and also in the thicker kinds of 
smoke; lastly, in dust, raised and remaining in the air, in 
all of which there is no incorporation: and the above repre 
sentation in this respect is not a bad one, if it be first dili 
gently investigated, whether there can be such a difference 
of nature between spirituous substances, as between liquids, 
for then these images might conveniently be substituted by 

And although we have observed of these supplementary 
instances, that information is to be derived from them, when 
appropriate instances are wanting, by way of refuge, yet we 
would have it understood, that they are also of great use, 
when the appropriate instances are at hand, in order to con 
firm the information afforded by them; of which we will 
speak more at length, when our subject leads us, in due 
course, to the support of induction. 


XL1II. In the twentieth rank of prerogative instances 
we will place lancing instances, which we are also wont 
(bat for a different reason) to call twitching instances. We 
adopt the latter name, because they twitch the understand 
ing, and the former because they pierce nature, whence we 
style them occasionally the instances of Democritus." 
They are such as warn the understanding of the admir 
able and exquisite subtilty of nature, so that it becomes 
roused and awakened to attention, observation, and proper 
inquiry; as, for instance, that a little drop of ink should 
be drawn out into so many letters; that silver merely gilt 
on its surface should be stretched to such a length of gilt 
wire; that a little worm, such as you may find on the skin, 
should possess both a spirit and a varied conformation of 
its parts; that a little saffron should imbue a whole tub 
of water with its color; that a little musk or aroma should 
imbue a much greater extent of air with its perfume; that 
a cloud of smoke should be raised by a little incense; that 
such accurate differences of sounds as articulate words 
should be conveyed in all directions through the air, and 
even penetrate the pores of wood and water (though they 
become much weakened), that they should be, moreover, 
reflected, and that with such distinctness and velocity; that 
light and color should for such an extent and so rapidly 
pass through solid bodies, such as glass and water, with 
so great and so exquisite a variety of images, and should 
be refracted and reflected; that the magnet should attract 
through every description of body, even the most compact; 
but (what is still more wonderful) that in all these cases the 
action of one should not impede that of another in a common 

n Alluding to his theory of atoms. 


medium, such as air; and tliat there should be borne through 
the air, at the same time, so many images of visible objects, 
so many impulses of articulation, so many different per 
fumes, as of the violet, rose, etc., besides cold and heat, 
and magnetic attractions; all of them, I say, at once, with 
out any impediment from each other, as if each had its paths 
and peculiar passage set apart for it, without infringing 
against or meeting each other. 

To these lancing instances, however, we are wont, not 
without some advantage, to add those which we call the 
limits of such instances. Thus, in the cases we have 
pointed out, one action does not disturb or impede an 
other of a different nature, yet those of a similar nature 
subdue and extinguish each other; as the light of the sun 
does that of the candle, the sound of a cannon that of the 
voice, a strong perfume a more delicate one, a powerful heat 
a more gentle one, a plate of iron between the magnet and 
other iron the effect of the magnet. But the proper place 
for mentioning these will be also among the supports of 

XLIV. We have now spoken of the instances which 
assist the senses, and which are principally of service as 
regards information; for information begins from the senses. 
But our whole labor terminates in practice, and as the 
former is the beginning, so is the latter the end of our 
subject. The following instances, therefore, will be those 
which are chiefly useful in practice. They are compre 
hended in two classes, and are seven in number. We call 
them all by the general name of practical instances. Now 
there are two defects in practice, and as many divisions of 
important instances. Practice is either deceptive or too 
laborious. It is generally deceptive (especially after a dili- 


gent examination of natures), on account of the power and 
actions of bodies being ill defined and determined. Now 
the powers and actions of bodies are defined and determined 
either by space or by time, or by the quantity at a given 
period, or by the predominance of energy ; and if these four 
circumstances be not well and diligently considered, the 
sciences may indeed be beautiful in theory, but are of no 
effect in practice. We call the four instances referred to 
this class, mathematical instances and instances of measure. 

Practice is laborious either from the multitude of instru 
ments, or the bulk of matter and substances requisite for 
any given work. Those instances, therefore, are valuable, 
which either direct practice to that which is of most conse 
quence to mankind, or lessen the number of instruments 
or of matter to be worked upon. We assign to the three 
instances relating to this class, the common name of pro 
pitious or benevolent instances. We will now separately 
discuss these seven instances, and conclude with them that 
part of our work which relates to the prerogative or illus 
trious instances. 

XLV. In the twenty-first rank of prerogative instances 
we will place the instances of the rod or rule, which we are 
also wont to call the instances of completion or non ultrct. 
For the powers and motions of bodies do not act and take 
effect through indefinite and accidental, but through limited 
and certain spaces ; and it is of great importance to practice 
that these should be understood and noted in every nature 
which is investigated, not only to prevent deception, but 
to render practice more extensive and efficient. For it is 
sometimes possible to extend these powers, and bring the 
distance, as it were, nearer, as in the example of telescopes. 

Many powers act and take effect only by actual touch, as 


in the percussion of bodies, where the one does not remove 
the other, unless the impelling touch the impelled body. 
External applications in medicine, as ointment and plasters, 
do not exercise their efficacy except when in contact with 
the body. Lastly, the objects of touch and taste only strike 
those senses when in contact with their organs. 

Other powers act at a distance, though it be very small, 
of which but few liave as yet been noted, although there 
be more than men suspect; this happens (to take everyday 
instances) when amber or jet attracts straws, bubbles dis 
solve bubbles, some purgative medicines draw humors from 
above, and the like. The magnetic power by which iron 
and the magnet, or two magnets, are attracted together, 
acts within a definite and narrow sphere, but if there be 
any magnetic power emanating from the earth a little below 
its surface, and affecting the needle in its polarity, it must 
act at a great distance. 

Again, if there be any magnetic force which acts by sym 
pathy between the globe of the earth and heavy bodies, or 
between that of the moon and the waters of the sea (as seems 
most probable from the particular floods and ebbs which 
occur twice in the month), or between the starry sphere and 
the planets, by which they are summoned and raised to 
their apogees, these must all operate at very great dis 
tances. 74 

74 Observe the approximation to Newton s theory. The same notion re 
peated still more clearly in the ninth motion. Newton believed that the 
planets might so conspire as to derange the earth s annual revolution, and to 
elongate the line of the apsides and ellipsis that the eartli describes in its an 
nual revolution round the sun. In the supposition that all the planets meet 
on the same straight line, Venus and Mercury on one side of the sun, and the 
earth, moon, Mars, Jupiter and Saturn on the side diametrically opposite; then 
Saturn would attract Jupiter, Jupiter Mars, Mars the moon, which must in its 


Again, some conflagrations and the kindling of flames 
take place at very considerable distances with particular 
substances, as they report of the naphtha of Babylon. 
Heat, too, insinuates itself at wide distances, as does also 
cold, so that the masses of ice which are broken off and 
float upon the Northern Ocean, and are borne through the 
Atlantic to the coast of Canada, become perceptible by 
the inhabitants, and strike them with cold from a distance. 
Perfumes also (though here there appears to be always, some 
corporeal emission) act at remarkable distances, as is experi 
enced by persons sailing by the coast of Florida, or parts 
of Spain, where there are whole woods of lemons, oranges, 
and other odoriferous plants, or rosemary and marjoram 
bushes, and the like. Lastly, the rays of light and the im 
pressions of sound act at extensive distances. 

Yet all these powers, whether acting at a small or great 
distance, certainly act within definite distances, which are 
well ascertained by nature, so that there is a limit depend 
ing either on the mass or quantity of the bodies, the vigor 
or faintness of the powers, or the favorable or impeding na 
ture of the medium, all of which should be taken into 

turn attract the earth in proportion to the force with which it was drawn out 
of its orbit. The result of this combined action on our planet would elongate 
its ecliptic orbit, and so far draw it from the source of heat, as to produce an 
intensity of cold destructive to animal life. But this movement would imme 
diately cease with the planetary concurrence which produced it, and the earth, 
like a compressed spring, bound almost as near to the sun as she had been 
drawn from it, the reaction of the heat on its surface being about as intense as 
the cold caused by the first removal was severe. The earth, until it gained its 
regular track, would thus alternately vibrate between each side of its orbit, 
with successive changes in its atmosphere, proportional to the square of the 
variation of its distance from the sun. In no place is Bacon s genius more 
conspicuous than in these repeated guesses at truth. He would have been a 
strong Copemican, had not Gilbert defended the system. Ed. 


account and observed. We must also note the boundaries 
of violent motions, such as missiles, projectiles, wheels and 
the like, since they are also manifestly confined to certain 

Some motions and virtues are to be found of a directly 
contrary nature to these, which act in contact but not at a 
distance; namely, such as operate at a distance and not in 
contact, and again act with less force at a less distance, and 
the reverse. Sight, for instance, is not easily effective in 
contact, but requires a medium and distance; although I 
remember having heard from a person deserving of credit, 
that in being cured of a cataract (which was done by put 
ting a small silver needle within the first coat of the eye, to 
remove the thin pellicle of the cataract, and force it into a 
corner of the eye), he had distinctly seen the needle moving 
across the pupil. Still, though this may be true, it is clear 
that large bodies cannot be seen well or distinctly, unless at 
the vertex of a cone, where the rays from the object meet 
at some distance from the eye. In old persons the eye sees 
better if the object be moved a little further, and not nearer. 
Again, it is certain that in projectiles the impact is not so 
violent at too short a distance as a little afterward. 76 Such 
are the observations to be made on the measure of motions 
as regards distance. 

There is another measure of motion in space which must 

15 This is not true except when the projectile acquires greater velocity 
at every successive instant of its course, which is never the case except with 
falling bodies. Bacon appears to have been led into the opinion from observ 
ing that gunshots pierce many objects at a distance from which they rebound 
when brought within a certain proximity of contact. This apparent inconsist 
ency, however, arises from the resistance of the parts of the object, which 
velocity combined with force is necessary to overcome. Ed. 


not be passed over, not relating to progressive but spherical 
motion that is, the expansion of bodies into a greater, or 
their contraction into a lesser sphere. For in our measure 
of this motion we must inquire what degree of compression 
or extension bodies easily and readily admit of, accord 
ing to their nature, and at what point they begin to resist 
it, so as at last to bear it no further as when an inflated 
bladder is compressed, it allows a certain compression of 
the air, but if this be increased, the air does not suffer 
it, and the bladder is burst. 

We have proved this by a more delicate experiment. 
We took a metal bell, of a light and thin sort, such as is 
used for salt-cellars, and immersed it in a basin of water, 
so as to carry the air contained in its interior down with it 
to the bottom of the basin. We had first, however, placed 
a small globe at the bottom of the basin, over which we 
placed the bell. The result was, that if the globe were 
small compared with the interior of the bell, the air would 
contract itself, and be compressed without being forced out, 
but if it were too large for the air readily to yield to it, 
the latter became impatient of the pressure, raised the bell 
partly up, and ascended in bubbles. 

To prove, also, the extension (as well as the compres 
sion) which air admits of, we adopted the following method: 
We took a glass egg, with a small hole at one end; we 
drew out the air by violent suction at this hole, and then 
closed the hole with the finger, immersed the egg in water, 
and then removed the finger. The air being constrained by 
the effort made in suction, and dilated beyond its natural 
state, and therefore striving to recover and contract itself 
(so that if the egg had not been immersed in water, it would 
have drawn in the air with a hissing sound), now drew in 


a sufficient quantity of water to allow the air to recover 
its former dimensions. 78 

It is well ascertained that rare bodies (such as air) admit 
of considerable contraction, as has been before observed; 
but tangible bodies (such as water) admit of it much less 
readily, and to a less extent. "We investigated the latter 
point by the following experiment: 

We had a leaden globe made, capable of containing 
about two pints, wine measure, and of tolerable thickness, 
so as to support considerable pressure. We poured water 
into it through an aperture, which we afterward closed with 
melted^lead, as soon as the globe was filled with water, so 
that the whole became perfectly solid. We next flattened 
the two opposite sides with a heavy hammer, which neces 
sarily caused the water to occupy a less space, since the 
sphere is the solid of greatest content; and when hammer 
ing failed from the resistance of the water, we made use of 
a mill or press, till at last the water, refusing to submit 
to a greater pressure, exuded like a fine dew through the 
solid lead. We then computed the extent to which the 
original space had been reduced, and concluded that water 
admitted such a degree of compression when constrained 
by great violence. 

The more solid, dry or compact bodies, such as stones, 
wood and metals, admit of much less, and indeed scarcely 
any perceptible compression or expansion, but escape by 
breaking, slipping forward, or other efforts; as appears in 
bending wood, or steel for watch-springs, in projectiles, 
hammering and many other motions, all of which, together 

76 This passage shows that the pressure of the external atmosphere, which 
forces Ihe water into the egg, was not in Bacon s time understood. Ed. 


with their degrees, are to be observed and examined in the 
investigation of nature, either to a certainty, or by esti 
mation, or comparison, as opportunity permits. 

XLY1. In the twenty-second rank of prerogative in 
stances we will place the instances of the course, which 
we are also wont to call water instances, borrowing our 
expression from the water hour-glasses employed by the 
ancients instead of those with sand. They are such as 
measure nature by the moments of time, as the last in 
stances do by the degrees of space. For all motion or nat 
ural action takes place in time, more or less rapidly, but 
still in determined moments well ascertained by nature. 
Even those actions which appear to take effect suddenly, 
and in the twinkling of an eye (as we express it), are 
found to admit of greater or less rapidity. 

In the first place, then, we see that the return f the 
heavenly bodies to the same place takes place in regular 
times, as does the flood and ebb of the sea. The descent 
of heavy bodies toward the earth, and the ascent of light 
bodies toward the heavenly sphere, take place in definite 
times, 77 according to the nature of the body, and of the 
medium through which it moves. The sailing of ships, 
the motions of animals, the transmission of projectiles, all 

" We have already alluded, in a note prefixed to the same aphorism of the 
first book, to Newton s error of the absolute lightness of bodies. In speaking 
again of the volatile or spiritual substances (Aph. xl. b. ii.), which he sup 
posed with the Platonists and some of the schoolmen to enter into the composi 
tion of every body, he ascribes to them a power of lessening the weight of the 
material coating in which he supposes them inclosed. It would appear from 
these passages and the text that Bacon had no idea of the relative density of 
bodies, and the capability which some have to diminish the specific gravity of 
the heavier substances by the dilation of their parts; or if he had, the reveries 
in which Aristotle indulged in treating of the soul, about the appetency of 
bodies to fly to kindred substances flame and spirit to the sky, and solid 
opaque substances to the earth, must have vitiated his mind. Ed. 


take place in times the sums of which can be computed. 
With regard to heat, we see that boys in winter bathe 
their hands in the flame without being burned; and con 
jurers, by quick and regular movements, overturn vessels 
filled with wine or water, and replace them without spilling 
the liquid, with several similar instances. The compres 
sion, expansion and eruption of several bodies, take place 
more or less rapidly, according to the nature of the body 
and its motion, but still in definite moments. 

In the explosion of several cannon at once (which are 
sometimes heard at the distance of thirty miles), the sound 
of those nearest to the spot is heard before that of the most 
distant. Even in sight (whose action is most rapid), it is 
clear that a definite time is necessary for its exertion, 
which is proved by certain objects being invisible from 
the velocity of their motion, such as a musket-ball; for 
the flight of the ball is too swift to allow an impression 
of its figure to be conveyed to the sight. 

This last instance, and others of a like nature, have 
sometimes excited in us a most marvellous doubt, no less 
than whether the image of the sky and stars is perceived 
as at the actual moment of its existence, or rather a little 
after, and whether there is not (with regard to the visible 
appearance of the heavenly bodies) a true and apparent 
time, as well as a true and apparent place, which is ob 
served by astronomers in parallaxes. It appeared so in 
credible to us, that the images or radiations of heavenly 
bodies could suddenly be conveyed through such immense 
spaces to the sight, and it seemed that they ought rather 
to be transmitted in a definite time. 8 That doubt, however 

18 Romer, a Danish astronomer, was the first to demonstrate, by connecting 
the irregularities of the eclipses of Jupiter s satellites with their distances from 


(as far as regards any great difference between the true and 
apparent time), was subsequently completely set at rest, 
when we considered the infinite loss and diminution of 
size as regards the real and apparent magnitude of a star, 
occasioned by its distance, and at the same time observed 
at how great a distance (at least sixty miles) bodies which 
are merely white can be suddenly seen by us. For there 
is no doubt, that the light of the heavenlv bodies not only 
far surpasses the vivid appearance of \vhite, but even the 
light of any flame (with which we are acquainted) in the 
vigor of its radiation. The immense velocity of the bodies 
themselves, which is perceived in their diurnal motion, and 
has so astonished thinking men, that they have been more 
ready to believe in the motion of the earth, renders the 
motion of radiation from them (marvellous as it is in its 
rapidity) more worthy of belief. That which has weighed 
most with us, however, is, that if there were any consider 
able interval of time between the reality and the appear 
ance, the images would often be interrupted and confused 
by clouds formed in the meantime, and similar disturb 
ances of the medium. Let this suffice with regard to the 
simple measures of time. 

It is not merely the absolute, but still more the relative 
measure of motions and actions which must be inquired 
into, for this latter is of great use and application. We 
perceive that the flame of firearms is seen sooner than the 
sound is heard, although the ball must have struck the air 
before the flame, which was behind it, could escape: the 
reason of which is, that light moves with greater velocity 

the earth, the necessity of time for the propagation of light. The idea occurred 
to Dominic Cassini as well as Bacon, but both allowed the discovery to slip out 
of their hands. Ed. 


than sound. We perceive, also, that visible images are re 
ceived by the sight with greater rapidity than they are dis 
missed, and for this reason, a violin string touched with the 
finger appears double or triple, because the new image is 
received before the former one is dismissed. Hence, also, 
rings when spinning appear globular, and a lighted torch, 
borne rapidly along at night, appears to have a tail. Upon 
the principle of the inequality of motion, also, Galileo at 
tempted an explanation of the flood and ebb of the sea, 
supposing the earth to move rapidly, and the water slowly, 
by which means the water, after accumulating, would at 
intervals fall back, as is shown in a vessel of water made 
to move rapidly. He has, however, imagined this on data 
which cannot be granted (namely, the earth s motion), and 
besides, does not satisfactorily account for the tide taking 
place every six hours. 

An example of our present point (the relative measure 
of motion), and, at the same time, of its remarkable use of 
which we have spoken, is conspicuous in mines filled with 
gunpowder, where immense weights of earth, buildings, 
and the like, are overthrown and prostrated by a small 
quantity of powder; the reason of which is decidedly this, 
that the motion of the expansion of the gunpowder is much 
more rapid than that of gravity, 79 which would resist it, so 
that the former has terminated before the latter has com 
menced. Hence, also, in missiles, a strong blow will not 
carry them so far as a sharp and rapid one. Nor could a 
small portion of animal spirit in animals, especially in such 

79 The author in the text confounds inertness, which is a simple indifference 
of bodies to action, with gravity, which is a force acting always in proportion 
to their density. He falls into the same error further on. Ed, 


vast bodies as those of the whale and elephant, have ever 
bent or directed such a mass of body, were it not owing to 
the velocity of the former, and the slowness of the latter in 
resisting its motion. 

In short, this point is one of the principal foundations 
of the magic experiments (of which we shall presently 
speak), where a small mass of matter overcomes and regu 
lates a much larger, if there but be an anticipation of 
motion, by the velocity of one before the other is pre 
pared to act. 

Finally, the point of the first and last should be ob 
served in all natural actions. Thus, in an infusion of rhu 
barb the purgative property is first extracted, and then the 
astringent; we have experienced something of the same 
kind in steeping violets in vinegar, which first extracts the 
sweet and delicate odor of the flower, and then the more 
earthy part, which disturbs the perfume; so that if the vio 
lets be steeped a whole day, a much fainter perfume is 
extracted than if they were steeped for a quarter of an hour 
only, and then taken out; and since the odoriferous spirit 
in the violet is not abundant, let other and fresh violets be 
steeped in the vinegar every quarter of an hour, as many as 
six times, when the infusion becomes so strengthened, that 
although the violets have not altogether remained there for 
more than one hour and a half, there remains a most pleas 
ing perfume, not inferior to the flower itself, for a whole 
year. It must be observed, however, that the perfume 
does not acquire its full strength till about a month after 
the infusion. In the distillation of aromatic plants macer 
ated in spirits of wine, it is well known that an aqueous 
and useless phlegm rises first, then water containing more 
of the spirit, and, lastly, water containing more of the 


aroma; and many observations of the like kind, well worthy 
of notice, are to be made in distillations. But let these 
suffice as examples. 80 

The experiments of the last two classes of instances are considered only 
in relation to practice, and Bacon does not so much as mention their infinitely 
greater importance in the theoretical part of induction. The important law of 
gravitation in physical astronomy could never have been demonstrated but by 
such observations and experiments as assigned accurate geometrical measures 
to the quantities compared. It was necessary to determine with precision the 
demi-diameter of the earth, the velocity of falling bodies at its surface, the dis 
tance of the moon, and the speed with which she describes her orbit, before 
the relation could be discovered between the force which draws a stone to the 
ground and that which retains the moon in her sphere. 

In many cases the result of a number of particular facts, or the collective 
instances rising out of them, can only be discovered by geometry, which so far 
becomes necessary to complete the work of induction. For instance, in the 
case of optics, when light passes from one transparent medium to another, it 
is refracted, and the angle which the ray of incidence makes .with the super 
ficies which bounds the two media determines that which the refracted ray 
makes with the same superficies. Xow, all experiment can do for us in thia 
case is, to determine for any particular angle of incidence the corresponding 
angle of refraction. But with respect to the general rule which in every pos 
sible case deduces one of these angles from the other, or expresses the constant 
and invariable relation which subsists between them, experiment gives no direct 
information. Geometry must, consequently, be called in, which, when a con 
stant though unknown relation subsists between two angles, or two variable 
qualities of any kind, and when an indefinite number of values of those quanti 
ties are assigned, furnishes infallible means of discovering that unknown rela 
tion either accurately or by approximation. In this way it has been found, 
when the two media remain the same, the cosines of the above-mentioned 
angles have a constant ratio to each other. Hence, when the relations of the 
simple elements of phenomena are discovered to afford a general rule which 
will apply to any concrete case, the deductive method must be applied, and the 
elementary principles made through its agency to account for the laws of their 
more complex combinations. The reflection and refraction of light by the rain 
falling from a cloud opposite to the sun was thought, even before Newton s 
day, to contain the form of the rainbow. This philosopher transformed a prob 
able conjecture into a certain fact when he deduced from the known laws of 
reflection and refraction the breadth of the colored arch, the diameter of the 
circle of which it is a part, and the relation of the latter to the place of the 
spectator and the sun. Doubt was at once silenced when there came out of 
his calculus a combination of the same laws of the simple elements of optics 
answering to the phenomena in nature. Ed. 


XLVII. In the twenty-third rank of prerogative in 
stances we will place instances of quantity, which we are 
also wont to call the doses of nature (borrowing a word 
from medicine). They are such as measure the powers by 
the quantity of bodies, and point out the effect of the quan 
tity in the degree of power. And in the first place, some 
powers only subsist in the universal quantity, or such as 
bears a relation to the confirmation and fabric of the uni 
verse. Thus the earth is fixed, its parts fall. The waters 
in the sea flow and ebb, but not in the rivers, except by the 
admission of the sea. Then, again, almost all particular 
powers act according to the greater or less quantity of the 
body. Large masses of water are not easily rendered foul, 
small are. New wine and beer become ripe and drinkable 
in small skins much more readily than in large casks. If a 
herb be placed in a considerable quantity of liquid, infusion 
takes place rather than impregnation; if in less, the reverse. 
A bath, therefore, and a light sprinkling, produce different 
effects on the human body. Light dew, again, never falls, 
but is dissipated and incorporated with the air; thus we see 
that in breathing on gems, the slight quantity of moisture, 
like a small cloud in the air, is immediately dissolved. 
Again, a piece of the same magnet does not attract so much 
iron as the whole magnet did. There are some powers 
where the smallness of the quantity is of more avail; as in 
boring, a sharp point pierces more readily than a blunt one; 
/the diamond, when pointed, makes an impression on glass, 
and the like. 

Here, too, we must not rest contented with a vague 
result, but inquire into the exact proportion of quantity 
requisite for a particular exertion of power; for one would 

be apt to suppose that the power bears an exact proportion 

SCIENCE Vol. 2211 


to the quantity; that if a leaden bullet of one ounce, for 
instance, would fall in a given time, one of two ounces 
ought to fall twice as rapidly, which is most erroneous. 
Nor does the same ratio prevail in every kind of power, 
their difference being considerable. The measure, there 
fore, must be determined by experiment, and not by proba 
bility or conjecture. 

Lastly, we must in all our investigations of nature ob 
serve what quantity, or dose, of the body is requisite for a 
given effect, and must at the same time be guarded against 
estimating it at too much or too little. 

XLYI1I. In the twenty-fourth rank of prerogative in 
stances we will place wrestling instances, which we are also 
wont to call instances of predominance. They are such as 
point out the predominance and submission of powers com 
pared with each other, and which of them is the more ener 
getic and superior, or more weak and inferior. For the 
motions and effects of bodies are compounded, decom 
posed, and combined, no less than the bodies themselves. 
We will exhibit, therefore, the principal kinds of motions 
or active powers, in order that their comparative strength, 
and thence a demonstration and definition of the instances 
in question, may be rendered more clear. 

Let the first motion be that of the resistance of matter, 
which exists in every particle, and completely prevents its 
annihilation; so that no conflagration, weight, pressure, vio 
lence, or length of time can reduce even the smallest por 
tion of matter to nothing, or prevent it from being some 
thing, and occupying some space, and delivering itself 
(whatever straits it be put to), by changing its form or 
place, or, if that be impossible, remaining as it is; nor can 
it ever happen that it should either be nothing or nowhere. 


This motion is designated by the schools (which generally 
name and define everything by its effects and inconven 
iences rather than by its inherent cause) by the axiom, that 
two bodies cannot exist in the same place, or they call it a 
motion to prevent the penetration of dimensions. It is use 
less to give examples of this motion, since it exists in 
every body. 

Let the second motion be that which we term the motion 
of connection, by which bodies do not allow themselves to 
be separated at any point from the contact of another body, 
delighting, as it were, in the mutual connection and contact. 
This is called by the schools a motion to prevent a vacuum. 
It takes place when water is drawn up by suction or a 
syringe, the flesh by cupping, or when the water remains 
without escaping from perforated jars, unless the mouth be 
opened to admit the air, and innumerable instances of a like 

Let the third be that which we term the motion of lib 
erty, by which bodies strive to deliver themselves from any 
unnatural pressure or tension, and to restore themselves to 
the dimensions suited to their mass; and of which, also, 
there are innumerable examples. Thus, we have examples 
of their escaping from pressure, in the water in swimming, 
in the air in flying, in the water again in rowing, and in the 
air in the undulation of the winds, and in springs of 
watches. An exact instance of the motion of compressed 
air is seen in children s popguns, which they make by 
scooping out elder-branches or some such matter, and 
forcing in a piece of some pulpy root or the like, at each 
end ; then they force the root or other pellet with a ramrod 
to the opposite end, from which the lower pellet is emitted 
and projected with a report, and that before it is touched 


by the other piece of root or pellet, or by the ramrod. We 
have examples of their escape from tension, in the motion 
of the air that remains in glass eggs after suction, in strings, 
leather, and cloth, which recoil after tension, unless it be 
long continued. The schools define this by the term of 
motion from the form of the element; injudiciously enough, 
since this motion is to be found not only in air, water, or 
fire, but in every species of solid, as wood, iron, lead, cloth, 
parchment, etc., each of which has its own proper size, and 
is with difficulty stretched to any other. Since, however, 
this motion of liberty is the most obvious of all, and to be 
seen in an infinite number of cases, it will be as well to dis 
tinguish it correctly and clearly; for some most carelessly 
confound this with the two others of resistance and connec 
tion; namely, the freedom from pressure with the former, 
and that from tension with the latter, as if bodies when com 
pressed yielded or expanded to prevent a penetration of 
dimensions, and when stretched rebounded and contracted 
themselves to prevent a vacuum. But if the air, when 
compressed, could be brought to the density of water, or 
wood to that of stone, there would be no need of any pene 
tration of dimensions, and yet the compression would be 
much greater than they actually admit of. So if water 
could be expanded till it became as rare as air, or stone as 
rare as wood, there would be no need of a vacuum, and yet 
the expansion would be much greater than they actually 
admit of. 

We do not, therefore, arrive at a penetration of dimen 
sions or a vacuum before the extremes of condensation 
and rarefaction, while the motion we speak of stops 
and exerts itself much within them, and is nothing more 
than a desire of bodies to preserve their specific density (or, 


if it be preferred, their form), and not to desert them sud 
denly, but only to change by degrees, and of their own 
accord. It is, however, much more necessary to intimate 
to mankind (because many other points depend upon this), 
that the violent motion which we call mechanical, and 
Democritus (who, in explaining his primary motions, is 
to be ranked even below the middling class of philoso 
phers) termed the motion of a blow, is nothing else than 
this motion of liberty, namely, a tendency to relaxation 
from compression. For in all simple impulsion or flight 
through the air, the body is not displaced or moved in 
space, until its parts are placed in an unnatural state, and 
compressed by the impelling force. When that takes 
place, the different parts urging the other in succes 
sion, the whole is moved, and that with a rotatory as 
well as progressive motion, in order that the parts may, 
by this means also, set themselves at liberty, or more 
readily submit. Let this suffice for the motion in 

Let the fourth be that which we term the motion of mat 
ter, and which is opposed to the last; for in the motion of 
liberty, bodies abhor, reject, and avoid a new size or vol 
ume, or any new expansion or contraction (for these differ 
ent terms have the same meaning), and strive, with all their 
power, to rebound and resume their former density; on the 
contrary, in the motion of matter, they are anxious to ac 
quire a new volume or dimension, and attempt it willingly 
and rapidly, and occasionally by a most vigorous effort, as 
in the example of gunpowder. The most powerful, or at 
least most frequent, though not the only instruments of 
this motion, are heat and cold. For instance, the air, if 
expanded by tension (as by suction in the glass egg), strug- 


glcs anxiously to restore itself; but if heat be applied, it 
strives, on the contrary, to dilate itself, and longs for a 
larger volume, regularly passing and migrating into it, as 
into a new form (as it is termed); nor after a certain degree 
of expansion is it anxious to return, unless it be invited to 
do so by the application of cold, which is not indeed a re 
turn, but a fresh change. So also water, when confined by 
compression, resists, and wishes to become as it was before, 
namely, more expanded; but if there happen an intense 
and continued cold, it changes itself readily, and of its own 
accord, into the condensed state of ice; and if the cold be 
long continued, without any intervening warmth (as in 
grottoes and deep caves), it is changed into crystal or simi 
lar matter, and never resumes its form. 

Let the fifth be that which we term the motion of con 
tinuity. We do not understand by this simple and primary 
continuity with any other body (for that is the motion of 
connection), but the continuity of a particular body in 
itself; for it is most certain that all bodies abhor a solu 
tion of continuity, some more and some less, but all par 
tially. In hard bodies (such as steel and glass) the resist 
ance to an interruption of continuity is most powerful and 
efficacious, while although in liquids it appears to be faint 
and languid, yet it is not altogether null, but exists in the 
lowest degree, and shows itself in many experiments, such 
as bubbles, the round form of drops, the thin threads which 
drip from roofs, the cohesion of glutinous substances, and 
the like. It is most conspicuous, however, if an attempt 
be made to push this separation to still smaller particles. 
Thus, in mortars, the pestle produces no effect after a cer 
tain degree of contusion, water does not penetrate small 
fissures, and the air itself, notwithstanding its subtilty, 


does not penetrate the pores of solid vessels at once, but 
only by long-continued insinuation. 

Let the sixth be that which we term the motion of acqui 
sition, or the motion of need. 81 It is that by which bodies 
placed among others of a heterogeneous and, as it were, 
hostile nature, if they meet with the means or opportunity 
of avoiding them, and uniting themselves with others of 
a more analogous nature, even when these latter are not 
closely allied to them, immediately seize and, as it were, 
select them, and appear to consider it as something acquired 
(whence we derive the name), and to have need of these 
latter bodies. For instance, gold, or any other metal in 
leaf, does not like the neighborhood of air; if, therefore, 
they meet with any tangible and thick substance (such as 
the finger, paper, or the like), they immediately adhere to 
it, and are not easily torn from it. Paper, too, and cloth, 
and the like, do not agree with the air, which is inherent 
and mixed in their pores. They readily, therefore, imbibe 
water or other liquids, and get rid of the air. Sugar, or a 
sponge, dipped in water or wine, and though part of it be 
out of the water or wine, and at some height above it, will 
yet gradually absorb them. 82 

Hence an excellent rule is derived for the opening 
and dissolution of bodies; for (not to mention corrosive 
and strong waters, which force their way) if a body can 
be found which is more adapted, suited, and friendly to 
a given solid, than that with which it is by some necessity 
united, the given solid immediately opens and dissolves 

81 As far as this motioii results from attraction and repulsion, it is only a 
simple consequence of the last two. Ed. 

8S These two cases are now resolved into the property of the capillary tubes 
and present only another feature of the law of attraction. Ed. 


itself to receive the former, and excludes or removes the 
latter. 83 Nor is the effect or power of this motion confined 
to contact, for the electric energy (of which Gilbert and 
others after him have told so many fables) is only the 
energy excited in a body by gentle friction, and which 
does not endure the air, but prefers some tangible substance 
if there be any at hand. 

Let the seventh be that which we term the motion of 
greater congregation, by which bodies are borne toward 
masses of a similar nature, for instance, heavy bodies toward 
the earth, light to the sphere of heaven. The schools termed 
this natural motion, by a superficial consideration of it, be 
cause produced by no external visible agent, which made 
them consider it innate in the substances; or perhaps 
because it does not cease, which is little to be wondered 
at, since heaven and earth are always present, while the 
causes and sources of many other motions are sometimes 
absent and sometimes present. They therefore called this 
perpetual and proper, because it is never interrupted, but 
instantly takes place when the others are interrupted, and 
they called the others adscititious. The former, however, 
is in reality weak and slow, since it yields, and is inferior 
to the others as long as they act, unless the mass of the 
body be great; and although this motion have so filled 
men s minds, as almost to have obscured all others, yet 
they know but little about it, and commit many errors in 
its estimate. 

Let the eighth be that which we term the motion of 
lesser congregation, by which the homogeneous parts in 

83 This is one of the moat useful practical methods in chemistry at the 
present day. 


any body separate themselves from the heterogeneous and 
unite together, and whole bodies of a similar substance 
coalesce and tend toward each other, and are sometimes 
congregated, attracted, and meet, from some distance; thus 
in milk the cream rises after a certain time, and in wine the 
dregs and tartar sink; which effects are not to be attributed 
to gravity and levity only, so as to account for the rising 
of some parts and the sinking of others, but much more to 
the desire of the homogeneous bodies to meet and unite. 
This motion differs from that of need in two points: 1st, 
because the latter is the stimulus of a malignant and con 
trary nature, while in this of which we treat (if there be no 
impediment or restraint), the parts are united by their 
affinity, although there be no foreign nature to create a 
struggle; 2dly, because the union is closer and more 
select. For in the other motion, bodies which have no 
great affinity unite, if they can but avoid the hostile body, 
while in this, substances which are connected by a decided 
kindred resemblance come together and are molded into 
one. It is a motion existing in all compound bodies, and 
would be readily seen in each, if it were not confined and 
checked by the other affections and necessities of bodies 
which disturb the union. 

This motion is usually confined in the three following 
manners: by the torpor of the bodies; by the power of the 
predominating body; by external motion. With regard to 
the first, it is certain that there is more or less sluggishness 
in tangible bodies, and an abhorrence of locomotion; so that 
unless excited they prefer remaining contented with their 
actual state, to placing themselves in a better position. 
There are three means of breaking through this sluggish 
ness heat; the active power of a similar body; vivid and 


powerful motion. With regard to the first, heat is, on this 
account, defined as that which separates heterogeneous, and 
draws together homogeneous substances; a definition of 
the Peripatetics which is justly ridiculed by Gilbert, who 
says it is as if one were to define man to be that which 
sows wheat and plants vineyards; being only a definition 
deduced from effects, and those but partial. But it is still 
more to be blamed, because those effects, such as they are, 
are not a peculiar property of heat, but a mere accident (for 
cold, as we shall afterward show, does the same), arising 
from the desire of the homogeneous parts to unite; the 
heat then assists them in breaking through that sluggish 
ness which before restrained their desire. With regard to 
the assistance derived from the power of a similar body, it 
is most conspicuous in the magnet when armed with steel, 
for it excites in the steel a power of adhering to steel, as a 
homogeneous substance, the power of the magnet breaking 
through the sluggishness of the steel. With regard to the 
assistance of motion, it is seen in wooden arrows or points, 
which penetrate more deeply into wood than if they were 
tipped with iron, from the similarity of the substance, the 
swiftness of the motion breaking through the sluggishness 
of the wood; of which two last experiments we have spoken 
above in the aphorism on clandestine instances. 84 

The confinement of the motion of lesser congregation, 
which arises from the power of the predominant body, is 
shown in the decomposition of blood and urine by cold.* 
For as long as these substances are filled with the active 
spirit, which regulates and restrains each of their component 
parts, as the predominant ruler of the whole, the several 

84 See Aphorism xxv. 


different parts do not collect themselves separately on ac 
count of the check; but as soon as that spirit has evapo 
rated, or has been choked by the cold, then the decomposed 
parts unite, according to their natural desire. Hence it 
happens, that all bodies which contain a sharp spirit (as 
salts and the like), last without decomposition, owing 
to the permanent and durable power of the predominating 
and imperious spirit. 

The confinement of the motion of lesser congregation, 
which arises from external motion, is very evident in that 
agitation of bodies which preserves them from putrefaction. 
For all putrefaction depends on the congregation of the 
homogeneous parts, whence, by degrees, there ensues a 
corruption of the first form (as it is called), and the gen 
eration of another. For the decomposition of the original 
form, which is itself the union of the homogeneous parts, 
precedes the putrefaction, which prepares the way for the 
generation of another. This decomposition, if not inter 
rupted, is simple; but if there be various obstacles, putre 
factions ensue, which are the rudiments of a new genera 
tion. But if (to come to our present point) a frequent 
agitation be excited by external motion, the motion toward 
union (which is delicate and gentle, and requires to be free 
from all external influence) is disturbed, and ceases; which 
we perceive to be the case in innumerable instances. Thus, 
the daily agitation or flowing of water prevents putrefaction ; 
winds prevent the air from being pestilent; corn turned 
about and shaken in granaries continues clean: in short, 
everything which is externally agitated will with difficulty 
rot internally. 

We must not omit that union of the parts of bodies 
which is the principal cause of induration and desiccation. 


When the spirit or moisture, which has evaporated into 
spirit, has escaped from a porous body (such as wood, 
bone, parchment, and the like), the thicker parts are drawn 
together, and united with a greater effort, and induration 
or desiccation is the consequence; and this we attribute not 
so much to the motion of connection (in order to prevent a 
vacuum), as to this motion of friendship and union. 

Union from a distance is rare, and yet is to be met with 
in more instances than are generally observed. We per 
ceive it when one bubble dissolves another, when medi 
cines attract humors from a similarity of substance, when 
one string moves another in unison with it on different 
instruments, and the like. We are of opinion that this 
motion is very prevalent also in animal spirits, but are 
quite ignorant of the fact. It is, however, conspicuous in 
the magnet, and magnetized iron. While speaking of the 
motions of the magnet, we must plainly distinguish them, 
for there are four distinct powers or effects of the magnet 
which should not be confounded, although the wonder and 
astonishment of mankind has classed them together. 1. The "" 
attraction of the magnet to the magnet, or of iron to the 
magnet, or of magnetized iron to iron. 2. Its polarity 
toward the north and south, and its variation. 3. Its pene 
tration through gold, glass, stone, and all other substances. 
4. The communication of power from the mineral to iron, 
and from iron to iron, without any communication of the 
substances. Here, however, we only speak of the first. 
There is also a singular motion of attraction between quick- / 
silver and gold, so that the gold attracts quicksilver even 
when made use of in ointment; and those who work sur 
rounded by the vapors of quicksilver, are wont to hold a 
piece of gold in their mouths, to collect the exhalations, 


which would otherwise attack their heads and bones, and 
this piece soon grows white. 86 Let this suffice for the mo- 
tiou of lesser congregation. 

Let the ninth be the magnetic motion, which, although 
of the nature of that last mentioned, yet, when operating 
at great distances, and on great masses, deserves a separate 
inquiry, especially if it neither begin in contact, as most 
motions of congregation do, nor end by bringing the sub 
stances into contact, as all do, but only raise them, and 
make them swell without any further effect. For if the 
moon raise the waters, or cause moist substances to swell, 
or if the starry sphere attract the planets toward their 
apogees, or the sun confine the planets Mercury and "Venus 
to within a certain distance of his mass; 88 these motions do 
not appear capable of being classed under either of those 
of congregation, but to be, as it were, intermediately and 
imperfectly congregative, and thus to form a distinct species. 

Let the tenth motion be that of avoidance, or that which 
is opposed to the motion of lesser congregation, by which 
bodies, with a kind of antipathy, avoid and disperse, and 
separate themselves from, or refuse to unite themselves 
with others of a hostile nature. For although this may 
sometimes appear to be an accidental motion, necessarily 
attendant upon that of the lesser congregation, because the 
homogeneous parts cannot unite, unless the heterogeneous 
be first removed and excluded, yet it is still to be classed 
separately, 87 and considered as a distinct species, because, 

65 Query? 

86 Observe this approximation to Newton s theory. 

87 Those differences which are generated by the masses and respective dis 
tances of bodies are only differences of quantity, and not specific; consequently 
those three classes are only one. Ed. 


in many cases, the desire of avoidance appears to be more 
marked than that of union. 

It is very conspicuous in the excrements of animals, 
nor less, perhaps, in objects odious to particular senses, 
especially the smell and taste; for a fetid smell is rejected 
by the nose, so as to produce a sympathetic motion of ex 
pulsion at the mouth of the stomach; a bitter and rough 
taste is rejected by the palate or throat, so as to produce 
a sympathetic concussion and shivering of the head. This 
motion is visible also in other cases. Thus it is observed 
in some kinds of antiperistasis, as in the middle region of 
the air, the cold of which appears to be occasioned by the 
rejection of cold from the regions of the heavenly bodies; 
and also in the heat and combustion observed in subter 
ranean spots, which appear to be owing to the rejection of 
heat from the centre of the earth. For heat and cold, when 
in small quantities, mutually destroy each other, while in 
larger quantities, like armies equally matched, they remove 
and eject each other in open conflict. It is said, also that 
cinnamon and other perfumes retain their odor longer when 
placed near privies and foul places, because they will not 
unite and mix witli stinks. It is well known that quick 
silver, which would otherwise reunite into a complete mass, 
is prevented from so doing by man s spittle, pork lard, tur 
pentine and the like, from the little affinity of its parts with 
those substances, so that when surrounded by them it draws 
itself back, and its avoidance of these intervening obstacles 
is greater than its desire of reuniting itself to its homoge 
neous parts; which is what they term the mortification of 
quicksilver. Again, the difference in weight of oil and 
water is not the only reason for their refusing to mix, but 
it is also owing to the little a f Unity of the two; for spirits 


of wine, which are lighter than oil, mix very well with 
water. A very remarkable instance of the motion in ques 
tion is seen in nitre, and crude bodies of a like nature, 
which abhor flame, as may be observed in gunpowder, 
quicksilver and gold. The avoidance of one pole of the 
magnet by iron is not (as Gilbert has well observed), 
strictly speaking, an avoidance, but a conformity, or at 
traction to a more convenient situation. 

Let the eleventh motion be that of assimilation, or self- 
multiplication, or simple generation, by which latter term 
we do not mean the simple generation of integral bodies, 
such as plants or animals, but of homogeneous bodies. 
By this motion homogeneous bodies convert those which 
are allied to them, or at least well disposed and prepared, 
into their own substance and nature. Thus flame multi 
plies itself over vapors and oily substances and generates 
fresh flame; the air over water and watery substances mul 
tiplies itself and generates fresh air; the vegetable and ani 
mal spirit, over the thin particles of a watery or oleaginous 
spirit contained in its food, multiplies itself and generates 
fresh spirit; the solid parts of plants and animals, as the 
leaf, flower, the flesh, bone and the like, each of them 
assimilate some part of the juices contained in their food, 
and generate a successive and daily substance. For let 
none rave with Paracelsus, who (blinded by his distilla 
tions) would have it, that nutrition takes place by mere 
separation, and that the eye, nose, brain and liver lie con 
cealed in bread and meat, the root, leaf and flower, in the 
juice of the earth; asserting that just as the artist brings 
out a leaf, flower, eye, nose, hand, foot and the like, from 
a rude mass of stone or wood by the separation and rejec 
tion of what is superfluous; so the great artist within us 


brings out our several limbs and parts by separation and 
rejection. But to leave such trifling, it is most certain that 
all the parts of vegetables and animals, as well the homo 
geneous as organic, first of all attract those juices contained 
in their food, which are nearly common, or at least not very 
different, and then assimilate and convert them into their 
own nature. Nor does this assimilation, or simple genera 
tion, take place in animated bodies only, but the inanimate 
also participate in the same property (as we have observed 
of flame and air), and that languid spirit, which is contained 
in every tangible animated substance, is perpetually work 
ing upon the coarser parts, and converting them into spirit, 
which afterward is exhaled, whence ensues a diminution of 
weight, and a desiccation of which we have spoken else 
where." 8 

Nor should we, in speaking of assimilation, neglect 
to mention the accretion which is usually distinguished 
from aliment, and which is observed when mud grows into 
a mass between stones, and is converted into a stony sub 
stance, and the scaly substance round the teeth is converted 
into one no less hard than the teeth themselves; for we are 
of opinion that there exists in all bodies a desire of assim 
ilation, as well as of uniting with homogeneous masses. 
Each of these powers, however, is confined, although in 
different manners, and should be diligently investigated, 
because they are connected with the revival of old age. 
Lastly, it is worthy of observation, that in the nine 
preceding motions, bodies appear to aim at the mere 
preservation of their nature, while in this they attempt 
its propagation. 

88 See the citing instances, Aphorism xl. 


Let the twelfth motion be that of excitement, which 
appears to be a species of the last, and is sometimes men 
tioned by us under that name. It is, like that, a diffu 
sive, communicative, transitive and multiplying motion; 
and they agree remarkably in their effect, although they 
differ in their mode of action, and in their subject matter. 
The former proceeds imperiously and with authority; it 
orders and compels the assimilated to be converted and 
changed into the assimilating body. The latter proceeds 
by art, insinuation and stealth, inviting and disposing the 
excited toward the nature of the exciting body. The for 
mer both multiplies and transforms bodies and substances; 
thus a greater quantity of flame, air, spirit and flesh is 
formed; but in the latter, the powers only are multiplied 
and changed, and heat, the magnetic power, and putrefac 
tion, in the above instances, are increased. Heat does not 
diffuse itself when heating other bodies by any communica 
tion of the original heat, but only by exciting the parts of 
the heated body to that motion which is the form of heat, 
and of which we spoke in the first vintage of the nature 
of heat. Heat, therefore, is excited much less rapidly and 
readily in stone or metal than in air, on account of the in 
aptitude and sluggishness of those bodies in acquiring that 
motion, so that it is probable, that there may be some sub 
stances, toward the centre of the earth, quite incapable of 
being heated, on account of their density, which may de 
prive them of the spirit by which the motion of excitement 
is usually commenced. Thus also the magnet creates in the 
iron a new disposition of its parts, and a conformable mo 
tion, without losing any of its virtue. So the leaven of 
bread, yeast, rennet and some poisons, excite and invite 
successive and continued motion in dough, beer, cheese or 


the human body; not so much from the power of the 
exciting, as the predisposition and yielding of the excited 

Let the thirteenth motion be that of impression, which 
is also a species of motion of assimilation, and the most 
subtile of diffusive motions. We have thought it right, 
however, to consider it as a distinct species, on account of 
its remarkable difference from the last two; for the simple 
motion of assimilation transforms the bodies themselves, so 
that if you remove the first agent, you diminish not the 
effect of those which succeed; thus, neither the first light 
ing of flame, nor the first conversion into air, are of any 
importance to the flame or air next generated. So, also, 
the motion of excitement still continues for a considerable 
time after the removal of the first agent, as in a heated 
body on the removal of the original heat, in the excited 
iron on the removal of the magnet, and in the dough on 
the removal of the leaven. But the motion of impression, 
although diffusive and transitive, appears, nevertheless, to 
depend on the first agent, so that upon the removal of the 
latter the former immediately fails and perishes; for which 
reason also it takes effect in a moment, or at least a very 
short space of time. We are wont to call the two former 
motions the motions of the generation of Jupiter, because 
when born they continue to exist; and the latter, the mo 
tion of the generation of Saturn, because it is immediately 
devoured and absorbed. It may be seen in three instances: 
1, in the rays of light; 2, in the percussions of sounds; 3, 
in magnetic attractions as regards communication. For, on 
the removal of light, colors and all its other images disap 
pear, as on the cessation of the first percussion and the 
vibration of the body, sound soon fails, and although 


sounds are agitated by the wind, like waves, yet it is 
to be observed, that the same sound does not last during 
the whole time of the reverberation. Thus, when a bell 
is struck, the sound appears to be continued for a consid 
erable time, and one might easily be led into the mistake 
of supposing it to float and remain in the air during the 
whole time, which is most erroneous. 89 For the reverbera 
tion is not one identical sound, but the repetition of sounds, 
which is made manifest by stopping and confining the sono 
rous body; thus, if a bell be stopped and held tightly, so 
as to be immovable, the sound fails, and there is no further 
reverberation, and if a musical string be touched after the 
first vibration, either with the finger (as in the harp), or a 
quill (as in the harpsichord), the sound immediately ceases. 
If the magnet be removed the iron falls. The moon, how 
ever, cannot be removed from the sea, nor the earth] from a 
heavy falling body, and we can, therefore, make no experi 
ment upon them; but the case is the same. 

Let the fourteenth motion be that configuration or po 
sition, by which bodies appear to desire a peculiar situa 
tion, collocation, and configuration with others, rather than 
union or separation,, This is a very abstruse notion, and 
has not been well investigated; and, in some instances, 
appears to occur almost without any cause, although we 

89 Aristotle s doctrine, that sound takes place when bodies strike the air, 
which the modern science of acoustics has completely established, was rejected 
by Bacon in a treatise upon the same subject: "The collision or thrusting of 
air, ; he says, "which they will have to be the cause of sound, neither denotes 
the form nor the latent process of sound, but is a term of ignorance and of 
superficial contemplation." To get out of the difficulty, he betook himself to 
his theory of spirits, a species of phenomena which he constantly introduces 
to give himself the air of explaining things he could not understand, or would 
not admit upon the hypothesis of his opponents. Ed. 


be mistaken in supposing this to be really the case. For 
if it be asked, why the heavens revolve from east to west, 
rather than from west to east, or why they turn on poles 
situate near the Bears, rather than round Orion or any 
other part of the heaven, such a question appears to be 
unreasonable, since these phenomena should be received as 
determinate and the objects of our experience. There are, 
indeed, some ultimate and self-existing phenomena in na 
ture, but those which we have just mentioned are not to 
be referred to that class: for we attribute them to a cer 
tain harmony and consent of the universe, which has not 
yet been properly observed. But if the motion of the 
earth from west to east be allowed, the same question may 
be put, for it must also revolve round certain poles, and 
why should they be placed where they are, rather than 
elsewhere ? The polarity and variation of the needle come 
under our present head. There is also observed in both 
natural and artificial bodies, especially solids rather than 
fluids, a particular collocation and position of parts, resem 
bling hairs or fibres, which should be diligently investi 
gated, since, without a discovery of them, bodies cannot be 
conveniently controlled or wrought upon. The eddies ob 
servable in liquids by which, when compressed, they suc 
cessively raise different parts of their mass before they can 
escape, so as to equalize the pressure, is more correctly 
assigned to the motion of liberty. 

Lei the fifteenth motion be that of transmission or of 
passage, by which the powers of bodies are more or less 
impeded or advanced by the medium, according to the 
nature of the bodies and their effective powers, and also 
according to that of the medium. For one medium is 
adapted to light, another to sound, another to heat and 


cold, another to magnetic action, and so on with regard 
to the other actions. 

Let the sixteenth be that which we term the royal or 
political motion, by which the predominant and governing 
parts of any body check, subdue, reduce, and regulate the 
others, and force them to unite, separate, stand still, move, 
or assume a certain position, not from any inclination of 
their own, but according to a certain order, and as best 
suits the convenience of the governing part, so that there 
is a sort of dominion and civil government exercised by 
the ruling part over its subjects. The motion is very con 
spicuous in the spirits of animals, where, as long as it is in 
force, it tempers all the motions of the other parts. It is 
found in a less degree in other bodies, as we have observed 
in blood and urine, which are not decomposed until the 
spirit, which mixed and retained their parts, has been 
emitted or extinguished. Nor is this motion peculiar to 
spirits only, although in most bodies the spirit predomi 
nates, owing to its rapid motion and penetration; for the 
grosser parts predominate in denser bodies, which are not 
filled with a quick and active spirit (such as exists in 
quicksilver or vitriol), so that unless this check or yoke be 
thrown off by some contrivance, there is no hope of any 
transformation of such bodies. And let not any one sup 
pose that we have forgotten our subject, because we speak 
of predominance in this classification of motions, which is 
made entirely with the view of assisting the investigation 
of wrestling instances, or instances of predominance. For 
we do not now treat of the general predominance of motions 
or powers, but of that of parts in whole bodies, which con 
stitutes the particular species here considered. 

Let the seventeenth motion be the spontaneous motion 


of revolution, by which bodies having a tendency to move, 
and placed in a favorable situation, enjoy their peculiar 
nature, pursuing themselves and nothing else, and seek 
ing, as it were, to embrace themselves. For bodies seem 
either to move without any limit, or to tend toward a limit, 
arrived at which they either revolve according to their 
peculiar nature, or rest. Those which are favorably situ 
ated, and have a tendency to motion, move in a circle with 
an eternal and unlimited motion; those which are favor 
ably situated and abhor motion, rest. Those which are 
not favorably situated move in a straight line (as their 
shortest path), in order to unite with others of a congenial 
nature. This motion of revolution admits of nine differ 
ences: 1, with regard to the centre about which the bodies 
move; 2, the poles round which they move; 3, the circum 
ference or orbit relatively to its distance from the centre; 
4, the velocity, or greater or less speed with which they 
revolve; 5, the direction of the motion as from east to 
west, or the reverse; 6, the deviation from a perfect circle, 
by spiral lines at a greater or less distance from the centre; 
7, the deviation from the circle, by spiral lines at a greater 
or less distance from the poles; 8, the greater or less dis 
tance of these spirals from each other; 9, and lastly, the 
variation of the poles if they be movable; which, however, 
only affects revolution when circular. The motion in ques 
tion is, according to common and long-received opinion, 
considered to be that of the heavenly bodies. There ex 
ists, however, with regard to this, a considerable dispute 
between some of the ancients as well as moderns, who have 
attributed a motion of revolution to the earth. A much 
more reasonable controversy, perhaps, exists (if it be not a 
matter beyond dispute), whether the motion in question (on 


the hypothesis of the earth s being fixed) is confined to the 
heavens, or rather descends and is communicated to the air 
and water. The rotation of missiles, as in darts, musket- 
balls, and the like, we refer entirely to the motion of liberty. 

Let the eighteenth motion be that of trepidation, 90 to 
which (in the sense assigned to it by astronomers) we do 
Dot give much credit; but in our serious and general search 
after the tendencies of natural bodies, this motion occurs, 
and appears worthy of forming a distinct species. It is the 
motion of an (as it were) eternal captivity; when bodies, 
for instance, being placed not altogether according to their 
nature, and yet not exactly ill, constantly tremble, and are 
restless, not contented with their position, and yet not dar 
ing to advance. Such is the motion of the heart and pulse 
of animals, and it must necessarily occur in all bodies which 
are situated in a mean state, between conveniences and 
inconveniences; so that being removed from their proper 
position, they strive to escape, are repulsed, and again 
continue to make the attempt. 

Let the nineteenth and last motion be one which can 
scarcely be termed a motion, and yet is one; and which we 
may call the motion of repose, or of abhorrence of motion. 
It is by this motion that the earth stands by its own weight, 
while its extremes move toward the middle, not to an im 
aginary centre, but in order to unite. It is owing to the 
same tendency, that all bodies of considerable density 
abhor motion, and their only tendency is not to move, 
which nature they preserve, although excited and urged 

90 The motion of trepidation, as Bacon calls it, was attributed by the ancient 
astronomers to the eight spheres, relative to the precession of the equinoxes. 
Galileo was the first to observe this kind of lunar motion. Rl. 


in a variety of ways to motion. But if they be compelled 
to move, yet do they always appear anxious to recover 
their former state, and to cease from motion, in which re 
spect they certainly appear active, and attempt it with suffi 
cient swiftness and rapidity, as if fatigued, and impatient 
of delay. We can only have a partial representation of 
this tendency, because with us every tangible substance is 
not only not condensed to the utmost, but even some spirit 
is added, owing to the action and concocting influence of 
the heavenly bodies. 

We have now, therefore, exhibited the species, or sim 
ple elements of the motions, tendencies, and active powers, 
which are most universal in nature; and no small portion 
of natural science has been thus sketched out. We do not, 
however, deny that other instances can perhaps be added, 
and our divisions changed according to some more natural 
order of things, and also reduced to a less number; in which 
respect we do not allude to any abstract classification, as if 
one were to say, that bodies desire the preservation, exal 
tation, propagation, or fruition of their nature; or, that 
motion tends to the preservation and benefit either of the 
universe (as in the case of those of resistance and connec 
tion), or of extensive wholes, as in the case of those of the 
greater congregation, revolution, and abhorrence of motion, 
or of particular forms, as in the case of the others. For 
although such remarks be just, yet, unless they terminate 
in matter and construction, according to true definitions, 
they are speculative, and of little use. In the meantime, 
our classification will suffice, and be of much use in the 
consideration of the predominance of powers, and examin 
ing the wrestling instances which constitute our present 


For of the motions here laid down, some are quite in 
vincible, some more powerful than others, which they con 
fine, check, and modify ; others extend to a greater distance, 
others are more immediate and swift, others strengthen, 
increase, and accelerate the rest. 

The motion of resistance is most adamantine and invin 
cible. We are yet in doubt whether such be the nature of 
that of connection; for we cannot with certainty determine 
whether there be a vacuum, either extensive or intermixed 
with matter. Of one thing, however, we are satisfied, that 
the reason assigned by Leucippus and Democritus for the 
introduction of a vacuum (namely, that the same bodies 
could not otherwise comprehend, and fill greater and less 
spaces) is false. For there is clearly a folding of matter, 
by which it wraps and unwraps itself in space within cer 
tain limits, without the intervention of a vacuum. Nor is 
there two thousand times more of vacuum in air than in 
gold, as there should be on this hypothesis; a fact demon 
strated by the very powerful energies of fluids (which would 
otherwise float like fine dust in vacuo), and many other 
proofs. The other motions direct, and are directed by each 
other, according to their strength, quantity, excitement, 
emission, or the assistance or impediments they meet with. 

For instance; some armed magnets hold and support 
iron of sixty times their own weight; so far does the mo 
tion of lesser congregation predominate over that of the 
greater; but if the weight be increased, it yields. A lever 
of a certain strength will raise a given weight, and so far 
the motion of liberty predominates over that of the greater 
congregation, but if the weight be greater, the former 
motion yields. A piece of leather stretched to a certain 

point does not break, and so far the motion of continuity 

SCIENCE Vol. 23 12 


predominates over that of tension, but if the tension be 
greater, the leather breaks, and the motion of continuity 
yields. A certain quantity of water flows through a chink, 
and so far the motion of greater congregation predominates 
over that of continuity, but if the chink be smaller it yields. 
If a musket be charged with ball and powdered sulphur 
alone, and fire be applied, the ball is not discharged, in 
which case the motion of greater congregation overcomes 
that of matter; but when gunpowder is used, the motion of 
matter in the sulphur predominates, being assisted by that 
motion, and the motion of avoidance in the nitre; and so 
of the rest. For wrestling instances (which show the pre 
dominance of powers, and in what manner and proportion 
they predominate and yield) must be searched for with 
active and industrious diligence. 

The methods and nature of this yielding must also be 
diligently examined, as for instance, whether the motions 
completely cease, or exert themselves, but are constrained. 
For in the bodies with which we are acquainted, there is no 
real but an apparent rest, either in the whole or in parts. 
This apparent rest is occasioned either by equilibrium, or 
the absolute predominance of motions. By equilibrium, 
as in the scales of the balance, which rest if the weights 
be equal. By predominance, as in perforated jars, in which 
the water rests, and is prevented from falling by the pre 
dominance of the motion of connection. It is, however, to 
be observed (as we have said before), how far the yielding 
motions exert themselves. For if a man be held stretched 
out on the ground against his will, with arms and legs 
bound down, or otherwise confined, and yet strive with all 
his power to get up, the struggle is not the less, although 
ineffectual. The real state of the case (namely, whether 


the yielding motion be, as it were, annihilated by the pre 
dominance, or there be rather a continued, although an in 
visible effort) will, perhaps, appear in the concurrence of 
motions, although it escape our notice in their conflict, 
For instance: let an experiment be made with muskets; 
whether a musket-ball, at its utmost range in a straight 
line, or (as it is commonly called) point-blank, strike with 
less force when projected upward, where the motion of the 
blow is simple, than when projected downward, where 
the motion of gravity concurs with the blow. 

The rules of such instances of predominance as occur 
should be collected: such as the following; the more gen 
eral the desired advantage is, the stronger will be the mo 
tion; the motion of connection, for instance, which relates 
to the intercourse of the parts of the universe, is more 
powerful than that of gravity, which relates to the inter 
course of dense bodies only. Again, the desire of a private 
good does not in general prevail against that of a public 
one, except where the quantities are small. Would that 
such were the case in civil matters! 

XLIX. In the twenty-fifth rank of prerogative instances 
we will place suggesting instances; such as suggest, or point 
out, that which is advantageous to mankind; for bare power 
and knowledge in themselves exalt rather than enrich 
human nature. We must, therefore, select from the gen 
eral store such things as are most useful to mankind. We 
shall have a better opportunity of discussing these when 
we treat of the application to practice; besides, in the work 
of interpretation, we leave room, on every subject, for the 
human or optative chart; for it is a part of science to make 
judicious inquiries and wishes. 

L. In the twenty-sixth rank of prerogative instances we 


will place the generally useful instances. They are such 
as relate to various points, and frequently occur, sparing 
by that means considerable labor and new trials. The 
proper place for treating of instruments and contrivances, 
will be that in which we speak of the application to practice, 
and the methods of experiment. All that has hitherto been 
ascertained, and made use of, will be described in the par 
ticular history of each art. At present, we will subjoin a 
few general examples of the instances in question. 

Man acts, then, upon natural bodies (besides merely 
bringing them together or removing them) by seven prin 
cipal methods: 1, by the exclusion of all that impedes and 
disturbs; 2, by cfompression, extension, agitation, and the 
like; 3, by heat and cold; 4, by detention in a suitable 
place; 5, by checking or directing motion; 6, by peculiar 
harmonies; 7, by a seasonable and proper alternation, series, 
and succession of all these, or, at least, of some of them. 

1. With regard to the first common air, which is al 
ways at hand, and forces its admission, as also the rays of 
the heavenly bodies, create much disturbance. Whatever, 
therefore, tends to exclude them may well be considered as 
generally useful. The substance and thickness of vessels 
in which bodies are placed when prepared for operations 
may be referred to this head. So also may the accurate 
methods of closing vessels by consolidation, or the lutum 
sapiential, as the chemists call it. The exclusion of air by 
means of liquids at the extremity is also very useful, as 
when they pour oil on wine, or the juices of herbs, which 
by spreading itself upon the top like a cover, preserves 
them uninjured from the air. Powders, also, are service 
able, for although they contain air mixed up in them, yet 
they ward off the power of the mass of circumambient air, 


which is seen in the preservation of grapes and other fruits 
in sand or flour. Wax, honey, pitch, and other resinous 
bodies, are well used in order to make the exclusion more 
perfect, and to remove the air and celestial influence. We 
have sometimes made an experiment by placing a vessel or 
other bodies in quicksilver, the most dense of all substances 
capable of being poured round others. Grottoes and subter 
raneous caves are of great use in keeping off the effects of 
the sun, and the predatory action of air, and in the north 
of Germany are used for granaries. The depositing of 
bodies at the bottom of water may be also mentioned here; 
and I remember having heard of some bottles of wine being 
let down into a deep well in order to cool them, but left 
there by chance, carelessness, and forgetfulness for several 
years, and then taken out; by which means the wine not 
only escaped becoming flat or dead, but was much more 
excellent in flavor, arising (as it appears) from a more com 
plete mixture of its parts. But if the case require that 
bodies should be sunk to the bottom of water, as in rivers 
or the sea, and yet should not touch the water, nor be in 
closed in sealed vessels, but surrounded only by air, it 
would be right to use that vessel which has been some 
times employed under water above ships that have sunk, 
in order to enable the divers to remain below and breathe 
occasionally by turns. It was of the following nature: A 
hollow tub of metal was formed, and sunk so as to have its 
bottom parallel with the surface of the water; it thus carried 
down with it to the bottom of the sea all the air contained 
in the tub. It stood upon three feet (like a tripod), being 
of rather less height than a man, so that, when the diver 
was in want of breath, he could put his head into the 
hollow of the tub, breathe, and then continue his work. 


We hear that some sort of boat or vessel has now been 
invented, capable of carrying men some distance under 
water. Any bodies, however, can easily be suspended 
under some such vessel as we have mentioned, which has 
occasioned our remarks upon the experiment. 

Another advantage of the careful and hermetical closing 
of bodies is this not only the admission of external air is 
prevented (of which we have treated), but the spirit of 
bodies also is prevented from making its escape, which 
is an internal operation. For any one operating on natural 
bodies must be certain as to their quantity, and that noth 
ing has evaporated or escaped, since profound alterations 
take place in bodies, when art prevents the loss or escape 
of any portion, while nature prevents their annihilation. 
With regard to this circumstance, a false idea has prevailed 
(which if true would make us despair of preserving quan 
tity without diminution), namely, that the spirit of bodies, 
and air when rarefied by a great degree of heat, cannot be 
so kept in by being inclosed in any vessel as not to escape 
by the small pores. Men are led into this idea by the com 
mon experiments of a cup inverted over water, with a candle 
or piece of lighted paper in it, by which the water is drawn 
up, and of those cups which, when heated, draw up the 
flesh. For they think that in each experiment the rarefied 
air escapes, and that its quantity is therefore diminished, 
by which means the water or flesh rises by the motion of 
connection. This is, however, most incorrect. For the air 
is not diminished in quantity, but contracted in dimen 
sions, 91 nor does this motion of the rising of the water 

91 Purl of the air is expanded and escapes, and part is consumed by th 
flame. When condensed, therefore, by the cold application, it cannot offer sui- 


begin till the flame is extinguished, or the air cooled, so 
that physicians place cold sponges, moistened with water, 
on the cups, in order to increase their attraction. There is, 
therefore, no reason why men should fear much from the 
ready escape of air: for although it be true that the most 
solid bodies have their pores, yet neither air, nor spirit, 
readily suffers itself to be rarefied to such an extreme de 
gree; just as water will not escape by a small chink. 

2. With regard to the second of the seven above- 
mentioned methods, we must especially observe, that com 
pression and similar violence have a most powerful effect 
either in producing locomotion, and other motions of the 
same nature, as may be observed in engines and projectiles, 
or in destroying the organic body, and those qualities, which 
consist entirely in motion (for all life, and every description 
of flame and ignition are destroyed by compression, which 
also injures and deranges every machine); or in destroying 
those qualities which consist in position and a coarse differ 
ence of parts, as in colors; for the color of a flower when 
whole, differs from that it presents when bruised, and the 
same may be observed of whole and powdered amber; or 
in tastes, for the taste of a pear before it is ripe, and of the 
same pear when bruised and softened, is different, since 
it becomes perceptibly more sweet. But such violence is of 
little avail in the more noble transformations and changes 
of homogeneous bodies, for they do not, by such means, 
acquire any constantly and permanently new state, but one 
that is transitory, and always struggling to return to its 
former habit and freedom. It would not, however, be use- 

ficient resistance to the external atmosphere to prevent the liquid or flesh from 
being forced into the glass. 


less to make some more diligent experiments with regard 
to this; whether, for instance, the condensation of a per 
fectly homogeneous body (such as air, water, oil, and the 
like) or their rarefaction, when effected by violence, can 
become permanent, fixed, and. as it were, so changed, as 
to become a nature. This might at first be tried by simple 
perseverance, and then by means of helps and harmonies. 
It might readily have been attempted (if we had but thought 
of it), when we condensed water (as was mentioned above), 
by hammering and compression, until it burst out. For we 
ought to have left the flattened globe untouched for some 
days, and then to have drawn off the water, in order to 
try whether it would have immediately occupied the same 
dimensions as it did before the condensation. If it had not 
done so, either immediately, or soon afterward, the conden 
sation would have appeared to have been rendered constant; 
if not, it would have appeared that a restitution took place, 
and that the condensation had been transitory. Something 
of the same kind might have been tried with the glass eggs; 
the egg should have been sealed up suddenly and firmly, 
after a complete exhaustion of the air, and should have been, 
allowed to remain so for some days, and it might then have 
been tried whether, on opening the aperture, the air would 
be drawn in with a hissing noise, or whether as much water 
would be drawn into it when immersed, as would have been 
drawn into it at first, if it had not continued sealed. For 
it is probable (or, at least, worth making the experiment) 
that this might have happened, or might happen, because 
perseverance has a similar effect upon bodies which are a 
little less homogeneous. A stick bent together for some 
time does not rebound, which is not owing to any loss of 
quantity in the wood during the time, for the same would 


occur (after a larger time) in a plate of steel, which does 
not evaporate. If the experiment of simple perseverance 
should fail, the matter should not be given up, but other 
means should be employed. For it would be no small ad 
vantage, if bodies could be endued with fixed and constant 
natures by violence. Air could then be converted into 
water by condensation, with other similar effects; for man 
is more the master of violent motions than of any other 

3. The third of our seven methods is referred to that 
great practical engine of nature, as well as of art, cold 
and heat. Here, man s power limps, as it were, with one 
leg. For we possess the heat of fire, which is infinitely 
more powerful and intense than that of the sun (as it 
reaches us), and that of animals. But we want cold, 92 ex 
cept such as we can obtain in winter, in caverns, or by 
surrounding objects with snow and ice, which, perhaps, 
may be compared in degree with the noontide heat of the 
sun in tropical countries, increased by the reflection of 
mountains and walls. For this degree of heat and cold 
can be borne for a short period only by animals, yet it 
is nothing compared with the heat of a burning furnace, 
or the corresponding degree of cold. 93 Everything with us 
has a tendency to become rarefied, dry and wasted, and noth- 

92 Heat can now be abstracted by a very simple process, till the degree of 
cold be of almost any required intensity. Ed. 

}3 It is impossible to compare a degree of heat with a degree of cold, without 
the assumption of some arbitrary test, to which the degrees are to be referred. 
In the next sentence Bacon appears to have taken the power of animal life to 
support heat or cold as the test, and then the comparison can only be between 
the degree of heat or of cold that will produce death. 

The zero must be arbitrary which divides equally a certain degree of heat 
from a certain degree of cold. Ed. 


ing to become condensed or soft, except by mixtures, and, 
as it were, spurious methods. Instances of cold, therefore, 
should be searched for most diligently, such as may be 
found by exposing bodies upon buildings in a hard frost, 
in subterraneous caverns, by surrounding bodies with snow 
and ice in deep places excavated for that purpose, by let 
ting bodies down into wells, by burying bodies in quick 
silver and metals, by immersing them in streams which 
petrify wood, by buying them in the earth (which the 
Chinese are reported to do with their china, masses of 
which, made for that purpose, are said to remain in the 
ground for forty or fifty years, and to be transmitted to 
their heirs as a sort of artificial mine) and the like. The 
condensations which take place in nature, by means of cold, 
should also be investigated, that by learning their causes, 
they may be introduced into the arts; such as arc observed 
in the exudation of marble and stones, in the dew upon the 
panes of glass in a room toward morning after a frosty 
night, in the formation and the gathering of vapors under 
the earth into water, whence spring fountains and the like. 
Besides the substances which are cold to the touch, 
there are others which have also the effect of cold, and 
condense; they appear, however, to act only upon the 
bodies of animals, and scarcely any further. Of these we 
have many instances, in medicines and plasters. Some 
condense the flesh and tangible parts, such as astringent 
and inspissating medicines, others the spirits, such as 
soporifics. There are two modes of condensing the spirits, 
by soporifics or provocatives to sleep; the one by calming 
the motion, the other by expelling the spirit. The violet, 
dried roses, lettuces, and other benign or mild remedies, by 
their friendly and gently cooling vapors, invite the spirits 


to unite, and restrain their violent and perturbed motion. 
Rose-water, for instance, applied to the nostrils in fainting 
fits, causes the resolved and relaxed spirits to recover them 
selves, and, as it were, cherishes them. But opiates, and 
the like, banish the spirits by their malignant and hostile 
quality. If they be applied, therefore, externally, the 
spirits immediately quit the part and no longer readily 
flow into it; but if they be taken internally, their vapor, 
mounting to the head, expels, in all directions, the spirits 
contained in the ventricles of the brain, and since these 
spirits retreat, but cannot escape, they consequently meet 
and are condensed, and are sometimes completely extin 
guished and suffocated; although the same opiates, when 
taken in moderation, by a secondary accident (the conden 
sation which succeeds their union), strengthen the spirits, 
render them more robust, and check their useless and in 
flammatory motion, by which means they contribute not a 
little to the cure of diseases, and the prolongation of life. 

The preparations of bodies, also, for the reception of cold 
should not be omitted, such as that water a little warmed is 
more easily frozen than that which is quite cold, and the 

Moreover, since nature supplies cold so sparingly, .we 
must act like the apothecaries, who, when they cannot 
obtain any simple ingredient, take a succedaneum, or quid 
pro quo, as they term it, such as aloes for xylobalsamum, 
cassia for cinnamon. In the same manner we should look 
diligently about us, to ascertain whether there may be any 
substitutes for cold, that is to say, in what other manner 
condensation can be effected, which is the peculiar opera 
tion of cold. Such condensations appear hitherto to be of 
four kinds only. 1. By simple compression, which is of lit- 


tie avail toward permanent condensation, on account of the 
elasticity of substances, but may still, however, be of some 
assistance. 2. By the contraction of the coarser, after the 
escape or departure of the finer parts of a given body; as is 
exemplified in induration by fire, and the repeated heating 
and extinguishing of metals, and the like. 3. By the 
cohesion of the most solid homogeneous parts of a given 
body, which were previously separated, and mixed with 
others less solid, as in the return of sublimated mercury to 
its simple state, in which it occupies much less space than 
it did in powder, and the same may be observed of the 
cleansing of all metals from their dross. 4. By harmony, 
or the application of substances which condense by some 
latent power. These harmonies are as yet but rarely ob 
served, at which we cannot be surprised, since there is little 
to hope for from their investigation, unless the discovery of 
forms and confirmation be attained. With regard to ani 
mal bodies, it is not to be questioned that there are many 
internal and external medicines which condense by har 
mony, as we have before observed, but this action is rare 
in inanimate bodies. Written accounts, as well as report, 
have certainly spoken of a tree in one of the Tercera or 
Canary Islands (for I do not exactly recollect which) that 
drips perpetually, so as to supply the inhabitants, in some 
degree, with water; and Paracelsus says that the herb called 
ros solis is filled with dew at noon, while the sun gives out 
its greatest heat, and all other herbs around it are dry. We 
treat both these accounts as fables; they would, however, if 
true, be of the most important service, and most worthy of 
examination. As to the honey-dew, resembling manna, 
which is found in May on the leaves of the oak, we are of 
opinion that it is not condensed by any harmony or peculi- 


arity of the oak leaf, but that while it falls equally upon 
other leaves it is retained and continues on those of the 
oak, because their texture is closer, and not so porous as 
that of most of the other leaves. 94 

With regard to heat, man possesses abundant means and 
power; but his observation and inquiry are defective in 
some respects, and those of the greatest importance, not 
withstanding the boasting of quacks. For the effects of 
intense heat are examined and observed, while those of a 
more gentle degree of heat, being of the most frequent oc 
currence in the paths of nature, are, on that very account, 
least known. We see, therefore, the furnaces, which are 
most esteemed, employed in increasing the spirits of bodies 
to a great extent, as in the strong acids, and some chemical 
oils; while the tangible parts are hardened, and, when the 
volatile part has escaped, become sometimes fixed; the 
homogeneous parts are separated, and the heterogeneous 
incorporated and agglomerated in a coarse lump; and (what 
is chiefly worthy of remark) the junction of compound 
bodies, and the more delicate conformations are destroyed 
and confounded. But the operation of a less violent heat 
should be tried and investigated, by which more delicate 
mixtures and regular conformations may be produced and 
elicited, according to the example of nature, and in imita 
tion of the effect of the sun, which we have alluded to in 
the aphorism on the instances of alliance. For the works 
of nature are carried on in much smaller portions, and in 
more delicate and varied positions than those of fire, as we 
now employ it. But man will then appear to have really 
augmented his power, when the works of nature can be 

94 It may often be observed on the leaves of the lime and other trees. 


imitated in species, perfected in power, and varied in quan 
tity; to which should be added the acceleration in point of 
time. Eust, for instance, is the result of a long process, 
but crocus martis is obtained immediately; and the same 
may be observed of natural verdigris and ceruse. Crystal 
is formed slowly, while glass is blown immediately: stones 
increase slowly, while bricks are baked immediately, etc. 
In the meantime (with regard to our present subject) every 
different species of heat should, with its peculiar effects, be 
diligently collected and inquired into; that of the heavenly 
bodies, whether their rays be direct, reflected, or refracted, 
or condensed by a burning-glass; that of lightning, flame, 
and ignited charcoal; that of fire of different materials, 
either open or confined, straitened or overflowing, quali 
fied by the different forms of the furnaces, excited by the 
bellows, or quiescent, removed to a greater or less distance, 
or passing through different media; moist heats, such as 
the balneum Marice, and the dunghill; the external and in 
ternal heat of animals; dry heats, such as the heat of ashes, 
lime, warm sand; in short, the nature of every kind of heat, 
and its degrees. 

We should, however, particularly attend to the investi 
gation and discovery of the effects and operations of heat, 
when made to approach and retire by degrees, regularly, 
periodically, and by proper intervals of space and time. 
For this systematical inequality is in truth the daughter of 
heaven and mother of generation, nor can any great result 
be expected from a vehement, precipitate, or desultory heat. 
For this is not only most evident in vegetables, but in the 
wombs of animals also there arises a great inequality of 
heat, from the motion, sleep, food, "and passions of the 
female. The same inequality prevails in those subterrane- 


ous beds where metals and fossils are perpetually forming, 
which renders yet more remarkable the ignorance of some 
of the reformed alchemists, who imagined they could attain 
their object by the equable heat of lamps, or the like, burn 
ing uniformly. Let this suffice concerning the operation 
and effects of heat; nor is it time for us to investigate them 
thoroughly before the forms and conformations of bodies 
have been further examined and brought to light. When 
we have determined upon our models, we may seek, apply, 
and arrange our instruments. 

4. The fourth mode of action is by continuance, the very 
steward and almoner, as it were, of nature. We apply the 
term continuance to the abandonment of a body to itself for 
an observable time, guarded and protected in the meanwhile 
from all external force. For the internal motion then com 
mences to betray and exert itself when the external and 
adventitious is removed. The effects of time, however, are 
far more delicate than those of fire. Wine, for instance, 
cannot be clarified by fire as it is by continuance. Nor are 
the ashes produced by combustion so fine as the particles 
dissolved or wasted by the lapse of ages. The incorpora 
tions and mixtures, which are hurried by fire, are very 
inferior to those obtained by continuance; and the various 
conformations assumed by bodies left to themselves, such 
as mouldi ness, etc., are put a stop to by fire or a strong 
heat. It is not, in the meantime, unimportant to remark 
that there is a certain degree of violence in the motion of 
bodies entirely confined; for the confinement impedes the 
proper motion of the body. Continuance in an open ves 
sel, therefore, is useful for separations, and in one hermet 
ically sealed for mixtures, that in a vessel partly closed, but 
admitting the air, for putrefaction. But instances of the 


operation and effect of continuance must be collected dili 
gently from every quarter. 

5. The direction of motion (which is the fifth method 
of action) is of no small use. We adopt this term, when 
speaking of a body which, meeting with another, either 
arrests, repels, allows, or directs its original motion. This 
is the case principally in the figure and position of vessels. 
An upright cone, for instance, promotes the condensation 
of vapor in alembics, but when reversed, as in inverted 
vessels, it assists the refining of sugar. Sometimes a curved 
form, or one alternately contracted and dilated, is required. 
Strainers may be ranged under this head, where the opposed 
body opens a way for one portion of another substance and 
impedes the rest. Nor is this process or any other direction 
of motion carried on externally only, but sometimes by one 
body within another. Thus, pebbles are thrown into water 
to collect the muddy particles, and syrups are refined by 
the white of an egg, which glues the grosser particles to 
gether so as to facilitate their removal. Telesius, indeed, 
rashly and ignorantly enough attributes the formation of 
animals to this cause, by means of the channels and folds 
of the womb. lie ought to have observed a similar forma 
tion of the young in eggs which have no wrinkles or in 
equalities. One may observe a real result of this direction 
of motion in casting and modelling. 

6. The effects produced by harmony and aversion (which 
is the sixtli method) are frequently buried in obscurity; for 
these occult and specific properties (as they are termed), the 
sympathies and antipathies, are for the most part but a 
corruption of philosophy. Nor can we form any great 
expectation of the discovery of the harmony which exists 
between natural objects, before that of their forms and 


simple conformations, for it is nothing more than the sym 
metry between these forms and conformations. 

The greater and more universal species of harmony are 
not, however, so wholly obscure, and with them, therefore, 
we must commence. The first and principal distinction be 
tween them is this; that some bodies differ considerably in 
the abundance and rarity of their substance, but correspond 
in their conformation ; others, on the contrary, correspond in 
the former and differ in the latter. Thus the chemists have 
well observed, that in their trial of first principles sulphur 
and mercury, as it were, pervade the universe; their reason 
ing about salt, however, is absurd, and merely introduced 
to comprise earthy dry fixed bodies. In the other two, 
indeed, one of the most universal species of natural har 
mony manifests itself. Thus there is a correspondence be 
tween sulphur, oil, greasy exhalations, flame, and, perhaps, 
the substance of the stars. On the other hand, there is a 
like correspondence between mercury, water, aqueous vapor, 
air, and, perhaps, pure inter-sidereal ether. Yet do these 
two quaternions, or great natural tribes (each within its own 
limits), differ immensely in quantity and density of sub 
stance, while they generally agree in conformation, as is 
manifest in many instances. On the other hand, the metals 
agree in such quantity and density (especially when com 
pared with vegetables, etc.), but differ in many respects in 
conformation. Animals and vegetables, in like manner, 
vary in their almost infinite modes of conformation, but 
range within very limited degrees of quantity and density 
of substance. 

The next most general correspondence is that between 
individual bodies and those which supply them by way of 
menstruum or support. Inquiry, therefore, must be made 


as to the climate, soil, and depth at which each metal is 
generated, and the same of gems, whether produced in rocks 
or mines, also as to the soil in which particular trees, shrubs, 
and herbs, mostly grow and, as it were, delight; and as to 
the best species of manure, whether dung, chalk, sea sand, 
or ashes, etc., and their different propriety and advantage 
according to the variety of soils. So also the grafting and 
setting of trees and plants (as regards the readiness of graft 
ing one particular species on another) depends very much 
upon harmony, and it would be amusing to try an experi 
ment I have lately heard of, in grafting forest trees (garden 
trees alone having hitherto been adopted), by which means 
the leaves and fruit are enlarged, and the trees produce 
more shade. The specific food of animals again should be 
observed, as well as that which cannot be used. Thus the 
carnivorous cannot be fed on herbs, for which reason the 
order of feuilletans, the experiment having been made, 
has nearly vanished; human nature being incapable of 
supporting their regimen, although the human will has 
more power over the bodily frame than that of other 
animals. The different kinds of putrefaction from which 
animals are generated should be noted. 

The harmony of principal bodies with those subordinate 
to them (such indeed may be deemed those we have alluded 
to above) are sufficiently manifest, to which may be added 
those that exist between different bodies and their objects, 
and, since these latter are more apparent, they may throw 
great light when well observed and diligently examined 
upon those which are more latent. 

The more internal harmony and aversion, or friendship 
and enmity (for superstition and folly have rendered the 
terms of sympathy and antipathy almost disgusting), have 


been either falsely assigned, or mixed with fable, or most 
rarely discovered from neglect. For if one were to allege 
that there is an enmity between the vine and the cabbage, 
because they will not come up well when sown together, 
there is a sufficient reason for it in the succulent and ab 
sorbent nature of each plant, so that the one defrauds the 
other. Again, if one were to say that there is a harmony 
and friendship between the corn and the corn-flower, or the 
wild poppy, because the latter seldom grow anywhere but 
in cultivated soils, he ought rather to say, there is an enmity 
between them, for the poppy and the corn-flower are pro 
duced and created by those juices which the corn has left 
and rejected, so that the sowing of the corn prepares the 
ground for their production. And there are a vast number 
of similar false assertions. As for fables, they must be 
totally exterminated. There remains, then, but a scanty 
supply of such species of harmony as has borne the test 
of experiment, such as that between the magnet and iron, 
gold and quicksilver, and the like. In chemical experi 
ments on metals, however, there are some others worthy of 
notice, but the greatest abundance (where the whole are so 
few in numbers) is discovered in certain medicines, which, 
from their occult and specific qualities (as they are termed), 
affect particular limbs, humors, diseases, or constitutions. 
Nor should we omit the harmony between the motion and 
phenomena of the moon, and their effects on lower bodies, 
which may be brought together by an accurate and honest 
selection from the experiments of agriculture, navigation, 
and medicine, or of other sciences. By as much as these 
general instances, however, of more latent harmony, are 
rare, with so much the more diligence are they to be in 
quired after, through tradition, and faithful and honest 


reports, but without rashness and credulity, with an anx 
ious and, as it were, hesitating degree of reliance. There 
remains one species of harmony which, though simple in 
its mode of action, is yet most valuable in its use, and must 
by no means be omitted, but rather diligently investigated. 
It is the ready or difficult coition or union of bodies in com 
position, or simple juxtaposition. For some bodies readily 
and willingly mix, and are incorporated, others tardily and 
perversely; thus powders mix best with water, chalk and 
ashes with oils, and the like. Nor are these instances of 
readiness and aversion to mixture to be alone collected, 
but others, also, of the collocation, distribution, and diges 
tion of the parts when mingled, and the predominance after 
the mixture is complete. 

7. Lastly, there remains the seventh, and last of the 
seven, modes of action; namely, that by the alternation 
and interchange of the other six; but of this, it will not 
be the right time to offer any examples, until some deeper 
investigation shall have taken place of each of the others. 
The series, or chain of this alternation, in its mode of appli 
cation to separate effects, is no less powerful in its operation 
than difficult to be traced. But men are possessed with the 
most extreme impatience, both of such inquiries, and their 
practical application, although it be the clew of the laby 
rinth in. all greater works. Thus far of the generally useful 

LI. The twenty-seventh and last place we will assign 
to the magical instances, a term which we apply to those 
wnere the matter or efficient agent is scanty or small, in 
comparison with the grandeur of the work or effect pro 
duced; so that even when common they appear miraculous, 
some at first sight, others even upon more attentive obser- 


vatioa. Nature, however, of herself, supplies these but 
sparingly. What she will do when her whole store is 
thrown open, and after the discovery of forms, processes, 
and conformation, will appear hereafter. As far as we can 
yet conjecture, these magic effects are produced in three 
ways, either by self-multiplication, as in fire, and the 
poisons termed specific, .and the motions transferred and 
multiplied from wheel to wheel; or by the excitement, or, 
as it were, invitation of another substance, as in the magnet, 
which excites innumerable needles without losing or dimin 
ishing its power; and again in leaven, and the like; or by 
the excess of rapidity of one species of motion over another, 
as has been observed in the case of gunpowder, cannon, 
and mines. The two former require an investigation of 
harmonies, the latter of a measure of motion. Whether 
there be any mode of changing bodies per minima (as it 
is termed), and transferring the delicate conformations 
of matter, which is of importance in all transformations 
of bodies, so as to enable art to effect, in a short time, that 
which nature works out by divers expedients, is a point of 
which we have as yet no indication. But, as we aspire 
to the extremest and highest results in that which is solid 
and true, so do we ever detest, and, as far as in us lies, 
expel all that is empty and vain. 

fLIl. Let this suffice as to the respective dignity of pre 
rogatives of instances. But it must be noted, that in this 
our organ, we treat of logic, and not of philosophy. Seeing, 
however, that our logic instructs and informs the under 
standing, in order that it may not, with the small hooks, as 
it were, of the mind, catch at, and grasp mere abstractions, 
but rather actually penetrate nature, and discover the prop 
erties and effects of bodies, and the determinate laws of 


their substance (so that this science of ours springs from 
the nature of things, as well as from that of the mind); it 
is not to be wondered at, if it have been continually inter 
spersed and illustrated with natural observations and ex 
periments, as instances of our method. The prerogative 
instances are, as appears from what has preceded, twenty- 
seven in number, and are termed, solitary instances, migrat 
ing instances, conspicuous instances, clandestine instances, 
constitutive instances, similar instances, singular instances, 
deviating instances, bordering instances, instances of power, 
accompanying and hostile instances, subjunctive instances, "7 
instances of alliance, instances of the cross, instances of 
divorce, instances of the gate, citing instances, instances 
of the road, supplementary instances, lancing instances, in 
stances of the rod, instances of the course, doses of nature, 
wrestling instances, suggesting instances, generally useful 
instances, and magical instances. The advantage, by which 
these instances excel the more ordinary, regards specifically 
either theory or practice, or both. With regard to theory, 
they assist either the senses or the understanding; the senses, 
as in the five instances of the lamp; the understanding, 
either by expediting the exclusive mode of arriving at the 
form, as in solitary instances, or by confining, and more 
immediately indicating the affirmative, as in the migrating, 
conspicuous, accompanying, and subjunctive instances; or 
by elevating the understanding, and leading it to general 
and common natures, and that either immediately, as in the 
clandestine and singular instances, and those of alliance; or 
very nearly so, as in the constitutive; or still less so, as in 
the similar instances; or by correcting the understanding 
of its habits, as in the deviating instances; or by leading to 
the grand form or fabric of the universe, as in the bordering 


instances; or by guarding it from false forms and causes, 
as in those of the cross and of divorce. With regard to 
practice, they either point it out, or measure, or elevate 
it. They point it out, either by showing where we must 
commence in order not to repeat the labors of others, as in 
the instances of power; or by inducing us to aspire to that 
which may be possible, as in the suggesting instances; the 
four mathematical instances measure it. The generally use 
ful and the magical elevate it. 

Again, out of these twenty-seven instances, some must 
be collected immediately, without waiting for a particular 
investigation of properties. Such are the similar, singular, 
deviating, and bordering instances, those of power, and of 
the gate, and suggesting, generally useful, and magical in 
stances; for these either assist and cure the understanding 
and senses, or furnish our general practice. The remainder 
are to be collected when we finish our synoptical tables for 
the work of the interpreter, upon any particular nature; 
for these instances, honored and gifted with such preroga 
tives, are like the soul amid the vulgar crowd of instances, 
and (as we from the first observed) a few of them are worth 
a multitude of the others. When, therefore, we are forming 
our tables they must be searched out with the greatest zeal, 
and placed in the table. And, since mention must be made 
of them in what follows, a treatise upon their nature has 
necessarily been prefixed. We must next, however, pro 
ceed to the supports and corrections of induction, and 
thence to concretes, the latent process, and latent confor 
mations, and the other matters, which we have enumerated 
in their order in the twenty-first aphorism, in order that, 
\ike good and faithful guardians, we may yield up their 
fortune to mankind upon the emancipation and majority 


of their understanding; from which must necessarily follow 
au improvement of their estate, and an increase of their 
i power over nature. For man, by the fall, lost at once his 
i state of innocence, and his empire over creation, both of 
which can be partially recovered even in this life, the first 
by religion and faith, the second by the arts and sciences. 
For creation did not become entirely and utterly rebellious 
by the curse, but in consequence of the Divine decree, "in 
the sweat of thy brow shalt thou eat bread," she is com 
pelled by our labors (not assuredly by our disputes or 
magical ceremonies), at length, to afford mankind in some 
degree his bread, that is to say, to supply man s daily wants. 




Wovum Organum.