AnEnquiryConcerningHumanUnderstanding

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            AN ENQUIRY CONCERNING

             HUMAN UNDERSTANDING



                     by

                 DAVID HUME



          Harvard Classics Volume 37

      Copyright 1910 P.F. Collier & Son



     Prepared by 





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SECTION I

OF THE DIFFERENT SPECIES OF PHILOSOPHY.



  MORAL philosophy, or the science of human nature, 

may be treated after two different manners; each 

of which has its peculiar merit, and may contribute 

to the entertainment, instruction, and reformation of man- 

kind. The one considers man chiefly as born for action; 

and as influenced in his measures by taste and sentiment; 

pursuing one object, and avoiding another, according to 

the value which these objects seem to possess, and accord- 

ing to the light in which they present themselves. As vir- 

tue, of all objects, is allowed to be the most valuable, this 

species of philosophers paint her in the most amiable 

colours; borrowing all helps from poetry and eloquence, and 

treating their subject in an easy and obvious manner, and 

such as is best fitted to please the imagination, and engage 

the affections. They select the most striking observations 

and instances from common life; place opposite characters 

in a proper contrast; and alluring us into the paths of virtue 

by the views of glory and happiness, direct our steps in 

these paths by the soundest precepts and most illustrious 

examples. They make us feel the difference between vice 

and virtue; they excite and regulate our sentiments; and 

so they can but bend our hearts to the love of probity and 

true honour, they think, that they have fully attained the 

end of all their labours. 



  The other species of philosophers consider man in the 

light of a reasonable rather than an active being, and 

endeavour to form his understanding more than cultivate 

his manners. They regard human nature as a subject of 

speculation; and with a narrow scrutiny examine it, in 

order to find those principles, which regulate our under- 

standing, excite our sentiments, and make us approve or 

blame any particular object, action, or behaviour. They 

think it a reproach to all literature, that philosophy should 

not yet have fixed, beyond controversy, the foundation of 

morals, reasoning, and criticism; and should for ever talk 

of truth and falsehood, vice and virtue, beauty and de- 

formity, without being able to determine the source of 

these distinctions. While they attempt this arduous task, 

they are deterred by no difficulties; but proceeding from 

particular instances to general principles, they still push on 

their enquiries to principles more general, and rest not 

satisfied till they arrive at those original principles, by 

which, in every science, all human curiosity must be 

bounded. Though their speculations seem abstract, and 

even unintelligible to common readers, they aim at the 

approbation of the learned and the wise; and think them- 

selves sufficiently compensated for the labour of their whole 

lives, if they can discover some hidden truths, which may 

contribute to the instruction of posterity. 



  It is certain that the easy and obvious philosophy will 

always, with the generality of mankind, have the preference 

above the accurate and abstruse; and by many will be 

recommended, not only as more agreeable, but more useful 

than the other. It enters more into common life; moulds 

the heart and affections; and, by touching those principles 

which actuate men, reforms their conduct, and brings them 

nearer to that model of perfection which it describes. On 

the contrary, the abstruse philosophy, being founded on a 

turn of mind, which cannot enter into business and action, 

vanishes when the philosopher leaves the shade, and comes 

into open day; nor can its principles easily retain any in- 

fluence over our conduct and behaviour. The feelings of 

our heart, the agitation of our passions, the vehemence of 

our affections, dissipate all its conclusions, and reduce the 

profound philosopher to a mere plebeian. 



  This also must be confessed, that the most durable, 

as well as justest fame, has been acquired by the easy 

philosophy, and that abstract reasoners seem hitherto to 

have enjoyed only a momentary reputation, from the caprice 

or ignorance of their own age, but have not been able 

to support their renown with more equitable posterity. It 

is easy for a profound philosopher to commit a mistake 

in his subtile reasonings; and one mistake is the necessary 

parent of another, while he pushes on his consequences, 

and is not deterred from embracing any conclusion, by 

its unusual appearance, or its contradiction to popular 

opinion. But a philosopher, who purposes only to represent 

the common sense of mankind in more beautiful and more 

engaging colours, if by accident he falls into error, goes no 

farther; but renewing his appeal to common sense, and the 

natural sentiments of the mind, returns into the right path, 

and secures himself from any dangerous illusions. The 

fame of Cicero flourishes at present; but that of Aristotle 

is utterly decayed. La Bruyere passes the seas, and still 

maintains his reputation: but the glory of Malebranche 

is confined to his own nation, and to his own age. And 

Addison, perhaps, will be read with pleasure, when Locke 

shall be entirely forgotten. 



  The mere philosopher is a character, which is commonly 

but little acceptable in the world, as being supposed to 

contribute nothing either to the advantage or pleasure 

of society; while he lives remote from communication with 

mankind, and is wrapped up in principles and notions equally 

remote from their comprehension. On the other hand, 

the mere ignorant is still more despised; nor is any thing 

deemed a surer sign of an illiberal genius in an age and 

nation where the sciences flourish, than to be entirely 

destitute of all relish for those noble entertainments. The 

most perfect character is supposed to lie between those 

extremes; retaining an equal ability and taste for books, 

company, and business; preserving in conversation that 

discernment and delicacy which arise from polite letters; 

and in business, that probity and accuracy which are 

the natural result of a just philosophy. In order to diffuse 

and cultivate so accomplished a character, nothing can be 

more useful than compositions of the easy style and manner, 

which draw not too much from life, require no deep appli- 

cation or retreat to be comprehended, and send back the 

student among mankind full of noble sentiments and wise 

precepts, applicable to every exigence of human life. By 

means of such compositions, virtue becomes amiable, 

science agreeable, company instructive, and retirement en- 

tertaining. 



  Man is a reasonable being; and as such, receives from 

science his proper food and nourishment: But so narrow 

are the bounds of human understanding, that little satisfac- 

tion can be hoped for in this particular, either from the 

extent of security or his acquisitions. Man is a sociable, no 

less than a reasonable being: but neither can he always 

enjoy company agreeable and amusing, or preserve the 

proper relish for them. Man is also an active being; and 

from that disposition, as well as from the various necessities 

of human life, must submit to business and occupation: 

but the mind requires some relaxation, and cannot always 

support its bent to care and industry. It seems, then, that 

nature has pointed out a mixed kind of life as most suitable 

to the human race, and secretly admonished them to allow 

none of these biases to draw too much, so as to incapacitate 

them for other occupations and entertainments. Indulge 

your passion for science, says she, but let your science be 

human, and such as may have a direct reference to action 

and society. Abstruse thought and profound researches I 

prohibit, and will severely punish, by the pensive melancholy 

which they introduce, by the endless uncertainty in which 

they involve you, and by the cold reception which your 

pretended discoveries shall meet with, when communicated. 

Be a philosopher; but, amidst all your philosophy, be still 

a man. 



  Were the generality of mankind contented to prefer the 

easy philosophy to the abstract and profound, without 

throwing any blame or contempt on the latter, it might 

not be improper, perhaps, to comply with this general 

opinion, and allow every man to enjoy, without opposition, 

his own taste and sentiment. But as the matter is often 

carried farther, even to the absolute rejecting of all pro- 

found reasonings, or what is commonly called metaphysics, 

we shall now proceed to consider what can reasonably be 

pleaded in their behalf. 



  We may begin with observing, that one considerable 

advantage, which results from the accurate and abstract 

philosophy, is, its subserviency to the easy and humane; 

which, without the former, can never attain a sufficient 

degree of exactness in its sentiments, precepts, or reasonings. 

All polite letters are nothing but pictures of human life 

in various attitudes and situations; and inspire us with 

different sentiments, of praise or blame, admiration or ridi- 

cule, according to the qualities of the object, which they set 

before us. An artist must be better qualified to succeed in 

this undertaking, who, besides a delicate taste and a quick 

apprehension, possesses an accurate knowledge of the in- 

ternal fabric, the operations of the understanding, the 

workings of the passions, and the various species of senti- 

ment which discriminate vice and virtue. How painful 

soever this inward search or enquiry may appear, it becomes, 

in some measure, requisite to those, who would describe 

with success the obvious and outward appearances of life 

and manners. The anatomist presents to the eye the most 

hideous and disagreeable objects; but his science is useful 

to the painter in delineating even a Venus or an Helen. 

While the latter employs all the richest colours of his art, 

and gives his figures the most graceful and engaging airs; 

he must still carry his attention to the inward structure 

of the human body, the position of the muscles, the fabric 

of the bones, and the use and figure of every part or organ. 

Accuracy is, in every case, advantageous to beauty, and just 

reasoning to delicate sentiment. In vain would we exalt 

the one by depreciating the other. 



  Besides, we may observe, in every art or profession, even 

those which most concern life or action, that a spirit of 

accuracy, however acquired, carries all of them nearer their 

perfection, and renders them more subservient to the 

interests of society. And though a philosopher may live 

remote from business, the genius of philosophy, if carefully 

cultivated by several, must gradually diffuse itself through- 

out the whole society, and bestow a similar correctness on 

every art and calling. The politician will acquire greater 

foresight and subtility, in the subdividing and balancing 

of power; the lawyer more method and finer principles 

in his reasonings; and the general more regularity in his 

discipline, and more caution in his plans and operations. 

The stability of modern governments above the ancient, 

and the accuracy of modern philosophy, have improved, and 

probably will still improve, by similar gradations. 



  Were there no advantage to be reaped from these studies, 

beyond the gratification of an innocent curiosity, yet ought 

not even this to be despised; as being one accession to 

those few safe and harmless pleasures, which are bestowed 

on the human race. The sweetest and most inoffensive path 

of life leads through the avenues of science and learning; and 

whoever can either remove any obstructions in this way, 

or open up any new prospect, ought so far to be esteemed 

a benefactor to mankind. And though these researches 

may appear painful and fatiguing, it is with some minds 

as with some bodies, which being endowed with vigorous 

and florid health, require severe exercise, and reap a pleasure 

from what, to the generality of mankind, may seem burden- 

some and laborious. Obscurity, indeed, is painful to the 

mind as well as to the eye; but to bring light from 

obscurity, by whatever labour, must needs be delightful and 

rejoicing. 



  But this obscurity in the profound and abstract philos- 

ophy, is objected to, not only as painful and fatiguing, but 

as the inevitable source of uncertainty and error. Here in- 

deed lies the justest and most plausible objection against 

a considerable part of metaphysics, that they are not properly 

a science; but arise either from the fruitless efforts of 

human vanity, which would penetrate into subjects utterly 

inaccessible to the understanding, or from the craft of pop- 

ular superstitions, which, being unable to defend themselves 

on fair ground, raise these intangling brambles to cover and 

protect their weakness. Chased from the open country, these 

robbers fly into the forest, and lie in wait to break in upon 

every unguarded avenue of the mind, and overwhelm it 

with religious fears and prejudices. The stoutest antagonist, 

if he remit his watch a moment, is oppressed. And many, 

through cowardice and folly, open the gates to the enemies, 

and willingly receive them with reverence and submission, 

as their legal sovereigns. 



  But is this a sufficient reason, why philosophers should 

desist from such researches, and leave superstition still 

in possession of her retreat? Is it not proper to draw an 

opposite conclusion, and perceive the necessity of carrying 

the war into the most secret recesses of the enemy? In 

vain do we hope, that men, from frequent disappointment, 

will at last abandon such airy sciences, and discover the 

proper province of human reason. For, besides, that many 

persons find too sensible an interest in perpetually recalling 

such topics; besides this, I say, the motive of blind despair 

can never reasonably have place in the sciences; since, how- 

ever unsuccessful former attempts may have proved, there 

is still room to hope, that the industry, good fortune, or 

improved sagacity of succeeding generations may reach 

discoveries unknown to former ages. Each adventurous 

genius will still leap at the arduous prize, and find himself 

stimulated, rather than discouraged, by the failures of his 

predecessors; while he hopes that the glory of achieving 

so hard an adventure is reserved for him alone. The only 

method of freeing learning, at once, from these abstruse 

questions, is to enquire seriously into the nature of human 

understanding, and show, from an exact analysis of its 

powers and capacity, that it is by no means fitted for 

such remote and abstruse subjects. We must submit to 

this fatigue in order to live at ease ever after: and must 

cultivate true metaphysics with some care, in order to 

destroy the false and adulterate. Indolence, which, to some 

persons, affords a safeguard against this deceitful philos- 

ophy, is, with others, overbalanced by curiosity; and de- 

spair, which, at some moments, prevails, may give place after- 

wards to sanguine hopes and expectations. Accurate and 

just reasoning is the only catholic remedy, fitted for all 

persons and all dispositions; and is alone able to subvert 

that abstruse philosophy and metaphysical jargon, which 

being mixed up with popular superstition, renders it in 

a manner impenetrable to careless reasoners, and gives it 

the air of science and wisdom. 



  Besides this advantage of rejecting, after deliberate en- 

quiry, the most uncertain and disagreeable part of learning, 

there are many positive advantages, which result from an 

accurate scrutiny into the powers and faculties of human 

nature. It is remarkable concerning the operations of the 

mind, that, though most intimately present to us, yet, 

whenever they become the object of reflexion, they seem 

involved in obscurity; nor can the eye readily find those 

lines and boundaries, which discriminate and distinguish 

them. The objects are too fine to remain long in the same 

aspect or situation; and must be apprehended in an in- 

stant, by a superior penetration, derived from nature, and 

improved by habit and reflexion. It becomes, therefore, 

no inconsiderable part of science barely to know the different 

operations of the mind, to separate them from each other, to 

class them under their proper heads, and to correct all that 

seeming disorder, in which they lie involved, when made 

the object of reflexion and enquiry. This talk of ordering 

and distinguishing, which has no merit, when performed 

with regard to external bodies, the objects of our senses, 

rises in its value, when directed towards the operations 

of the mind, in proportion to the difficulty and labour, 

which we meet with in performing it. And if we can go no 

farther than this mental geography, or delineation of the 

distinct parts and powers of the mind, it is at least a satis- 

faction to go so far; and the more obvious this science 

may appear (and it is by no means obvious) the more con- 

temptible still must the ignorance of it be esteemed, in all 

pretenders to learning and philosophy. 



  Nor can there remain any suspicion, that this science 

is uncertain and chimerical; unless we should entertain 

such a scepticism as is entirely subversive of all speculation, 

and even action. It cannot be doubted, that the mind 

is endowed with several powers and faculties, that these 

powers are distinct from each other, that what is really 

distinct to the immediate perception may be distinguished 

by reflexion; and consequently, that there is a truth and 

falsehood in all propositions on this subject, and a truth 

and falsehood, which lie not beyond the compass of human 

understanding. There are many obvious distinctions of 

this kind, such as those between the will and understanding, 

the imagination and passions, which fall within the com- 

prehension of every human creature; and the finer and 

more philosophical distinctions are no less real and certain, 

though more difficult to be comprehended. Some instances, 

especially late ones, of success in these enquiries, may give 

us a juster notion of the certainty and solidity of this branch 

of learning. And shall we esteem it worthy the labour of 

a philosopher to give us a true system of the planets, and 

adjust the position and order of those remote bodies; 

while we affect to overlook those, who, with so much 

success, delineate the parts of the mind, in which we are so 

intimately concerned? 



  But may we not hope, that philosophy, cultivated with 

care, and encouraged by the attention of the public, may 

carry its researches still farther, and discover, at least in 

some degree, the secret springs and principles, by which the 

human mind is actuated in its operations? Astronomers 

had long contented themselves with proving, from the 

phaenomena, the true motions, order, and magnitude of 

the heavenly bodies: till a philosopher, at last, arose, 

who seems, from the happiest reasoning, to have also deter- 

mined the laws and forces, by which the revolutions of the 

planets are governed and directed. The like has been 

performed with regard to other parts of nature. And there 

is no reason to despair of equal success in our enquiries 

concerning the mental powers and economy, if prosecuted 

with equal capacity and caution. It is probable, that one 

operation and principle of the mind depends on another; 

which, again, may be resolved into one more general and 

universal: and how far these researches may possibly 

be carried, it will be difficult for us, before, or even after, 

a careful trial, exactly to determine. This is certain, that 

attempts of this kind are every day made even by those 

who philosophize the most negligently: and nothing can 

be more requisite than to enter upon the enterprize with 

thorough care and attention; that, if it lie within the 

compass of human understanding, it may at last be happily 

achieved; if not, it may, however, be rejected with some 

confidence and security. This last conclusion, surely, is not 

desirable; nor ought it to be embraced too rashly. For how 

much must we diminish from the beauty and value of this 

species of philosophy, upon such a supposition? Moralists 

have hitherto been accustomed, when they considered the 

vast multitude and diversity of those actions that excite 

our approbation or dislike, to search for some common 

principle, on which this variety of sentiments might depend. 

And though they have sometimes carried the matter too far, 

by their passion for some one general principle; it must, 

however, be confessed, that they are excusable in expecting 

to find some general principles, into which all the vices 

and virtues were justly to be resolved. The like has been 

the endeavour of critics, logicians, and even politicians: 

nor have their attempts been wholly unsuccessful; though 

perhaps longer time, greater accuracy, and more ardent 

application may bring these sciences still nearer their per- 

fection. To throw up at once all pretensions of this kind 

may justly be deemed more rash, precipitate, and dogmatical, 

than even the boldest and most affirmative philosophy, that 

has ever attempted to impose its crude dictates and prin- 

ciples on mankind. 



  What though these reasonings concerning human nature 

seem abstract, and of difficult comprehension? This affords 

no presumption of their falsehood. On the contrary, it 

seems impossible, that what has hitherto escaped so many 

wise and profound philosophers can be very obvious and 

easy. And whatever pains these researches may cost us, we 

may think ourselves sufficiently rewarded, not only in point 

of profit but of pleasure, if, by that means, we can make 

any addition to our stock of knowledge, in subjects of 

such unspeakable importance. 



  But as, after all, the abstractedness of these speculations 

is no recommendation, but rather a disadvantage to them, 

and as this difficulty may perhaps be surmounted by care 

and art, and the avoiding of all unnecessary detail, we have, 

in the following enquiry, attempted to throw some light 

upon subjects, from which uncertainty has hitherto deterred 

the wise, and obscurity the ignorant. Happy, if we can 

unite the boundaries of the different species of philosophy, 

by reconciling profound enquiry with clearness, and truth 

with novelty! And still more happy, if, reasoning in this 

easy manner, we can undermine the foundations of an 

abstruse philosophy, which seems to have hitherto served 

only as a shelter to superstition, and a cover to absurdity 

and error! 





SECTION II

OF THE ORIGIN OF IDEAS



  EVERY one will readily allow, that there is a consider- 

able difference between the perceptions of the mind, 

when a man feels the pain of excessive heat, or the 

pleasure of moderate warmth, and when he afterwards re- 

calls to his memory this sensation, or anticipates it by his 

imagination. These faculties may mimic or copy the percep- 

tions of the senses; but they never can entirely reach the 

force and vivacity of the original sentiment. The utmost we 

say of them, even when they operate with greatest vigour, is, 

that they represent their object in so lively a manner, that we 

could almost say we feel or see it: But, except the mind be 

disordered by disease or madness, they never can arrive 

at such a pitch of vivacity, as to render these perceptions 

altogether undistinguishable. All the colours of poetry, 

however splendid, can never paint natural objects in such 

a manner as to make the description be taken for a real 

landskip. The most lively thought is still inferior to the 

dullest sensation. 



  We may observe a like distinction to run through all the 

other perceptions of the mind. A man in a fit of anger, is 

actuated in a very different manner from one who only 

thinks of that emotion. If you tell me, that any person 

is in love, I easily understand your meaning, and from 

a just conception of his situation; but never can mistake 

that conception for the real disorders and agitations of the 

passion. When we reflect on our past sentiments and 

affections, our thought is a faithful mirror, and copies its 

objects truly; but the colours which it employs are faint 

and dull, in comparison of those in which our original per- 

ceptions were clothed. It requires no nice discernment or 

metaphysical head to mark the distinction between them. 



  Here therefore we may divide all the perceptions of the 

mind into two classes or species, which are distinguished 

by their different degrees of force and vivacity. The less 

forcible and lively are commonly denominated Thoughts or 

Ideas. The other species want a name in our language, 

and in most others; I suppose, because it was not requisite 

for any, but philosophical purposes, to rank them under 

a general term or appellation. Let us, therefore, use a little 

freedom, and call them Impressions; employing that word 

in a sense somewhat different from the usual. By the term 

impression, then, I mean all our more lively perceptions, 

when we hear, or see, or feel, or love, or hate, or desire, 

or will. And impressions are distinguished from ideas, 

which are the less lively perceptions, of which we are 

conscious, when we reflect on any of those sensations or 

movements above mentioned. 



  Nothing, at first view, may seem more unbounded than 

the thought of man, which not only escapes all human 

power and authority, but is not even restrained within the 

limits of nature and reality. To form monsters, and join 

incongruous shapes and appearances, costs the imagination 

no more trouble than to conceive the most natural and 

familiar objects. And while the body is confined to one 

planet, along which it creeps with pain and difficulty; the 

thought can in an instant transport us into the most dis- 

tant regions of the universe; or even beyond the universe, 

into the unbounded chaos, where nature is supposed to 

lie in total confusion. What never was seen, or heard 

of, may yet be conceived; nor is any thing beyond 

the power of thought, except what implies an absolute 

contradiction. 



  But though our thought seems to possess this unbounded 

liberty, we shall find, upon a nearer examination, that it is 

really confined within very narrow limits, and that all this 

creative power of the mind amounts to no more than 

the faculty of compounding, transposing, augmenting, or 

diminishing the materials afforded us by the senses and 

experience. When we think of a golden mountain, we 

only join two consistent ideas, gold, and mountain, with 

which we were formerly acquainted. A virtuous horse we 

can conceive; because, from our own feeling, we can 

conceive virtue; and this we may unite to the figure and 

shape of a horse, which is an animal familiar to us. In 

short, all the materials of thinking are derived either from 

our outward or inward sentiment: the mixture and com- 

position of these belongs alone to the mind and will. Or, 

to express myself in philosophical language, all our ideas or 

more feeble perceptions are copies of our impressions or 

more lively ones. 



  To prove this, the two following arguments will, I hope, 

be sufficient. First, when we analyze our thoughts or ideas, 

however compounded or sublime, we always find that they 

resolve themselves into such simple ideas as were copied 

from a precedent feeling or sentiment. Even those ideas, 

which, at first view, seem the most wide of this origin, are 

found, upon a nearer scrutiny, to be derived from it. The 

idea of God, as meaning an infinitely intelligent, wise, and 

good Being, arises from reflecting on the operations of our 

own mind, and augmenting, without limit, those qualities 

of goodness and wisdom. We may prosecute this enquiry 

to what length we please; where we shall always find, that 

every idea which we examine is copied from a similar 

impression. Those who would assert that this position is 

not universally true nor without exception, have only one, 

and that an easy method of refuting it; by producing that 

idea, which, in their opinion, is not derived from this source. 

It will then be incumbent on us, if we would maintain our 

doctrine, to produce the impression, or lively perception, 

which corresponds to it. 



  Secondly. If it happen, from a defect of the organ, 

that a man is not susceptible of any species of sensation, 

we always find that he is as little susceptible of the cor- 

respondent ideas. A blind man can form no notion of 

colours; a deaf man of sounds. Restore either of them 

that sense in which he is deficient; by opening this new 

inlet for his sensations, you also open an inlet for the ideas; 

and he finds no difficulty in conceiving these objects. The 

case is the same, if the object, proper for exciting any 

sensation, has never been applied to the organ. A Lap- 

lander or Negro has no notion of the relish of wine. 

And though there are few or no instances of a like 

deficiency in the mind, where a person has never felt or 

is wholly incapable of a sentiment or passion that belongs 

to his species; yet we find the same observation to take 

place in a less degree. A man of mild manners can form 

no idea of inveterate revenge or cruelty; nor can a selfish 

heart easily conceive the heights of friendship and gener- 

osity. It is readily allowed, that other beings may possess 

many senses of which we can have no conception; because 

the ideas of them have never been introduced to us in the 

only manner by which an idea can have access to the mind, 

to wit, by the actual feeling and sensation. 



  There is, however, one contradictory phenomenon, which 

may prove that it is not absolutely impossible for ideas 

to arise, independent of their correspondent impressions. 

I believe it will readily be allowed, that the several distinct 

ideas of colour, which enter by the eye, or those of sound, 

which are conveyed by the ear, are really different from 

each other; though, at the same time, resembling. Now 

if this be true of different colours, it must be no less so of 

the different shades of the same colour; and each shade 

produces a distinct idea, independent of the rest. For if 

this should be denied, it is possible, by the continual grada- 

tion of shades, to run a colour insensibly into what is most 

remote from it; and if you will not allow any of the means 

to be different, you cannot, without absurdity, deny the 

extremes to be the same. Suppose, therefore, a person 

to have enjoyed his sight for thirty years, and to have 

become perfectly acquainted with colours of all kinds 

except one particular shade of blue, for instance, which it 

never has been his fortune to meet with. Let all the 

different shades of that colour, except that single one, be 

placed before him, descending gradually from the deepest 

to the lightest; it is plain that he will perceive a blank, 

where that shade is wanting, and will be sensible that there 

is a greater distance in that place between the contiguous 

colour than in any other. Now I ask, whether it be 

possible for him, from his own imagination, to supply this 

deficiency, and raise up to himself the idea of that particular 

shade, though it had never been conveyed to him by his 

senses? I believe there are few but will be of opinion 

that he can: and this may serve as a proof that the simple 

ideas are not always, in every instance, derived from the 

correspondent impressions; though this instance is so 

singular, that it is scarcely worth our observing, and does 

not merit that for it alone we should alter our general 

maxim. 



  Here, therefore, is a proposition, which not only seems, 

in itself, simple and intelligible; but, if a proper use were 

made of it, might render every dispute equally intelligible, 

and banish all that jargon, which has so long taken 

possession of metaphysical reasonings, and drawn disgrace 

upon them. All ideas, especially abstract ones, are naturally 

faint and obscure: the mind has but a slender hold of them: 

they are apt to be confounded with other resembling ideas; 

and when we have often employed any term, though with- 

out a distinct meaning, we are apt to imagine it has a deter- 

minate idea annexed to it. On the contrary, all impressions, 

that is, all sensations, either outward or inward, are strong 

and vivid: the limits between them are more exactly deter- 

mined: nor is it easy to fall into any error or mistake with 

regard to them. When we entertain, therefore, any suspicion 

that a philosophical term is employed without any meaning 

or idea (as is but too frequent), we need but enquire, from 

what impression is that supposed idea derived? And if it 

be impossible to assign any, this will serve to confirm our 

suspicion. By bringing ideas into so clear a light we may 

reasonably hope to remove all dispute, which may arise, 

concerning their nature and reality.[1] 



[1] It is probable that no more was meant by these, who denied innate

ideas, than that all ideas were copies of our impressions; though it must

be confessed, that the terms, which they employed, were not chosen with

such caution, nor so exactly defined, as to prevent all mistakes about their

doctrine. For what is meant by innate? If innate be equivalent to natural,

then all the perceptions and ideas of the mind must be allowed to be innate

or natural, in whatever sense we take the latter word, whether in opposi-

tion to what is uncommon, artificial, or miraculous. If by innate be meant,

contemporary to our birth, the dispute seems to be frivolous; nor is it

worth while to enquire at what time thinking begins, whether before, at,

or after our birth. Again, the word idea, seems to be commonly taken in

a very loose sense, by LOCKE and others; as standing for any of our per-

ceptions, our sensations and passions, as well as thoughts. Now in this

sense, I should desire to know, what can be meant by asserting, that self-

love, or resentment of injuries, or the passion between the sexes is not innate?



But admitting these terms, impressions and ideas, in the sense above

explained, and understanding by innate, what is original or copied from

no precedent perception, then may we assert that all our impressions are

innate, and our ideas not innate.



To be ingenuous, I must own it to be my opinion, that LOCKE was

betrayed into this question by the schoolmen, who, making use of unde-

fined terms, draw out their disputes to a tedious length, without ever touch-

ing the point in question. A like ambiguity and circumlocution seem to run

through that philosopher's reasonings on this as well as most other subjects.





SECTION III

OF THE ASSOCIATION OF IDEAS



  IT IS evident that there is a principle of connexion be- 

tween the different thoughts or ideas of the mind, and 

that in their appearance to the memory or imagination, 

they introduce each other with a certain degree of method 

and regularity. In our more serious thinking or discourse 

this is so observable that any particular thought, which 

breaks in upon the regular tract or chain of ideas, is 

immediately remarked and rejected. And even in our 

wildest and most wandering reveries, nay in our very 

dreams, we shall find, if we reflect, that the imagination 

ran not altogether at adventures, but that there was still 

a connexion upheld among the different ideas, which suc- 

ceeded each other. Were the loosest and freest conversa- 

tion to be transcribed, there would immediately be observed 

something which connected it in all its transitions. Or 

where this is wanting, the person who broke the thread of 

discourse might still inform you, that there had secretly 

revolved in his mind a succession of thought, which had 

gradually led him from the subject of conversation. Among 

different languages, even where we cannot suspect the least 

connexion or communication, it is found, that the words, 

expressive of ideas, the most compounded, do yet nearly 

correspond to each other: a certain proof that the simple 

ideas, comprehended in the compound ones, were bound 

together by some universal principle, which had an equal 

influence on all mankind. 



  Though it be too obvious to escape observation, that 

different ideas are connected together; I do not find that 

any philosopher has attempted to enumerate or class all 

the principles of association; a subject, however, that seems 

worthy of curiosity. To me, there appear to be only three 

principles of connexion among ideas, namely, Resemblance, 

Contiguity in time or place, and Cause or Effect. 



  That these principles serve to connect ideas will not, I 

believe, be much doubted. A picture naturally leads our 

thoughts to the original:[1] the mention of one apartment 

in a building naturally introduces an enquiry or discourse 

concerning the others:[2] and if we think of a wound, we 

can scarcely forbear reflecting on the pain which follows it.[3] 

But that this enumeration is complete, and that there are 

no other principles of association except these, may be 

difficult to prove to the satisfaction of the reader, or even 

to a man's own satisfaction. All we can do, in such cases, 

is to run over several instances, and examine carefully the 

principle which binds the different thoughts to each other, 

never stopping till we render the principle as general as 

possible.[4] The more instances we examine, and the more 

care we employ, the more assurance shall we acquire, that 

the enumeration, which we form from the whole, is com- 

plete and entire. 



[1] Resemblance.



[2] Contiguity.



[3] Cause and effect.



[4] For instance, Contrast or Contrariety is also a connexion among Ideas:

but it may perhaps, be considered as a mixture of Causation and Resem-

blance. Where two objects are contrary, the one destroys the other; that

is, the cause of its annihilation, and the idea of the annihilation of an

object, implies the idea of its former existence.





SECTION IV

SCEPTICAL DOUBTS CONCERNING THE OPERATIONS OF 

THE UNDERSTANDING



PART I 



  ALL the objects of human reason or enquiry may 

naturally be divided into two kinds, to wit, Rela- 

tions of Ideas, and Matters of Fact. Of the first 

kind are the sciences of Geometry, Algebra, and Arithmetic; 

and in short, every affirmation which is either intuitively or 

demonstratively certain. That the square of the hypothenuse 

is equal to the square of the two sides, is a proposition 

which expresses a relation between these figures. That 

three times five is equal to the half of thirty, expresses a 

relation between these numbers. Propositions of this kind 

are discoverable by the mere operation of thought, without 

dependence on what is anywhere existent in the universe. 

Though there never were a circle or triangle in nature, the 

truths demonstrated by Euclid would for ever retain their 

certainty and evidence. 



  Matters of fact, which are the second objects of human 

reason, are not ascertained in the same manner; nor is our 

evidence of their truth, however great, of a like nature with 

the foregoing. The contrary of every matter of fact is still 

possible; because it can never imply a contradiction, and 

is conceived by the mind with the same facility and dis- 

tinctness, as if ever so conformable to reality. That the 

sun will not rise to-morrow is no less intelligible a propo- 

sition, and implies no more contradiction than the affirma- 

tion, that it will rise. We should in vain, therefore, attempt 

to demonstrate its falsehood. Were it demonstratively false, 

it would imply a contradiction, and could never be dis- 

tinctly conceived by the mind. 



  It may, therefore, be a subject worthy of curiosity, to 

enquire what is the nature of that evidence which assures 

us of any real existence and matter of fact, beyond the 

present testimony of our senses, or the records of our 

memory. This part of philosophy, it is observable, has been 

little cultivated, either by the ancients or moderns; and 

therefore our doubts and errors, in the prosecution of so 

important an enquiry, may be the more excusable; while 

we march through such difficult paths without any guide 

or direction. They may even prove useful, by exciting 

curiosity, and destroying that implicit faith and security, 

which is the bane of all reasoning and free enquiry. The 

discovery of defects in the common philosophy, if any such 

there be, will not, I presume, be a discouragement, but 

rather an incitement, as is usual, to attempt something 

more full and satisfactory than has yet been proposed to 

the public. 



  All reasonings concerning matter of fact seem to be 

founded on the relation of Cause and Effect. By means of 

that relation alone we can go beyond the evidence of our 

memory and senses. If you were to ask a man, why he 

believes any matter of fact, which is absent; for instance, 

that his friend is in the country, or in France; he would 

give you a reason; and this reason would be some other 

fact; as a letter received from him, or the knowledge of his 

former resolutions and promises. A man finding a watch 

or any other machine in a desert island, would conclude 

that there had once been men in that island. All our rea- 

sonings concerning fact are of the same nature. And here 

it is constantly supposed that there is a connexion between 

the present fact and that which is inferred from it. Were 

there nothing to bind them together, the inference would 

be entirely precarious. The hearing of an articulate voice 

and rational discourse in the dark assures us of the pres- 

ence of some person: Why? because these are the effects 

of the human make and fabric, and closely connected with 

it. If we anatomize all the other reasonings of this nature, 

we shall find that they are founded on the relation of cause 

and effect, and that this relation is either near or remote, 

direct or collateral. Heat and light are collateral effects 

of fire, and the one effect may justly be inferred from the 

other. 



  If we would satisfy ourselves, therefore, concerning the 

nature of that evidence, which assures us of matters of fact, 

we must enquire how we arrive at the knowledge of cause 

and effect. 



  I shall venture to affirm, as a general proposition, which 

admits of no exception, that the knowledge of this relation 

is not, in any instance, attained by reasonings a priori; but 

arises entirely from experience, when we find that any 

particular objects are constantly conjoined with each other. 

Let an object be presented to a man of ever so strong natural 

reason and abilities; if that object be entirely new to him, 

he will not be able, by the most accurate examination of 

its sensible qualities, to discover any of its causes or effects. 

Adam, though his rational faculties be supposed, at the 

very first, entirely perfect, could not have inferred from 

the fluidity and transparency of water that it would suffo- 

cate him, or from the light and warmth of fire that it would 

consume him. No object ever discovers, by the qualities 

which appear to the senses, either the causes which pro- 

duced it, or the effects which will arise from it; nor can 

our reason, unassisted by experience, ever draw any in- 

ference concerning real existence and matter of fact. 



  This proposition, that causes and effects are discoverable, 

not by reason but by experience, will readily be admitted 

with regard to such objects, as we remember to have once 

been altogether unknown to us; since we must be conscious 

of the utter inability, which we then lay under, of foretelling 

what would arise from them. Present two smooth pieces of 

marble to a man who has no tincture of natural philosophy; 

he will never discover that they will adhere together in such 

a manner as to require great force to separate them in a 

direct line, while they make so small a resistance to a 

lateral pressure. Such events, as bear little analogy to 

the common course of nature, are also readily confessed to 

be known only by experience; nor does any man imagine 

that the explosion of gunpowder, or the attraction of a load- 

stone, could ever be discovered by arguments a priori. In 

like manner, when an effect is supposed to depend upon an 

intricate machinery or secret structure of parts, we make no 

difficulty in attributing all our knowledge of it to experience. 

Who will assert that he can give the ultimate reason, why 

milk or bread is proper nourishment for a man, not for 

a lion or a tiger? 



  But the same truth may not appear, at first sight, to have 

the same evidence with regard to events, which have become 

familiar to us from our first appearance in the world, which 

bear a close analogy to the whole course of nature, and 

which are supposed to depend on the simple qualities of 

objects, without any secret structure of parts. We are apt 

to imagine that we could discover these effects by the mere 

operation of our reason, without experience. We fancy, 

that were we brought on a sudden into this world, we 

could at first have inferred that one Billiard-ball would 

communicate motion to another upon impulse; and that we 

needed not to have waited for the event, in order to pro- 

nounce with certainty concerning it. Such is the influence of 

custom, that, where it is strongest, it not only covers our 

natural ignorance, but even conceals itself, and seems not to 

take place, merely because it is found in the highest degree. 



  But to convince us that all the laws of nature, and all 

the operations of bodies without exception, are known only 

by experience, the following reflections may, perhaps, suf- 

fice. Were any object presented to us, and were we 

required to pronounce concerning the effect, which will 

result from it, without consulting past observation; after 

what manner, I beseech you, must the mind proceed in this 

operation? It must invent or imagine some event, which 

it ascribes to the object as its effect; and it is plain that 

this invention must be entirely arbitrary. The mind can 

never possibly find the effect in the supposed cause, by the 

most accurate scrutiny and examination. For the effect is 

totally different from the cause, and consequently can never 

be discovered in it. Motion in the second Billiard-ball is a 

quite distinct event from motion in the first; nor is there 

anything in the one to suggest the smallest hint of the 

other. A stone or piece of metal raised into the air, and 

left without any support, immediately falls: but to consider 

the matter a priori, is there anything we discover in this 

situation which can beget the idea of a downward, rather 

than an upward, or any other motion, in the stone or metal? 



  And as the first imagination or invention of a particular 

effect, in all natural operations, is arbitrary, where we con- 

sult not experience; so must we also esteem the supposed 

tie or connexion between the cause and effect, which binds 

them together, and renders it impossible that any other 

effect could result from the operation of that cause. When 

I see, for instance, a Billiard-ball moving in a straight line 

towards another; even suppose motion in the second ball 

should by accident be suggested to me, as the result of their 

contact or impulse; may I not conceive, that a hundred dif- 

ferent events might as well follow from that cause? May 

not both these balls remain at absolute rest? May not the 

first ball return in a straight line, or leap off from the second 

in any line or direction? All these suppositions are con- 

sistent and conceivable. Why then should we give the 

preference to one, which is no more consistent or conceivable 

than the rest? All our reasonings a priori will never be 

able to show us any foundation for this preference. 



  In a word, then, every effect is a distinct event from its 

cause. It could not, therefore, be discovered in the cause, 

and the first invention or conception of it, a priori, must be 

entirely arbitrary. And even after it is suggested, the con- 

junction of it with the cause must appear equally arbitrary; 

since there are always many other effects, which, to reason, 

must seem fully as consistent and natural. In vain, there- 

fore, should we pretend to determine any single event, or 

infer any cause or effect, without the assistance of observa- 

tion and experience. 



  Hence we may discover the reason why no philosopher, 

who is rational and modest, has ever pretended to assign 

the ultimate cause of any natural operation, or to show 

distinctly the action of that power, which produces any 

single effect in the universe. It is confessed, that the 

utmost effort of human reason is to reduce the principles, 

productive of natural phenomena, to a greater simplicity, 

and to resolve the many particular effects into a few gen- 

eral causes, by means of reasonings from analogy, experi- 

ence, and observation. But as to the causes of these general 

causes, we should in vain attempt their discovery; nor shall 

we ever be able to satisfy ourselves, by any particular ex- 

plication of them. These ultimate springs and principles 

are totally shut up from human curiosity and enquiry. Elas- 

ticity, gravity, cohesion of parts, communication of motion 

by impulse; these are probably the ultimate causes and prin- 

ciples which we shall ever discover in nature; and we may 

esteem ourselves sufficiently happy, if, by accurate enquiry 

and reasoning, we can trace up the particular phenomena 

to, or near to, these general principles. The most perfect 

philosophy of the natural kind only staves off our ignorance 

a little longer: as perhaps the most perfect philosophy of 

the moral or metaphysical kind serves only to discover larger 

portions of it. Thus the observation of human blindness 

and weakness is the result of all philosophy, and meets us at 

every turn, in spite of our endeavours to elude or avoid it. 



  Nor is geometry, when taken into the assistance of natural 

philosophy, ever able to remedy this defect, or lead us into 

the knowledge of ultimate causes, by all that accuracy of 

reasoning for which it is so justly celebrated. Every part 

of mixed mathematics proceeds upon the supposition that 

certain laws are established by nature in her operations; 

and abstract reasonings are employed, either to assist ex- 

perience in the discovery of these laws, or to determine 

their influence in particular instances, where it depends 

upon any precise degree of distance and quantity. Thus, it 

is a law of motion, discovered by experience, that the mo- 

ment or force of any body in motion is in the compound 

ratio or proportion of its solid contents and its velocity; 

and consequently, that a small force may remove the greatest 

obstacle or raise the greatest weight, if, by any contrivance 

or machinery, we can increase the velocity of that force, 

so as to make it an overmatch for its antagonist. Geometry 

assists us in the application of this law, by giving us the 

just dimensions of all the parts and figures which can enter 

into any species of machine; but still the discovery of the 

law itself is owing merely to experience, and all the abstract 

reasonings in the world could never lead us one step towards 

the knowledge of it. When we reason a priori, and consider 

merely any object or cause, as it appears to the mind, inde- 

pendent of all observation, it never could suggest to us the 

notion of any distinct object, such as its effect; much less, 

show us the inseparable and inviolable connexion between 

them. A man must be very sagacious who could discover 

by reasoning that crystal is the effect of heat, and ice of 

cold, without being previously acquainted with the operation 

of these qualities. 



PART II 



  BUT we have not yet attained any tolerable satisfac- 

tion with regard to the question first proposed. Each 

solution still gives rise to a new question as difficult as 

the foregoing, and leads us on to farther enquiries. When 

it is asked, What is the nature of all our reasonings 

concerning matter of fact? the proper answer seems to be, 

that they are founded on the relation of cause and effect. 

When again it is asked, What is the foundation of all our 

reasonings and conclusions concerning that relation? it may 

be replied in one word, Experience. But if we still carry on 

our sifting humour, and ask, What is the foundation of all 

conclusions from experience? this implies a new question, 

which may be of more difficult solution and explication. 

Philosophers, that give themselves airs of superior wisdom 

and sufficiency, have a hard task when they encounter per- 

sons of inquisitive dispositions, who push them from every 

corner to which they retreat, and who are sure at last to 

bring them to some dangerous dilemma. The best expedient 

to prevent this confusion, is to be modest in our preten- 

sions; and even to discover the difficulty ourselves before 

it is objected to us. By this means, we may make a kind of 

merit of our very ignorance. 



  I shall content myself, in this section, with an easy task, 

and shall pretend only to give a negative answer to the 

question here proposed. I say then, that, even after we 

have experience of the operations of cause and effect, our 

conclusions from that experience are not founded on reason- 

ing, or any process of the understanding. This answer we 

must endeavour both to explain and to defend. 



  It must certainly be allowed, that nature has kept us 

at a great distance from all her secrets, and has afforded 

us only the knowledge of a few superficial qualities of ob- 

jects; while she conceals from us those powers and prin- 

ciples on which the influence of those objects entirely de- 

pends. Our senses inform us of the colour, weight, and 

consistence of bread; but neither sense nor reason can ever 

inform us of those qualities which fit it for the nourish- 

ment and support of a human body. Sight or feeling con- 

veys an idea of the actual motion of bodies; but as to that 

wonderful force or power, which would carry on a moving 

body for ever in a continued change of place, and which 

bodies never lose but by communicating it to others; of 

this we cannot form the most distant conception. But not- 

withstanding this ignorance of natural powers[1] and princi- 

ples, we always presume, when we see like sensible quali- 

ties, that they have like secret powers, and expect that 

effects, similar to those which we have experienced, will 

follow from them. If a body of like colour and consistence 

with that bread, which we have formerly eat, be pre- 

sented to us, we make no scruple of repeating the experi- 

ment, and foresee, with certainty, like nourishment and 

support. Now this is a process of the mind or thought, 

of which I would willingly know the foundation. It is 

allowed on all hands that there is no known connexion 

between the sensible qualities and the secret powers; and 

consequently, that the mind is not led to form such a con- 

clusion concerning their constant and regular conjunction, 

by anything which it knows of their nature. As to past 

Experience, it can be allowed to give direct and certain 

information of those precise objects only, and that precise 

period of time, which fell under its cognizance: but why 

this experience should be extended to future times, and to 

other objects, which for aught we know, may be only in 

appearance similar; this is the main question on which 

I would insist. The bread, which I formerly eat, nourished 

me; that is, a body of such sensible qualities was, at that 

time, endued with such secret powers: but does it follow, 

that other bread must also nourish me at another time, and 

that like sensible qualities must always be attended with 

like secret powers? The consequence seems nowise neces- 

sary. At least, it must be acknowledged that there is here 

a consequence drawn by the mind; that there is a certain 

step taken; a process of thought, and an inference, which 

wants to be explained. These two propositions are far 

from being the same. I have found that such an object has 

always been attended with such an effect, and I foresee, that 

other objects, which are, in appearance, similar, will be 

attended with similar effects. I shall allow, if you please, 

that the one proposition may justly be inferred from the 

other: I know, in fact, that it always is inferred. But if you 

insist that the inference is made by a chain of reasoning, 

I desire you to produce that reasoning. The connexion 

between these propositions is not intuitive. There is re- 

quired a medium, which may enable the mind to draw such 

an inference, if indeed it be drawn by reasoning and argu- 

ment. What that medium is, I must confess, passes my 

comprehension; and it is incumbent on those to produce it, 

who assert that it really exists, and is the origin of all our 

conclusions concerning matter of fact. 



  This negative argument must certainly, in process of 

time, become altogether convincing, if many penetrating 

and able philosophers shall turn their enquiries this way 

and no one be ever able to discover any connecting propo- 

sition or intermediate step, which supports the understand- 

ing in this conclusion. But as the question is yet new, 

every reader may not trust so far to his own penetration, 

as to conclude, because an argument escapes his enquiry, 

that therefore it does not really exist. For this reason it 

may be requisite to venture upon a more difficult task; and 

enumerating all the branches of human knowledge, en- 

deavour to show that none of them can afford such an 

argument. 



  All reasonings may be divided into two kinds, namely, 

demonstrative reasoning, or that concerning relations of 

ideas, and moral reasoning, or that concerning matter of 

fact and existence. That there are no demonstrative argu- 

ments in the case seems evident; since it implies no con- 

tradiction that the course of nature may change, and that 

an object, seemingly like those which we have experi- 

enced, may be attended with different or contrary effects. 

May I not clearly and distinctly conceive that a body, 

falling from the clouds, and which, in all other respects, 

resembles snow, has yet the taste of salt or feeling of 

fire? Is there any more intelligible proposition than to 

affirm, that all the trees will flourish in December and 

January, and decay in May and June? Now whatever 

is intelligible, and can be distinctly conceived, implies no 

contradiction, and can never be proved false by any demon- 

strative argument or abstract reasoning a priori. 



  If we be, therefore, engaged by arguments to put trust 

in past experience, and make it the standard of our future 

judgment, these arguments must be probable only, or such 

as regard matter of fact and real existence according to the 

division above mentioned. But that there is no argument 

of this kind, must appear, if our explication of that species 

of reasoning be admitted as solid and satisfactory. We 

have said that all arguments concerning existence are 

founded on the relation of cause and effect; that our 

knowledge of that relation is derived entirely from experi- 

ence; and that all our experimental conclusions proceed 

upon the supposition that the future will be conformable 

to the past. To endeavour, therefore, the proof of this last 

supposition by probable arguments, or arguments regarding 

existence, must be evidently going in a circle, and taking 

that for granted, which is the very point in question. 



  In reality, all arguments from experience are founded on 

the similarity which we discover among natural objects, 

and by which we are induced to expect effects similar to 

those which we have found to follow from such objects. 

And though none but a fool or madman will ever pretend 

to dispute the authority of experience, or to reject that 

great guide of human life, it may surely be allowed a philoso- 

pher to have so much curiosity at least as to examine the 

principle of human nature, which gives this mighty authority 

to experience, and makes us draw advantage from that 

similarity which nature has placed among different objects. 

>From causes which appear similar we expect similar effects. 

This is the sum of all our experimental conclusions. Now 

it seems evident that, if this conclusion were formed by 

reason, it would be as perfect at first, and upon one in- 

stance, as after ever so long a course of experience. But 

the case is far otherwise. Nothing so like as eggs; yet no 

one, on account of this appearing similarity, expects the 

same taste and relish in all of them. It is only after a long 

course of uniform experiments in any kind, that we attain 

a firm reliance and security with regard to a particular 

event. Now where is that process of reasoning which, 

from one instance, draws a conclusion, so different from 

that which it infers from a hundred instances that are 

nowise different from that single one? This question I 

propose as much for the sake of information, as with an 

intention of raising difficulties. I cannot find, I cannot 

imagine any such reasoning. But I keep my mind still 

open to instruction, if any one will vouchsafe to bestow 

it on me. 



  Should it be said that, from a number of uniform experi- 

ments, we infer a connexion between the sensible qualities 

and the secret powers; this, I must confess, seems the 

same difficulty, couched in different terms. The question 

still recurs, on what process of argument this inference is 

founded? Where is the medium, the interposing ideas, 

which join propositions so very wide of each other? It is 

confessed that the colour, consistence, and other sensible 

qualities of bread appear not, of themselves, to have any 

connexion with the secret powers of nourishment and sup- 

port. For otherwise we could infer these secret powers 

from the first appearance of these sensible qualities, without 

the aid of experience; contrary to the sentiment of all 

philosophers, and contrary to plain matter of fact. Here, 

then, is our natural state of ignorance with regard to the 

powers and influence of all objects. How is this remedied 

by experience? It only shows us a number of uniform 

effects, resulting from certain objects, and teaches us that 

those particular objects, at that particular time, were en- 

dowed with such powers and forces. When a new object, 

endowed with similar sensible qualities, is produced, we 

expect similar powers and forces, and look for a like effect. 

>From a body of like colour and consistence with bread we 

expect like nourishment and support. But this surely is 

a step or progress of the mind, which wants to be explained. 

When a man says, I have found, in all past instances, such 

sensible qualities conjoined with such secret powers: And 

when he says, Similar sensible qualities will always be con- 

joined with similar secret powers, he is not guilty of a tau- 

tology, nor are these propositions in any respect the same. 

You say that the one proposition is an inference from the 

other. But you must confess that the inference is not 

intuitive; neither is it demonstrative: Of what nature is it, 

then? To say it is experimental, is begging the question. 

For all inferences from experience suppose, as their founda- 

tion, that the future will resemble the past, and that similar 

powers will be conjoined with similar sensible qualities. 

If there be any suspicion that the course of nature may 

change, and that the past may be no rule for the future, all 

experience becomes useless, and can give rise to no in- 

ference or conclusion. It is impossible, therefore, that any 

arguments from experience can prove this resemblance of 

the past to the future; since all these arguments are 

founded on the supposition of that resemblance. Let the 

course of things be allowed hitherto ever so regular; that 

alone, without some new argument or inference, proves 

not that, for the future, it will continue so. In vain do 

you pretend to have learned the nature of bodies from your 

past experience. Their secret nature, and consequently 

all their effects and influence, may change, without any 

change in their sensible qualities. This happens some- 

times, and with regard to some objects: Why may it not 

happen always, and with regard to all objects? What logic, 

what process or argument secures you against this supposi- 

tion? My practice, you say, refutes my doubts. But you 

mistake the purport of my question. As an agent, I am 

quite satisfied in the point; but as a philosopher, who has 

some share of curiosity, I will not say scepticism, I want to 

learn the foundation of this inference. No reading, no 

enquiry has yet been able to remove my difficulty, or give 

me satisfaction in a matter of such importance. Can I do 

better than propose the difficulty to the public, even though, 

perhaps, I have small hopes of obtaining a solution? We 

shall at least, by this means, be sensible of our ignorance, 

if we do not augment our knowledge. 



  I must confess that a man is guilty of unpardonable 

arrogance who concludes, because an argument has es- 

caped his own investigation, that therefore it does not really 

exist. I must also confess that, though all the learned, for 

several ages, should have employed themselves in fruit- 

less search upon any subject, it may still, perhaps, be rash 

to conclude positively that the subject must, therefore, 

pass all human comprehension. Even though we examine 

all the sources of our knowledge, and conclude them un- 

fit for such a subject, there may still remain a suspicion, 

that the enumeration is not complete, or the examination 

not accurate. But with regard to the present subject, there 

are some considerations which seem to remove all this 

accusation of arrogance or suspicion of mistake. 



  It is certain that the most ignorant and stupid peasants-- 

nay infants, nay even brute beasts--improve by experience, 

and learn the qualities of natural objects, by observing the 

effects which result from them. When a child has felt the 

sensation of pain from touching the flame of a candle, he 

will be careful not to put his hand near any candle; but 

will expect a similar effect from a cause which is similar in 

its sensible qualities and appearance. If you assert, there- 

fore, that the understanding of the child is led into this 

conclusion by any process of argument or ratiocination, 

I may justly require you to produce that argument; nor 

have you any pretence to refuse so equitable a demand. 

You cannot say that the argument is abstruse, and may 

possibly escape your enquiry; since you confess that it is 

obvious to the capacity of a mere infant. If you hesitate, 

therefore, a moment, or if, after reflection, you produce any 

intricate or profound argument, you, in a manner, give up 

the question, and confess that it is not reasoning which 

engages us to suppose the past resembling the future, and 

to expect similar effects from causes which are, to appear- 

ance, similar. This is the proposition which I intended to 

enforce in the present section. If I be right, I pretend not 

to have made any mighty discovery. And if I be wrong, 

I must acknowledge myself to be indeed a very backward 

scholar; since I cannot now discover an argument which, 

it seems, was perfectly familiar to me long before I was 

out of my cradle. 



[1] The word, Power, is here used in a loose and popular sense. The more

accurate explication of it would give additional evidence to this argument.

See Sect. 7.





SECTION V

SCEPTICAL SOLUTION OF THESE DOUBTS



PART I 



  THE passion for philosophy, like that for religion, 

seems liable to this inconvenience, that, though it 

aims at the correction of our manners, and extirpation 

of our vices, it may only serve, by imprudent management, 

to foster a predominant inclination, and push the mind, 

with more determined resolution, towards that side which 

already draws too much, by the bias and propensity of the 

natural temper. It is certain that, while we aspire to the 

magnanimous firmness of the philosophic sage, and en- 

deavour to confine our pleasures altogether within our own 

minds, we may, at last, render our philosophy like that of 

Epictetus, and other Stoics, only a more refined system of 

selfishness, and reason ourselves out of all virtue as well 

as social enjoyment. While we study with attention the 

vanity of human life, and turn all our thoughts towards 

the empty and transitory nature of riches and honours, we 

are, perhaps, all the while flattering our natural indolence, 

which, hating the bustle of the world, and drudgery of 

business, seeks a pretence of reason to give itself a full 

and uncontrolled indulgence. There is, however, one 

species of philosophy which seems little liable to this in- 

convenience, and that because it strikes in with no dis- 

orderly passion of the human mind, nor can mingle it- 

self with any natural affection or propensity; and that is 

the Academic or Sceptical philosophy. The academics al- 

ways talk of doubt and suspense of judgment, of danger 

in hasty determinations, of confining to very narrow bounds 

the enquiries of the understanding, and of renouncing all 

speculations which lie not within the limits of common life 

and practice. Nothing, therefore, can be more contrary 

than such a philosophy to the supine indolence of the 

mind, its rash arrogance, its lofty pretensions, and its super- 

stitious credulity. Every passion is mortified by it, except 

the love of truth; and that passion never is, nor can be, 

carried to too high a degree. It is surprising, therefore, 

that this philosophy, which, in almost every instance, must 

be harmless and innocent, should be the subject of so 

much groundless reproach and obloquy. But, perhaps, 

the very circumstance which renders it so innocent is 

what chiefly exposes it to the public hatred and resentment. 

By flattering no irregular passion, it gains few partizans: 

By opposing so many vices and follies, it raises to itself 

abundance of enemies, who stigmatize it as libertine, pro- 

fane, and irreligious. 



  Nor need we fear that this philosophy, while it endeavours 

to limit our enquiries to common life, should ever undermine 

the reasonings of common life, and carry its doubts so far 

as to destroy all action, as well as speculation. Nature 

will always maintain her rights, and prevail in the end over 

any abstract reasoning whatsoever. Though we should 

conclude, for instance, as in the foregoing section, that, in 

all reasonings from experience, there is a step taken by the 

mind which is not supported by any argument or process 

of the understanding; there is no danger that these rea- 

sonings, on which almost all knowledge depends, will ever 

be affected by such a discovery. If the mind be not en- 

gaged by argument to make this step, it must be induced 

by some other principle of equal weight and authority; and 

that principle will preserve its influence as long as human 

nature remains the same. What that principle is may well 

be worth the pains of enquiry. 



  Suppose a person, though endowed with the strongest 

faculties of reason and reflection, to be brought on a sudden 

into this world; he would, indeed, immediately observe 

a continual succession of objects, and one event following 

another; but he would not be able to discover anything 

farther. He would not, at first, by any reasoning, be able 

to reach the idea of cause and effect; since the particular 

powers, by which all natural operations are performed, 

never appear to the senses; nor is it reasonable to conclude, 

merely because one event, in one instance, precedes another, 

that therefore the one is the cause, the other the effect. 

Their conjunction may be arbitrary and casual. There 

may be no reason to infer the existence of one from the 

appearance of the other. And in a word, such a person, 

without more experience, could never employ his conjecture 

or reasoning concerning any matter of fact, or be assured 

of anything beyond what was immediately present to his 

memory and senses. 



  Suppose, again, that he has acquired more experience, 

and has lived so long in the world as to have observed 

familiar objects or events to be constantly conjoined to- 

gether; what is the consequence of this experience? He 

immediately infers the existence of one object from the 

appearance of the other. Yet he has not, by all his ex- 

perience, acquired any idea or knowledge of the secret 

power by which the one object produces the other; nor 

is it by any process of reasoning, he is engaged to draw 

this inference. But still he finds himself determined to 

draw it: and though he should be convinced that his 

understanding has no part in the operation, he would 

nevertheless continue in the same course of thinking. There 

is some other principle which determines him to form such 

a conclusion. 



  This principle is Custom or Habit. For wherever the 

repetition of any particular act or operation produces a 

propensity to renew the same act or operation, without 

being impelled by any reasoning or process of the under- 

standing, we always say, that this propensity is the effect 

of Custom. By employing that word, we pretend not to 

have given the ultimate reason of such a propensity. We 

only point out a principle of human nature, which is 

universally acknowledged, and which is well known by its 

effects. Perhaps we can push our enquiries no farther, or 

pretend to give the cause of this cause; but must rest 

contented with it as the ultimate principle, which we can 

assign, of all our conclusions from experience. It is suf- 

ficient satisfaction, that we can go so far, without repining 

at the narrowness of our faculties because they will carry 

us no farther. And it is certain we here advance a very 

intelligible proposition at least, if not a true one, when 

we assert that, after the constant conjunction of two ob- 

jects--heat and flame, for instance, weight and solidity-- 

we are determined by custom alone to expect the one from 

the appearance of the other. This hypothesis seems even 

the only one which explains the difficulty, why we draw, 

from a thousand instances, an inference which we are not 

able to draw from one instance, that is, in no respect, 

different from them. Reason is incapable of any such 

variation. The conclusions which it draws from consider- 

ing one circle are the same which it would form upon 

surveying all the circles in the universe. But no man, 

having seen only one body move after being impelled by 

another, could infer that every other body will move after 

a like impulse. All inferences from experience, therefore, 

are effects of custom, not of reasoning.[1]



  Custom, then, is the great guide of human life. It is 

that principle alone which renders our experience useful 

to us, and makes us expect, for the future, a similar train 

of events with those which have appeared in the past. 

Without the influence of custom, we should be entirely 

ignorant of every matter of fact beyond what is immediately 

present to the memory and senses. We should never know 

how to adjust means to ends, or to employ our natural 

powers in the production of any effect. There would 

be an end at once of all action, as well as of the chief 

part of speculation. 



  But here it may be proper to remark, that though our 

conclusions from experience carry us beyond our memory 

and senses, and assure us of matters of fact which hap- 

pened in the most distant places and most remote ages, 

yet some fact must always be present to the senses or 

memory, from which we may first proceed in drawing these 

conclusions. A man, who should find in a desert country 

the remains of pompous buildings, would conclude that 

the country had, in ancient times, been cultivated by civil- 

ized inhabitants; but did nothing of this nature occur 

to him, he could never form such an inference. We learn 

the events of former ages from history; but then we must 

peruse the volumes in which this instruction is contained, 

and thence carry up our inferences from one testimony to 

another, till we arrive at the eyewitnesses and spectators of 

these distant events. In a word, if we proceed not upon 

some fact, present to the memory or senses, our reasonings 

would be merely hypothetical; and however the particular 

links might be connected with each other, the whole chain 

of inferences would have nothing to support it, nor could 

we ever, by its means, arrive at the knowledge of any real 

existence. If I ask why you believe any particular matter 

of fact, which you relate, you must tell me some reason; 

and this reason will be some other fact, connected with it. 

But as you cannot proceed after this manner, in infinitum, 

you must at last terminate in some fact, which is present to 

your memory or senses; or must allow that your belief is 

entirely without foundation. 



  What, then, is the conclusion of the whole matter? A 

simple one; though, it must be confessed, pretty remote 

from the common theories of philosophy. All belief of 

matter of fact or real existence is derived merely from some 

object, present to the memory or senses, and a customary 

conjunction between that and some other object. Or in 

other words; having found, in many instances, that any 

two kinds of objects--flame and heat, snow and cold--have 

always been conjoined together; if flame or snow be pre- 

sented anew to the senses, the mind is carried by custom 

to expect heat or cold, and to believe that such a quality 

does exist, and will discover itself upon a nearer approach. 

This belief is the necessary result of placing the mind in 

such circumstances. It is an operation of the soul, when 

we are so situated, as unavoidable as to feel the passion of 

love, when we receive benefits; or hatred, when we meet 

with injuries. All these operations are a species of natural 

instincts, which no reasoning or process of the thought and 

understanding is able either to produce or to prevent. 



  At this point, it would be very allowable for us to stop 

our philosophical researches. In most questions we can 

never make a single step farther; and in all questions we 

must terminate here at last, after our most restless and 

curious enquiries. But still our curiosity will be pardonable, 

perhaps commendable, if it carry us on to still farther 

researches, and make us examine more accurately the na- 

ture of this belief, and of the customary conjunction, whence 

it is derived. By this means we may meet with some ex- 

plications and analogies that will give satisfaction; at least 

to such as love the abstract sciences, and can be enter- 

tained with speculations, which, however accurate, may 

still retain a degree of doubt and uncertainty. As to 

readers of a different taste; the remaining part of this 

section is not calculated for them, and the following en- 

quiries may well be understood, though it be neglected. 



PART II 



  NOTHING is more free than the imagination of man; and 

though it cannot exceed that original stock of ideas fur- 

nished by the internal and external senses, it has unlimited 

power of mixing, compounding, separating, and dividing 

these ideas, in all the varieties of fiction and vision. It 

can feign a train of events, with all the appearance of 

reality, ascribe to them a particular time and place, conceive 

them as existent, and paint them out to itself with every 

circumstance, that belongs to any historical fact, which it 

believes with the greatest certainty. Wherein, therefore, 

consists the difference between such a fiction and belief? 

It lies not merely in any peculiar idea, which is annexed to 

such a conception as commands our assent, and which is 

wanting to every known fiction. For as the mind has 

authority over all its ideas, it could voluntarily annex this 

particular idea to any fiction, and consequently be able to 

believe whatever it pleases; contrary to what we find by 

daily experience. We can, in our conception, join the head 

of a man to the body of a horse; but it is not in our 

power to believe that such an animal has ever really 

existed. 



  It follows, therefore, that the difference between fiction 

and belief lies in some sentiment or feeling, which is 

annexed to the latter, not to the former, and which depends 

not on the will, nor can be commanded at pleasure. It 

must be excited by nature, like all other sentiments; and 

must arise from the particular situation, in which the mind 

is placed at any particular juncture. Whenever any object 

is presented to the memory or senses, it immediately, by the 

force of custom, carries the imagination to conceive that 

object, which is usually conjoined to it; and this conception 

is attended with a feeling or sentiment, different from the 

loose reveries of the fancy. In this consists the whole 

nature of belief. For as there is no matter of fact which 

we believe so firmly that we cannot conceive the contrary, 

there would be no difference between the conception as- 

sented to and that which is rejected, were it not for some 

sentiment which distinguishes the one from the other. If 

I see a billiard-ball moving toward another, on a smooth 

table, I can easily conceive it to stop upon contact. This 

conception implies no contradiction; but still it feels very 

differently from that conception by which I represent to 

myself the impulse and the communication of motion from 

one ball to another. 



  Were we to attempt a definition of this sentiment, we 

should, perhaps, find it a very difficult, if not an impossible 

task; in the same manner as if we should endeavour to 

define the feeling of cold or passion of anger, to a creature 

who never had any experience of these sentiments. Belief 

is the true and proper name of this feeling; and no one is 

ever at a loss to know the meaning of that term; because 

every man is every moment conscious of the sentiment 

represented by it. It may not, however, be improper to 

attempt a description of this sentiment; in hopes we may, 

by that means, arrive at some analogies, which may afford 

a more perfect explication of it. I say, then, that belief is 

nothing but a more vivid, lively, forcible, firm, steady con- 

ception of an object, than what the imagination alone is 

ever able to attain. This variety of terms, which may 

seem so unphilosophical, is intended only to express that 

act of the mind, which renders realities, or what is taken for 

such, more present to us than fictions, causes them to 

weigh more in the thought, and gives them a superior 

influence on the passions and imagination. Provided we 

agree about the thing, it is needless to dispute about the 

terms. The imagination has the command over all its 

ideas, and can join and mix and vary them, in all the 

ways possible. It may conceive fictitious objects with all 

the circumstances of place and time. It may set them, in 

a manner, before our eyes, in their true colours, just as 

they might have existed. But as it is impossible that this 

faculty of imagination can ever, of itself, reach belief, it is 

evident that belief consists not in the peculiar nature or 

order of ideas, but in the manner of their conception, and in 

their feeling to the mind. I confess, that it is impossible 

perfectly to explain this feeling or manner of conception. 

We may make use of words which express something near 

it. But its true and proper name, as we observed before, is 

belief; which is a term that every one sufficiently under- 

stands in common life. And in philosophy, we can go no 

farther than assert, that belief is something felt by the mind, 

which distinguishes the ideas of the judgement from the 

fictions of the imagination. It gives them more weight and 

influence; makes them appear of greater importance; en- 

forces them in the mind; and renders them the governing 

principle of our actions. I hear at present, for instance, a 

person's voice, with whom I am acquainted; and the sound 

comes as from the next room. This impression of my 

senses immediately conveys my thought to the person, to- 

gether with all the surrounding objects. I paint them out 

to myself as existing at present, with the same qualities and 

relations, of which I formerly knew them possessed. These 

ideas take faster hold of my mind than ideas of an en- 

chanted castle. They are very different to the feeling, and 

have a much greater influence of every kind, either to give 

pleasure or pain, joy or sorrow. 



  Let us, then, take in the whole compass of this doctrine, 

and allow, that the sentiment of belief is nothing but a 

conception more intense and steady than what attends the 

mere fictions of the imagination, and that this manner of 

conception arises from a customary conjunction of the 

object with something present to the memory or senses: 

I believe that it will not be difficult, upon these supposi- 

tions, to find other operations of the mind analogous to it, 

and to trace up these phenomena to principles still more 

general. 



  We have already observed that nature has established 

connexions among particular ideas, and that no sooner 

one idea occurs to our thoughts than it introduces its cor- 

relative, and carries our attention towards it, by a gentle 

and insensible movement. These principles of connexion 

or association we have reduced to three, namely, Resem- 

blance, Contiguity and Causation; which are the only bonds 

that unite our thoughts together, and beget that regular 

train of reflection or discourse, which, in a greater or less 

degree, takes place among all mankind. Now here arises 

a question, on which the solution of the present difficulty 

will depend. Does it happen, in all these relations, that, 

when one of the objects is presented to the senses or 

memory, the mind is not only carried to the conception 

of the correlative, but reaches a steadier and stronger 

conception of it than what otherwise it would have been 

able to attain? This seems to be the case with that 

belief which arises from the relation of cause and effect. 

And if the case be the same with the other relations 

or principles of associations, this may be established as 

a general law, which takes place in all the operations of 

the mind. 



  We may, therefore, observe, as the first experiment 

to our present purpose, that, upon the appearance of the 

picture of an absent friend, our idea of him is evidently 

enlivened by the resemblance, and that every passion, which 

that idea occasions, whether of joy or sorrow, acquires 

new force and vigour. In producing this effect, there 

concur both a relation and a present impression. Where 

the picture bears him no resemblance, at least was not 

intended for him, it never so much as conveys our thought 

to him: and where it is absent, as well as the person, 

though the mind may pass from the thought of the one to 

that of the other, it feels its idea to be rather weakened 

than enlivened by that transition. We take a pleasure in 

viewing the picture of a friend, when it is set before us; 

but when it is removed, rather choose to consider him 

directly than by reflection in an image, which is equally 

distant and obscure. 



  The ceremonies of the Roman Catholic religion may 

be considered as instances of the same nature. The dev- 

otees of that superstition usually plead in excuse for the 

mummeries, with which they are upbraided, that they 

feel the good effect of those external motions, and pos- 

tures, and actions, in enlivening their devotion and quick- 

ening their fervour, which otherwise would decay, if 

directed entirely to distant and immaterial objects. We 

shadow out the objects of our faith, say they, in sensible 

types and images, and render them more present to us 

by the immediate presence of these types, than it is pos- 

sible for us to do merely by an intellectual view and 

contemplation. Sensible objects have always a greater in- 

fluence on the fancy than any other; and this influence 

they readily convey to those ideas to which they are 

related, and which they resemble. I shall only infer from 

these practices, and this reasoning, that the effect of resem- 

blance in enlivening the ideas is very common; and as in 

every case a resemblance and a present impression must 

concur, we are abundantly supplied with experiments to 

prove the reality of the foregoing principle. 



  We may add force to these experiments by others of 

a different kind, in considering the effects of contiguity as 

well as of resemblance. It is certain that distance dimin- 

ishes the force of every idea, and that, upon our approach 

to any object; though it does not discover itself to our 

senses; it operates upon the mind with an influence, which 

imitates an immediate impression. The thinking on any 

object readily transports the mind to what is contiguous; 

but it is only the actual presence of an object, that trans- 

ports it with a superior vivacity. When I am a few miles 

from home, whatever relates to it touches me more nearly 

than when I am two hundred leagues distant; though even 

at that distance the reflecting on any thing in the neigh- 

bourhood of my friends or family naturally produces an 

idea of them. But as in this latter case, both the objects 

of the mind are ideas; notwithstanding there is an easy 

transition between them; that transition alone is not able to 

give a superior vivacity to any of the ideas, for want of 

some immediate impression.[2]



  No one can doubt but causation has the same influence 

as the other two relations of resemblance and contiguity. 

Superstitious people are fond of the reliques of saints and 

holy men, for the same reason, that they seek after types 

or images, in order to enliven their devotion, and give them 

a more intimate and strong conception of those exemplary 

lives, which they desire to imitate. Now it is evident, that 

one of the best reliques, which a devotee could procure, 

would be the handywork of a saint; and if his cloaths and 

furniture are ever to be considered in this light, it is be- 

cause they were once at his disposal, and were moved and 

affected by him; in which respect they are to be considered 

as imperfect effects, and as connected with him by a shorter 

chain of consequences than any of those, by which we learn 

the reality of his existence. 



  Suppose, that the son of a friend, who had been long 

dead or absent, were presented to us; it is evident, that 

this object would instantly revive its correlative idea, and 

recall to our thoughts all past intimacies and familiarities, 

in more lively colours than they would otherwise have ap- 

peared to us. This is another phaenomenon, which seems 

to prove the principle above mentioned.