1748
                   AN ENQUIRY CONCERNING HUMAN UNDERSTANDING
                                 by David Hume
           Sect. I. Of the different Species of Philosophy

  1. 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 mankind. 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 according to the light in
which they present themselves. As virtue, 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.
  2. The other species of philosophers considers man in the light of a
reasonable rather than an active being, and endeavours 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
understanding, 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 deformity, 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 themselves sufficiently
compensated for the labour of their whole lives, if they can
discover some hidden truths, which may contribute to the instruction
of posterity.
  3. 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 influence 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.
  4. 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
anything 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 application 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 entertaining.
  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 satisfaction 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 biasses 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.
  5. 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 profound
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 ridicule,
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 internal fabric, the operations of the
understanding, the workings of the passions, and the various species
of sentiment 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 throughout 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.
  6. 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 burdensome 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 philosophy, is
objected to, not only as painful and fatiguing, but as the
inevitable source of uncertainty and error. Here indeed 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 popular 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.
  7. 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, however
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 that 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 philosophy, is, with others, overbalanced by
curiosity; and despair, which, at some moments, prevails, may give
place afterwards 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.
  8. Besides this advantage of rejecting, after deliberate enquiry,
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 instant, 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 satisfaction to go so far; and the more obvious
this science may appear (and it is by no means obvious) the more
contemptible 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
comprehension 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?
  9. But may we not hope, that philosophy, if 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 determined 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
perfection. 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 principles on mankind.
  10. 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!
                 Sect. II. Of the Origin of Ideas

  11. Every one will readily allow, that there is a considerable
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 recalls to his memory this sensation, or anticipates
it by his imagination. These faculties may mimic or copy the
perceptions 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 form 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 perceptions were clothed. It requires no nice
discernment or metaphysical head to mark the distinction between them.
  12. 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.
  13. 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 distant 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 composition 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.
  14. 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.
  15. 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 correspondent 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 Laplander 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 generosity. 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.
  16. 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 gradation 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
colours 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.
  17. 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 without a distinct
meaning, we are apt to imagine it has a determinate 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 determined: 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.*

  * It is probable that no more was meant by those, 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 opposition 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
perceptions, 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
undefined terms, draw out their disputes to a tedious length,
without ever touching 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.
                Sect. III. Of the Association of Ideas

  18. IT is evident that there is a principle of connexion between 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 succeeded
each other. Were the loosest and freest conversation 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.
  19. 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:*
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 complete and entire.

  * 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 Resemblance. 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.
               Sect. IV. Sceptical Doubts concerning the
                   Operations of the Understanding

                               PART I.

  20. All the objects of human reason or enquiry may naturally be
divided into two kinds, to wit, Relations 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.
  21. 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 distinctness, as if ever so conformable to
reality. That the sun will not rise tomorrow is no less intelligible a
proposition, and implies no more contradiction than the affirmation,
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 distinctly 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.
  22. All reasonings concerning matter of fact seem to be founded on
the realtion 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 reasonings 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 presence 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.
  23. 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 suffocate 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 produced
it, or the effects which will arise from it; nor can our reason,
unassisted by experience, ever draw any inference concerning real
existence and matter of fact.
  24. 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 loadstone, 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 pronounce 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.
  25. 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, suffice. 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 consult 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 different 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 consistent 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 conjunction 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, therefore, should we pretend to determine any single
event, or infer any cause or effect, without the assistance of
observation and experience.
  26. 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
general causes, by means of reasonings from analogy, experience, 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 explication of them. These
ultimate springs and principles are totally shut up from human
curiosity and enquiry. Elasticity, gravity, cohesion of parts,
communication of motion by impulse; these are probably the ultimate
causes and principles 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.
  27. 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 experience 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 moment 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, independent 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.

  28. But we have not yet attained any tolerable satisfaction 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 persons 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 pretensions; 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 reasoning, or any process of the understanding.
This answer we must endeavour both to explain and to defend.
  29. 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 objects; while she
conceals from us those powers and principles on which the influence of
those objects entirely depends. 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 nourishment and
support of a human body. Sight or feeling conveys 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
notwithstanding this ignorance of natural powers* and principles, we
always presume, when we see like sensible qualities, 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
presented to us, we make no scruple of repeating the experiment, 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 conclusion
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 necessary. 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 required a medium, which may enable the mind to
draw such an inference, if indeed it be drawn by reasoning and
argument. 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.

  * 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.

  30. 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 proposition or intermediate step,
which supports the understanding 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, endeavour 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 arguments in the case seems evident;
since it implies no contradiction that the course of nature may
change, and that an object, seemingly like those which we have
experienced, 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 demonstrative
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 judgement, 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 experience; 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.
  31. 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 philosopher 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 instance,
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.
  32. Should it be said that, from a number of uniform experiments, 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 support. 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 endowed 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 conjoined with similar secret powers, he is not
guilty of a tautology, 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 foundation, 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 inference 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 sometimes, and with regard to some objects:
Why may it not happen always, and with regard to all objects? What
logic, what process of argument secures you against this
supposition? 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.
  33. I must confess that a man is guilty of unpardonable arrogance
who concludes, because an argument has escaped 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 fruitless 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 unfit
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, therefore,
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 appearance, 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.
               Sect. V. Sceptical Solution of these Doubts

                                PART I.

  34. 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 endeavour 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 inconvenience,
and that because it strikes in with no disorderly passion of the human
mind, nor can mingle itself with any natural affection or
propensity; and that is the Academic or Sceptical philosophy. The
academics always talk of doubt and suspense of judgement, 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 superstitious
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, profane, 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 reasonings, on
which almost all knowledge depends, will ever be affected by such a
discovery. If the mind be not engaged 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.
  35. 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 together; 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
experience, 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.
  36. 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 understanding, 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 sufficient
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 objects- 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 considering 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.*

  * Nothing is more useful than for writers, even, on moral,
political, or physical subjects, to distinguish between reason and
experience, and to suppose, that these species of argumentation are
entirely different from each other. The former are taken for the
mere result of our intellectual faculties, which, by considering
priori the nature of things, and examining the effects, that must
follow from their operation, establish particular principles of
science and philosophy. The latter are supposed to be derived entirely
from sense and observation, by which we learn what has actually
resulted from the operation of particular objects, and are thence able
to infer, what will, for the future, result from them. Thus, for
instance, the limitations and restraints of civil government, and a
legal constitution, may be defended, either from reason, which
reflecting on the great frailty and corruption of human nature,
teaches, that no man can safely be trusted with unlimited authority;
or from experience and history, which inform us of the enormous
abuses, that ambition, in every age and country, has been found to
make of so imprudent a confidence.
  The same distinction between reason and experience is maintained
in all our deliberations concerning the conduct of life; while the
experienced statesman, general, physician, or merchant is trusted
and followed; and the unpractised novice, with whatever natural
talents endowed, neglected and despised. Though it be allowed, that
reason may form very plausible conjectures with regard to the
consequences of such a particular conduct in such particular
circumstances; it is still supposed imperfect, without the
assistance of experience, which is alone able to give stability and
certainty to the maxims, derived from study and reflection.
  But notwithstanding that this distinction be thus universally
received, both in the active speculative scenes of life, I shall not
scruple to pronounce, that it is, at bottom, erroneous, at least,
superficial.
  If we examine those arguments, which, in any of the sciences above
mentioned, are supposed to be mere effects of reasoning and
reflection, they will be found to terminate, at last, in some
general principle or conclusion, for which we can assign no reason but
observation and experience. The only difference between them and those
maxims, which are vulgarly esteemed the result of pure experience, is,
that the former cannot be established without some process of thought,
and some reflection on what we have observed, in order to
distinguish its circumstances, and trace its consequences: Whereas
in the latter, the experienced event is exactly and fully familiar
to that which we infer as the result of any particular situation.
The history of a Tiberius or a Nero makes us dread a like tyranny,
were our monarchs freed from the restraints of laws and senates: But
the observation of any fraud or cruelty in private life is sufficient,
with the aid of a little thought, to give us the same apprehension;
while it serves as an instance of the general corruption of human
nature, and shows us the danger which we must incur by reposing an
entire confidence in mankind. In both cases, it is experience which is
ultimately the foundation of our inference and conclusion.
  There is no man so young and unexperienced, as not to have formed,
from observation, many general and just maxims concerning human
affairs and the conduct of life; but it must be confessed, that,
when a man comes to put these in practice, he will be extremely liable
to error, till time and farther experience both enlarge these
maxims, and teach him their proper use and application. In every
situation or incident, there are many particular and seemingly
minute circumstances, which the man of greatest talent is, at first,
apt to overlook, though on them the justness of his conclusions, and
consequently the prudence of his conduct, entirely depend. Not to
mention, that, to a young beginner, the general observations and
maxims occur not always on the proper occasions, nor can be

immediately applied with due calmness and distinction. The truth is,
an unexperienced reasoner could be no reasoner at all, were he
absolutely unexperienced; and when we assign that character to any
one, we mean it only in a comparative sense, and suppose him possessed
of experience, in a smaller and more imperfect degree.

  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.
  37. 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 happened 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 civilized 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.
  38. 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 presented 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 further; 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 nature
of this belief, and of the customary conjunction, whence it is
derived. By this means we may meet with some explications and
analogies that will give satisfaction; at least to such as love the
abstract sciences, and can be entertained 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 enquiries
may well be understood, though it be neglected.
                             PART II.

  39. Nothing is more free than the imagination of man; and though
it cannot exceed that original stock of ideas furnished 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
assented 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 towards 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.
  40. 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 conception 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 understands 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;
enforces 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, together 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 enchanted 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 suppositions, to find other operations of the mind analogous
to it, and to trace up these phenomena to principles still more
general.
  41. 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 correlative, and carries
our attention towards it, by a gentle and insensible movement. These
principles of connexion or association we have reduced to three,
namely, Resemblance, 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 devotees 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 postures, and actions, in enlivening their devotion and quickening
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
possible for us to do merely by an intellectual view and
contemplation. Sensible objects have always a greater influence 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 resemblance 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.
  42. 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 diminishes 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 transports 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 anything in
the neighbourhood 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.*

  * "Naturane nobis, inquit, datum dicam, an errore quodam, ut, cum ea
loca videamus, in quibus memoria dignos viros acceperimus multum
esse versatos, magis moveamur, quam siquando eorum ipsorum aut facta
audiamus aut scriptum aliquod legamus? Velut ego nunc moveor. Venit
enim mihi Plato in mentem, quem accepimus primum hic disputare
solitum: cuius etiam illi hortuli propinqui non memoriam solum mihi
afferunt, sed ipsum videntur in conspectu meo hic ponere. Hic
Speusippus, hic Xenocrates, hic eius auditor Polemo; cuius ipsa illa
sessio fuit, quam videmus. Equidem etiam curiam nostram, Hostiliam
dico, non hanc novam, quae mihi minor esse videtur postquam est maior,
solebam intuens, Scipionem, Catonem, Laelium, nostrum vero in primis
avum cogitare. Tanta vis admonitionis est in locis; ut non sine
causa ex his memoriae deducta sit disciplina."
                                        Cicero, De finibus, Book V.

  43. 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 because 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 recal to our thoughts all
past intimacies and familiarities, in more lively colours than they
would otherwise have appeared to us. This is another phaenomenon,
which seems to prove the principle above mentioned.
  44. We may observe, that, in these phaenomena, the belief of the
correlative object is always presupposed; without which the relation
could have no effect. The influence of the picture supposes, that we
believe our friend to have once existed. Continguity to home can never
excite our ideas of home, unless we believe that it really exists. Now
I assert, that this belief, where it reaches beyond the memory or
senses, is of a similar nature, and arises from similar causes, with
the transition of thought and vivacity of conception here explained.
When I throw a piece of dry wood into a fire, my mind is immediately
carried to conceive, that it augments, not extinguishes the flame.
This transition of thought from the cause to the effect proceeds not
from reason. It derives its origin altogether from custom and
experience. And as it first begins from an object, present to the
senses, it renders the idea or conception of flame more strong and
lively than any loose, floating reverie of the imagination. That
idea arises immediately. The thought moves instantly towards it, and
conveys to it all that force of conception, which is derived from
the impression present to the senses. When a sword is levelled at my
breast, does not the idea of wound and pain strike me more strongly,
than when a glass of wine is presented to me, even though by
accident this idea should occur after the appearance of the latter
object? But what is there in this whole matter to cause such a
strong conception, except only a present object and a customary
transition to the idea of another object, which we have been
accustomed to conjoin with the former? This is the whole operation
of the mind, in all our conclusions concerning matter of fact and
existence; and it is a satisfaction to find some analogies, by which
it may be explained. The transition from a present object does in
all cases give strength and solidity to the related idea.
  Here, then, is a kind of pre-established harmony between the
course of nature and the succession of our ideas; and though the
powers and forces, by which the former is governed, be wholly
unknown to us; yet our thoughts and conceptions have still, we find,
gone on in the same train with the other works of nature. Custom is
that principle, by which this correspondence has been effected; so
necessary to the subsistence of our species, and the regulation of our
conduct, in every circumstance and occurrence of human life. Had not
the presence of an object, instantly excited the idea of those
objects, commonly conjoined with it, all our knowledge must have
been limited to the narrow sphere of our memory and senses; and we
should never have been able to adjust means to ends, or employ our
natural powers, either to the producing of good, or avoiding of
evil. Those, who delight in the discovery and contemplation of final
causes, have here ample subject to employ their wonder and admiration.
  45. I shall add, for a further confirmation of the foregoing theory,
that, as this operation of the mind, by which we infer like effects
from like causes, and vice versa, is so essential to the subsistence
of all human creatures, it is not probable, that it could be trusted
to the fallacious deductions of our reason, which is slow in its
operations; appears not, in any degree, during the first years of
infancy; and at best is, in every age and period of human life,
extremely liable to error and mistake. It is more conformable to the
ordinary wisdom of nature to secure so necessary an act of the mind,
by some instinct or mechanical tendency, which may be infallible in
its operations, may discover itself at the first appearance of life
and thought, and may be independent of all the laboured deductions
of the understanding. As nature has taught us the use of our limbs,
without giving us the knowledge of the muscles and nerves, by which
they are actuated; so has she implanted in us an instinct, which
carries forward the thought in a correspondent course to that which
she has established among external objects; though we are ignorant
of those powers and forces, on which this regular course and
succession of objects totally depends.
                      Sect. VI. Of Probability*

  * Mr. Locke divides all arguments into demonstrative and probable.
In this view, we must say, that it is only probable all men must
die, or that the sun will rise to-morrow. But to conform our
language more to common use, we ought to divide arguments into
demonstrations, proofs, and probabilities. By proofs meaning such
arguments from experience as leave no room for doubt or opposition.

  46. THOUGH there be no such thing as Chance in the world; our
ignorance of the real cause of any event has the same influence on the
understanding, and begets a like species of belief or opinion.
  There is certainly a probability, which arises from a superiority of
chances on any side; and according as this superiority encreases,
and surpasses the opposite chances, the probability receives a
proportionable encrease, and begets still a higher degree of belief or
assent to that side, in which we discover the superiority. If a die
were marked with one figure or number of spots on four sides, and with
another figure or number of spots on the two remaining sides, it would
be more probable, that the former would turn up than the latter;
though, if it had a thousand sides marked in the same manner, and only
one side different, the probability would be much higher, and our
belief or expectation of the event more steady and secure. This
process of the thought or reasoning may seem trivial and obvious;
but to those who consider it more narrowly, it may, perhaps, afford
matter for curious speculation.
  It seems evident, that, when the mind looks forward to discover
the event, which may result from the throw of such a die, it considers
the turning up of each particular side as alike probable; and this the
very nature of chance, to render all the particular events,
comprehended in it, entirely equal. But finding a greater number of
sides concur in the one event than in the other, the mind is carried
more frequently to that event, and meets it oftener, in revolving
the various possibilities or chances, on which the ultimate result
depends. This concurrence of several views in one particular event
begets immediately, by an inexplicable contrivance of nature, the
sentiment of belief, and gives that event the advantage over its
antagonist, which is supported by a smaller number of views, and
recurs less frequently to the mind. If we allow, that belief is
nothing but a firmer and stronger conception of an object than what
attends the mere fictions of the imagination, this operation may,
perhaps, in some measure, be accounted for. The concurrence of these
several views or glimpses imprints the idea more strongly on the
imagination; gives it superior force and vigour; renders its influence
on the passions and affections more sensible; and in a word, begets
that reliance or security, which constitutes the nature of belief
and opinion.
  47. The case is the same with the probability of causes, as with
that of chance. There are some causes, which are entirely uniform
and constant in producing a particular effect; and no instance has
ever yet been found of any failure or irregularity in their operation.
Fire has always burned, and water suffocated every human creature: The
production of motion by impulse and gravity is an universal law, which
has hitherto admitted of no exception. But there are other causes,
which have been found more irregular and uncertain; nor has rhubarb
always proved a purge, or opium a soporific to every one, who has
taken these medicines. It is true, when any cause fails of producing
its usual effect, philosophers ascribe not this to any irregularity in
nature; but suppose, that some secret causes, in the particular
structure of parts, have prevented the operation. Our reasonings,
however, and conclusions concerning the event are the same as if
this principle had no place. Being determined by custom to transfer
the past to the future, in all our inferences; where the past has been
entirely regular and uniform, we expect the event with the greatest
assurance, and leave no room for any contrary supposition. But where
different effects have been found to follow from causes, which are
to appearance exactly similar, all these various effects must occur to
the mind in transferring the past to the future, and enter into our
consideration, when we determine the probability of the event.
Though we give the preference to that which has been found most usual,
and believe that this effect will exist, we must not overlook the
other effects, but must assign to each of them a particular weight and
authority, in proportion as we have found it to be more or less
frequent. It is more probable, in almost every country of Europe, that
there will be frost sometime in January, than that the weather will
continue open throughout that whole month; though this probability
varies according to the different climates, and approaches to a
certainty in the more northern kingdoms. Here then it seems evident,
that, when we transfer the past to the future, in order to determine
the effect, which will result from any cause, we transfer all the
different events, in the same proportion as they have appeared in
the past, and conceive one to have existed a hundred times, for
instance, another ten times, and another once. As a great number of
views do here concur in one event, they fortify and confirm it to
the imagination, beget that sentiment which we call belief, and give
its object the preference above the contrary event, which is not
supported by an equal number of experiments, and recurs not so
frequently to the thought in transferring the past to the future.
Let any one try to account for this operation of the mind upon any
of the received systems of philosophy, and he will be sensible of
the difficulty. For my part, I shall think it sufficient, if the
present hints excite the curiosity of philosophers, and make them
sensible how defective all common theories are in treating of such
curious and such sublime subjects.
               Sect. VII. Of the Idea of necessary Connexion

                             PART I.

  48 THE great advantage of the mathematical sciences above the
moral consists in this, that the ideas of the former, being
sensible, are always clear and determinate, the smallest distinction
between them is immediately perceptible, and the same terms are
still expressive of the same ideas, without ambiguity or variation. An
oval is never mistaken for a circle, nor an hyperbola for an ellipsis.
The isosceles and scalenum are distinguished by boundaries more
exact than vice and virtue, right and wrong. If any term be defined in
geometry, the mind readily, of itself, substitutes, on all
occasions, the definition for the term defined: Or even when no
definition is employed, the object itself may be presented to the
senses, and by that means be steadily and clearly apprehended. But the
finer sentiments of the mind, the operations of the understanding, the
various agitations of the passions, though really in themselves
distinct, easily escape us, when surveyed by reflection; nor is it
in our power to recal the original object, as often as we have
occasion to contemplate it. Ambiguity, by this means, is gradually
introduced into our reasonings: Similar objects are readily taken to
be the same: And the conclusion becomes at last very wide of the
premises.
  One may safely, however, affirm, that, if we consider these sciences
in a proper light, their advantages and disadvantages nearly
compensate each other, and reduce both of them to a state of equality.
If the mind, with greater facility, retains the ideas of geometry
clear and determinate, it must carry on a much longer and more
intricate chain of reasoning, and compare ideas much wider of each
other, in order to reach the abstruser truths of that science. And
if moral ideas are apt, without extreme care, to fall into obscurity
and confusion, the inferences are always much shorter in these
disquisitions, and the intermediate steps, which lead to the
conclusion, much fewer than in the sciences which treat of quantity
and number. In reality, there is scarcely a proposition in Euclid so
simple, as not to consist of more parts, than are to be found in any
moral reasoning which runs not into chimera and conceit. Where we
trace the principles of the human mind through a few steps, we may
be very well satisfied with our progress; considering how soon
nature throws a bar to all our enquiries concerning causes, and
reduces us to an acknowledgment of our ignorance. The chief
obstacle, therefore, to our improvement in the moral or metaphysical
sciences is the obscurity of the ideas, and ambiguity of the terms.
The principal difficulty in the mathematics is the length of
inferences and compass of thought, requisite to the forming of any
conclusion. And, perhaps, our progress in natural philosophy is
chiefly retarded by the want of proper experiments and phaenomena,
which are often discovered by chance, and cannot always be found, when
requisite, even by the most diligent and prudent enquiry. As moral
philosophy seems hitherto to have received less improvement than
either geometry or physics, we may conclude, that, if there be any
difference in this respect among these sciences, the difficulties,
which obstruct the progress of the former, require superior care and
capacity to be surmounted.
  49. There are no ideas, which occur in metaphysics, more obscure and
uncertain, than those of power, force, energy or necessary
connexion, of which it is every moment necessary for us to treat in
all our disquisitions. We shall, therefore, endeavour, in this
section, to fix, if possible, the precise meaning of these terms,
and thereby remove some part of that obscurity, which is so much
complained of in this species of philosophy.
  It seems a proposition, which will not admit of much dispute, that
all our ideas are nothing but copies of our impressions, or, in
other words, that it is impossible for us to think of anything,
which we have not antecedently felt, either by our external or
internal senses. I have endeavoured* to explain and prove this
proposition, and have expressed my hopes, that, by a proper
application of it, men may reach a greater clearness and precision
in philosophical reasonings, than what they have hitherto been able to
attain. Complex ideas may, perhaps, be well known by definition, which
is nothing but an enumeration of those parts or simple ideas, that
compose them. But when we have pushed up definitions to the most
simple ideas, and find still some ambiguity and obscurity; what
resource are we then possessed of? By what invention can we throw
light upon these ideas, and render them altogether precise and
determinate to our intellectual view? Produce the impressions or
original sentiments, from which the ideas are copied. These
impressions are all strong and sensible. They admit not of
ambiguity. They are not only placed in a full light themselves, but
may throw light on their correspondent ideas, which lie in
obscurity. And by this means, we may, perhaps, attain a new microscope
or species of optics, by which, in the moral sciences, the most
minute, and most simple ideas may be so enlarged as to fall readily
under our apprehension, and be equally known with the grossest and
most sensible ideas, that can be the object of our enquiry.

  * Section II.

  50. To be fully acquainted, therefore, with the idea of power or
necessary connexion, let us examine its impression; and in order to
find the impression with greater certainty, let us search for it in
all the sources, from which it may possibly be derived.
  When we look about us towards external objects, and consider the
operation of causes, we are never able, in a single instance, to
discover any power or necessary connexion; any quality, which binds
the effect to the cause, and renders the one an infallible consequence
of the other. We only find, that the one does actually, in fact,
follow the other. The impulse of one billiard-ball is attended with
motion in the second. This is the whole that appears to the outward
senses. The mind feels no sentiment or inward impression from this
succession of objects: Consequently, there is not, in any single,
particular instance of cause and effect, anything which can suggest
the idea of power or necessary connexion.
  From the first appearance of an object, we never can conjecture what
effect will result from it. But were the power or energy of any
cause discoverable by the mind, we could foresee the effect, even
without experience; and might, at first, pronounce with certainty
concerning it, by mere dint of thought and reasoning.
  In reality, there is no part of matter, that does ever, by its
sensible qualities, discover any power or energy, or give us ground to
imagine, that it could produce any thing, or be followed by any
other object, which we could denominate its effect. Solidity,
extension, motion; these qualities are all complete in themselves, and
never point out any other event which may result from them. The scenes
of the universe are continually shifting, and one object follows
another in an uninterrupted succession; but the power of force,
which actuates the whole machine, is entirely concealed from us, and
never discovers itself in any of the sensible qualities of body. We
know, that, in fact, heat is a constant attendant of flame; but what
is the connexion between them, we have no room so much as to
conjecture or imagine. It is impossible, therefore, that the idea of
power can be derived from the contemplation of bodies, in single
instances of their operation; because no bodies ever discover any
power, which can be the original of this idea.*

  * Mr. Locke, in his chapter of power, says that, finding from
experience, that there are several new productions in matter, and
concluding that there must somewhere be a power capable of producing
them, we arrive at last by this reasoning at the idea of power. But no
reasoning can ever give us a new, original, simple idea; as this
philosopher himself confesses. This, therefore, can never be the
origin of that idea.

  51. Since, therefore, external objects as they appear to the senses,
give us no idea of power or necessary connexion, by their operation in
particular instances, let us see, whether this idea be derived from
reflection on the operations of our own minds, and be copied from
any internal impression. It may be said, that we are every moment
conscious of internal power; while we feel, that, by the simple
command of our will, we can move the organs of our body, or direct the
faculties of our mind. An act of volition produces motion in our
limbs, or raises a new idea in our imagination. This influence of
the will we know by consciousness. Hence we acquire the idea of
power or energy; and are certain, that we ourselves and all other
intelligent beings are possessed of power. This idea, then, is an idea
of reflection, since it arises from reflecting on the operations of
our own mind, and on the command which is exercised by will, both over
the organs of the body and faculties of the soul.
  52. We shall proceed to examine this pretension; and first with
regard to the influence of volition over the organs of the body.
This influence, we may observe, is a fact, which, like all other
natural events, can be known only be experience, and can never be
foreseen from any apparent energy or power in the cause, which
connects it with the effect, and renders the one an infallible
consequence of the other. The motion of our body follows upon the
command of our will. Of this we are every moment conscious. But the
means, by which this is effected; the energy, by which the will
performs so extraordinary an operation; of this we are so far from
being immediately conscious, that it must for ever escape our most
diligent enquiry.
  For first; is there any principle in all nature more mysterious than
the union of soul with body; by which a supposed spiritual substance
acquires such an influence over a material one, that the most
refined thought is able to actuate the grossest matter? Were we
empowered, by a secret wish, to remove mountains, or control the
planets in their orbit; this extensive authority would not be more
extraordinary, nor more beyond our comprehension. But if by
consciousness we perceived any power or energy in the will, we must
know this power; we must know its connexion with the effect; we must
know the secret union of soul and body, and the nature of both these
substances; by which the one is able to operate, in so many instances,
upon the other.
  Secondly, We are not able to move all the organs of the body with
a like authority; though we cannot assign any reason besides
experience, for so remarkable a difference between one and the
other. Why has the will an influence over the tongue and fingers,
not over the heart or liver? This question would never embarrass us,
were we conscious of a power in the former case, not in the latter. We
should then perceive, independent of experience, why the authority
of will over the organs of the body is circumscribed within such
particular limits. Being in that case fully acquainted with the
power or force, by which it operates, we should also know, why its
influence reaches precisely to such boundaries, and no farther.
  A man, suddenly struck with palsy in the leg or arm, or who had
newly lost those members, frequently endeavours, at first to move
them, and employ them in their usual offices. Here he is as much
conscious of power to command such limbs, as a man in perfect health
is conscious of power to actuate any member which remains in its
natural state and condition. But consciousness never deceives.
Consequently, neither in the one case nor in the other, are we ever
conscious of any power. We learn the influence of our will from
experience alone. And experience only teaches us, how one event
constantly follows another; without instructing us in the secret
connexion, which binds them together, and renders them inseparable.
  Thirdly, We learn from anatomy, that the immediate object of power
in voluntary motion, is not the member itself which is moved, but
certain muscles, and nerves, and animal spirits, and, perhaps,
something still more minute and more unknown, through which the motion
is successively propagated, ere it reach the member itself whose
motion is the immediate object of volition. Can there be a more
certain proof, that the power, by which this whole operation is
performed, so far from being directly and fully known by an inward
sentiment or consciousness, is, to the last degree, mysterious and
unintelligible? Here the mind wills a certain event: Immediately
another event, unknown to ourselves, and totally different from the
one intended, is produced: This event produces another, equally
unknown: Till at last, through a long succession, the desired event is
produced. But if the original power were felt, it must be known:
Were it known, its effect also must be known; since all power is
relative to its effect. And vice versa, if the effect be not known,
the power cannot be known nor felt. How indeed can we be conscious
of a power to move our limbs, when we have no such power; but only
that to move certain animal spirits, which, though they produce at
last the motion of our limbs, yet operate in such a manner as is
wholly beyond our comprehension?
  We may, therefore, conclude from the whole, I hope, without any
temerity, though with assurance; that our idea of power is not
copied from any sentiment or consciousness of power within
ourselves, when we give rise to animal motion, or apply our limbs to
their proper use and office. That their motion follows the command
of the will is a matter of common experience, like other natural
events: But the power or energy by which this is effected, like that
in other natural events, is unknown and inconceivable.*

  * It may be pretended, that the resistance which we meet with in
bodies, obliging us frequently to exert our force, and call up all our
power, this gives us the idea of force and power. It is this nisus, or
strong endeavour, of which we are conscious, that is the original
impression from which this idea is copied. But, first, we attribute
power to a vast number of objects, where we never can suppose this
resistance of exertion of force to take place; to the Supreme Being,
who never meets with any resistance; to the mind in its command over
its ideas and limbs, in common thinking and motion, where the effect
follows immediately upon the will, without any exertion or summoning
up of force; to inanimate matter, which is not capable of this
sentiment. Secondly, This sentiment of an endeavour to overcome
resistance has no known connexion with any event: What follows it,
we know by experience; but could not know it a priori. It must,
however, be confessed, that the animal nisus, which we experience,
though it can afford no accurate precise idea of power, enters very
much into that vulgar, inaccurate idea, which is formed of it.

  53. Shall we then assert, that we are conscious of a power or energy
in our own minds, when, by an act or command of our will, we raise
up a new idea, fix the mind to the contemplation of it, turn it on all
sides, and at last dismiss it for some other idea, when we think
that we have surveyed it with sufficient accuracy? I believe the
same arguments will prove, that even this command of the will gives us
no real idea of force or energy.
  First, It must be allowed, that, when we know a power, we know
that very circumstance in the cause, by which it is enabled to produce
the effect: For these are supposed to be synonimous. We must,
therefore, know both the cause and effect, and the relation between
them. But do we pretend to be acquainted with the nature of the
human soul and the nature of an idea, or the aptitude of the one to
produce the other? This is a real creation; a production of
something out of nothing: Which implies a power so great, that it
may seem, at first sight, beyond the reach of any being, less than
infinite. At least it must be owned, that such a power is not felt,
nor known, nor even conceivable by the mind. We only feel the event,
namely, the existence of an idea, consequent to a command of the will:
But the manner, in which this operation is performed, the power by
which it is produced, is entirely beyond our comprehension.
  Secondly, The command of the mind over itself is limited, as well as
its command over the body; and these limits are not known by reason,
or any acquaintance with the nature of cause and effect, but only by
experience and observation, as in all other natural events and in
the operation of external objects. Our authority over our sentiments
and passions is much weaker than that over our ideas; and even the
latter authority is circumscribed within very narrow boundaries.
Will any one pretend to assign the ultimate reason of these
boundaries, or show why the power is deficient in one case, not in
another.
  Thirdly, This self-command is very different at different times. A
man in health possesses more of it than one languishing with sickness.
We are more master of our thoughts in the morning than in the evening:
Fasting, than after a full meal. Can we give any reason for these
variations, except experience? Where then is the power, of which we
pretend to be conscious? Is there not here, either in a spiritual or
material substance, or both, some secret mechanism or structure of
parts, upon which the effect depends, and which, being entirely
unknown to us, renders the power or energy of the will equally unknown
and incomprehensible?
  Volition is surely an act of the mind, with which we are
sufficiently acquainted. Reflect upon it. Consider it on all sides. Do
you find anything in it like this creative power, by which it raises
from nothing a new idea, and with a kind of Fiat, imitates the
omnipotence of its Maker, if I may be allowed so to speak, who
called forth into existence all the various scenes of nature? So far
from being conscious of this energy in the will, it requires as
certain experience as that of which we are possessed, to convince us
that such extraordinary effects do ever result from a simple act of
volition.
  54. The generality of mankind never find any difficulty in
accounting for the more common and familiar operations of nature- such
as the descent of heavy bodies, the growth of plants, the generation
of animals, or the nourishment of bodies by food: But suppose that, in
all these cases, they perceive the very force or energy of the
cause, by which it is connected with its effect, and is for ever
infallible in its operation. They acquire, by long habit, such a
turn of mind, that, upon the appearance of the cause, they immediately
expect with assurance its usual attendant, and hardly conceive it
possible that any other event could result from it. It is only on
the discovery of extraordinary phaenomena, such as earthquakes,
pestilence, and prodigies of any kind, that they find themselves at
a loss to assign a proper cause, and to explain the manner in which
the effect is produced by it. It is usual for men, in such
difficulties, to have recourse to some invisible intelligent
principle* as the immediate cause of that event which surprises
them, and which, they think, cannot be accounted for from the common
powers of nature. But philosophers, who carry their scrutiny a
little farther, immediately perceive that, even in the most familiar
events, the energy of the cause is as unintelligible as in the most
unusual, and that we only learn by experience the frequent Conjunction
of objects, without being ever able to comprehend anything like
Connexion between them.

  * Theos apo mechanes (deus ex machina).

  55. Here, then, many philosophers think themselves obliged by reason
to have recourse, on all occasions, to the same principle, which the
vulgar never appeal to but in cases that appear miraculous and
supernatural. They acknowledge mind and intelligence to be, not only
the ultimate and original cause of all things, but the immediate and
sole cause of every event which appears in nature. They pretend that
those objects which are commonly denominated causes, are in reality
nothing but occasions; and that the true and direct principle of every
effect is not any power or force in nature, but a volition of the
Supreme Being, who wills that such particular objects should for
ever be conjoined with each other. Instead of saying that one
billiard-ball moves another by a force which it has derived from the
author of nature, it is the Deity himself, they say, who, by a
particular volition, moves the second ball, being determined to this
operation by the impulse of the first ball, in consequence of those
general laws which he has laid down to himself in the government of
the universe. But philosophers advancing still in their inquiries,
discover that, as we are totally ignorant of the power on which
depends the mutual operation of bodies, we are no less ignorant of
that power on which depends the operation of mind on body, or of
body on mind; nor are we able, either from our senses or
consciousness, to assign the ultimate principle in one case more
than in the other. The same ignorance, therefore, reduces them to
the same conclusion. They assert that the Deity is the immediate cause
of the union between soul and body; and that they are not the organs
of sense, which, being agitated by external objects, produce
sensations in the mind; but that it is a particular volition of our
omnipotent Maker, which excites such a sensation, in consequence of
such a motion in the organ. In like manner, it is not any energy in
the will that produces local motion in our members: It is God himself,
who is pleased to second our will, in itself impotent, and to
command that motion which we erroneously attribute to our own power
and efficacy. Nor do philosophers stop at this conclusion. They
sometimes extend the same inference to the mind itself, in its
internal operations. Our mental vision or conception of ideas is
nothing but a revelation made to us by our Maker. When we
voluntarily turn our thoughts to any object, and raise up its image in
the fancy, it is not the will which creates that idea: It is the
universal Creator, who discovers it to the mind, and renders it
present to us.
  56. Thus, according to these philosophers, every thing is full of
God. Not content with the principle, that nothing exists but by his
will, that nothing possesses any power but by his concession: They rob
nature, and all created beings, of every power, in order to render
their dependence on the Deity still more sensible and immediate.
They consider not that, by this theory, they diminish, instead of
magnifying, the grandeur of those attributes, which they affect so
much to celebrate. It argues surely more power in the Deity to
delegate a certain degree of power to inferior creatures than to
produce every thing by his own immediate volition. It argues more
wisdom to contrive at first the fabric of the world with such
perfect foresight that, of itself, and by its proper operation, it may
serve all the purposes of providence, than if the great Creator were
obliged every moment to adjust its parts, and animate by his breath
all the wheels of that stupendous machine.
  But if we would have a more philosophical confutation of this
theory, perhaps the two following reflections may suffice.
  57. First, it seems to me that this theory of the universal energy
and operation of the Supreme Being is too bold ever to carry
conviction with it to a man, sufficiently apprized of the weakness
of human reason, and the narrow limits to which it is confined in
all its operations. Though the chain of arguments which conduct to
it were ever so logical, there must arise a strong suspicion, if not
an absolute assurance, that it has carried us quite beyond the reach
of our faculties, when it leads to conclusions so extraordinary, and
so remote from common life and experience. We are got into fairy land,
long ere we have reached the last steps of our theory; and there we
have no reason to trust our common methods of argument, or to think
that our usual analogies and probabilities have any authority. Our
line is too short to fathom such immense abysses. And however we may
flatter ourselves that we are guided, in every step which we take,
by a kind of verisimilitude and experience, we may be assured that
this fancied experience has no authority when we thus apply it to
subjects that lie entirely out of the sphere of experience. But on
this we shall have occasion to touch afterwards.*

  * Section XII.

  Secondly, I cannot perceive any force in the arguments on which this
theory is founded. We are ignorant, it is true, of the manner in which
bodies operate on each other: Their force or energy is entirely
incomprehensible: But are we not equally ignorant of the manner or
force by which a mind, even the supreme mind, operates either on
itself or on body? Whence, I beseech you, do we acquire any idea of
it? We have no sentime