HUME
TREATISE ON HUMAN UNDERSTANDING
Epistemological considerations:
BOOK I.
{1:.
PART 1. OF IDEAS, THEIR ORIGIN, COMPOSITION, CONNEXION, ABSTRACTION, ETC.
S/ECT. I. -- Of the Origin of our Ideas.
All the perceptions of the human mind resolve themselves into two distinct kinds, which I
shall call IMPRESSIONS and IDEAS. The difference betwixt these consists in the degrees of force and
liveliness, with which they strike upon the mind, and make their way into our thought or consciousness.
Those perceptions, which enter with most force and violence, we may name impressions: and under this
name I comprehend all our sensations, passions and emotions, as they make their first appearance in the
soul. By ideas I mean the faint images of these in thinking and reasoning; such as, for instance, are all
the perceptions excited by the present discourse, excepting only those which arise from the sight and
touch, and excepting the immediate pleasure or uneasiness it may occasion. I believe it will -not be very
necessary to employ many words in explaining this distinction. Every one of himself will readily perceive
the difference betwixt feeling and thinking. The common degrees of these are easily distinguished; tho' it
is not impossible but in particular instances they may very nearly approach to each other. Thus in sleep,
in a fever, in madness, or in any very violent emotions of soul, our ideas may approach to our
impressions, As on the other hand it sometimes happens, that our impressions are so faint and low, that
we cannot distinguish {1:312} them from our ideas. But notwithstanding this near resemblance in a few
instances, they are in general so very different, that no-one can make a scruple to rank them under
distinct heads, and assign to each a peculiar name to mark the difference.
There is another division of our perceptions, which it will be convenient to observe, and which
extends itself both to our impressions and ideas. This division is into SIMPLE and COMPLEX. Simple
perceptions or impressions and ideas are such as admit of no distinction nor separation. The complex are
the contrary to these, and may be distinguished into parts. Tho' a particular colour, taste, and smell, are
qualities all united together in this apple, 'tis easy to perceive they are not the same, but are at least
distinguishable from each other...
Upon a more accurate survey I find I have been carried away too far by the first appearance, and
that I must make use of the distinction of perceptions into simple and complex, to limit this general
decision, that all our ideas and impressions {1:313} are resembling. I observe, that many of our complex
ideas never had impressions, that corresponded to them, and that many of our complex impressions
never are exactly copied in ideas. I can imagine to myself such a city as the New Jerusalem, whose
pavement is gold and walls are rubies, tho' I never saw any such. I have seen Paris; but shall I affirm I
can form such an idea of that city, as will perfectly represent all its streets and houses in their real and
just proportions?
Thus we find, that all simple ideas and impressions resemble each other; and as the complex are
formed from them, we may affirm in general, that these two species of perception are exactly
correspondent. Having discovered this relation, which requires no farther examination, I am curious to
find some other of their qualities. Let us consider how. they stand with regard to their existence, and
which of the impressions and ideas are causes, and which effects.
The full examination of this question is the subject of the {1:314} present treatise; and therefore
we shall here content ourselves with establishing one general proposition, That all our simple ideas in
their first appearance are deriv'd from simple impressions, which are correspondent to them, and which
they exactly represent.'
In seeking for phenomena to prove this proposition, I find only those of two kinds; but in each
kind the phenomena are obvious, numerous, and conclusive. I first make myself certain, by a new,
review, of what I have already asserted, that every simple impression is attended with a correspondent
idea, and every simple idea with a correspondent impression. From this constant conjunction of
resembling perceptions I immediately conclude, that there is a great connexion betwixt our correspondent
impressions and ideas, and that the existence of the one has a -considerable influence upon that of the
other. Such a constant conjunction, in such an infinite number of instances, can never arise from chance;
but clearly proves a dependence of the impressions on the ideas, or of the ideas on the impressions. That I
may know on which side this dependence lies, I consider the order of their first appearance; and find by
constant experience, that the simple impressions always take the precedence of their correspondent ideas,
but never appear in the contrary order. To give a child an idea of scarlet or orange, of sweet or bitter, I
present the objects, or in other words, convey to him these impressions; but proceed not so absurdly, as to
endeavour to produce -the impressions by exciting the ideas. Our ideas upon their appearance produce
not their correspondent impressions, nor do we perceive any colour, or feel any sensation merely upon
thinking of them@ On the other hand we find, that any impression either of the mind or body is
constantly followed by an idea, which resembles it, and is only different in the degrees of force and
liveliness, The constant conjunction of our resembling perceptions, is a convincing proof, that the one are
the causes of the other; and this priority of the impressions is an equal proof, that our impressions are
the causes of our ideas, not our ideas .of our, impressions...
But besides this exception, it may not be amiss to remark on this head, that the principle of the
priority of impressions to ideas must be understood with another limitation, <viz>. that as our ideas are
images of our impressions, so we can form secondary ideas, which are images of the primary; as appears
from this very reasoning concerning them. This is not, properly speaking, an exception to the rule so
much as an explanation of it. Ideas produce the images of them. selves in new ideas; but as the first ideas
are supposed to be derived from impressions, it still remains true, that all our simple ideas proceed
either mediately or immediately, from their correspondent impressions.
This then is the first principle I establish in the science of human nature; nor ought we to despise
it because of the simplicity of its appearance. For 'tis remarkable, that the present question concerning
the precedency of our impressions or ideas, is the same with what has made so much noise in other terms,
when it has been disputed whether there be any <innate ideas>, or whether all ideas be derived from
sensation and reflexion. We may observe, that in order to prove the ideas of extension and colour not to
be innate, philosophers do nothing but shew that they are conveyed by our senses. To prove the ideas of
passion and desire not to be innate, they observe that we have a preceding experience of these emotions in
ourselves., Now if we carefully examine these arguments, we shall find that they prove nothing but that
ideas are preceded by other more lively perceptions, from which the are derived, and which they
represent. I hope this clear stating of the question will remove all disputes concerning it, and win render
this principle of more use in our reasonings, than it seems hitherto to have been.
... Since it appears, that our simple impressions are prior to their correspondent ideas, and that.the
exceptions are very rare, method seems to require we should examine our impressions, before we consider
our ideas. Impressions way be divided into two kinds, those Of SENSATION and those of {1:317}
REFLEXION. The first kind arises in the soul originally,from unknown causes. The second is derived in
a great measure from our ideas, and that in the following order. An impression first strikes upon the
senses, and makes us perceive heat or cold, thirst or hunger, pleasure or pain of some kin(I or other. Of
this impression there is a copy taken by the mind, which remains after the impression ceases; and this we
call an idea. This idea of pleasure or pain, when it returns upon the soul, produces the new impressions
of desire and aversion, hope and fear, which may properly be called impressions of reflexion, because
derived from it. These again are copied by the memory and imagination, and become ideas; which
perhaps in their turn give rise to other impressions and ideas. So that the impressions of reflexion are
only antecedent to their correspondent ideas; but posterior to those of sensation, and deriv'd from them.
The examination of our sensations belongs more to anatomists and natural philosophers than to moral;
and therefore shall not at present be enter'd upon. And as the impressions of reflexion, viz. passions,
desires, and emotions, which principally deserve our attention, arise mostly from ideas, 'twill be
necessary to reverse that method, which at first si-ht seems most natural; and in order to explain the
nature and principles of the human mind, give a particular account of ideas, before we proceed to
impressions. For this reason I have here chosen to begin with ideas...
SECT. III.-Of the Ideas of the Memory and Imagination.
We find by experience, that when any impression bas been present with the mind, it again makes
its appearance there a,s an idea; and this it may do after two different ways: either when in its new
appearance it retains a considerable degree of its @t vivacity, and is somewhat intermediate betwixt an
impression and an idea: or when it entirely loses that vivacity, and is a perfect idea. The faculty, by
which we repeat our impressions in the first manner, is called the M/EMORY\, and the other the
IMAGINATION. 'Tis evident at first sight, that the ideas of the memory are much more lively and strong
than those of the imagination, and that {1:318} the former faculty paints its objects in more distinct
colours, than any which are employ'd by the latter. When we remember any past event, the idea of it
flows in upon the mind in a forcible manner; whereas in the imagination the perception is faint and
languid, and cannot without difficulty be preserv'd by the mind steddy and uniform for any
considerable time. Here then is a sensible difference betwixt one species of ideas and another. But of this
more fully hereafter...
SECT. IV.-Of the Connexion or Association of Ideas.
As all simple ideas may be separated by the imagination, and may be united again in what form
it pleases, nothing wou'd be more unaccountable than the operations of that faculty, were it not guided
by some universal principles, which render it, in some measure, uniform with itself in all times and
places. Were ideas entirely loose and unconnected, chance alone wou'd join them; and 'tis impossible the
same simple ideas should fall regularly into complex ones (as they Commonly do) without some bond of
union among them, some associating quality, by which one idea naturally introduces another. This
uniting principle among ideas is not to be consider'd as an inseparable connexion; for that ha,s been
already excluded from the imagination: Nor yet are we to conclude, -that without it the mind cannot join
two ideas; for nothing is more free than that faculty: but we are only to regard it as a gentle force, which
commonly prevails, and is the cause why, among other things, languages so nearly correspond to each
other; nature in a manner pointing out to every one those simple ideas, which are most proper to be
united in a complex one. The qualities, from which this association arises, and by which the mind is
after this manner convey'd from one idea to another, are three, -viz. RESEMBLANCE., CONTIGUITY in
time or place, and CAUSE and EFFECT.
I believe it will not be very necessary to prove, that these qualities produce an association among
ideas, and upon the appearance of one idea naturally introduce another. 'Tis plain, that in the course of
our thinking, and in the constant revolution of our ideas, our imagination runs easily from one idea to
any other that resembles it, and that this quality alone is to the fancy a sufficient bond and association.
'Tis likewise evident that as the senses, in changing their objects, {1:320} are necessitated to change them
regularly, and take them as they lie <contiguous> to each other, the imagination must by long custom
acquire the same method of thinking, and run along the parts of space and time in conceiving its objects.
As to the connexion, that is made by the relation of cause and effect, we shall have occasion afterwards to
examine it to the bottom, and therefore shall not at present insist upon it. 'Tis sufficient to observe, that
there is no relation, which produces a stronger connexion in the fancy, and makes one idea more readily
recall another, than the relation of cause and effect betwixt their objects.
That we may understand the full extent of these relations, we must consider, that two objects are
connected together in the imagination, not only when the one @ immediately resembling, contiguous to,
or the cause of the other, but also when there is interposed betwixt them a third object, which bears to
both of them any of these relations. This may be carried on to a great length; tho' at the same time we
may observe, that each remove considerably weakens the relation. Cousins in the fourth degree are
connected by causation, if I may be allowed to use that term; but not so closely as brothers, much less as
child and parent. In general we may observe, that all the relations of blood depend upon cause and effect,
and are esteemed near or remote, according to the number of connecting causes interpos'd betwixt the
persons.
Of the three relations above-mention'd this of causation is the most extensive. Two objects may be
considered as plac'd in this relation, as well when one is the cause of any of the actions or motions of the
other, as when the former is the cause of the existence of the latter. For as that action or motion is nothing
but the object itself, consider'd in a certain light, and as the object continues the same in all its different
situations, 'tis easy to imagine how such an influence of objects upon one another may connect them in
the imagination.
We may carry this farther, and remark, not only that two objects are connected by the relation of
cause and effect, when the one produces a motion or any action in the other, but also when it has a power
of producing it. And this we may observe to be the source of all the relation,; of interest and duty, by
which men influence each other in society, and {1:321} are plac'd in the ties of government and
subordination. A master is such-a-one as by his situation, arising either from force or agreement, has a
power of directing in certain particulars the actions of another, whom we call servant. A judge is one,
who in all disputed cases can fix by his opinion the possession or property of any thing betwixt any
members of the society. When a person is possess'd of any power, there is no more required to convert it
into action, but the exertion of the will; and that in every case is considered as possible, and in many as
probable; especially in the case of authority, where the obedience of the subject is a pleasure and
advantage to the superior.
These are therefore the principles of union or cohesion among our simple ideas, and in the
imagination supply the place of that inseparable connexion, by which they are united in our memory.
Here is a kind of ATTRACTION, which in the mental world will be found to have as extraordinary
effects as in the natural, and to shew itself in as many and as various forms. Its effects are every where
conspicuous; but as to its causes, they are mostly unknown, and must be resolv'd into original qualities
of human nature, which I pretend not to explain. Nothing is more requisite for a true philosopher, than
to restrain the intemperate desire of searching into causes, and having established any doctrine upon a
sufficient number of experiments, rest contented with that, when he sees a farther examination would
lead him into obscure and uncertain speculations. In that case his enquiry wou'd be much better
employ'd in examining the effects than the causes of his principle.
Amongst the effects of this union or association of ideas, there are none more remarkable, than
those complex ideas, which are the common subjects of our thoughts and reasoning, and generally arise
from some principle of union among our simple ideas. These complex ideas may be divided into
Relations, Modes, and Substances. We shall briefly examine each of these in order, and shall subjoin
some considerations concerning our general and particular ideas, before we leave the present subject,
which may be consider'd as the elements of this philosophy. {1:322}
SECT. V.-Of Relations.
The word RELATION is commonly used in two senses considerably different from each other.
Either for that quality, by which two ideas are connected together in the imagination, and the one
naturally introduces the other, after the manner above-explained: or for that particular circumstance, in
which, even upon the arbitrary union of two ideas in the fancy, we may think proper to compare them. In
common language the former is always the sense, in which we use the word, relation; and tis only in
philosophy, that we extend it to mean any particular subject of comparison, without a connecting
principle. Thus distance will be allowed by philosophers to be a true relation, because we acquire an
idea of it by the comparing of objects: But in a common way we say, that nothing can be more distant
than such or such things from each other, nothing can have less relation: as if distance and relation were
incompatible.'
Reason is the discovery of truth or falsehood. Truth or falsehood consists in an agreement or disagreement either to the real relations of ideas, or to real existence and matter of fact. Whatever, therefore, is not susceptible of this agreement or disagreement, is incapable of being true or false, and can never be an object of our reason. Now `tis evident our passions, volitions, and actions, are not susceptible of any such agreement or disagreement; being original facts and realities, compleat in themselves, and implying no reference to other passions, volitions, and actions. Tis impossible, therefore, they can be pronounced either true or false, and be either contrary or conformable to reason.
This argument is of double advantage to our present purpose. For it proves directly, that actions do not derive their merit from a conformity to reason, nor their blame from a contrariety to it; and it proves the same truth more indirectly, by shewing us, that as reason can never immediately prevent or produce any action by contradicting or approving of it, it cannot be the source of moral good and evil, which are found to have that influence. Actions may be laudable or blameable; but they cannot be reasonable: Laudable or blameable, therefore, are not the same with reasonable or unreasonable. The merit and demerit of actions frequently contradict, and sometimes control our natural propensities. But reason has no such influence. Moral distinctions, therefore, are not the offspring of reason. Reason is wholly inactive, and can never be the source of so active a principle as conscience, or a sense of morals...
Thus upon the whole, `tis impossible, that the distinction betwixt moral good and evil, can be made to reason; sincethat distinction has an influence upon our actions, of which reason alone is incapable. Reason and judgment may, indeed, be the mediate cause of an action, by prompting, or by directing a passion: But it is not pretended, that a judgment of this kind, either in its truth or falshood, is attended with virtue or vice. And as to the judgments, which are caused by our judgments, they can still less bestow those moral qualities on the actions, which are their causes...
Let us, therefore, begin with examining this hypothesis, and endeavour, if possible, to fix those moral qualities, which have been so long the objects of our fruitless researches. Point out distinctly the relations, which constitute morality or obligation, that we may know wherein they consist, and after what manner we must judge of them.
If you assert, that vice and virtue consist in relations susceptible of certainty and demonstration, you must confine yourself to those four relations, which alone admit of that degree of evidence; and in that case you run into absurdities, from which you will never be able to extricate yourself. For as you make the very essence of morality to lie in the relations, and as there is no one of these relations but what is applicable, not only to an irrational, but also to an inanimate object; it follows, that even such objects must be susceptible of merit or demerit. Resemblance, contrariety, degrees in quality, and proportions in quantity and number; all these relations belong as properly to matter, as to our actions, passions, and volitions. Tis unquestionable, therefore, that morality lies not in any of these relations, nor the sense of it in their discovery.
... First, As moral good and evil belong only to the actions of the mind, and are deriv'd from our situation with regard to external objects, the relations, from which these moral distinctions arise, must lie only betwixt internal actions, and external objects, and must not be applicable either to internal actions, compared among themselves, or to external objects, when placed in opposition to other external objects. For as morality is supposed to attend certain relations, if these relations cou'd belong to internal actions consider'd singly, it wou'd follow, that we might be guilty of crimes in ourselves, and independent of our situation, with respect to the universe: And in like manner, if these moral relations cou'd be apply'd to external objects, it wou'd follow, that even inanimate beings wou'd be susceptible of moral beauty and deformity. Now it seems difficult to imagine, that any relation can be discover'd betwixt our passions, volitions and actions, compared to external objects, which relation might not belong either to these passions and volitions, or to these external objects, compar'd among themselves. But it will be still more difficult to fulfil the second condition, requisite to justify this system. According to the principles of those who maintain an abstract rational difference betwixt moral good and evil, and a natural fitness and unfitness of things, `tis not only suppos'd, that these relations, being eternal and immutable, are the same, when consider'd by every rational creature, but their effects are also suppos'd to be necessarily the same; and `tis concluded they have no less, or rather a greater, influence in directing the will of the deity, than in governing the rational and virtuous of our own species. These two particulars are evidently distinct. Tis one thing to know virtue, and another to conform the will to it. In order, therefore, to prove, that the measures of right and wrong are eternal laws, obligatory on every rational mind, `tis not sufficient to shew the relations upon which they are founded: We must also point out the connexion betwixt the relation and the will; and must prove that this connexion is so necessary, that in every well-disposed mind, it must take place and have its influence; tho' the difference betwixt these minds be in other respects immense and infinite. Now besides what I have already prov'd, that even in human nature no relation can ever alone produce any action: besides this, I say, it has been shewn, in treating of the understanding, that there is no connexion of cause and effect, such as this is suppos'd to be, which is discoverable otherwise than by experience, and of which we can pretend to have any security by the simple consideration of the objects. All beings in the universe, consider'd in themselves, appear entirely loose and independent of each other. Tis only by experience we learn their influence and connexion; and this influence we ought never to extend beyond experience.
Thus it will be impossible to fulfil the first condition required to the system of eternal measures of right and wrong; because it is impossible to shew those relations, upon which such a distinction may be founded: And `tis as impossible to fulfil the second condition; because we cannot prove a priori, that these relations, if they really existed and were perceiv'd, wou'd be universally forcible and obligatory.
But to make these general reflections more dear and convincing, we may illustrate them by some particular instances, wherein this character of moral good or evil is the most universally acknowledged. Of all crimes that human creatures are capable of committing, the most horrid and unnatural is ingratitude, especially when it is committed against parents, and appears in the more flagrant instances of wounds and death. This is acknowledg'd by all mankind, philosophers as well as the people; the question only arises among philosophers, whether the guilt or moral deformity of this action be discover'd by demonstrative reasoning, or be felt by an internal sense, and by means of some sentiment, which the reflecting on such an action naturally occasions. This question will soon be decided against the former opinion, if we can shew the same relations in other objects, without the notion of any guilt or iniquity attending them. Reason or science is nothing but the comparing of ideas, and the discovery of their relations; and if the same relations have different characters, it must evidently follow, that those characters are not discover'd merely by reason. To put the affair, therefore, to this trial, let us chuse any inanimate object, such as an oak or elm; and let us suppose, that by the dropping of its seed, it produces a sapling below it, which springing up by degrees, at last overtops and destroys the parent tree: I ask, if in this instance there be wanting any relation, which is discoverable in parricide or ingratitude? Is not the one tree the cause of the other's existence; and the latter the cause of the destruction of the former, in the same manner as when a child murders his parent? Tis not sufficient to reply, that a choice or will is wanting. For in the case of parricide, a will does not give rise to any different relations, but is only the cause from which the action is deriv'd; and consequently produces the same relations, that in the oak or elm arise from some other principles. `Tis a will or choice, that determines a man to kill his parent; and they are the laws of matter and motion, that determine a sapling to destroy the oak, from which it sprung. Here then the same relations have different causes; but still the relations are the same: And as their discovery is not in both cases attended with a notion of immorality, it follows, that that notion does not arise from such a discovery.
...Nor does this reasoning only prove, that morality consists not in any relations, that are the objects of science; but if examin'd, will prove with equal certainty, that it consists not in any matter of fact, which can be discover'd by the understanding. This is the second part of our argument; and if it can be made evident, we may conclude, that morality is not an object of reason. But can there be any difficulty in proving, that vice and virtue are not matters of fact, whose existence we can infer by reason? Take any action allow'd to be vicious: Wilful murder, for instance. Examine it in all lights, and see if you can find that matter of fact, or real existence, which you call vice. In which-ever way you take it, you find only certain passions, motives, volitions and thoughts. There is no other matter of fact in the case. The vice entirely escapes you, as long as you consider the object. You never can find it, till you turn your reflection into your own breast, and find a sentiment of disapprobation, which arises in you, towards this action. Here is a matter of fact; but `tis the object of feeling, not of reason. It lies in yourself, not in the object. So that when you pronounce any action or character to be vicious, you mean nothing, but that from the constitution of your nature you have a feeling or sentiment of blame from the contemplation of it. Vice and virtue, therefore, may be compar'd to sounds, colours, heat and cold, which, according to modern philosophy, are not qualities in objects, but perceptions in the mind: And this discovery in morals, like that other in physics, is to be regarded as a considerable advancement of the speculative sciences; tho', like that too, it has little or no influence on practice. Nothing can be more real, or concern us more, than our own sentiments of pleasure and uneasiness; and if these be favourable to virtue, and unfavourable to vice, no more can be requisite to the regulation of our conduct and behaviour.
I cannot forbear adding to these reasonings an observation, which may, perhaps, be found of some importance. In every system of morality, which I have hitherto met with, I have always remark'd, that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when of a sudden I am surpriz'd to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, `tis necessary that it shou'd be observ'd and explain'd; and at the same time that a reason should be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it. But as authors do not commonly use this precaution, I shall presume to recommend it to the readers; and am persuaded, that this small attention wou'd subvert all the vulgar systems of morality, and let us see, that the distinction of vice and virtue is not founded merely on the relations of objects, nor is perceiv'd by reason...
Thus the course of the argument leads us to conclude, that since vice and virtue are not discoverable merely by
reason, or the comparison of ideas, it must be by means of some impression or sentiment they occasion, that we are able to mark the difference betwixt them. Our decisions concerning moral rectitude and depravity are evidently perceptions; and as all perceptions are either impressions or ideas, the exclusion of the one is a convincing argument for the other. Morality, therefore, is more properly felt than judg'd of; tho' this feeling or sentiment is commonly so soft and gentle, that we are apt to confound it with an idea, according to our common custom of taking all things for the same, which have any near resemblance to each other.