A Treatise of Human Nature by David Hume, - HTML preview

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to recollect our dreams in a morning, and examine them with the same

rigour, that we would our most serious and most deliberate actions.

Our character is the same throughout, say they, and appears best

where artifice, fear, and policy have no place, and men can neither be

hypocrites with themselves nor others. The generosity, or baseness

of our temper, our meekness or cruelty, our courage or pusilanimity,

influence the fictions of the imagination with the most unbounded

liberty, and discover themselves in the most glaring colours. In like

manner, I am persuaded, there might be several useful discoveries made

from a criticism of the fictions of the antient philosophy, concerning

substances, and substantial form, and accidents, and occult qualities;

which, however unreasonable and capricious, have a very intimate

connexion with the principles of human nature.

It is confest by the most judicious philosophers, that our ideas of

bodies are nothing but collections formed by the mind of the ideas of

the several distinct sensible qualities, of which objects are composed,

and which we find to have a constant union with each other. But however

these qualities may in themselves be entirely distinct, it is certain

we commonly regard the compound, which they form, as ONE

thing, and

as continuing the SAME under very considerable alterations. The

acknowledged composition is evidently contrary to this supposed

simplicity, and the variation to the identity. It may, therefore, be

worth while to consider the causes, which make us almost universally

fall into such evident contradictions, as well as the means by which we

endeavour to conceal them.

It is evident, that as the ideas of the several distinct, successive

qualities of objects are united together by a very close relation, the

mind, in looking along the succession, must be carryed from one part

of it to another by an easy transition, and will no more perceive the

change, than if it contemplated the same unchangeable object. This easy

transition is the effect, or rather essence of relation; I and as the

imagination readily takes one idea for another, where their influence

on the mind is similar; hence it proceeds, that any such succession

of related qualities is readily considered as one continued object,

existing without any variation. The smooth and uninterrupted progress of

the thought, being alike in both cases, readily deceives the mind, and

makes us ascribe an identity to the changeable succession of connected

qualities.

But when we alter our method of considering the succession, and instead

of traceing it gradually through the successive points of time, survey

at once Any two distinct periods of its duration, and compare the

different conditions of the successive qualities; in that case the

variations, which were insensible when they arose gradually, do now

appear of consequence, and seem entirely to destroy the identity. By

this means there arises a kind of contrariety in our method of thinking,

from the different points of view, in which we survey the object, and

from the nearness or remoteness of those instants of time, which we

compare together. When we gradually follow an object in its successive

changes, the smooth progress of the thought makes us ascribe an identity

to the succession; because it is by a similar act of the mind we

consider an unchangeable object. When we compare its situation after

a considerable change the progress of the thought is broke; and

consequently we are presented with the idea of diversity: In order to

reconcile which contradictions the imagination is apt to feign something

unknown and invisible, which it supposes to continue the same under

all these variations; and this unintelligible something it calls a

substance, or original and first matter.

We entertain a like notion with regard to the simplicity of substances,

and from like causes. Suppose an object perfectly simple and indivisible

to be presented, along with another object, whose coexistent parts are

connected together by a strong relation, it is evident the actions of

the mind, in considering these two objects, are not very different. The

imagination conceives the simple object at once, with facility, by a

single effort of thought, without change or variation.

The connexion of

parts in the compound object has almost the same effect, and so unites

the object within itself, that the fancy feels not the transition in

passing from one part to another. Hence the colour, taste, figure,

solidity, and other qualities, combined in a peach or melon, are

conceived to form one thing; and that on account of their close

relation, which makes them affect the thought in the same manner, as if

perfectly uncompounded. But the mind rests not here.

Whenever it views

the object in another light, it finds that all these qualities are

different, and distinguishable, and separable from each other; which

view of things being destructive of its primary and more natural

notions, obliges the imagination to feign an unknown something, or

original substance and matter, as a principle of union or cohesion among

these qualities, and as what may give the compound object a title to be

called one thing, notwithstanding its diversity and composition.

The peripatetic philosophy asserts the original matter to be perfectly

homogeneous in all bodies, and considers fire, water, earth, and air, as

of the very same substance; on account of their gradual revolutions and

changes into each other. At the same time it assigns to each of these

species of objects a distinct substantial form, which it supposes to be

the source of all those different qualities they possess, and to be a

new foundation of simplicity and identity to each particular species.

All depends on our manner of viewing the objects. When we look along the

insensible changes of bodies, we suppose all of them to be of the same

substance or essence. When we consider their sensible differences, we

attribute to each of them a substantial and essential difference. And

in order to indulge ourselves in both these ways of considering our

objects, we suppose all bodies to have at once a substance and a

substantial form.

The notion of accidents is an unavoidable consequence of this method

of thinking with regard to substances and substantial forms; nor can

we forbear looking upon colours, sounds, tastes, figures, and other

properties of bodies, as existences, which cannot subsist apart, but

require a subject of inhesion to sustain and support them. For having

never discovered any of these sensible qualities, where, for the reasons

above-mentioned, we did not likewise fancy a substance to exist; the

same habit, which makes us infer a connexion betwixt cause and effect,

makes us here infer a dependence of every quality on the unknown

substance. The custom of imagining a dependence has the same effect as

the custom of observing it would have. This conceit, however, is no more

reasonable than any of the foregoing. Every quality being a distinct

thing from another, may be conceived to exist apart, and may exist

apart, not only from every other quality, but from that unintelligible

chimera of a substance.

But these philosophers carry their fictions still farther in their

sentiments concerning occult qualities, and both suppose a substance

supporting, which they do not understand, and an accident supported, of

which they have as imperfect an idea. The whole system, therefore, is

entirely incomprehensible, and yet is derived from principles as natural

as any of these above-explained.

In considering this subject we may observe a gradation of three

opinions, that rise above each other, according as the persons, who form

them, acquire new degrees of reason and knowledge. These opinions are

that of the vulgar, that of a false philosophy, and that of the true;

where we shall find upon enquiry, that the true philosophy approaches

nearer to the sentiments of the vulgar, than to those of a mistaken

knowledge. It is natural for men, in their common and care, less way of

thinking, to imagine they perceive a connexion betwixt such objects

as they have constantly found united together; and because custom has

rendered it difficult to separate the ideas, they are apt to fancy such

a separation to be in itself impossible and absurd. But philosophers,

who abstract from the effects of custom, and compare the ideas of

objects, immediately perceive the falshood of these vulgar sentiments,

and discover that there is no known connexion among objects. Every

different object appears to them entirely distinct and separate; and

they perceive, that it is not from a view of the nature and qualities of

objects we infer one from another, but only when in several instances we

observe them to have been constantly conjoined. But these philosophers,

instead of drawing a just inference from this observation, and

concluding, that we have no idea of power or agency, separate from

the mind, and belonging to causes; I say, instead of drawing this

conclusion, they frequently search for the qualities, in which this

agency consists, and are displeased with every system, which their

reason suggests to them, in order to explain it. They have sufficient

force of genius to free them from the vulgar error, that there is a

natural and perceivable connexion betwixt the several sensible qualities

and actions of matter; but not sufficient to keep them from ever

seeking for this connexion in matter, or causes. Had they fallen upon

the just conclusion, they would have returned back to the situation

of the vulgar, and would have regarded all these disquisitions with

indolence and indifference. At present they seem to be in a very

lamentable condition, and such as the poets have given us but a faint

notion of in their descriptions of the punishment of Sisyphus and

Tantalus. For what can be imagined more tormenting, than to seek with

eagerness, what for ever flies us; and seek for it in a place, where it

is impossible it can ever exist?

But as nature seems to have observed a kind of justice and compensation

in every thing, she has not neglected philosophers more than the rest

of the creation; but has reserved them a consolation amid all their

disappointments and afflictions. This consolation principally consists

in their invention of the words: faculty and occult quality. For

it being usual, after the frequent use of terms, which are really

significant and intelligible, to omit the idea, which we would express

by them, and to preserve only the custom, by which we recal the idea at

pleasure; so it naturally happens, that after the frequent use of terms,

which are wholly insignificant and unintelligible, we fancy them to be

on the same footing with the precedent, and to have a secret meaning,

which we might discover by reflection. The resemblance of their

appearance deceives the mind, as is usual, and makes us imagine a

thorough resemblance and conformity. By this means these philosophers

set themselves at ease, and arrive at last, by an illusion, at the

same indifference, which the people attain by their stupidity, and true

philosophers by their moderate scepticism. They need only say, that

any phenomenon, which puzzles them, arises from a faculty or an occult

quality, and there is an end of all dispute and enquiry upon the matter.

But among all the instances, wherein the Peripatetics have shewn they

were guided by every trivial propensity of the imagination, no one is

more-remarkable than their sympathies, antipathies, and horrors of

a vacuum. There is a very remarkable inclination in human nature, to

bestow on external objects the same emotions, which it observes in

itself; and to find every where those ideas, which are most present to

it. This inclination, it is true, is suppressed by a little reflection,

and only takes place in children, poets, and the antient philosophers.

It appears in children, by their desire of beating the stones, which

hurt them: In poets, by their readiness to personify every thing: And in

the antient philosophers, by these fictions of sympathy and antipathy.

We must pardon children, because of their age; poets, because they

profess to follow implicitly the suggestions of their fancy: But

what excuse shall we find to justify our philosophers in so signal a

weakness?

SECT. IV. OF THE MODERN PHILOSOPHY.

But here it may be objected, that the imagination, according to my own

confession, being the ultimate judge of all systems of philosophy, I

am unjust in blaming the antient philosophers for making use of that

faculty, and allowing themselves to be entirely guided by it in their

reasonings. In order to justify myself, I must distinguish in the

imagination betwixt the principles which are permanent, irresistible,

and universal; such as the customary transition from causes to effects,

and from effects to causes: And the principles, which are changeable,

weak, and irregular; such as those I have just now taken notice of. The

former are the foundation of all our thoughts and actions, so that upon

their removal human nature must immediately perish and go to ruin. The

latter are neither unavoidable to mankind, nor necessary, or so much as

useful in the conduct of life; but on the contrary are observed only to

take place in weak minds, and being opposite to the other principles

of custom and reasoning, may easily be subverted by a due contrast and

opposition. For this reason the former are received by philosophy, and

the latter rejected. One who concludes somebody to be near him, when

he hears an articulate voice in the dark, reasons justly and naturally;

though that conclusion be derived from nothing but custom, which infixes

and inlivens the idea of a human creature, on account of his usual

conjunction with the present impression. But one, who is tormented

he knows not why, with the apprehension of spectres in the dark, may,

perhaps, be said to reason, and to reason naturally too: But then it

must be in the same sense, that a malady is said to be natural; as

arising from natural causes, though it be contrary to health, the most

agreeable and most natural situation of man.

The opinions of the antient philosophers, their fictions of substance

and accident, and their reasonings concerning substantial forms and

occult qualities, are like the spectres in the dark, and are derived

from principles, which, however common, are neither universal nor

unavoidable in human nature. The modern philosophy pretends to be

entirely free from this defect, and to arise only from the solid,

permanent, and consistent principles of the imagination.

Upon what

grounds this pretension is founded must now be the subject of our

enquiry.

The fundamental principle of that philosophy is the opinion concerning

colours, sounds, tastes, smells, heat and cold; which it asserts to

be nothing but impressions in the mind, derived from the operation of

external objects, and without any resemblance to the qualities of the

objects. Upon examination, I find only one of the reasons commonly

produced for this opinion to be satisfactory, viz. that derived from the

variations of those impressions, even while the external object, to all

appearance, continues the same. These variations depend upon several

circumstances. Upon the different situations of our health: A man in a

malady feels a disagreeable taste in meats, which before pleased him the

most. Upon the different complexions and constitutions of men That seems

bitter to one, which is sweet to another. Upon the difference of their

external situation and position: Colours reflected from the clouds

change according to the distance of the clouds, and according to the

angle they make with the eye and luminous body. Fire also communicates

the sensation of pleasure at one distance, and that of pain at another.

Instances of this kind are very numerous and frequent.

The conclusion drawn from them, is likewise as satisfactory as can

possibly be imagined. It is certain, that when different impressions of

the same sense arise from any object, every one of these impressions has

not a resembling quality existent in the object. For as the same object

cannot, at the same time, be endowed with different qualities of the

same sense, and as the same quality cannot resemble impressions entirely

different; it evidently follows, that many of our impressions have

no external model or archetype. Now from like effects we presume like

causes. Many of the impressions of colour, sound, &c.

are confest to be

nothing but internal existences, and to arise from causes, which no ways

resemble them. These impressions are in appearance nothing different

from the other impressions of colour, sound, &c. We conclude, therefore,

that they are, all of them, derived from a like origin.

This principle being once admitted, all the other doctrines of that

philosophy seem to follow by an easy consequence. For upon the removal

of sounds, colours, beat, cold, and other sensible qualities, from the

rank of continued independent existences, we are reduced merely to what

are called primary qualities, as the only real ones, of which we have

any adequate notion. These primary qualities are extension and solidity,

with their different mixtures and modifications; figure, motion,

gravity, and cohesion. The generation, encrease, decay, and corruption

of animals and vegetables, are nothing but changes of figure and motion;

as also the operations of all bodies on each other; of fire, of light,

water, air, earth, and of all the elements and powers of nature. One

figure and motion produces another figure and motion; nor does there

remain in the material universe any other principle, either active or

passive, of which we can form the most distant idea.

I believe many objections might be made to this system But at present

I shall confine myself to one, which is in my opinion very decisive. I

assert, that instead of explaining the operations of external objects by

its means, we utterly annihilate all these objects, and reduce ourselves

to the opinions of the most extravagant scepticism concerning them. If

colours, sounds, tastes, and smells be merely perceptions, nothing we

can conceive is possest of a real, continued, and independent existence;

not even motion, extension and solidity, which are the primary qualities

chiefly insisted on.

To begin with the examination of motion; it is evident this is a quality

altogether inconceivable alone, and without a reference to some other

object. The idea of motion necessarily supposes that of a body moving.

Now what is our idea of the moving body, without which motion is

incomprehensible? It must resolve itself into the idea of extension or

of solidity; and consequently the reality of motion depends upon that of

these other qualities.

This opinion, which is universally acknowledged concerning motion, I

have proved to be true with regard to extension; and have shewn that it

is impossible to conceive extension, but as composed of parts, endowed

with colour or solidity. The idea of extension is a compound idea;

but as it is not compounded of an infinite number of parts or inferior

ideas, it must at last resolve itself into such as are perfectly simple

and indivisible. These simple and indivisible parts, not being ideas of

extension, must be non entities, unless conceived as coloured or solid.

Colour is excluded from any real existence. The reality, therefore, of

our idea of extension depends upon the reality of that of solidity, nor

can the former be just while the latter is chimerical.

Let us, then,

lend our attention to the examination of the idea of solidity.

The idea of solidity is that of two objects, which being impelled by the

utmost force, cannot penetrate each other; but still maintain a

separate and distinct existence. Solidity, therefore, is perfectly

incomprehensible alone, and without the conception of some bodies, which

are solid, and maintain this separate and distinct existence. Now what

idea have we of these bodies? The ideas of colours, sounds, and other

secondary qualities are excluded. The idea of motion depends on that

of extension, and the idea of extension on that of solidity. It is

impossible, therefore, that the idea of solidity can depend on either of

them. For that would be to run in a circle, and make one idea depend on

another, while at the same time the latter depends on the former. Our

modern philosophy, therefore, leaves us no just nor satisfactory idea of

solidity; nor consequently of matter.

This argument will appear entirely conclusive to every one that

comprehends it; but because it may seem abstruse and intricate to the

generality of readers, I hope to be excused, if I endeavour to render

it more obvious by some variation of the expression. In order to form

an idea of solidity, we must conceive two bodies pressing on each other

without any penetration; and it is impossible to arrive at this idea,

when we confine ourselves to one object, much more without conceiving

any. Two non-entities cannot exclude each other from their places;

because they never possess any place, nor can be endowed with any

quality. Now I ask, what idea do we form of these bodies or objects,

to which we suppose solidity to belong? To say, that we conceive them

merely as solid, is to run on in infinitum. To affirm, that we paint

them out to ourselves as extended, either resolves all into a false

idea, or returns in a circle. Extension must necessarily be considered

either as coloured, which is a false idea; I or as solid, which

brings us back to the first question. We may make the same observation

concerning mobility and figure; and upon the whole must conclude, that

after the exclusion of colours, sounds, heat and cold from the rank of

external existences, there remains nothing, which can afford us a just

and constituent idea of body.

Add to this, that, properly speaking, solidity or impenetrability is

nothing, but an impossibility of annihilation, as [Part II. Sect. 4.]

has been already observed: For which reason it is the more necessary

for us to form some distinct idea of that object, whose annihilation we

suppose impossible. An impossibility of being annihilated cannot exist,

and can never be conceived to exist, by itself: but necessarily

requires some object or real existence, to which it may belong. Now

the difficulty still remains, how to form an idea of this object

or existence, without having recourse to the secondary and sensible

qualities.

Nor must we omit on this occasion our accustomed method of examining

ideas by considering those impressions, from which they are derived. The

impressions, which enter by the sight and hearing, the smell and taste,

are affirmed by modern philosophy to be without any resembling objects;

and consequently the idea of solidity, which is supposed to be real, can

never be derived from any of these senses. There remains, therefore,

the feeling as the only sense, that can convey the impression, which is

original to the idea of solidity; and indeed we naturally imagine, that

we feel the solidity of bodies, and need but touch any object in order