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

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that faculty, which judges, and having adjusted these two together,

we are obliged by our reason to add a new doubt derived from the

possibility of error in the estimation we make of the truth and fidelity

of our faculties. This is a doubt, which immediately occurs to us, and

of which, if we would closely pursue our reason, we cannot avoid giving

a decision. But this decision, though it should be favourable to our

preceding judgment, being founded only on probability, must weaken still

further our first evidence, and must itself be weakened by a fourth

doubt of the same kind, and so on in infinitum: till at last there

remain nothing of the original probability, however great we may

suppose it to have been, and however small the diminution by every new

uncertainty. No finite object can subsist under a decrease repeated IN

INFINITUM; and even the vastest quantity, which can enter into human

imagination, must in this manner be reduced to nothing.

Let our first

belief be never so strong, it must infallibly perish by passing through

so many new examinations, of which each diminishes somewhat of its force

and vigour. When I reflect on the natural fallibility of my judgment,

I have less confidence in my opinions, than when I only consider the

objects concerning which I reason; and when I proceed still farther,

to turn the scrutiny against every successive estimation I make of my

faculties, all the rules of logic require a continual diminution, and at

last a total extinction of belief and evidence.

Should it here be asked me, whether I sincerely assent to this argument,

which I seem to take such pains to inculcate, and whether I be really

one of those sceptics, who hold that all is uncertain, and that our

judgment is not in any thing possest of any measures of truth and

falshood; I should reply, that this question is entirely superfluous,

and that neither I, nor any other person was ever sincerely and

constantly of that opinion. Nature, by an absolute and uncontroulable

necessity has determined us to judge as well as to breathe and feel; nor

can we any more forbear viewing certain objects in a stronger and

fuller light, upon account of their customary connexion with a present

impression, than we can hinder ourselves from thinking as long, as

we are awake, or seeing the surrounding bodies, when we turn our eyes

towards them in broad sunshine. Whoever has taken the pains to refute

the cavils of this total scepticism, has really disputed without an

antagonist, and endeavoured by arguments to establish a faculty, which

nature has antecedently implanted in the mind, and rendered unavoidable.

My intention then in displaying so carefully the arguments of that

fantastic sect, is only to make the reader sensible of the truth of my

hypothesis, that all our reasonings concerning causes and effects are

derived from nothing but custom; and that belief is more properly an act

of the sensitive, than of the cogitative part of our natures. I

have here proved, that the very same principles, which make us form

a decision upon any subject, and correct that decision by the

consideration of our genius and capacity, and of the situation of our

mind, when we examined that subject; I say, I have proved, that these

same principles, when carryed farther, and applied to every new reflex

judgment, must, by continually diminishing the original evidence, at

last reduce it to nothing, and utterly subvert all belief and opinion.

If belief, therefore, were a simple act of the thought, without any

peculiar manner of conception, or the addition of a force and vivacity,

it must infallibly destroy itself, and in every case terminate in a

total suspense of judgment. But as experience will sufficiently convince

any one, who thinks it worth while to try, that though he can find no

error in the foregoing arguments, yet he still continues to believe, and

think, and reason as usual, he may safely conclude, that his reasoning

and belief is some sensation or peculiar manner of conception, which it

is impossible for mere ideas and reflections to destroy.

But here, perhaps, it may be demanded, how it happens, even upon my

hypothesis, that these arguments above-explained produce not a total

suspense of judgment, and after what manner the mind ever retains a

degree of assurance in any subject? For as these new probabilities,

which by their repetition perpetually diminish the original evidence,

are founded on the very same principles, whether of thought or

sensation, as the primary judgment, it may seem unavoidable, that in

either case they must equally subvert it, and by the opposition,

either of contrary thoughts or sensations, reduce the mind to a total

uncertainty. I suppose, there is some question proposed to me, and

that after revolving over the impressions of my memory and senses,

and carrying my thoughts from them to such objects, as are commonly

conjoined with them, I feel a stronger and more forcible conception on

the one side, than on the other. This strong conception forms my first

decision. I suppose, that afterwards I examine my judgment itself,

and observing from experience, that it is sometimes just and sometimes

erroneous, I consider it as regulated by contrary principles or causes,

of which some lead to truth, and some to error; and in ballancing these

contrary causes, I diminish by a new probability the assurance of my

first decision. This new probability is liable to the same diminution as

the foregoing, and so on, IN INFINITUM. It is therefore demanded, how

it happens, that even after all we retain a degree of belief, which is

sufficient for our purpose, either in philosophy or common life.

I answer, that after the first and second decision; as the action of

the mind becomes forced and unnatural, and the ideas faint and obscure;

though the principles of judgment, and the ballancing of opposite

causes be the same as at the very beginning; yet their influence on the

imagination, and the vigour they add to, or diminish from the thought,

is by no means equal. Where the mind reaches not its objects with

easiness and facility, the same principles have not the same effect as

in a more natural conception of the ideas; nor does the imagination feel

a sensation, which holds any proportion with that which arises from

its common judgments and opinions. The attention is on the stretch: The

posture of the mind is uneasy; and the spirits being diverted from their

natural course, are not governed in their movements by the same laws, at

least not to the same degree, as when they flow in their usual channel.

If we desire similar instances, it will not be very difficult to find

them. The present subject of metaphysics will supply us abundantly. The

same argument, which would have been esteemed convincing in a reasoning

concerning history or politics, has little or no influence in these

abstruser subjects, even though it be perfectly comprehended; and that

because there is required a study and an effort of thought, in order

to its being comprehended: And this effort of thought disturbs the

operation of our sentiments, on which the belief depends. The case is

the same in other subjects. The straining of the imagination always

hinders the regular flowing of the passions and sentiments. A tragic

poet, that would represent his heroes as very ingenious and witty in

their misfortunes, would never touch the passions. As the emotions of

the soul prevent any subtile reasoning and reflection, so these latter

actions of the mind are equally prejudicial to the former. The mind, as

well as the body, seems to be endowed with a certain precise degree of

force and activity, which it never employs in one action, but at the

expense of all the rest. This is more evidently true, where the actions

are of quite different natures; since in that case the force of the mind

is not only diverted, but even the disposition changed, so as to render

us incapable of a sudden transition from one action to the other, and

still more of performing both at once. No wonder, then, the conviction,

which arises from a subtile reasoning, diminishes in proportion to the

efforts, which the imagination makes to enter into the reasoning, and

to conceive it in all its parts. Belief, being a lively conception, can

never be entire, where it is not founded on something natural and easy.

This I take to be the true state of the question, and cannot approve of

that expeditious way, which some take with the sceptics, to reject

at once all their arguments without enquiry or examination. If the

sceptical reasonings be strong, say they, it is a proof, that reason may

have some force and authority: if weak, they can never be sufficient to

invalidate all the conclusions of our understanding.

This argument is

not just; because the sceptical reasonings, were it possible for them

to exist, and were they not destroyed by their subtility, would

be successively both strong and weak, according to the successive

dispositions of the mind. Reason first appears in possession of the

throne, prescribing laws, and imposing maxims, with an absolute sway and

authority. Her enemy, therefore, is obliged to take shelter under

her protection, and by making use of rational arguments to prove the

fallaciousness and imbecility of reason, produces, in a manner, a

patent under her band and seal. This patent has at first an authority,

proportioned to the present and immediate authority of reason, from

which it is derived. But as it is supposed to be contradictory to

reason, it gradually diminishes the force of that governing power

and its own at the same time; till at last they both vanish away into

nothing, by a regulax and just diminution. The sceptical and dogmatical

reasons are of the same kind, though contrary in their operation and

tendency; so that where the latter is strong, it has an enemy of equal

force in the former to encounter; and as their forces were at first

equal, they still continue so, as long as either of them subsists; nor

does one of them lose any force in the contest, without taking as much

from its antagonist. It is happy, therefore, that nature breaks the

force of all sceptical arguments in time, and keeps them from having any

considerable influence on the understanding. Were we to trust entirely

to their self-destruction, that can never take place, until they have

first subverted all conviction, and have totally destroyed human reason.

SECT. II. OF SCEPTICISM WITH REGARD TO THE SENSES.

Thus the sceptic still continues to reason and believe, even though be

asserts, that he cannot defend his reason by reason; and by the same

rule he must assent to the principle concerning the existence of body,

though he cannot pretend by any arguments of philosophy to maintain its

veracity. Nature has not left this to his choice, and has doubtless,

esteemed it an affair of too great importance to be trusted to our

uncertain reasonings and speculations. We may well ask, What causes

induce us to believe in the existence of body? but it is in vain to ask,

Whether there be body or not? That is a point, which we must take for

granted in all our reasonings.

The subject, then, of our present enquiry is concerning the causes which

induce us to believe in the existence of body: And my reasonings on this

head I shall begin with a distinction, which at first sight may

seem superfluous, but which will contribute very much to the perfect

understanding of what follows. We ought to examine apart those two

questions, which are commonly confounded together, viz.

Why we attribute

a continued existence to objects, even when they are not present to the

senses; and why we suppose them to have an existence DISTINCT from the

mind and perception. Under this last head I comprehend their

situation as well as relations, their external position as well as

the independence of their existence and operation. These two questions

concerning the continued and distinct existence of body are intimately

connected together. For if the objects of our senses continue to

exist, even when they are not perceived, their existence is of course

independent of and distinct from the perception: and vice versa, if

their existence be independent of the perception and distinct from it,

they must continue to exist, even though they be not perceived. But

though the decision of the one question decides the other; yet that we

may the more easily discover the principles of human nature, from whence

the decision arises, we shall carry along with us this distinction, and

shall consider, whether it be the senses, reason, or the imagination,

that produces the opinion of a continued or of a distinct existence.

These are the only questions, that are intelligible on the present

subject. For as to the notion of external existence, when taken for

something specially different from our perceptions

[Part. II. Sect. 6.],

we have already shewn its absurdity.

To begin with the SENSES, it is evident these faculties are incapable of

giving rise to the notion of the continued existence of their objects,

after they no longer appear to the senses. For that is a contradiction

in terms, and suppose that the senses continue to operate, even after

they have ceased all manner of operation. These faculties, therefore, if

they have any influence in the present case, must produce the opinion

of a distinct, not of a continued existence; and in order to that, must

present their impressions either as images and representations, or as

these very distinct and external existences.

That our senses offer not their impressions as the images of something

distinct, or independent, and external, is evident; because they convey

to us nothing but a single perception, and never give us the least

intimation of any thing beyond. A single perception can never produce

the idea of a double existence, but by some inference either of the

reason or imagination. When the mind looks farther than what immediately

appears to it, its conclusions can never be put to the account of the

senses; and it certainly looks farther, when from a single perception it

infers a double existence, and supposes the relations of resemblance and

causation betwixt them.

If our senses, therefore, suggest any idea of distinct existences,

they must convey the impressions as those very existences, by a kind of

fallacy and illusion. Upon this bead we may observe, that all sensations

are felt by the mind, such as they really are, and that when we

doubt, whether they present themselves as distinct objects, or as

mere impressions, the difficulty is not concerning their nature, but

concerning their relations and situation. Now if the senses presented

our impressions as external to, and independent of ourselves, both the

objects and ourselves must be obvious to our senses, otherwise they

coued not be compared by these faculties. The difficulty, then, is how

fax we are ourselves the objects of our senses.

It is certain there is no question in philosophy more abstruse than

that concerning identity, and the nature of the uniting principle, which

constitutes a person. So far from being able by our senses merely to

determine this question, we must have recourse to the most profound

metaphysics to give a satisfactory answer to it; and in common life

it is evident these ideas of self and person are never very fixed nor

determinate. It is absurd, therefore, to imagine the senses can ever

distinguish betwixt ourselves and external objects.

Add to this, that every impression, external and internal, passions,

affections, sensations, pains and pleasures, are originally on the same

footing; and that whatever other differences we may observe among them,

they appear, all of them, in their true colours, as impressions or

perceptions. And indeed, if we consider the matter aright, it is scarce

possible it should be otherwise, nor is it conceivable that our senses

should be more capable of deceiving us in the situation and relations,

than in the nature of our impressions. For since all actions and

sensations of the mind are known to us by consciousness, they must

necessarily appear in every particular what they are, and be what they

appear. Every thing that enters the mind, being in reality a perception,

it is impossible any thing should to feeling appear different. This were

to suppose, that even where we are most intimately conscious, we might

be mistaken.

But not to lose time in examining, whether it is possible for our senses

to deceive us, and represent our perceptions as distinct from ourselves,

that is as external to and independent of us; let us consider whether

they really do so, and whether this error proceeds from an immediate

sensation, or from some other causes.

To begin with the question concerning EXTERNAL

existence, it may perhaps

be said, that setting aside the metaphysical question of the identity

of a thinking substance, our own body evidently belongs to us; and as

several impressions appear exterior to the body, we suppose them also

exterior to ourselves. The paper, on which I write at present, is beyond

my hand. The table is beyond the paper. The walls of the chamber beyond

the table. And in casting my eye towards the window, I perceive a great

extent of fields and buildings beyond my chamber. From all this it may

be infered, that no other faculty is required, beside the senses, to

convince us of the external existence of body. But to prevent this

inference, we need only weigh the three following considerations. First,

That, properly speaking, it is not our body we perceive, when we regard

our limbs and members, but certain impressions, which enter by the

senses; so that the ascribing a real and corporeal existence to these

impressions, or to their objects, is an act of the mind as difficult

to explain, as that which we examine at present.

Secondly, Sounds, and

tastes, and smelts, though commonly regarded by the mind as continued

independent qualities, appear not to have any existence in extension,

and consequently cannot appear to the senses as situated externally

to the body. The reason, why we ascribe a place to them, shall be:

considered afterwards. Thirdly, Even our sight informs us not of

distance or outness (so to speak) immediately and without a certain

reasoning and experience, as is acknowledged by the most rational

philosophers.

As to the independency of our perceptions on ourselves, this can never

be an object of the senses; but any opinion we form concerning it, must

be derived from experience and observation: And we shall see afterwards,

that our conclusions from experience are far from being favourable to

the doctrine of the independency of our perceptions.

Mean while we may

observe that when we talk of real distinct existences, we have commonly

more in our eye their independency than external situation in place,

and think an object has a sufficient reality, when its Being is

uninterrupted, and independent of the incessant revolutions, which we

are conscious of in ourselves.

Thus to resume what I have said concerning the senses; they give us no

notion of continued existence, because they cannot operate beyond the

extent, in which they really operate. They as little produce the opinion

of a distinct existence, because they neither can offer it to the mind

as represented, nor as original. To offer it as represented, they must

present both an object and an image. To make it appear as original, they

must convey a falshood; and this falshood must lie in the relations and

situation: In order to which they must be able to compare the object

with ourselves; and even in that case they do not, nor is it possible

they should, deceive us. We may, therefore, conclude with certainty,

that the opinion of a continued and of a distinct existence never arises

from the senses.

To confirm this we may observe, that there are three different kinds of

impressions conveyed by the senses. The first are those of the figure,

bulk, motion and solidity of bodies. The second those of colours,

tastes, smells, sounds, heat and cold. The third are the pains and

pleasures, that arise from the application of objects to our bodies, as

by the cutting of our flesh with steel, and such like.

Both philosophers

and the vulgar suppose the first of these to have a distinct continued

existence. The vulgar only regard the second as on the same footing.

Both philosophers and the vulgar, again, esteem the third to be merely

perceptions and consequently interrupted and dependent beings.

Now it is evident, that, whatever may be our philosophical opinion,

colours, Sounds, heat and cold, as far as appears to the senses, exist

after the same manner with motion and solidity, and that the difference

we make betwixt them in this respect, arises not from the mere

perception. So strong the prejudice for the distinct continued existence

Of the former qualities, that when the contrary opinion is advanced by

modern philosophers, people imagine they can almost refute it from

their feeling and experience, and that their very senses contradict this

philosophy. It is also evident, that colours, sounds,

&c. are originally

on the same footing with the pain that arises from steel, and pleasure

that proceeds from a fire; and that the difference betwixt them is

founded neither on perception nor reason, but on the imagination. For

as they are confest to be, both of them, nothing but perceptions arising

from the particular configurations and motions of the parts of body,

wherein possibly can their difference consist? Upon the whole, then, we

may conclude, that as far as the senses are judges, all perceptions are

the same in the manner of their existence.

We may also observe in this instance of sounds and colours, that we

can attribute a distinct continued existence to objects without ever

consulting REASON, or weighing our opinions by any philosophical

principles. And indeed, whatever convincing arguments philosophers may

fancy they can produce to establish the belief of objects independent of

the mind, it is obvious these arguments are known but to very few, and

that it is not by them, that children, peasants, and the greatest part

of mankind are induced to attribute objects to some impressions, and

deny them to others. Accordingly we find, that all the conclusions,

which the vulgar form on this head, are directly contrary to those,

which are confirmed by philosophy. For philosophy informs us, that every

thing, which appears to the mind, is nothing but a perception, and is

interrupted, and dependent on the mind: whereas the vulgar confound

perceptions and objects, and attribute a distinct continued existence

to the very things they feel or see. This sentiment, then, as it is

entirely unreasonable, must proceed from some other faculty than

the understanding. To which we may add, that as long as we take our

perceptions and objects to be the same, we can never infer the existence

of the one from that of the other, nor form any argument from the

relation of cause and effect; which is the only one that earl assure us

of matter of fact. Even after we distinguish our perceptions from

our objects, it will appear presently, that we are still incapable of

reasoning from the existence of one to that o