THE

MONTHLY REVIEW,

For JUL Y, 1764.

Conclufion of the Account of an Enquiry into the Human Mind, on the Principles of Common Senfe.

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Great part of what Dr. Reid has advanced, concerning the fenfe of Smelling, (of which we gave a full account in our Review for May) is to easily applied to those of Tafting and Hearing, that he faves his Keaders the trouble of a tedious repetition, and leaves the application entirely to their own. judgments. He introduces what he fays concerning Touch, with obferving, that the fenfes, already confidered, are very fimple and uniform, each of them exhibiting only one kind of fenfation, and thereby indicating only one quality of bodies. By the ear we perceive founds, and nothing elfe; by the palate, taftes; and by the nofe, odours: thefe qualities are all likewife of one order, being all fecondary qualities: whereas by touch we perceive not one quality only, but many, and those of very different kinds. The chief of them are heat and cold, hardness and foftness, roughness and fmoothness, figure, folidity, motion, and extenfion. These our Author confiders in order.

As to heat and cold, it will eafily be allowed, that they are fecondary qualities, of the fame order with fmell, tafte, and found. And, therefore, what has been faid of fmell, is eafily applicable to them; that is, that the words heat and cold have each of them two fignifications; they fometimes fignify certain fenfations of the mind, which can have no existence when they are not felt, nor can exift any where but in a mind, or fentient being; but more frequently they fignify a quality in bodies, which, by the laws of nature, occafions the fenfations of heat and cold in us: a quality which, though connected by custom fo closely with the fenfation, that we cannot without difficulty VOL. XXXI. separate

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separate them; yet hath not the leaft refemblance to it, and may continue to exift when there is no fenfation at all.

By the words hardness and foftarfs, we always understand real properties or qualities of bodies, of which we have a distinct conception. When the parts of a body adhere fo firmly, that it cannot eafily be made to change its figure, we call it hard; when its parts are eafily difplaced, we call it foft. This is the 'notion which, all mankind have of hardness and foftnefs; they are neither. fenfations, nor like any fenfation; they were real qualities before they were perceived by touch, and continue to be fo when they are not perceived; for if any man will affirm, that diamonds were not hard till they were handled, who would teafon with him?

There is no doubt, our Author fays, a fenfation by which we perceive a body to be hard or foft. This fenfation of hardness may easily be had, by preffing one's hand against the table, and attending to the feeling that enfues: fetting afide, as much as poffible, all thought of the table, and its qualities, or of any external thing. But it is one thing to have the fenfation, and another to attend to it, and make it a diftinct object of reflection. The firft is very eafy; the laft, in most cafes, extremely dif ficult.

We are fo accustomed, he fays, to ufe the fenfation as a fign, and to pafs immediately to the hardnefs fignified, that, as far as appears, it was never made an object of thought, either by the vulgar or Philofophers; nor has it a name in any language, There is no fenfation more diftinct, or more frequent; yet it is never attended to, but paffes through the mind inftantane-. aufly, and ferves only to introduce that quality in bodies, which by a law of our conftitution it fuggefts.

There are, indeed, fome cafès, continues hè, wherein it is no difficult matter to attend to the fenfation occafioned by the hardness of a body; for inftance, when it is fo violent as to occafion confiderable pain: then nature calls upon us to attend to it, and then we acknowlege, that it is a mere fenfation, and can only be in a fentient Being. If a man runs his head with violence against a pillar, I appeal to him, whether the pain he. feels resembles the hardness of the ftone; or if he can conceive. any thing like what he feels, to be in an inanimate piece of

matter.

The attention of the mind is here entirely turned towards the painful feeling; and, to fpeak in the common language of mankind, he feels nothing in the ftone, but feels a violent pain in his head. It is quite otherwife when he leans his head gently

against/

against the pillar; for then he will tell you, that he feels nothing in his head, but feels hardness in the ftone. Hath he not a fenfation in this cafe as well as in the other? Undoubtedly he hath but it is a fenfation which nature intended only as a fign of fomething in the ftone; and, accordingly, he inftantly fixes his attention upon the thing fignified; and cannot, without great difficulty, attend fo much to the fenfation, as to be perfuaded that there is any fuch thing, diftinct from the hardnefs it fignifies.

But however difficult it may be to attend to this fugitive fenfation, to stop its rapid progrefs, and to disjoin it from the external quality of hardness, in whofe fhadow it is apt immediately to hide itself; this is what a Philofopher by pains and practice must attain, otherwise it will be impoffible for him to reafon justly upon this fubject, or even to understand what is here advanced. For the laft appeal in fubjects of this nature, must be to what a man feels and perceives in his own mind.

It is, indeed, ftrange, that a fenfation which we have every time that we feel a body hard, and which, confequently, we can command as often, and continue as long as we pleafe, a fenfation as diftinct and determinate as any other, fhould yet be fo much unknown, as never to have been made an object, of thought and reflection, nor to have been honoured with a name in any language; that Philofophers, as well as the vulgar, should have entirely overlooked it, or confounded it with that quality of bodies which we call Hardnefs, to which it hath not the leaft fimilitude. May we not hence conclude, That the knowlege of the human faculties is but in its infancy? That we have not yet learned to attend to thofe operations of the mind of which we are conscious every hour of our lives? That there are habits of inattention acquired very early, which are as hard to be overcome as other habits? For I think it is proba ble, that the novelty of this fenfation will procure fome atten4 tion to it in children at firft; but being nowife interefting in itself, as foon as it becomes familiar, it is overlooked, and the attention turned folely to that which it fignifies. Thus, when one is learning a language, he attends to the founds; but when he is master of it, he attends only to the fenfe of what he would exprefs. If this is the cafe, we must become as little children again, if we will be Philofophers: we must overcome habits which have been gathering strength ever fince we began to think; habits, the usefulness of which, in common life, atones. for the difficulty it creates to the Philofopher in difcovering the firft principles of the human mind.

• The firm cohesion of the parts of a body, is no more like

that fenfation by which I perceive it to be hard, than the vibration of a fonorous body is like the found I hear: nor can I poffibly perceive, by my reafon, any connection between the one and the other. No man can give a reafon, why the vibration of a body might not have given the fenfation of fmelling, and the effluvia of bodies affected our hearing, if it had fo pleafed our Maker. In like manner, no man can give a reason, why the fenfations of fmell, or tafte, or found, might not have indicated hardness, as well as that fenfation, which, by our conftitution, does indicate it. Indeed, no man can conceive any senfation to refemble any known quality of bodies. Nor can any man fhew, by any good argument, that all our fenfations might not have been as they are, though no body, nor quality of body, had ever exifted.

Here then is a phenomenon of human nature, which comes to be refolved. Hardnefs of bodies is a thing that we conceive as diftinctly, and believe as firmly, as any thing in nature. We have no way of coming at this conception and belief, but by means of a certain fenfation of touch, to which hardness hath not the leaft fimilitude; nor can we, by any rules of reafoning, infer the one from the other. The queftion is, How we come by this conception and belief?

First, as to the conception: Shall we call it an idea of fenfation, or of reflection? The laft will not be affirmed; and as little can the firft, unless we will call that an idea of fenfation, which hath no refemblance to any fenfation. So that the origin of this idea of hardness, one of the most common and most distinct we have, is not to be found in all our fyftems of the mind: not even in those which have fo copioufly endeavoured to deduce all our notions from fenfation and reflection.

But, fecondly, fuppofing we have got the conception of hardness, how come we by the belief of it? Is it felf-evident, from comparing the ideas, that fuch a fenfation could not be felt, unlefs fuch a quality of bodies exifted? No. Can it be proved by probable or certain arguments? No, it cannot. Have we got this belief then by tradition, by education, or by experience? No, it is not got in any of these ways. Shall we then throw off this belief, as having no foundation in reason? Alas! it is not in our power; it triumphs over reason, and laughs at all the arguments of a Philofopher. Even the Author of the Treatife of human Nature, though he faw no reason for this belief, but many against it, could hardly conquer it in his fpeculative and folitary moments; at other times he fairly yielded to it, and confeffes that he found himfelf under a neceflity to do so.,

• What

What shall we fay then of this conception, and this belief, which are fo unaccountable and untractable? I fee nothing left, but to conclude, that, by an original principle of our conftitution, a certain fenfation of touch both fuggefts to the mind the conception of hardness, and creates the belief of it: or, in other words, that this fenfation is a natural fign of hardness.'

This our Author endeavours more fully to explain, and ob ferves, that as in artificial figns there is often neither fimilitude. between the fign and thing fignified, nor any connection that arifes neceffarily from the nature of the things; fo it is alfo in. natural figns. The word Gold has no fimilitude to the fubftance fignified by it; nor is it in its own nature more fit to fignify this than any other fubftance: yet, by habit and custom, it fuggefts this and no other. In like manner, a fenfation of touch fuggefts hardnefs, although it hath neither fimilitude to hardnefs, nor, as far as we can perceive, any neceflary connection with it. The difference betwixt thefe two figns lies only in this, that, in the firft, the fuggeftion is the effect of habit and cuftom; in the fecond, it is not the effect of habit, but of the original conftitution of our minds.

That we may more diftinctly conceive the relation between. our fenfations and the things they fuggeft, and what is meant by calling fenfations figns of external things, Dr. Reid obferves farther, that there are different orders of natural figns; and he points out the different claffes into which they may be diftinguished.

The first class of natural figns, we are told, comprehends those whofe connection with the thing fignified is eftablished by nature, but difcovered only by experience. The whole of genuine Philofophy confifts in difcovering fuch connections, and reducing them to general rules. What we commonly call natural caufes, might, our Author thinks, with more propriety be called natural figns; and what we call effects, the things fignified. The caufes have no proper efficiency or caufality, as far as we know; and all we can certainly affirm, is, that nature hath established a conftant conjunction between them and the things called their effects; and hath given to mankind a difpofition to obferve thofe connections, to confide in their continuance, and to make use of them for the improvement of our knowlege, and increase of our power.

A fecond clafs is that wherein the connection between the fign and thing fignified is not only eftablished by nature, but difcovered to us by a natural principle, without reafoning or experience. Of this kind are the natural figns of human thoughts,

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purposes,