constitute the perception of angular or curvilinear figure, there is something, in the nature of that part of the sensorial organ, which terminates on the general surface of the body, that impresses the mind, immediately, with a sensation, corresponding with the exact figure, in which the organ may itself exist. When the square, therefore, in the case imagined by us, is impressed upon the organ, the mental affection which constitutes our notion of a square may immediately arise, though it would not arise from the similar squareness of our organs of smell or hearing.

In answer to this mere supposition, I may remark, that the sensorial organ of touch exists, at every moment, of a certain shape, and that we yet have no perception of this shape, so as to be able to delineate the whole extent of our tactual organ, in the same manner as we could delineate the impressing square, in the case supposed: or, if it be said, that the configuration of the organ does not excite this mental affection, in the quiescent state of the part, but only when it is itself affected, I may remark, that we are as little able to delineate its figure, when we are exposed to the action of heat, which yet acts most powerfully upon this very organ, inducing sensations, at least as vivid as those of hardness or figure.

It may still, however, be contended, for in a question of this sort I wish fairly to imagine every possible argument-it may still be contended, that, though the organ of touch has no effect, in this way merely as configured, and might, in any other configuration operate, precisely in the same manner, on the sentient mind, --still the harmony of the bodily and mental changes is so arranged by nature, that the organic state in touch, whatever it may be, is immediately followed by the knowledge of the extension of the impressing body,-in the same manner as a certain state of the organ of smell, whatever that state may be, is immediately followed by that affection of the mind, which constitutes our sensation of the fragrance of a rose. Though this argument, in truth, rather begs the question, than attempts to meet it, let us give to it all the force which it may claim. The accurate determination of the point may, indeed, seem, at first almost impossible; since in whatever manner the seeming perception may arise, it must be admitted, that we now seem to perceive extension, as it were immediately, by touch; though not more immediately than in vision

we seem to perceive the positions of objects in different distances before our eyes.—But there is, fortunately, at least one test, which the point in question still admits. If the apparent perception of extension by touch, be truly and originally immediate, and not acquired, like the apparent perception of distance in vision, so as to involve a sort of intellectual measurement or suggestion of some sort, after the primary sensation, the perception must be constant and universal, not confined to a few simple and familiar forms, which, if we can distinguish these alone, we may be supposed to have learned from experience, but extending to forms of every kind; for it would certainly be a very strange abuse of the license of supposition, to imagine that we perceive a square immediately, but not a circle, or a circle but not a square, or indeed any other figure. Even at present, then-though the circumstances of the trial,when the experience of many years must have exhausted so many varieties of form, associating the notion of these with the particular tactual feeling whatever that may be-are surely very unfavourable to the opinion which I maintain,-even at present, I may safely trust to experiment, the determination of the question. When a body which we do not see, is pressed on any part of our tactual organ, do we immediately discover its form,-as immediately, as we are sensible of fragrance, when our organ of smell is in a healthy state, and an odoriferous body is presented to it, or of sound, when a cannon is fired beside us? This we certainly should do, if figure were as direct an object of the sense of touch, as fragrance and sound are of the senses of smell and hearing. Even though it be a form of the simplest kind, square, round, triangular, that is thus pressed upon our palm, we scarcely distinguish the precise species of figure for a moment, and are long before we can convince ourselves, that we have perceived its exact magnitude, in the determination of which, after all, we shall very probably be mistaken, if we confine ourselves to the mere intellectual measurement; though we should even add to the immediate sensation of touch, all the discriminating skill of our judgment and reflection. But, if the body be irregular in form, however slight the irregularity may be, and of a species that would not perplex in the slightest degree our sense of sight, and which certainly, therefore, should perplex as little our sense of touch, which supposed to be still more immediately perceptive of form,-we

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are incapable for some time, and I may even say are incapable altogether, of fixing, with precision, its magnitude and figure-that very magnitude and figure which are yet said to be the direct objects of touch. Of this a single trial may convince any one; it is a trial which as it seems to me decisive, I must request you to make. Are we then entitled to say, in the case of the square surface of the cube pressed upon our hand, that though we cannot discover other forms and magnitudes, we yet discover its extension, and consequently its figure, by the immediate sense of touch?-or may we not rather conclude with confidence, that what is true of other forms is true of this also, that it is only in consequence of more frequent experience we have learned as it were to distinguish, with some degree of certainty, the simpler forms, which, as mere forms, are not more direct objects of the sense of touch than forms the most irregular, and that without such experience, therefore, our mere sense of touch is incapable of informing us of the figure of bodies, immediately and originally.

If then the knowledge of extension be not derived from our immediate sense of touch, it must be derived from some other source, which allows it to be associated with the feelings of touch, and afterwards suggested by these, in the same manner as distant extent, in the case of vision, is suggested by a few slight varieties of colour. Let us endeavour, then, since some such source there must be, to discover what the source is.

345

LECTURE XXIII.

ANALYSIS OF THE FEELINGS USUALLY ASCRIBED TO THE SENSE OF TOUCH, CONTINUED.

My last Lecture, Gentlemen, was employed in considering the information which we receive from the sense of touch, or rather the information which we are commonly supposed to receive from that sense, but which, in a great part at least, I am inclined to ascribe to another source.

The qualities of bodies, supposed to be made known to us by touch, I reduced to two, of which all-whatever be the variety of names that express them, are mere varieties, RESISTANCE and EXTENSION :-solidity, liquidity, viscidity, hardness, softness, roughness, smoothness, being modes of RESISTANCE, and nothing more ;figure, magnitude, divisibility, as evidently nothing more than modes of EXTENSION: and I stated reasons, which induce me to believe, that neither our feeling of resistance nor that of extension, has its direct origin in the sense of touch; though the original simple feeling, which this organ affords, is now, from constant association, almost indiscriminately combined with both, in some one or other of their varieties.

The first of these classes, that which includes the various modifications of resistance,-I examined at great length, and showed, I trust, that it is not to our organ of touch we are indebted for these, but that they are feelings of another sense, of which our muscular frame is the organ, the feelings, in short, of which every one must have been conscious, who has attempted to grasp any body, or to press against it, when the full contraction of the mus cles must, of course, have been impeded. According as the body is hard or soft, rough or smooth, that is to say, according as it

resists, in various degrees, the progress of our effort of contraction, the muscular feeling, which arises from the variously impeded effort, will vary in proportion; and we call hard, soft, rough, smooth, that which produces one or other of the varieties of these muscular feelings of resistance, as we term sweet or bitter, blue or yellow, that which produces either of these sensations of taste or vision. With the feeling of resistance, there is, indeed, in eve ́ry case, combined, a certain tactual feeling, because we must touch whatever we attempt to grasp; but it is not of this mere tactual feeling we think, when we term bodies hard or soft,-it is of the greater or less resistance which they afford to our muscular contraction.

I next proceeded to consider the other class of supposed tangible qualities, which includes the various modifications of extension, and urged many arguments to show, in like manner, that, however indissolubly these may seem at present to be connected with the simple feelings of our organ of touch, it is not to our simple original feelings of this sense, that we owe our knowledge of them, as qualities of things without.

Though the notion of extension, however, may arise in the manner which I have supposed, this, it may be said, is not the notion of external existence. To what, then, are we to ascribe the belief of external reality, which now accompanies our sensations of touch? It appears to me to depend on the feeling of resistance, -the organ of which, as a muscular feeling, I before explained to you, which breaking in, without any known cause of difference, on an accustomed series, and combining with the notion of extension, and consequently of divisibility, previously acquired, furnishes the elements of that compound notion, which we term the notion of matter. Extension, resistance ;—to combine these simple notions in something which is not ourselves, and to have the notion of matter, are precisely the same thing; as it is the same thing to have combined the head and neck of a man with the body and legs of a horse, and to have the notion of that fabulous being, which the ancients denominated a centaur. It certainly, at least, would not be easy for any one to define matter more simply, than as that which has parts, and that which resists our effort to grasp it; and, in our analysis of the feelings of infancy, we have been able to discover how both these notions may have arisen in the mind, and arisen