Lectures on the Philosophy of the Human Mind (Vol. 1 of 3)

by Thomas Brown

In sensation, there is, as we have seen, a certain series,—the presence of the external body, whatever this may be in itself, independently of our perception,—the organic affection, whatever it may be, which attends the presence of this body,—and the affection of mind that is immediately subsequent to the organic affection. I speak only of one organic affection; because, with respect to the mind, it is of no consequence whether there be one only, or a series of these, prior to the new mental state induced. It is enough, that, whenever the immediate sensorial organ has begun to exist in a certain state, whether the change which produces this state be single, or second, third, fourth, or fifth, of a succession of changes, the mind is instantly affected in a certain manner. This new mental state induced is sensation.

But, says Dr Reid, the sensation is accompanied with a perception, which is very different from it; and on this difference of sensation and perception is founded the chief part of his system. The distinction thus made by him, has been commonly, though very falsely, considered as original; the radical difference itself, whether accurate or inaccurate, and the minor distinctions founded upon this, being laid down with precision in some of the common elementary works of logic, of a much earlier period.

“When I smell a rose,” he says, “there is in this operation both sensation and perception. The agreeable odour I feel, considered by itself, without relation to any external object, is merely a sensation. It affects the mind in a certain way; and this affection of the mind may be conceived, without a thought of the rose, or any other object. This sensation can be nothing else than it is felt to be. Its very essence consists in being felt; and when it is not felt, it is not. There is no difference between the sensation and the feeling of it; they are one and the same thing. It is for this reason, that we before observed, that, in sensation, there is no object distinct from that act of the mind by which it is felt; and this holds true with regard to all sensations.

“Let us next attend to the perception which we have in smelling a rose. Perception has always an external object; and the object of my perception, in this case, is that quality in the rose which I discern by the sense of smell. Observing that the agreeable sensation is raised when the rose is near, and ceases when it is removed, I am led, by my nature, to conclude some quality to be in the rose, which is the cause of this sensation. This quality in the rose is the object perceived; and that act of my mind, by which I have the conviction and belief of this quality, is what in this case I call perception.”[109]

That the reference to an external object is, in this case, something more than the mere sensation itself, is very evident; the only question is, whether it be necessary to ascribe the reference to a peculiar power termed perception, or whether it be not rather the result of a common and more general principle of the mind.

When I smell a rose, that is to say, when certain odorous particles act on my organ of smell, a certain state of mind is produced, which constitutes the sensation of that particular fragrance; and this is all which can justly be ascribed to the mind as simply sentient. But the mind is not sensitive merely, in the strict sense of that term, for there are many states of it, which do not depend on the immediate presence of external objects. Those feelings, of any kind, which have before existed, together, or in trains of succession, arise afterwards, as it were spontaneously, in consequence merely of the existence of some other part of the train. When the fragrance of a rose, therefore, has been frequently accompanied with the sensations of vision, that arise, when a rose is before us, with the muscular and tactual sensations, that arise on handling it, the mere fragrance, of itself, will afterwards suggest these sensations, and this suggestion is all, which, in the case of smell, instanced by Dr Reid, is termed the perception, as distinguished from the mere sensation. We ascribe the fragrance to the unseen external rose, precisely in the same manner as we ascribe smoke and ashes to previous combustion; or, from a portrait, or a pictured landscape, infer the existence of some artist who painted it. Yet, in inferring the artist from the picture, it is surely not to any mere power of sense, that we ascribe the inference, and as little should we trace to any such simple power, what is in this instance termed perception. The perception is a suggestion of memory, combined with the simple sensation. There are not, in ascribing the smell to odorous particles of a rose, as its cause, sensation, perception, and association or suggestion, as three powers or general principles of the mind. But there are sensation and the associate suggestion; and, when these coexist, perception coexists, because perception is the name which we give to the union of the former two. There is, indeed, the belief of some cause of the sensation, as there is a belief of some cause of every feeling of the mind, internal as well as external; but the cause, in the case of smell, is supposed to be external, and corporeal, merely because the presence of an external rose has been previously learned from another source, and is suggested when the sensation of fragrance recurs, in intimate association.

In the case of taste, to proceed to our other senses—the perception, as it is termed by Dr Reid, is precisely of the same kind—a mere reference of association. We have previously learned, from other sources, to believe in things without, and these, as sapid bodies acting on our tongue, are suggested by the mere sensation, which, but for the means of this suggestion, would have been a sensation alone, of which the cause would have been as little conceived to be corporeal as the causes of any of the internal affections of the mind. The melody of a flute, if we had had no sense but that of hearing—the redness of a rose, if we had had no sense but that of vision, would as little, as the sensation of smell when considered as a transient state of the mind, have involved, or given occasion to, the notion of corporeal substance. We refer the melody to the external flute, and redness to the external rose, because we have previously acquired the notions of extension and resistance—of a flute and of a rose as external substances—and this reference of mere suggestion is all, which, in these cases, distinguishes the perception from the sensation. Without the suggestions of memory, in short, we could not in these cases have had, in Dr Reid's sense of the term, any perceptions whatever, to distinguish the causes of our sensations as external, more than the causes of any of our other feelings. The great perception, then, in the sense, in which he understands the term, is that by which we primarily form the complex notion of extension and resistance—that which has parts, and that which resists our attempt to grasp it—since all the other perceptions, of which he speaks, in contradistinction from mere sensations, are only these complex notions, suggested by the particular sensations, and combined with them, in consequence of former association, and the general reference to a cause of some sort, which may be supposed to attend our feelings of every kind, internal as well as external, when considered as changes or new phenomena. It is not, however, from any peculiar power, to be distinguished by the name of perception, that this complex notion of extended resistance appears to me to arise, but from the union of our notion of extension, acquired by the mere remembrance of various progressive series of feelings, with the notion of resistance, when an accustomed series of muscular feelings without any change of circumstances, in the mind itself, is interrupted by that peculiar and very different muscular feeling which arises from impeded effort. Perception, in short, in all our senses, is nothing more than the association of this complex notion with our other sensations—the notion of something extended and resisting, suggested by these sensations, when the sensations themselves have previously arisen; and suggested in the same manner, and on the same principle, as any other associate feeling suggests any other associate feeling.

It is very evident that perception, in Dr Reid's sense, is not the mere reference to a cause of some sort, for it would then be as comprehensive as all the feelings or changes of the mind,—our hope, fear, anger, pity,—which we ascribe to some cause or antecedent, as much as our tastes and smells; it is the reference of certain feelings to a corporeal cause, that is say, to a cause extended and resisting. If, for example, without any previous knowledge of external things, on the first sensation of fragrance, or sweetness, or sound, or colour, we could be supposed to be capable of believing that there was some cause of this new state of our being, this would not be perception, in the sense in which he uses that term; and yet but for our organ of touch, or at least but for feelings which are commonly ascribed to that organ, it would be manifestly impossible for us to make more than this vague and general inference. When a rose is present, we find, and have uniformly found, that a certain sensation of fragrance arises, which ceases when the rose is removed. The influence of association, therefore, operates in this, as in every other case of ordinary co-existence. We do not merely suppose that the sensation has some cause, as we believe that our joys and sorrows have a cause, but we ascribe the fragrance to the external substance, the presence of which we have found to be so essential to the production of it. Perception in every case, as I have said, in which it is to be distinguished from the prior sensation, is a reference of this prior sensation to a material cause;—and this complex notion of a material cause,—that is to say, of something extended and resisting,—mere smell, mere taste, mere hearing, mere vision, never could have afforded. I have already explained how this notion of matter, as it appears to me, is produced, or may be imagined to be produced. A train of muscular feelings has been frequently repeated, so that the series has become familiar to the infant, constituting in its remembrance the notion of a certain progressive length.—When all the known antecedent circumstances have been the same, the well-known series is suddenly broken, so as to excite in the mind of the infant the notion of a cause which is not in itself;—this cause, which is something foreign to itself, is that which excites the particular muscular feeling of resistance,—and it is combined with the notion of a certain length, because it uniformly supplies the place of what has been felt as a certain length, so as at last, by the operation of the common laws of association, to become truly representative of it, or rather to involve it in one complex feeling, in the same manner as colour, in vision, seems to involve whole miles of distance. Such is all that seems to me to constitute what Dr Reid would term perception, even with respect to the feelings commonly termed tactual;—and in all the other classes of sensations it is obviously nothing more than the suggestion of these associate feelings, in the same way as any other feelings, in our trains of thought and emotions, are suggested by those conceptions or other feelings which have frequently accompanied them.—It is sufficient to think of a mind, possessing all the other susceptibilities of sensation, but those which give us the perceptions commonly ascribed to touch, to be sensible how truly what we term perception in the other senses, is the mere suggestion of these. If we were capable only of smelling,—or had no other sensations than those of mere taste, mere sound, mere colour,—what perception could we have had of a material cause of these sensations?—and if it be to the mere suggestion of the object of another sense that we owe what is termed perception in all these sensations,—in what circumstance does the reference of these to a resisting and extended substance, differ from any other of the common references which the principle of association enables us to make?

“Sensation,” says Dr Reid, “can be nothing else than it is felt to be. Its very essence consists in being felt; and when it is not felt, it is not. There is no difference between the sensation and the feeling of it; they are one and the same thing.”[110] But this is surely equally true, of what he terms perception, which, as a state of mind, it must be remembered, is, according to his own account of it, as different from the object perceived, as the sensation is. We may say of the mental state of perception too, in his own language, as indeed we must say of all our states of mind, whatever they may be, that it can be nothing else than it is felt to be. Its very essence consists in being felt; and when it is not felt, it is not. There is no difference between the perception and the feeling of it; they are one and the same thing. The sensation, indeed, which is mental, is different from the object exciting it, which we term material; but so also is the state of mind which constitutes perception; for Dr Reid was surely too zealous an opponent of the systems, which ascribe every thing to mind alone, or to matter alone, to consider the perception as itself the object perceived. That in sensation, as contradistinguished from perception, there is no reference made to an external object, is true; because, when the reference is made, we then use the new term of perception; but that in sensation there is no object distinct from that act of the mind by which it is felt; no object independent of the mental feeling, is surely a very strange opinion of this philosopher; since what he terms perception, is nothing but the reference of this very sensation to its external object. The sensation itself he certainly supposes to depend on the presence of an external object, which is all that can be understood, in the case of perception, when we speak of its objects, or, in other words, of those external causes, to which we refer our sensations; for the material object itself, he surely could not consider as forming a part of the perception which is a state of the mind alone. To be the object of perception, is nothing more than to be the foreign cause or occasion, on which this state of the mind directly or indirectly arises; and an object, in this only intelligible sense, as an occasion, or cause of a certain subsequent effect, must on his own principles, be equally allowed to sensation. Though he does not inform us, what he means by the term object, as peculiarly applied to perception—(and indeed, if he had explained it, I cannot but think that a great part of his system, which is founded on the confusion of this single word, as something different from a mere external cause of an internal feeling must have fallen to the ground,)—he yet tells us, very explicitly, that to be the object of perception, is something more than to be the external occasion, on which that state of the mind arises which he terms perception; for, in arguing against the opinion of a philosopher, who contends for the existence of certain images or traces in the brain, and yet says, “that we are not to conceive the images or traces in the brain to be perceived, as if there were eyes in the brain; these traces are only occasions, on which, by the laws of the union of soul and body, ideas are excited in the mind; and, therefore, it is not necessary, that there should be an exact resemblance between the traces and the things represented by them, any more than that words or signs should be exactly like the things signified by them:”[111]—He adds, “These two opinions, I think cannot be reconciled. For if the images or traces in the brain are perceived, they must be the objects of perception, and not the occasions of it only. On the other hand, if they are only the occasions of our perceiving, they are not perceived at all.”[112]—Did Dr Reid, then, suppose that the feeling, whatever it may be, which constitutes perception as a state of the mind, or, in short, all of which we are conscious in perception, is not strictly and exclusively mental, as much as all of which we are conscious in remembrance, or in love, or hate;—or did he wish us to believe that matter itself, in any of its forms, is, or can be, a part of the phenomena or states of the mind;—a part therefore of that mental state or feeling which we term a perception? Our sensations like our remembrances or emotions, we refer to some cause or antecedent. The difference is, that in the one case we consider the feeling as having for its cause some previous feeling or state of the mind itself; in the other case we consider it as having for its cause something which is external to ourselves, and independent of our transient feelings,—something which, in consequence of former feelings suggested at the moment, it is impossible for us not to regard as extended and resisting.—But still what we thus regard as extended and resisting, is known to us only by the feelings which it occasions in our mind. What matter, in its relation to the percipient mind, can be, but the cause or occasion, direct or indirect, of that class of feelings which I term sensations or perceptions, it is absolutely impossible for me to conceive.

The percipient mind, in no one of its affections, can be said to be the mass of matter which it perceives, unless the separate existence, either of matter or of mind, be abandoned by us, the existence of which, Dr Reid would have been the last of philosophers to yield. He acknowledges that our perceptions are consequent on the presence of external bodies, not from any necessary connexion subsisting between them, but merely from the arrangement which the Deity, in his wisdom, has chosen to make of their mutual phenomena; which is surely to say, that the Deity has rendered the presence of the external object the occasion of that affection of the mind, which is termed perception; or, if it be not to say this, it is to say nothing. Whatever state of mind perception may be; whether a primary result of a peculiar power, or a mere secondary reference of association that follows the particular sensation, of which the reference is made, it is itself, in either view of it, but a state of the mind; and to be the external occasion or antecedent of this state of mind, since it is to produce, directly or indirectly, all which constitutes perception, is surely, therefore, to be perceived, or there must be something in the mere word perceived, different from the physical reality which it expresses.