-- Chapter 2 --

Since we are sensible that we see and hear, we cannot but be sensible that we see by sight or by some other sense; but, if we see by some other sense, then it will be perceptive of sight and colour, the subject of sight; and thus there will be either two senses for the same office, or the sight itself will be the percipient. If, besides, there is some other than the visual sense for sight, we shall have to admit an infinite series of perceptions, or else this other sense, whatever it may be, will be the visual percipient; and this might as well have been conceded to the first sense. But here there is a difficulty—if to perceive by sight is seeing, and if that which is seen is colour or something having colour, then, if any sense is to see that which sees, that sense must first have colour. It is then manifest that perception by sight is not a single perception; for even when we may not see, it is still by sight that we judge both of darkness and light, although not in the same manner. That, moreover, which sees, must have been already imbued with colour, since each sentient organ must be receptive of the object of perception without its matter ; and this accounts for impressions and images being still present in the sentient organs, after objects have been withdrawn.

The action of the object of perception is one and the same with that of the sense, although they differ in mode of being—I mean, for example, sound in action and hearing in action ; for it may be that an individual, endowed with hearing, does not hear, as that a sonorous body does not give out sound. But when an individual, capable of hearing, listens, and when that which is sonorous gives out sound, then hearing in action coincides with sound in action, and the one may strictly be termed hearing, the other sound. If motion, production, and impression, are in the product, it follows that sound and hearing, in an active state, must pre-exist in hearing in a potential state; for the action of the creative and the motive exists, naturally, in that which is to be acted upon. It is, therefore, no way necessary that the motor should be itself in motion. The action, then, of the sonorous body is sound or sounding, that of the auditory sense is hearing or audition; for hearing is double as sound is double, and the same applies to other senses and perceptions. Since production and impression are, not in that which acts but, in that which is impressed, so the action of the object of perception and the sensibility is in the sentient being. But, while for some senses these two states have been specially distinguished by names, as sound and hearing, there are others for which one or other state is without appellation—the action of vision, for instance, is called sight, but the action of colour is unnamed; the action of the sapid sense is called taste, while that of savour is without appellation.

Since the action of the object of perception and that of the sentient being is one and the same, although different in mode of acting, it follows that hearing and sound, in this sense, must together be lost, or together be preserved; and this is true of taste and savour, and other senses and functions; but yet it does not hold good of those relations in potentiality.

The earlier physiologists have expressed themselves ill upon the subject, as they thought that there can be neither black nor white without sight, nor savour without Taste. And yet what they said was in part right and in part wrong; for as senses and sentient impressions have a twofold acceptation, according to their state of potentiality or activity, so what was advanced by them may be applicable to the one state, and inapplicable to the other. The fact is, those writers reasoned absolutely upon conditions, which do not admit of being so dealt with. If a voice of any kind is harmony, and if voice and hearing are, in one sense, the same, and, in another sense, not the same, then, as harmony is proportion, it follows that hearing must be proportion also. And hence it comes that every sound in excess, whether acute or grave, perverts the hearing, as every savour in excess does the taste; and every colour over-bright or dark dulls the sight, as every odour excessively pungent, whether grateful or offensive, does the smell, as if shewing that sensibility is a kind of proportion. Thus, qualities, as acid or sweet or saline, are agreeable whenever they are reduced, pure and unmixed, to a due proportion; for it is this only which renders them grateful. To speak generally, harmony is a combination of tones rather than the acute or the grave singly, as for the Touch, the warmed or cooled is genial, rather than the hot or cold, simply; for, as sensibility is proportion, so qualities, in excess, pain or pervert the senses.

Each sense is perceptive of its own appointed subjects, is innate in its own organ, as a special organ, and judges of the distinctions of qualities, as sight judges of white and black; taste of bitter and sweet, and so as to other senses and qualities. But since we judge of white, sweet, and each other quality by its relation to each sense, by what do we perceive that qualities differ? Now, it is evident that it must be by some sense, as the impressions are all sentient; and equally so that the flesh cannot be that final organism, as in order to judge of qualities it must, of necessity, first touch bodies. Neither is it admissible that, by different senses, we judge sweet to be different from white, as both qualities must be apparent to some single faculty; for, otherwise, it would be as if I should perceive one quality and you perceive another, and thus make it evident that they are different from one another. But it is here required that the same individual should perceive that they are different, for the sweet is different from the white, and what he perceives that he says; and thus, what he says that he thinks and perceives. It is then evident that we cannot, by different senses, judge of different qualities, as also, from what follows, that we cannot judge of them in a separate portion of time. Neither can an opinion be in a separate portion of time; for just as it is the same individual who says that good is other than bad, so when he says that the one is different from the other, he implies that the other is equally so, and does not employ the term when loosely—he does not use it, I mean, in the sense of now, in the phrase, "now I say that the object is different," without implying that it is different now. But, here, it is the same individual who employs the term now, and says that objects are different now and because now; for the impressions are coincident, as they are inseparable, and as the time is indivisible. It cannot, however, be, that the same individual, in so far as indivisible, should be subject to contrary impulses in time which is indivisible; yet if sweetness move sensation or thought in one way, bitterness must move them in an opposite, and whiteness in some other direction. Can, then, that which judges be, numerically, indivisible and inseparable, yet separable in its mode of being? If so, then, in some way, as divisible, it may perceive divisible, and, in some way, as indivisible, it may perceive indivisible qualities; for in its mode of being it is separable, but, locally and numerically, it is inseparable. But is not this impossible? The same may, in potentiality, be indivisible and divisible and be the contraries; but not so in mode of being, as it is divisible in action, and cannot possibly be at once white and black, nor be simultaneously impressed by the forms of those colours, provided sensation and thought are such as we have said they are. But it is with this, as with that which some call a point, and which, in so far as it is one or dual, is indivisible or divisible. Thus, in so far as that which judges is one, it is indivisible, and its perceptions are simultaneous; and in so far as it is divisible, it employs the same point twice, simultaneously. In so far, then, as it employs the boundary as two, it judges of two things by it and perceives that they are distinct, as the boundaries of the line are distinct; but in so far as it is one, it judges by one act, and judges simultaneously.

Let what has been said then suffice for the definition of that principle, by which we maintain that an animal is made a sentient being.