CHAPTER II

SUBJECT AND OBJECT IN SENSATION

             SINCE WE PERCEIVE THAT WE SEE AND HEAR, WE MUST see that we see either by sight or by another sense.§ 584

             And if by another sense, then either this is the sense by which we see, or another sense altogether. But [then] the same sense will bear on the coloured object and the sense of sight. Hence, either there will be two senses for one object, or one sense must be its own object.§ 585

             Further, if the sense perceptive of sight is other, either there is a process to infinity, or there must be some sense which takes account of its own operation: hence it is better to admit this in the first instance.§ 586

             Here is a problem: if to perceive by sight is to see, and colour, or what possesses it, is what is seen, then that which first sees must be coloured.§ 587

             It is clear, then, that 'to perceive by sight' has not only one meaning. For even when we are not seeing, it is by sight that we distinguish between light and dark, though not in the same way.§ 588

             Moreover, that which sees is, in a way, coloured; for each sensitive faculty is receptive of the sense-object without its material concomitant. Hence, in the absence of the sense-objects there remain sensations and phantasms in the sense-powers. The act of the sense-object and the sensation are one and the same: but these--I mean, for instance, sound in act or sight in act--are not identical in their being. For it happens that what has hearing does not hear all the time, and what has sound is not always sounding. But when that which is able to hear operates, and that which is able to sound sounds, both hearing in act and sound in act arise simultaneously. (Of which two, one might call one 'hearing', the other 'sounding'.)§§ 589-91

             If then movement and action and passion are in that which is acted upon, it follows that sound and hearing in act reside in that which is these potentially. For the act of what moves or causes is realised in the recipient; hence it is not necessary that what moves be itself in motion. The act of the sound-producing is therefore sound or a sounding; and of the hearing faculty, is hearing or audition. For 'hearing' and 'sounding' are both twofold. And the same reasoning applies to the other senses and their objects. For as the action and the reception are in the recipient, not in the agent, so the act of the sense-object and of the sense faculty are in the sensitive recipient. However, whereas both are named in some cases (as sounding and audition) in others one or the other is nameless. Vision is the act of seeing, but that of colour has no name; and tasting is the act of the tasting faculty, but the act of savour has no name.§§ 592-3

             Since the act of the sense-object and of the sense faculty is one and the same (though each has its own being) it is necessary that they pass away or remain simultaneously, as in the above-mentioned case of hearing and sounding; and, therefore, of taste and flavour and the rest. It is not, however, necessary to hold this of the potency.§ 594

             But on this point the earlier natural philosophers spoke erroneously, holding that there was no black or white without sight, no flavour without taste. In one way what they said was right, in another wrong. Inasmuch as both the sense-object and the sense-faculty exist in two ways, one in potency the other in act, what they alleged applies to the latter, but not to the former. But they made bald assertions about matters which call for distinctions.§§ 595-6

             Now, if voice is a harmony of some sort, and voice and the hearing of it are somehow one, and also, somehow, not one and the same; and if harmony is a proportion; then the hearing must be a kind of proportion. For this reason anything excessively shrill or deep destroys the hearing; and the same in flavours destroys the taste; and in colours, the sight, whether the excessively brilliant or the dark; and in smell, a strong odour, whether sweet or bitter; as if the sense were a certain proportion. Hence, too, those [savours] become delectable which, from having been pure and unmixed (e.g. the bitter or sweet or saline) are brought into a proportion. Then indeed they give pleasure. And in general what is compounded is more of a harmony than the sharp or low [sounds] alone; or in the case of touch, what can be both heated and chilled. Sense is a 'proportion' which is hurt or destroyed by extremes.§ 597-8