A widely-spread opinion (which has been held by such men as Schopenhauer, Spencer, Hartmann, Wundt, Helmholtz, and lately interestingly pleaded for by M. Binet)[118] will have it that perception should be called a sort of reasoning operation, more or less unconsciously and automatically performed. The question seems at first a verbal one, depending on how broadly the term reasoning is to be taken. If, every time a present sign suggests an absent reality to our mind, we make an inference; and if every time we make an inference we reason; then perception is indubitably reasoning. Only one sees no room in it for any unconscious part. Both associates, the present sign and the contiguous things which it suggests, are above-board, and no intermediary ideas are required. Most of those who have upheld the thesis in question have, however, made a more complex supposition. What they have meant is that perception is a mediate inference, and that the middle term is unconscious. When the sensation which I have called 'this' (p. 83, supra) is felt, they think that some process like the following runs through the mind:
'This' is M;
but M is A;
therefore 'this' is A.[119]
Now there seem no good grounds for supposing this additional wheelwork in the mind. The classification of 'this' as M is itself an act of perception, and should, if all perception were inference, require a still earlier syllogism for its performance, and so backwards in infinitum. The only extrication from this coil would be to represent the process in altered guise, thus:
'This' is like those;
Those are A;
Therefore 'this' is A.
The major premise here involves no association by contiguity, no naming of those as M, but only a suggestion of unnamed similar images, a recall of analogous past sensations with which the characters that make up A were habitually conjoined. But here again, what grounds of fact are there for admitting this recall? We are quite unconscious of any such images of the past. And the conception of all the forms of association as resultants of the elementary fact of habit-worn paths in the brain makes such images entirely superfluous for explaining the phenomena in point. Since the brain-process of 'this,' the sign of A, has repeatedly been aroused in company with the process of the full object A, direct paths of irradiation from the one to the other must be already established. And although roundabout paths may also be possible, as from 'this' to 'those,' and then from 'those' to 'A' (paths which would lead to practically the same conclusion as the straighter ones), yet there is no ground whatever for assuming them to be traversed now, especially since appearances point the other way. In explicit reasoning, such paths are doubtless traversed; in perception they are in all probability closed. So far, then, from perception being a species of reasoning properly so called, both it and reasoning are co-ordinate varieties of that deeper sort of process known psychologically as the association of ideas, and physiologically as the law of habit in the brain. To call perception unconscious reasoning is thus either a useless metaphor, or a positively misleading confusion between two different things.
One more point and we may leave the subject of Perception. Sir Wm. Hamilton thought that he had discovered a 'great law' which had been wholly overlooked by psychologists, and which, 'simple and universal,' is this: "Knowledge and Feeling,—Perception and Sensation, though always coexistent, are always in the inverse ratio of each other." Hamilton wrote as if perception and sensation were two coexistent elements entering into a single state of consciousness. Spencer refines upon him by contending that they are two mutually exclusive states of consciousness, not two elements of a single state. If sensation be taken, as both Hamilton and Spencer mainly take it in this discussion, to mean the feeling of pleasure or pain, there is no doubt that the law, however expressed, is true; and that the mind which is strongly conscious of the pleasantness or painfulness of an experience is ipso facto less fitted to observe and analyze its outward cause.[120] Apart from pleasure and pain, however, the law seems but a corollary of the fact that the more concentrated a state of consciousness is, the more vivid it is. When feeling a color, or listening to a tone per se, we get it more intensely, notice it better, than when we are aware of it merely as one among many other properties of a total object. The more diffused cerebral excitement of the perceptive state is probably incompatible with quite as strong an excitement of separate parts as the sensational state comports. So we come back here to our own earlier discrimination between the perceptive and the sensational processes, and to the examples which we gave on pp. 80, 81.[121]