The Help given by Association by Similarity.—It is probable, also, that man's superior association by similarity has much to do with those discriminations of character on which his higher flights of reasoning are based. As this latter is an important matter, and as little or nothing was said of it in the chapter on Discrimination, it behooves me to dwell a little upon it here.
What does the reader do when he wishes to see in what the precise likeness or difference of two objects lies? He transfers his attention as rapidly as possible, backwards and forwards, from one to the other. The rapid alteration in consciousness shakes out, as it were, the points of difference or agreement, which would have slumbered forever unnoticed if the consciousness of the objects compared had occurred at widely distant periods of time. What does the scientific man do who searches for the reason or law embedded in a phenomenon? He deliberately accumulates all the instances he can find which have any analogy to that phenomenon; and, by simultaneously filling his mind with them all, he frequently succeeds in detaching from the collection the peculiarity which he was unable to formulate in one alone; even though that one had been preceded in his former experience by all of those with which he now at once confronts it. These examples show that the mere general fact of having occurred at some time in one's experience, with varying concomitants, is not by itself a sufficient reason for a character to be dissociated now. We need something more; we need that the varying concomitants should in all their variety be brought into consciousness at once. Not till then will the character in question escape from its adhesion to each and all of them and stand alone. This will immediately be recognized by those who have read Mill's Logic as the ground of Utility in his famous 'four methods of experimental inquiry,' the methods of agreement, of difference, of residues, and of concomitant variations. Each of these gives a list of analogous instances out of the midst of which a sought-for character may roll and strike the mind.
Now it is obvious that any mind in which association by similarity is highly developed is a mind which will spontaneously form lists of instances like this. Take a present fact A, with a character m in it. The mind may fail at first to notice this character m at all. But if A calls up C, D, E, and F,—these being phenomena which resemble A in possessing m, but which may not have entered for months into the experience of the animal who now experiences A, why, plainly, such association performs the part of the reader's deliberately rapid comparison referred to above, and of the systematic consideration of like cases by the scientific investigator, and may lead to the noticing of m in an abstract way. Certainly this is obvious; and no conclusion is left to us but to assert that, after the few most powerful practical and æsthetic interests, our chief help towards noticing those special characters of phenomena which, when once possessed and named, are used as reasons, class names, essences, or middle terms, is this association by similarity. Without it, indeed, the deliberate procedure of the scientific man would be impossible: he could never collect his analogous instances. But it operates of itself in highly-gifted minds without any deliberation, spontaneously collecting analogous instances, uniting in a moment what in nature the whole breadth of space and time keeps separate, and so permitting a perception of identical points in the midst of different circumstances, which minds governed wholly by the law of contiguity could never begin to attain.
Fig. 66.
[Figure 66] shows this. If m, in the present representation A, calls up B, C, D, and E, which are similar to A in possessing it, and calls them up in rapid succession, then m, being associated almost simultaneously with such varying concomitants, will 'roll out' and attract our separate notice.
If so much is clear to the reader, he will be willing to admit that the mind in which this mode of association most prevails will, from its better opportunity of extricating characters, be the one most prone to reasoned thinking; whilst, on the other hand, a mind in which we do not detect reasoned thinking will probably be one in which association by contiguity holds almost exclusive sway.
Geniuses are, by common consent, considered to differ from ordinary minds by an unusual development of association by similarity. One of Professor Bain's best strokes of work is the exhibition of this truth. It applies to geniuses in the line of reasoning as well as in other lines.
The Reasoning Powers of Brutes.—As the genius is to the vulgarian, so the vulgar human mind is to the intelligence of a brute. Compared with men, it is probable that brutes neither attend to abstract characters, nor have associations by similarity. Their thoughts probably pass from one concrete object to its habitual concrete successor far more uniformly than is the case with us. In other words, their associations of ideas are almost exclusively by contiguity. So far, however, as any brute might think by abstract characters instead of by the association of concretes, he would have to be admitted to be a reasoner in the true human sense. How far this may take place is quite uncertain. Certain it is that the more intelligent brutes obey abstract characters, whether they mentally single them out as such or not. They act upon things according to their class. This involves some sort of emphasizing, if not abstracting, of the class-essence by the animal's mind. A concrete individual with none of his characters emphasized is one thing; a sharply conceived attribute marked off from everything else by a name is another. But between no analysis of a concrete, and complete analysis; no abstraction of an embedded character, and complete abstraction, every possible intermediary grade must lie. And some of these grades ought to have names, for they are certainly represented in the mind. Dr. Romanes has proposed the name recept, and Prof. Lloyd Morgan the name construct, for the idea of a vaguely abstracted and generalized object-class. A definite abstraction is called an isolate by the latter author. Neither construct nor recept seems to me a felicitous word; but poor as both are, they form a distinct addition to psychology, so I give them here. Would such a word as influent sound better than recept in the following passage from Romanes?