It is of course obvious that the influence of association extends to moral action as well. In general, our conduct follows the trend of established associations. We are likely to do in great moral crises about as we are in the habit of doing in small ones.
2. THE TYPES OF ASSOCIATION
Fundamental Law of Association.—Stated on the physiological side, the law of habit as set forth in the definition of association in the preceding section includes all the laws of association. In different phrasing we may say: (1) Neurone groups accustomed to acting together have the tendency to work in unison. (2) The more frequently such groups act together the stronger will be the tendency for one to throw the other into action. Also, (3) the more intense the excitement or tension under which they act together the stronger will be the tendency for activity in one to bring about activity in the other.
The corresponding facts may be expressed in psychological terms as follows: (1) Facts accustomed to being associated together in the mind have a tendency to reappear together. (2) The more frequently these facts appear together the stronger the tendency for the presence of one to insure the presence of the other. (3) The greater the tension, excitement or concentration when these facts appear in conjunction with each other, the more certain the presence of one is to cause the presence of the other.
Several different types of association have been differentiated by psychologists from Aristotle down. It is to be kept in mind, however, that all association types go back to the elementary law of habit-connections among the neurones for their explanation.
Association by Contiguity.—The recurrence in our minds of many of the elements from our past experience is due to the fact that at some time, possibly at many times, the recurring facts were contiguous in consciousness with some other element or fact which happens now to be again present. All have had the experience of meeting some person whom we had not seen for several months or years, and having a whole series of supposedly forgotten incidents or events connected with our former associations flood into the mind. Things we did, topics we discussed, trips we took, games we played, now recur at the renewal of our acquaintance. For these are the things that were contiguous in our consciousness with our sense of the personality and appearance of our friend. And who has not in similar fashion had a whiff of perfume or the strains of a song recall to him his childhood days! Contiguity is again the explanation.
At the Mercy of Our Associations.—Through the law thus operating we are in a sense at the mercy of our associations, which may be bad as well as good. We may form certain lines of interest to guide our thought, and attention may in some degree direct it, but one's mental make-up is, after all, largely dependent on the character of his associations. Evil thoughts, evil memories, evil imaginations—these all come about through the association of unworthy or impure images along with the good in our stream of thought. We may try to forget the base deed and banish it forever from our thinking, but lo! in an unguarded moment the nerve current shoots into the old path, and the impure thought flashes into the mind, unsought and unwelcomed. Every young man who thinks he must indulge in a little sowing of wild oats before he settles down to a correct life, and so deals in unworthy thoughts and deeds, is putting a mortgage on his future; for he will find the inexorable machinery of his nervous system grinding the hated images of such things back into his mind as surely as the mill returns to the sack of the miller what he feeds into the hopper. He may refuse to harbor these thoughts, but he can no more hinder their seeking admission to his mind than he can prevent the tramp from knocking at his door. He may drive such images from his mind the moment they are discovered, and indeed is guilty if he does not; but not taking offense at this rebuff, the unwelcome thought again seeks admission.
The only protection against the return of the undesirable associations is to choose lines of thought as little related to them as possible. But even then, do the best we may, an occasional "connection" will be set up, we know not how, and the unwelcome image stands staring us in the face, as the corpse of Eugene Aram's victim confronted him at every turn, though he thought it safely buried. A minister of my acquaintance tells me that in the holiest moments of his most exalted thought, images rise in his mind which he loathes, and from which he recoils in horror. Not only does he drive them away at once, but he seeks to lock and bar the door against them by firmly resolving that he will never think of them again. But alas! that is beyond his control. The tares have been sown among the wheat, and will persist along with it until the end. In his boyhood these images were given into the keeping of his brain cells, and they are only being faithful to their trust.
Association by Similarity and Contrast.—All are familiar with the fact that like tends to suggest like. One friend reminds us of another friend when he manifests similar traits of character, shows the same tricks of manner, or has the same peculiarities of speech or gesture. The telling of a ghost or burglar story in a company will at once suggest a similar story to every person of the group, and before we know it the conversation has settled down to ghosts or burglars. One boastful boy is enough to start the gang to recounting their real or imaginary exploits. Good and beautiful thoughts tend to call up other good and beautiful thoughts, while evil thoughts are likely to produce after their own kind; like produces like.
Another form of relationship is, however, quite as common as similars in our thinking. In certain directions we naturally think in opposites. Black suggests white, good suggests bad, fat suggests lean, wealth suggests poverty, happiness suggests sorrow, and so on.