The stimulus which originally pulled the trigger may have been a series of pictures in the mind aroused by printed or spoken words. These pictures fade and are hard to keep steady; their contours and their pulse fluctuate. Gradually the process sets in of knowing what you feel without being entirely certain why you feel it. The fading pictures are displaced by other pictures, and then by names or symbols. But the emotion goes on, capable now of being aroused by the substituted images and names. Even in severe thinking these substitutions take place, for if a man is trying to compare two complicated situations, he soon finds exhausting the attempt to hold both fully in mind in all their detail. He employs a shorthand of names and signs and samples. He has to do this if he is to advance at all, because he cannot carry the whole baggage in every phrase through every step he takes. But if he forgets that he has substituted and simplified, he soon lapses into verbalism, and begins to talk about names regardless of objects. And then he has no way of knowing when the name divorced from its first thing is carrying on a misalliance with some other thing. It is more difficult still to guard against changelings in casual politics.
For by what is known to psychologists as conditioned response, an emotion is not attached merely to one idea. There are no end of things which can arouse the emotion, and no end of things which can satisfy it. This is particularly true where the stimulus is only dimly and indirectly perceived, and where the objective is likewise indirect. For you can associate an emotion, say fear, first with something immediately dangerous, then with the idea of that thing, then with something similar to that idea, and so on and on. The whole structure of human culture is in one respect an elaboration of the stimuli and responses of which the original emotional capacities remain a fairly fixed center. No doubt the quality of emotion has changed in the course of history, but with nothing like the speed, or elaboration, that has characterized the conditioning of it.
People differ widely in their susceptibility to ideas. There are some in whom the idea of a starving child in Russia is practically as vivid as a starving child within sight. There are others who are almost incapable of being excited by a distant idea. There are many gradations between. And there are people who are insensitive to facts, and aroused only by ideas. But though the emotion is aroused by the idea, we are unable to satisfy the emotion by acting ourselves upon the scene itself. The idea of the starving Russian child evokes a desire to feed the child. But the person so aroused cannot feed it. He can only give money to an impersonal organization, or to a personification which he calls Mr. Hoover. His money does not reach that child. It goes to a general pool from which a mass of children are fed. And so just as the idea is second hand, so are the effects of the action second hand. The cognition is indirect, the conation is indirect, only the effect is immediate. Of the three parts of the process, the stimulus comes from somewhere out of sight, the response reaches somewhere out of sight, only the emotion exists entirely within the person. Of the child's hunger he has only an idea, of the child's relief he has only an idea, but of his own desire to help he has a real experience. It is the central fact of the business, the emotion within himself, which is first hand.