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.
Within limits that vary, the emotion is transferable both as regards stimulus and response. Therefore, if among a number of people, possessing various tendencies to respond, you can find a stimulus which will arouse the same emotion in many of them, you can substitute it for