"Introspection will convince us—perhaps to our own astonishment—how large a part of our thinking operations are conducted through the raising and recalling of remembered images."[1]
But it may be objected that one can not spend one's time in day-dreams, or in the mere pleasures of memory and imagination. You say that reason and action are the real things of life. Have these, too, such a physical as well as a mental basis? Let us follow one or two simple acts of reasoning for a moment. When you see a rose, although it is at a distance from you, you will admit that you believe it to have a fragrance. You conclude that it has, because in your former experience with roses you remember that, when you have held one near, you have always perceived its perfume. The association of the sight of the rose and the fragrance has become fixed in your mind, and when you see it your thought is led along to its fragrance, and you draw the conclusion that the rose is fragrant. That is an act of reasoning. Supposing some one says that the rose sounds sweetly. You have no association between such things as roses and sounds in nature, and your thought refuses to run along where there is no track. You reply that he is talking nonsense—that is, the unreasonable.
Or take another example. Your dog sees you go into the hall and take up your hat and cane; he at once jumps up and runs about, showing by his action that he has come to the conclusion that you are off for a walk, and that he wants to go with you. What is the basis of this process of reasoning? He has a mental image of this act of yours, associated with another mental image of a run on the lawn, and the first calls up to his mind the second. In his experience one act has usually followed the other, and he draws the conclusion that you are going out where he can run. You say at once that the dog has reasoned correctly. It may even be true that the dog has learned to understand language. Many dogs know the word "out," and it calls up to them as distinct a mental image as your act of putting on your hat. Sir John Lubbock has even taught his dog to read;[2] for, by showing him a large card on which the word "water" was printed, every time he gave him a drink, an association was established in the dog's mind between the card and the act; and, finally, when the dog wanted a drink, he would bring the card in his mouth to his master. Ten such different words were taught him, and he rarely made a mistake. So that the understanding of speech and of writing and the act of reasoning, so far as simple conclusions go, from the recollection of mental images, may be granted to animals as well as to man. And these acts of reasoning, like those
