This capacity or tendency the cats and dogs do, in my opinion, possess, though in a far less degree than the average child. They also suffer from lack of stimuli to the exercise of the capacity. Their confinement, for the most part, to the direct sensory experience of things and acts, is due in part to the weakness of the capacity or tendency of their neurones to act in great detail, and in part to the lack of such stimuli as visual exploration of things in detail, manual manipulation of the same thing in many ways, and the identification of elements of objects and acts by language. They get few free ideas because they are less ready than man to get them under the same conditions and because their instinctive behavior and social environment offer conditions that are less favorable. The task of getting an animal to have some free ideational representative of a red loop or of pushing up a button with the nose may be compared with that of getting a very stupid boy to have a free ideational representative of acceleration, or of the act of sounding _th_. The difference between them and man which is so emphasized in the text, though real and of enormous practical importance, is thus not at all a mysterious gap or trackless desert. We can see our way from animal to human learning. [16] A man may learn to swim from the general feeling, “I want to be able to swim.” While learning, he may think of this desire, of the difficulties of the motion, of the instruction given him, or of anything which may turn up in his mind. This is all extraneous and is not concerned in the acquisition of the association. Nothing like it, of course, goes on in the animal’s mind. Imagine a man thrown into the water repeatedly, and gradually floundering to the shore in better and better style until finally, when thrown in, he swims off perfectly, and deprive the man of all extraneous feelings, and you have an approximate homologue of the process in animals. He feels discomfort, certain impulses to flounder around, some of which are the right ones to move his body to the shore. The pleasure which follows stamps in these, and gradually the proper movements are made immediately on feeling the sense-impression of surrounding water. [17] See 10 in A, 3 in A, 10 in D; 10 in C, 4 in C, 3 in C; 6, 2, 5, 4 in E; 4 in F; 10 in H, 3 in H; 3, 4, 5, in I; 4 in G, 3 in G; 3 in K; 10 in L; dog 1 in N and CC; dog 1 in G and O. [18] This chapter appeared originally in the _Psychological Review_, Vol. VI, No. 3. [19] This double rating is necessary because of the fact that the chick often gives several distinct pecks in a single reaction. The ‘times reacted to’ mean the number of different times that the chicks noticed the color.