As long as man is thus attached to the earth and to places on the earth, as long as nostalgia and plain homesickness hold him and draw him inevitably back to the haunts and places he knows best, he will never fully realize that other characteristic ambition of mankind, namely, to move freely and untrammeled over the surface of mundane things, and to live, like pure spirit, in his mind and in his imagination alone. I mention these things merely to emphasize a single point, namely, mind is an incident of locomotion. The first and most convincing indication of mind is not motion merely, but, as I have said, locomotion. The plants don’t locomote, don’t move through space; they respond more or less to stimulation, even though they have no nerves, but they do not move through space, certainly not of their own motion. And when they do move, they have no goal, no destination, and that is because they have no imagination. Now it is characteristic of animals that they can and do change their spots. The ability to do this implies that they are able not merely to wag a tail or move a limb, but that they are able to co-ordinate and mobilize the whole organism in the execution of a single act. Mind, as we ordinarily understand it, is an organ of control. It does not so much initiate new movements as co-ordinate impulses, and so mobilize the organism for action; for mind, in its substantive aspect, is just our disposition to act; our instincts and attitudes, in other words. Mental activity begins on the periphery, with stimuli which are antecedent to, but ultimately discharged in, actions. But mind in the transitive, verbal aspect is a process by which, as we say, we “make up our minds” or change them; that is to say, it is a process by which we define the direction in which we are going to move, and locate in imagination the goal that we intend to seek. Plants carry on, apparently, all the processes of metabolism which are characteristic of animals—these are, in fact, what we mean by the vegetative processes—but they do not go anywhere. If the plants have minds, as some people assume they do, they must be of that brooding, vegetative sort characteristic of those mystics who, quite forgetful of the active world, are absorbed in the contemplation of their own inner processes. But the characteristic of the animal, and of the higher types of animal—everything above the oyster, in fact—is that they are made for locomotion and for action. Furthermore, it is in the processes of locomotion—involving, as they do, change of scene and change of location—that mankind is enabled to develop just those mental aptitudes most characteristic of man, namely, the aptitude and habit of abstract thought.