subconscious hie would have found traces there of the activities which were all the while affecting the area of greatest vividness.
Not only is consciousness as a whole thus correlated to a system of physical forces, but we find that its several elements are also related to certain subordinate systems of forces which, while forming part of that total, have a certain degree of independence. It is known, for example, that the activities which take place in the occipital or hinder portion of the cortex are accompanied by sensations and ideas of color; those that take place in the temporal region, in the neighborhood of the ear, have to do with sensations and ideas of sound; those of the Rolandic region, which forms an archlike band passing over the brain from a point a little in front of the ear, are probably the basis of sensations and ideas of movements as felt. Since the awakening of these latter tends to produce or sustain the movement in question, and since volition is but another name for the initiation of a movement through an idea representing it or something with which it is associated, this is also a region essential to the performance of voluntary movements. And it is probable that all the definite qualities of sensation and the corresponding ideas are related to more or less well defined portions of the cortex. But we know that even our very simple ideas—as those of a rose, or a book, or a man—involve elements drawn from many of these sources. We must then suppose that the idea of a rose depends upon a co-ordination of processes which, although situated in different portions of the brain, act together in the production of this idea. As my thought flits from the color to the fragrance, to the touch, to the plucking of the rose, so do the pulses of energy pass along the conducting fibers from the region of vision to that of smell, to that of touch, to that of movement. Further, as the rose is to me a relatively stable thing, we must suppose that these physical processes are not merely co-ordinated for the time being, but are organized into a quite permanent system which retains its coherence and existence as a system as long as the idea of a rose remains to me one and the same idea, although consisting of unlike mental elements.
I can not undertake to work out in detail many of the more complex organizations or systems which we can detect in mind. To do that would be to write a treatise on psychology, and my only object at present is to make clear the conceptions of coordination and organization. Yet to two of these more complex forms—and they are unfortunately the most complex of all—I must make some reference, since a comprehension of them is presupposed in the application of this theory to the curious phenomena which we wish to explain.
I have shown that the state of consciousness at any given mo-
