H. MAUDSLEY'S BODY AXD WILL. 139 It is but fair to ask who or what possesses this internal sense. It cannot be brain ; for this is assumed to be, not the percipient, but the thing which produces the perceived impression. We seem compelled to postulate something very like what is commonly called a soul. Yet anything but this is the conclusion towards which Dr. Maudsley wished to lead us. The latter half of this chapter treats of our belief in an external world. One of the arguments urged involves the curious assump- tion that, if all reality consists in consciousness, the reality of each of us must be, not in our own consciousness, but in that of our neighbours. But the point mainly insisted on as proving that we have as good testimony to the external world as we have to our own existence, is the " necessary synthesis of Ego and Non- ego." Now it is of course obvious that, if "Ego" and "Non-ego" mutually imply each other, and if the " Non-ego " is identical with the " external world," we cannot logically admit the ex- istence of an " Ego " and yet deny the existence of an " external world ". But it is equally obvious that the nature of the " ex- ternal world " proved depends on the nature of the "Non-ego" with which it is identified. Unfortunately " Non-ego " is one of those words to which Dr. Maudsley attaches " no clear and definite ideas ". Sometimes it is used by him as synonymous with "motor" as distinguished from "passive" consciousness, some- times as equivalent to the so-called physical conditions of sensa- tion. Whichever of these two meanings we adopt, it is evident that the " external world " proved will be one which no man ever dreamed of denying. Before quitting the purely metaphysical division of the book, we must notice the author's own positive speculations. His funda- mental principle is that mind is a function of the organism. When molecular movement becomes sufficiently complicated, thought is the result. If we inquire how movement, merely by becoming complex, gives rise to something which is not movement, a hint is thrown out that the analog) 7 of chemical processes may solve our difficulty. Now this seems to be a suicidal argument. It is of course true that, for the chemist, there are properties in the compound, which cannot be accounted for as the resultant of the properties of the components. But these properties invariably depend on the peculiar quality of the effects produced by the com- pound on other things, and especially on our senses. Now what is this other thing, in which brain-movements, of sufficient com- plexity, set up such peculiar affections '? We are again thrown back on the old-fashioned hypothesis of an immaterial principle. The chief positive argument urged in favour of materialism is drawn from the existence of sub-conscious or unconscious mental processes. It seems to be assumed that these cannot be explained on purely psychological grounds. If a mental state is not " illumi- nated by consciousness," it must be an " insensible condition of body." Yet it is admitted that such states may be subjectively discovered.
