question is precisely what kinds of changing molecular processes — thermic, electrical, chemical, vital, etc. — take place, and in what related convolutions and parts of convolutions, corresponding to all the changes in conscious thoughts and feelings. To make any advance toward answering this question, "nerve-physiology" and the "localization of cerebral function" must go cautiously hand in hand. But the assumption of the congruity is in no wise dependent upon the advance of science. It was made by Spinoza as rigidly as it can be made by any one. Yet we are almost infinitely farther off to-day than his contemporaries seemed to themselves to be, from a satisfactory scientific knowledge of this congruity, without any metaphysical assumptions whatsoever.
Of the conception of psychology, its nature, problems, and method, which is proposed in these volumes, and of the defence in detail of this conception, the following statements seem to me true: The conception is such, and so narrow, that a consistent adherence to it compels us to admit the utter impossibility of establishing psychology as a natural science. It excludes almost all the really scientific data and conclusions; it includes only those data and conjectures which are most remote from genuine science. But the author does not adhere to this conception. Neither does he adhere to his determination to exclude metaphysics. The metaphysics of mind is often admitted, with confession of apparent inconsistency ; the metaphysics of physics is freely admitted, generally without confession or apparent consciousness of inconsistency. As descriptive science, the work is admirable; for its author is a born, and a thoroughly trained, psychologist. As explanatory science also, — wherever it departs most widely from its own conception — it is generally admirable. As explanatory science, without metaphysics, in the form of the aforesaid "blank unmediated correspondences," it is, at best, not science at all.
These general conclusions I shall now briefly test by application to two or three particular problems. And, first of all, let us inquire how Professor James solves, by his method, the problem of "the consciousness of self" (chap. x). Preceding the chapter devoted to the "finer work" of tracing the psychology of
