physical assumptions as those shared in by all other students of psychology. But the author's attempts to bring this treatment into accord with his own conception of psychology as a natural science, by pointing out "blank unmediated correspondences" between brain-processes and intuitions and conceptions of space-qualities and space-relations is — so it seems to me a complete failure. "Overlappings" in cerebral commotions, which shall be in such correspondence to our perceptions, cannot be pointed out; all the modern science of perception seems to me to indicate this. But if they could, I fear that a large number of thoughtful minds, afflicted — no doubt — with the incurable pest of an inclination to metaphysics, would still feel the need of retreat to some "Kantian machine-shop," or some place where "glib Herbartian jargon" is manufactured, or "cheap and nasty editions" of the soul are issued to deceive the unscientific.
I will speak of one point more, and that only very briefly. In his final chapter Professor James shows the most splendid courage of his convictions. Here he applies his view of psychology as a natural science to the explanation of the rise and binding authority of so-called "Necessary Truths — Effects of Experience." This title is extended (II, p. 629 f.) over seven kinds of "Elementary Mental Categories." Among these are all the instincts and ideas of worth, aesthetic ideas, as well as ideas of time, space, number, identity, causal dependence, and the fundamental laws of logic.
Mr. Spencer's attempt to account for the origin of so-called necessary truths according to principles of cerebral evolution is keenly criticised and promptly rejected by Professor James. Personally, the author has no objections to the terms "intuitive," "innate," or "a priori" "There is," says he (p. 661) "no denying the fact that the mind is filled with necessary and eternal relations which it finds between certain of its ideal conceptions, and which form a determinate system, independent of the order of frequency in which experience may have associated the conception’s originals in time and space." Yet this filling of the mind with "necessary and eternal relations" between "ideal conceptions,"
