Page:Mind (New Series) Volume 9.djvu/260

246 CBITICAL NOTICES : the present writer at least feels both the vindication of idealistic principles and the exposure of " scientific " assumptions afforded by Prof. Ward to be in the main irrefragable that he regards the Gifford Lectures of 1896-98 as so great a contribution to English philosophy. The doctrine against which the main argument of Dr. Ward's treatise is directed is of course the theory, of late years con- veniently christened " Naturalism," which teaches that in the concept of the world as a single mechanical system of constant mass and energy and rigorously conforming to the laws of kine- matics we have a true and adequate account of " what really goes on " and that everything mental must in consequence be regarded as epi-phenomenal, as a mere " collateral product " of a physical evolution, running " parallel " indeed with the series of physical causes and effects but never entering into causal relations with it. As he has admirably shown, the main supports of this now popular philosophy are three in number, (1) the mechanical theory of physical processes ; (2) the theory of evolution ; (3) the theory of psychophysical parallelism. If naturalism is to be accepted as an adequate account of " what goes on " in the real world, then three fundamental propositions must be asserted. All physical processes must be capable of being resolved into the velocitis and accelerations of masses ; organic beings must be held to have been produced by an evolution of some kind out of inor- ganic masses ; the mental series must run parallel with the bodily series, but must never interfere with it. Conversely, if any one of these three positions, not to say all of them, is untenable, if the facts of the physical world cannot be adequately represented in diagrams of velocity or acceleration, if evolution itself is incon- ceivable apart from the operation of that mental factor it is supposed to produce, if mind can be shown to exercise a causal function in the physical world, the whole philosophic structure of naturalism is no better than in Dr. Ward's phrase " a house of cards," and must go by the board. In the first three parts of his book the author sets himself to show in elaborate detail that this is really the case. The " mechanical theory," " the theory of evolution," and the theory of " psycho-physical parallelism " are all examined and found wanting, and we are left early in volume ii. with the conviction that naturalism has entirely failed to make good its pretension to give an account of "what really goes on" behind "the veil of appearances". In these three sections of his work Dr. Ward is thus primarily engaged in the metaphysical criticism of the principles of phy- sical and psychological science. In what remains he is chiefly concerned with questions of epistemology. The break-down of naturalism has left us with three possible philosophical alterna- tives. If mind is not an " epiphenomenon," then either (a) there are two utterly disparate but equally real worlds, a world of things and a world of minds, or (b) the one world is in constitu-