thoughts and feelings. We are nowhere, so far as I can discover, even told whether their author supposes that changes in centres of the processes — "overlappings," and "discharges" — are the only changes which condition changes in mental phenomena; or whether it is also changes in the processes themselves which constitute, in part, the necessary cerebral conditions of mental changes. The diagrams and language, in general, imply the former position. Is, then, no real science of nerve-physiology, as a part of molecular theory, necessary in order to have a psychology worthy to be dignified with the name of " natural science"?
In one place at least, however, Professor James implies that the brain-processes to which, in this "blank unmediated" fashion, the thoughts and feelings correspond, may differ in kind and not simply in locality and intensity (I, p. 566 f.). Well then, what we wish to have in the name of cerebral psychology, is a description, in terms of a comprehensible theory of molecular physics, what these differences are; and, also, a statement of the formulæ which define the relations between the molecular changes and the "corresponding" orders of mental phenomena. But this is precisely what Professor James avoids doing, even to the extent which so-called "nerve-physiology" makes possible. And, as I have already repeatedly said, nothing worthy of the name "science" is possible for any one in this branch of cerebral psycho-physics.
When, then, Professor James maintains that his oral or schematic descriptions of the brain-processes, which correspond" in a blank unmediated way" to thoughts and feelings, "show what a deep congruity there is between mental processes and mechanical processes of some kind"; I must beg his pardon and flatly contradict him. They show nothing of the sort; they show nothing of any sort. They assume some sort of unknown congruity; they also serve to impress the uninitiated reader with the feeling that he is being shown something.
But only exact and verifiable description of what, and where, are the processes to which the particular factors and classes of the conscious states correspond can be called science. The
