value of individual adaptations, through which many variations may have become permanent that otherwise would have been ruthlessly stamped out. When phrased in this way, it is hard to conceive that any serious criticism should be directed against the hypothesis, save by those who wish to couch the whole series of developmental and evolutionary processes in totally different terms, e.g., physico-chemical reactions. To such persons natural selection is itself an abomination. There is, however, one phase of the theory to which further attention should be directed.
All is clear sailing so long as one contents oneself with the mere statement that organisms do in some manner accommodate themselves to the rigors of their peculiar environments, thus succeeding in surviving and secondarily succeeding in assisting the crystallization of useful variations. Such a statement is, like that of natural selection itself, simply a formulation of the general method by which certain results have been attained ; not an analytical apportionment of causal responsibility to specific factors in the process. But when one introduces consciousness into one's explanatory system explicitly to account for the execution of accommodatory movements, and especially when one attempts to sketch the details of the operation in terms of pleasure-pain phenomena, the dangers of scientific and philosophic shipwreck are immensely enhanced. Needless to say, Mr. Baldwin is thoroughly alive to this danger. He faces it without flinching, and his position deserves notice. It may be remarked in passing, that the whole range of evolutionary processes in plant life falls outside the limits of such a formulation as that of our author, unless one adopts the precarious hypothesis that plants are conscious.
Mr. Baldwin is what may be styled a 'scientific parallelist' (if he will pardon this gratuitous distribution of titles) and a 'philosophic monist' of the 'double aspect theory' variety. By which is meant that he accords to both the psychical and the physiological series of events in an organism the possibility—and for certain scientific purposes the necessity—of separate treatment. He would evidently countenance the validity of the mechanical categories in the physical series, so far as one might be consulting the interests of exact science. In the psychical series, however, another type of category holds sway. When he comes to such a question as that raised by the evolutionary hypothesis, i.e., How has the psychophysical organism come to be what it is? he passes on to his monistic position, in which he maintains that neither the psychical nor the physical phase of our organic entity can be neglected to the cost of the other, and that the categories
