Wundt has declared with equal frankness that the problem is beyond the reach of the experiment of the psycho-physicist: "Our psycho-physical experiments have to do with the consciousness of the evoluted man; . . . we learn little of psychic development through them. Their application to psychic disturbances will be presumably a limited one; it sheds light upon the nature of the more profound disturbances less by direct investigation than by giving information about the changes which are associated with the condition and rise of these disturbances. But preeminently the psycho-physical experiment is concerned with the analysis of relatively elementary processes, with simple acts of perception, will, and memory; only in a limited way can it follow out the association of these simpler processes. The development of the real thought process and of the higher forms of feeling and impulse is closed to it; at the most some insufficient observations can be made also on the external, temporal succession of these processes."[1]
The natural approach to this question is through anthropology; but the prominent methods of anthropology have been weighing, measuring, and classifying, and like those of psycho-physics, able to contribute to the developmental history of mind only in a meager and indirect way. If we examine, for example, two of these methods, determination of brain-weight, and craniometry, we shall see that they have had at best only a classificatory value, and no direct bearing on the laws of mind.
The human brain doubtless contains the whole story of its own development, if only the story could be read out; but morphologically it represents capacity of response to stimuli received from variables in the external world, beginning with the protozoan period, and its development cannot be studied profitably except in connection with these variables. Functionally, also, the importance of the brain has been unduly emphasized by certain anthropologists. There is far less direct connection between intelligence and brain mass and form than was at one time
- ↑ W. Wundt, Essays, p. 145.
