No science will become shallow so quickly as psychology if it deserts philosophy. Its separation from philosophy is the true cause of its impotency. Psychology will have to discover that the doctrine of sensations is practically useless to it. The empirical psychologists of to-day, in their search for the development of character, begin with investigation of touch and the common sensations. But the analysis of sensations is simply a part of the physiology of sense, and any attempt to bring it into relation with the real problems of psychology must fail.
It is a misfortune of the scientific psychology of the day that it has been influenced so deeply by two physicists, Fechner and von Helmholtz, with the result that it has failed to recognise that only the external and not the internal world can be reconstructed from sensations. The two most intelligent of the empirical psychologists of recent times, William James and R. Avenarius, have felt almost instinctively that psychology cannot really rest upon sensations of the skin and muscles, although, indeed, all modern psychology does depend upon study of sensations. Dilthey did not lay enough stress on his argument that existing psychology does nothing towards problems that are eminently psychological, such as murder, friendship, loneliness, and so forth. If anything is to be gained in the future there must be a demand for a really psychological psychology, and its first battle-cry must be: “Away with the study of sensations.”
In attempting the broad and deep characterology that I have indicated, I must set out with a conception of character itself as a unit existence. As in the fifth chapter of Part I., I tried to show that behind the fleeting physiological changes there is a permanent morphological form, so in characterology we must seek the permanent, existing something through the fleeting changes.
The character, however, is not something seated behind the thoughts and feelings of the individual, but something revealing itself in every thought and feeling. “All that a man does is physiognomical of him.” Just as every cell bears within it the characters of the whole individual, so every psychical manifestation of a man involves not merely a few little characteristic traits, but his whole being, of which at one moment one quality, at another moment another quality, comes into prominence.