The attitude of physiological psychology to sensations and feelings, considered as psychical elements, is, naturally, the attitude of psychology at large.
The distinguishing characteristics of mind are of a subjective sort; we know them only from the contents of our own consciousness.
We speak of virtue, honour, reason; but our thought does not translate any one of these concepts into a substance.
Physiological psychology is, therefore, first of all psychology.
The materialistic point of view in psychology can claim, at best, only the value of an heuristic hypothesis.
