Experimental psychology itself has, it is true, now and again suffered relapse into a metaphysical treatment of its problems.

We speak of virtue, honour, reason; but our thought does not translate any one of these concepts into a substance.

In the course of normal speaking the inhibitory function of the will is continuously directed to bringing the course of ideas and the articulatory movements into harmony with each other. If the expressive movement which which follows the idea is retarded through mechanical causes, as is the case in writing ... such anticipations make their appearance with particular ease.

There are other sources of psychological knowledge, which become accessible at the very point where the experimental method fails us.

Child psychology and animal psychology are of relatively slight importance, as compared with the sciences which deal with the corresponding physiological problems of ontogeny and phylogeny.

Physiological psychology is, therefore, first of all psychology.

In Aristotle the mind, regarded as the principle of life, divides into nutrition, sensation, and faculty of thought, corresponding to the inner most important stages in the succession of vital phenomena.