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.

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

Now, there are a very large number of bodily movements, having their source in our nervous system, that do not possess the character of conscious actions.

We know, from ordinary life, that we are not able to direct our attention perfectly steadily and uniformly to one and the same object... At times the attention turns towards the object most intensely, and at times the energy flags.

The results of ethnic psychology constitute, at the same time, our chief source of information regarding the general psychology of the complex mental processes.

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.

Physiology and psychology cover, between them, the field of vital phenomena; they deal with the facts of life at large, and in particular with the facts of human life.