In the first place, Descartes stands for the most explicit and uncompromising dualism between mind and matter.

The fact that tradition hinders the individual savage from thinking logically by no means proves that he cannot think logically.

Like all science, psychology is knowledge; and like science again, it is knowledge of a definite thing, the mind.

In the first place, Descartes stands for the most explicit and uncompromising dualism between mind and matter.

Heredity provides for the modification of its own machinery.

Pythagoras took the next important step by subordinating the mere matter of nature to its essential principle of form and order, identifying the latter with reason or the soul.

Feeling is the consciousness of the resulting conditions - of success, failure, equilibrium, compromise or balance, in this continuous rivalry of ideas.