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.

Psychology more than any other science has had its pseudo-scientific no less than its scientific period.

Plato stands for the union of truth and goodness in the supreme idea of God.

The dualism itself becomes a sort of presupposition or datum; its terms condition the further problem.

The reason of the close concurrence between the individuals progress and that of the race appears, therefore, when we remember the dependence of each upon the other.

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