Adolescence as the time when an individual ‘recapitulates’ the savage stage of the race’s past.

Civilization is so hard on the body that some have called it a disease, despite the arts that keep puny bodies alive to a greater average age, and our greater protection from contagious and germ diseases.

.. every step of the upward way is strewn with wreckage of body, mind, and morals.

Adolescence is when the very worst and best impulses in the human soul struggle against each other for possession.

The years from about eight to twelve constitute a unique period of human life.

All possible truth is practical. To ask whether our conception of chair or table corresponds to the real chair or table apart from the uses to which they may be put, is as utterly meaningless and vain as to inquire whether a musical tone is red or yellow. No other conceivable relation than this between ideas and things can exist. The unknowable is what I cannot react upon. The active part of our nature is not only an essential part of cognition itself, but it always has a voice in determining what shall be believed and what rejected.

Abundance and vigor of automatic movements are desirable, and even a considerable degree of restlessness is a good sign in young children.