Every theory of love, from Plato down teaches that each individual loves in the other sex what he lacks in himself.

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.

Puberty for a girl is like floating down a broadening river into an open sea.

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

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

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

The man of the future may, and even must, do things impossible in the past and acquire new motor variations not given by heredity.