This splendid subject [mathematics], queen of all exact sciences, and the ideal and norm of all careful thinking.

Muscles are in a most intimate and peculiar sense the organs of the will.

Education has now become the chief problem of the world, its one holy cause. The nations that see this will survive, and those that fail to do so will slowly perish. . . . There must be re-education of the will and of the heart as well as of the intellect; and the ideals of service must supplant those of selfishness and greed.

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

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

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

The teens are emotionally unstable and pathic. It is a natural impulse to experience hot and perfervid psychic states, and it is characterized by emotionalism. We see here the instability and fluctuations now so characteristic. The emotions develop by contrast and reaction into the opposite.