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

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

Dancing is imperatively needed to give poise to the nerves, schooling to the emotions, strength to the will, and to harmonize the feelings and the intellect with the body that supports them

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

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.

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

Man is largely a creature of habit, and many of his activities are more or less automatic reflexes from the stimuli of his environment.