Human institutions depend for their existence and stability on the impulse of self-preservation and its close associate, - the fear instinct.

The general tendency of evolution is from structure to function, from bondage to freedom of the individual elements.

Human institutions depend for their existence and stability on the impulse of self-preservation and its close associate, - the fear instinct.

Psychology must postulate uniformity of interrelation of physical, physiological, and psychic processes.

Psychology is the science of psychic states both as to content and form, regarded from an objective standpoint, and brought in relation to the living corporeal individual.

The principle of recognition of evil under all its guises is at the basis of the true education of man.

Not purpose but chance is at the heart of mental life.