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

The course of evolution is to a greater integration of similarly functioning ganglia.

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

Science is the description of phenomena and the formulation of their relations.

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 psycho-physiological hypothesis is both inductively and deductively the sine qua non of the science of psychology.

The man of genius whether as artist or thinker requires a mass of accidental variations to select from and a rigidly selective process of attention.

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

The fact that psychology postulates an external material world and studies it in so far as it comes to be reflected in consciousness, points to another postulate which psychology must assume in addition, namely, the existence of an inner world consciousness.

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