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

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

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.

The tendency of life is not the preservation of the species, but solely the preservation of each individual organism, as long as it is in existence at all, and is able to carry on its life processes.

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.

Self-preservation is the central aim of all life-activities.