Mental synthesis of psychic content in the unity of a moment-consciousness is a fundamental principle of psychology.

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.

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.

Superstitions, and especially the early cultivation of religion, with its "fear of the Lord" and of unknown mysterious agencies, are especially potent in the development of the instinct of fear. Even the early cultivation of morality and conscientiousness, with their fears of right and wrong, often causes psychoneurotic states in later life. Religious, social, and moral taboos and superstitions, associated with apprehension of threatening impending evil, based on the fear instinct, form the germs of psychopathic affections.

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

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

Social laughter is momentary, soon burns itself out and passes away like the fire and smokes of straw, but genius shakes the very skies with its lasting, inextinguishable laughter.