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

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

The main source of psychopathic diseases is the fundamental instinct of fear with its manifestations, the feeling of anxiety, anguish, and worry.

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.

The recognition, the diagnosis, and the preservation of psychopathic individuals account for the apparent increase of neurotics in civilized communities.