I have tried to show that a dialectic relationship exists between speech and psychic structure. The maturation of the physiological speech apparatus, the coordination of vocal-auditory experience, and the organization of that experience in specific linguistic patterns and categories, are concomitant with and correlated to the ontogenesis of the ego.

Language is an obligatory component of the human biological organization. It plays a mediating role in such vital ego functions as perception, memory, thought, reality testing, and the control of motility. It is proposed that the ego may, in fact, be regarded as a vocal-auditory organization—a language-determined and language-determining structure—which functions as the characteristically human organ of adaptation.