Everyone … has a feeling of inferiority. But the feeling of inferiority is not a disease; it is rather a stimulant to health, normal striving and development. It becomes a pathological condition only when the sense of inadequacy overwhelms the individual and, far from stimulating him to useful activity, makes him depressed and incapable of development.

Alfred Adler (1870–1937) Austrian psychologist

The Individual Psychology of Alfred Adler: A Systematic Presentation in Selections From His Writings, 9.D.2 (1929) [ed. Ansbacher & Ansbacher (1956)]