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)]