To be a human being means to possess a feeling of inferiority which constantly presses towards its own conquest. … The greater the feeling of inferiority that has been experienced, the more powerful is the urge for conquest and the more violent the emotional agitation.

Alfred Adler (1870–1937) Austrian psychologist

The Individual Psychology of Alfred Adler, ch. 3, sec 3 (1956) [ed. Ansbacher]