Alfred Adler (February 7, 1870 - May 28, 1937) was an Austrian medical doctor and psychologist, founder of the school of individual psychology.

Born in Rudolfsheim, Vienna, Austria and raised in Vienna, he trained as a doctor at the University of Vienna Medical School and qualified in 1895. He became interested in psychology as it related to physical disorders. He met Sigmund Freud in 1902 and they formed the Vienna Psychoanalytic Society with Adler as a president.

Adler was influenced by the mental construct ideas of Hans Vaihinger and developed a theory of organic inferiority and compensation (hypertrophy), with the "masculine protest" as the natural outcome in male-dominated society. Adler came to disagree with Freud's theories: the divergence became public in 1911 at the Weimar Psychoanalytic Congress. Adler contended with Freud's belief in the dominance of the sex instinct and whether ego drives were libidinal; he also attacked Freud's ideas over repression. Adler believed that the repression theory should be replaced with the concept of ego-defensive tendencies - the neurotic state derived from inferiority feelings and over compensation of the masculine protest, Oedipal complexes were insignificant. Adler left the Vienna society and formed the Society of Free Analytic Research, renamed the Society of Individual Psychology in 1912.

Read more about his efforts in various fields.