Freud's psychoanalytic theories
Sigmund Freud (6 May 1856 – 23 September 1939) is considered to be the founder of the psychodynamic approach to psychology, which looks to unconscious drives to explain human behavior. Freud believed that the mind is responsible for both conscious and unconscious decisions that it makes on the basis of psychological drives.
Source: Wikipedia — Freud's psychoanalytic theories (CC BY-SA 4.0)