The correct answer is: Sigmund Freud.
Freud (1856-1939) was an Austrian neurologist, known as the founding father of psychoanalysis- a branch of psychology that studies the unconscious mind, and how unconscious aspects of personality shape our day-to-day behavior. According to a Freudian approach to psychology, the core of all psychological issues and personality lies in the unconscious mind. Freud's famous theories include: the three levels of mind, defense mechanisms, and the psychosexual stages of development.
