Sigmund Freud (1856–1939) was the founder of psychoanalysis, an atheist and scientist. Because of the groundbreaking nature of most of his theory, Freud remains influential in the field of psychology, literary studies and history.
Jewish by birth, in 1938 he fled Vienna and persecution by the Nazis to North London, England, where he lived until his death in 1939. Sigmund Freud died of maxillary cancer at the age of 82 due to cigar smoking.
Freud wrote two works on the psycological dimension of religion, Moses and Monotheism, and The Future of an Illusion. Both, particularly the second, were attacks on religion.
Today Freud is best known for his theories of the unconscious mind, especially involving the mechanism of repression; his symbolic interpretation of dreams; his redefinition of sexual desire as mobile and directed towards a wide variety of objects; and his therapeutic technique, especially his understanding of transference in the therapeutic relationship and the symbolic interpretation of dreams as sources of insight into unconscious desires.
Freud proposed that the human psyche consists of three parts -- ego, super-ego, and id -- and that defense mechanisms are an attempt by the mind to resolve conflicts between the super-ego and the id. According to Freud's personality theory, the id represents the innate animal-like drives and instincts of the human being, consisting primarily of sexual and aggressive impulses. The super-ego consists of the learned rules and norms of the human being in their environment, derived from sources such as parental values, societal expectations, and religious teachings. When the id introduces impulses into the consciousness that are in conflict with the "rules" of the super-ego, anxiety can arise. For example, if one feels sexually attracted to the spouse of a family member, the super-ego promptly springs to action to remind us that these impulses are entirely unacceptable and offensive. The conflict between the id and the super-ego is thus born and the ego must resolve it or experience great anxiety.
Freud's theories are viewed by some as unscientific because they lack falsifiability, as claimed by Karl Popper. Adolf Grünbaum disagrees with Popper's view, and argues that some of Freud's theories are falsifiable and may conceivably be correct. Grünbaum gives as an example Freud's ideas about the development of homosexuality, referring to Freud's paper "The psychogenesis of a case of homosexuality in a woman." Hans Eysenck has said that Freud's theories are falsifiable and therefore are a science, although an incorrect one. 
Freud's therapeutic methods continue to have a lasting importance in psychotherapy. As recently as 1987 approximately 75% of practicing therapists relied on Freud's psychoanalytic ideas in therapy. Among the techniques instituted by Freud that are still in use today are:
- talk therapy (simply talking through problems),
- free association (allowing the client to say whatever comes to mind), and
- transference (promoting an emotional relationship between the therapist and client in order to aid in the healing process).
Psychoanalysis as a clinical method has in many cases been shown to be as effective as other talk therapies. Freud may have been aware of his work being damaging and unscientific, as he mentioned to a fellow immigrant on the way to America that "[Freud] was bringing [the West/America] the plague," in reference to his work.
On the other hand, Freud's debunkers declare his "cures" to be the product of wishful thinking and conscious fudging as well as to suffer from usage of circular logic. Peter D. Kramer, a psychiatrist and author of a biography of Freud maintains that every particular of Freudian psychology such as the universality of the Oedipus complex, penis envy, and infantile sexuality, is wrong. Even Freud's most orthodox adherents do not defend his entire body of work in all its details.
World War II
In order to prevent Nazis from banning psychoanalysis as "Jewish science", Sigmund Freud thought he needed a non-Jewish spokesperson for the psychoanalysis movement. He choose Carl Jung, an early supporter who later partially diverged from Freud's psychiatric theories.
- Gregory Zilboorg, Freud and Religion: a Restatement of an Old Controversy, 49.
- See also The Unconscious Before Freud, by Lancelot Law Whyte, 1979
- Masson, J. M. (1984). The Assault on Truth: Freud's Suppression of the Seduction Theory. New York: Farrar, Straus and Giroux. page 187
- Jones, E. (1953). Sigmund Freud: Life and Work. Volume 1. London: Hogarth Press, p. 289
- Gay, Peter (1988). Freud: A Life for Our Time, Norton, page 96.
- Popper, Karl R.: 'Science as Falsification', Conjectures and Refutations: The Growth of Scientific Knowledge (London, 1963)
- Grünbaum, Adolf, Validation in the Clinical Theory of Psychoanalysis, pp 320-321)
- Eysenck, Hans Decline and Fall of the Freudian Empire Transaction Publishers page 14
- (Pope, K.S., Tabachnick, B. & Keith-Spiegel, P. (1987). Ethics of practice: The beliefs and behaviors of psychologists as therapists. American Psychologist, 42, 993-1006).
- Different types of therapy
- "We are bringing them the plague." -Freud on his way to America in 1909. Quoted in Richard Noll, The Jung Cult: Origins of a Charismatic Movement (Princeton: Princeton University Press, 1994), 47.
- Jerry Adler (March 26, 2006 7:00 PM). Freud in Our Midst. newsweek.com. Retrieved on December 25, 2013.