Sigmund Freud (1856 - 1939) was the father of psychoanalysis and one of the 20th century's most influential thinkers. He was one of the most influential scientists in the fields of psychology and physiology. He was also a neurologist and the founder of psychoanalysis.

Mostly, during his life, Freud lived and worked in Vienna, having set up his clinical practice in that city. Prior to that happening, he began his medical career in 1882 at the Vienna General Hospital.This would be the chief place where many of his medical treatment ideas would be utilized.

In 1938 Freud left Austria to escape Nazis forces. He died in exile in the United Kingdom in 1939. He was 83 years old when he died. Overall, Freud's supporters very strongly praised him and his critics called him the smartest con-man to ever live. Still, they all would agree that he was one of the most influential scientists of the 20th century. Not only did he influence the professional practice of psychology and psychiatry, he forever changed the way people (in Western cultures) viewed themselves and thought about their lives.

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