The father of modern psychoanalysis, Freud develops a number of theories regarding the role our unconscious plays in influencing and even determining our actions, mostly through the process of sublimation, where drives and desires are transformed towards other goals and purposes.
Freud will be forced to flee Austria in 1938 to avoid further persecution at the hands of the Nazis. Before he is allowed to leave, however, he will be required to sign a document which testifies that he had been treated respectufully. At the bottom, however, he adds the sarcastic comment, "I can heartily recommend the Gestapo to anyone."
Over the course of 63 years he will publish around six hundred papers and books. Most of his work is based on a premise which can be labeled "psychic determinism."
All psychological phenomena, from dreams to slips of the tongue, proceed according to lawful and predictable patterns which are in turn formed in predictable ways by childhood experiences.