Audiobook 100 Quotes by Aristotle: Great Philosophers & their Inspiring Thoughts. Sigmund Freud is the father of psychoanalysis, a clinical method of treatment through dialogue. Modern thought owes him his theoretical description of the structure and functioning of the unconscious, through the discovery of the essential role of transference in the analytic process, the redefinition of sexuality including its infantile forms, the analysis of dreams, symptom formation and the mechanisms of repression.