The ‘Introduction’ provides an overview of psychoanalysis, its history, and its development. Psychoanalysis is an original method of therapy that is a form of inquiry, a theory of mind, and a mode of treatment concerned, above all, with the unconscious mind. Founded by Sigmund Freud (1856–1939), it became a movement and set of institutions, inspiring many, but also galvanizing numerous opponents. Freud’s method of free association involves allowing the patient to discuss anything that comes into their mind. The analyst is tasked with attending to possible unconscious meaning in what the patient brings. Critique of psychoanalysis has taken many forms. Sometimes disagreements spurred new ideas and modified techniques within the mainstream tradition.