Who was Jacques Lacan and what is his psychoanalytic theory?

Jacques Lacan, psychiatrist and philosopher, is considered one of the most disruptive thinkers of the twentieth century, who broke with classical logic and brought a new way of practicing psychoanalytic clinic. Trained in the phenomenological tradition of the 1930s, he began his incursion into psychoanalysis in the 1950s, and proposed what was characterized as a " return to Sigmund Freud"...