Jeffrey Moussaieff Masson (; born March 28, 1941, as Jeffrey Lloyd Masson) is an American author. Masson is best known for his conclusions about Sigmund Freud and psychoanalysis. In his The Assault on Truth (1984), Masson argues that Freud may have abandoned his seduction theory because he feared that granting the truth of his female patients' claims (that they had been sexually abused) would hinder the acceptance of his psychoanalytic methods. Masson is a veganism advocate and has written about animal rights.
