International movement established in the U.S. by L. Ron Hubbard in 1954.
He introduced his ideas to the general public in Dianetics: The Modern Science of Mental Health (1950). Dianetics sought to free subjects from the destructive imprints of past experiences, called engrams. Later Hubbard moved toward a structured system of belief involving the human soul, or thetan (each person's spiritual self), and the origins of life and the universe. The organization has often been the subject of controversy.