 Rank was one of Freud's six collaborators brought together in a secret "committee" or "ring" to defend the psychoanalytic mainstream as disputes with Adler and Jung developed.Rank was the most prolific author in the "ring" besides Freud himself, extending psychoanalytic theory to the study of legend, myth, art, and other works of creativity.He worked closely with Freud, contributing two chapters on myth and legend to "The Interpretation of Dreams".