The seventeenth-century Iroquois... practiced a dream psychotherapy that was remarkably similar to Freud's discoveries two hundred years later. The Iroquois recognized the existence of an unconscious, the force of unconscious desires, the way in which the conscious mind attempts to repress unpleasant thoughts, the emergence of unpleasant thoughts in dreams, and the mental and physical (psychosomatic) illnesses that may be caused by the frustration of unconscious desires. The Iroquois knew that their dreams did not deal in facts but rather in symbols.... And one of the techniques employed by the Iroquois seers to uncover the latent meanings behind a dream was free association...

Man's Rise to Civilization (1968)