dualism du·al·ism (dōō'ə-lĭz'əm, dyōō'-)
n.
The theory that blood cells have two origins, from the lymphatic system and from the bone marrow.
The view in psychology that the mind and body function separately, without interchange.
In philosophy and theology, any system that explains phenomena by two opposing principles. Many philosophers hold to a dualism of mind and matter, or mind and body. For many theologians, the two principles are those of good and evil.