The doctrine that the world is not governed by one perfect Being, but by a balance of the forces of good and evil. The doctrine elevates the devil, as the personification of evil, into a position of power comparable to that of God. It derives from Zoroastrianism and was held by the Manichees, followers of the Persian teacher Manes or Manichaeus. It flourished between the 3rd and 5th centuries ad. St Augustine adhered to Manichaeanism for several years, before becoming a bitter opponent.