The concept of good versus evil is often seen as an archetypal struggle, especially in mythology. The opposition between good and evil is the essence of the double, or doppelgânger, an archetype found in mythology and literature. In Hinduism there are a number of representations of the conflict between good and evil. In the ancient Greek pantheon, the gods and goddesses were not monolithically good or bad. The supreme god, Zeus, gives both good and bad fortune to mortals. The Old Testament is explicit that one god is responsible for both good and evil, and that one god, Yahweh, is the only god. The Onondaga of the Iroquoian tribes in the American Northeast, there is a story of how good and evil people came into the world, again involving twins. In folktales, scholars have stressed the simplistic polarity of good and evil on the level of both plot and character.