Ethical dualism or, as theorized by Descartes, between thought and extension. Ethical dualism on the other hand highlights the moral dimension instead or in addition to the metaphysical one, and envisions an inherent situation of conflict between two antagonistic forces, like light and darkness, Good and Evil. One of the most known and clear-cut interpretations of ethical dualism is the one conceptualized by Zoroastrianism, the ancient Persian religion, which bases its thought on the figure of the prophet Zoroaster (or Zarathustra), who claimed the existence of two original and contrasting principles, Ahura Mazda and Ahriman, respectively representing the forces of Good and
Thus Spoke Zarathustra by coinages. An example is "Untergang", literally "down-going" but used in German to mean "setting" (as of the sun) but also "sinking", "demise", "downfall" or "doom"; which Nietzsche pairs with its opposite "Übergang" (meaning "transition", literally "over-going"). Another example is "Übermensch" (overman or superman), discussed later in this article. The book chronicles the fictitious travels and speeches of Zarathustra. Zarathustra's namesake was the founder of Zoroastrianism, usually known in English as Zoroaster (). Nietzsche is clearly portraying a "new" or "different" Zarathustra, one who turns traditional morality on its head. He goes on to characterize "what the name of Zarathustra