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 and time", as evidence of this. More specifically, this note related to the concept of the eternal recurrence, which is, by Nietzsche's admission, the central idea of "Zarathustra"; this idea occurred to him by a "pyramidal block of stone" on the shores of Lake Silvaplana in the Upper Engadine, a high alpine region whose valley floor is at . Nietzsche planned to write the book in three parts over several years. He wrote that the ideas for "Zarathustra" first came to him while walking on two roads surrounding Rapallo, according to Elisabeth Förster-Nietzsche in the introduction of Thomas Common's early