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
Iranian philosophy of Zarathustra (Zoroaster) appeared in Persia at some point during the period 1700-1800 BCE. His wisdom became the basis of the religion Zoroastrianism, and generally influenced the development of the Iranian branch of Indo-Iranian philosophy. Zarathustra was the first who treated the problem of evil in philosophical terms. He is also believed to be one of the oldest monotheists in the history of religion. He espoused an ethical philosophy based on the primacy of "good thoughts (andiše-e-nik), good words (goftâr-e-nik), and good deeds (kerdâr-e-nik)." The works of Zoroaster and Zoroastrianism had a significant influence on Greek philosophy and Roman philosophy.