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
Zoroaster will. The purpose of humankind, like that of all other creation, is to sustain "aša". For humankind, this occurs through active participation in life and the exercise of constructive thoughts, words and deeds. Elements of Zoroastrian philosophy entered the West through their influence on Judaism and Middle Platonism and have been identified as one of the key early events in the development of philosophy. Among the classic Greek philosophers, Heraclitus is often referred to as inspired by Zoroaster's thinking. In 2005, the Oxford Dictionary of Philosophy ranked Zarathustra as first in the chronology of philosophers. Zarathustra's impact lingers today due