Mind–body dualism
Ontological dualism makes dual commitments about the nature of existence as it relates to mind and matter, and can be divided into three different types:Substance dualism is a type of dualism most famously defended by René Descartes, which states that there are two kinds of foundation: mental and body. This philosophy states that the mental can exist outside of the body, and the body cannot think. Substance dualism is important historically for having given rise to much thought regarding the famous mind–body problem. Substance dualism is a philosophical position compatible with most theologies which claim that immortal souls occupy an independent realm of existence distinct from that of the physical world.
Ethical dualism
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 Evil. The world is therefore identified as the battleground between these two contrasting entities, also associated with light and darkness.