Dualism
The term "dualism" has a variety of uses in the history of thought. In general, the idea is that, for some particular domain, there are two fundamental kinds or categories of things or principles. In theology, for example a "dualist" is someone who believes that Good and Evil, or God and the Devil, or Yin and Yang, are independent and more or less equal forces in the world. Dualism contrasts with Monism, which is the theory that there is only one fundamental kind, category of thing or principle; and, rather less commonly, with pluralism, which is the view that there are many kinds or categories. In the philosophy of mind, dualism is the theory that the mental and the physical – or mind and body or mind and brain – are, in some sense, radically different kinds of thing.