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.
Analytic philosophy
Motivated by the logical positivists' interest in verificationism, logical behaviorism was the most prominent theory of mind of analytic philosophy for the first half of the 20th century. Behaviorists tended to opine either that statements about the mind were equivalent to "statements about" behavior and dispositions to behave in particular ways or that mental states were directly equivalent to behavior and dispositions to behave. Behaviorism later became much less popular, in favor of type physicalism or functionalism, theories that identified mental states with brain states. During this period, topics of the philosophy of mind were often related strongly to topics of cognitive science such as modularity or innateness. Finally, analytic philosophy has featured a certain number of philosophers who were dualists, and recently forms of property dualism have had a resurgence; the most prominent representative is David Chalmers.