<P> 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 . </P> <P> Property dualism asserts that an ontological distinction lies in the differences between properties of mind and matter, and that consciousness is ontologically irreducible to neurobiology and physics . It asserts that when matter is organized in the appropriate way (i.e., in the way that living human bodies are organized), mental properties emerge . Hence, it is a sub-branch of emergent materialism . What views properly fall under the property dualism rubric is itself a matter of dispute . There are different versions of property dualism, some of which claim independent categorisation . </P> <P> Non-reductive physicalism is a form of property dualism in which it is asserted that all mental states are causally reducible to physical states . One argument for this has been made in the form of anomalous monism expressed by Donald Davidson, where it is argued that mental events are identical to physical events, and there can be strict law - governed causal relationships . Another argument for this has been expressed by John Searle, who is the advocate of a distinctive form of physicalism he calls biological naturalism . His view is that although mental states are ontologically irreducible to physical states, they are causally reducible (see causality). He has acknowledged that "to many people" his views and those of property dualists look a lot alike . But he thinks the comparison is misleading . </P> <P> Epiphenomenalism is a form of Property Dualism, in which it is asserted that one or more mental states do not have any influence on physical states (both ontologically and causally irreducible). It asserts that while material causes give rise to sensations, volitions, ideas, etc., such mental phenomena themselves cause nothing further: they are causal dead - ends . This can be contrasted to interactionism, on the other hand, in which mental causes can produce material effects, and vice versa . </P>

Who believes the mind and body are separable