physical states. Although one might suppose that mental states and neurological states are different in kind, that does not rule out the possibility that mental states are correlated with neurological states. In one such construction, anomalous monism, mental events supervene on physical events, describing the emergence of mental properties correlated with physical properties – implying causal reducibility. Non-reductive physicalism is therefore often categorised as property dualism rather than monism, yet other types of property dualism do not adhere to the causal reducibility of mental states (see epiphenomenalism). Incompatibilism requires a distinction between the mental and the physical, being a commentary on the incompatibility of (determined) physical reality and one's presumably distinct experience of will. Secondarily, metaphysical libertarian free will must assert influence on physical reality, and where mind is responsible for such influence (as opposed to ordinary system randomness), it must be distinct from body to accomplish this. Both substance and property dualism offer such a distinction, and those particular models thereof that are not causally inert with respect to the physical world provide a basis for illustrating incompatibilist free will (i.e. interactionalist dualism and non-reductive physicalism). It has been noted that the laws of physics have yet to resolve the hard problem of consciousness: "Solving the hard problem of consciousness involves determining how physiological processes such as ions flowing across the nerve membrane cause us to have experiences." According to some, "Intricately related to the hard problem of consciousness, the hard problem of free will represents the core problem of conscious free will: Does conscious volition impact the material world?" Others however argue that "consciousness plays a far smaller role in human life than Western culture has tended to believe." Compatibilism Compatibilists maintain that determinism is compatible with free will. They believe freedom can be present or absent in a situation for reasons that have nothing to do with metaphysics. For instance, courts of law make judgments about whether individuals are acting under their own free will under certain circumstances without bringing in metaphysics. Similarly, political liberty is a non-metaphysical concept. Likewise, some compatibilists define free will as freedom to act according to one's determined motives without hindrance from other individuals. So for example Aristotle in his Nicomachean Ethics, and the Stoic Chrysippus. In contrast, the incompatibilist positions are concerned with a sort of "metaphysically free will", which compatibilists claim has never been coherently defined. Compatibilists argue that determinism