Emergentism is the belief in emergence, particularly as it involves consciousness and the philosophy of mind. A property of a system is said to be emergent if it is a new outcome of some other properties of the system and their interaction, while it is itself different from them. Within the philosophy of science, emergentism is analyzed both as it contrasts with and parallels reductionism. Forms Emergentism can be compatible with physicalism, the theory that the universe is composed exclusively of physical entities, and in particular with the evidence relating changes in the brain with changes in mental functioning. Some varieties of emergentism are not specifically concerned with the mind–body problem but constitute a theory of the nature of the universe comparable to pantheism. They suggest a hierarchical or layered view of the whole of nature, with the layers arranged in terms of increasing complexity with each requiring its own special science. Relationship to vitalism Emmeche et al. (1998) state that "there is a very important difference between the vitalists and the emergentists: the vitalist's creative forces were relevant only in organic substances, not in inorganic matter. Emergence hence is creation of new properties regardless of the substance involved." "The assumption of an extra-physical vitalis (vital force, entelechy, élan vital, etc.), as formulated in most forms (old or new) of vitalism, is usually without any genuine explanatory power. It has served altogether too often as an intellectual tranquilizer or verbal sedative—stifling scientific inquiry rather than encouraging it to proceed in new directions." History Addressing emergentism (under the guise of non-reductive physicalism) as a solution to the mind–body problem Jaegwon Kim has raised an objection based on causal closure and overdetermination. Emergentism strives to be compatible with physicalism, and physicalism, according to Kim, has a principle of causal closure according to which every physical event is fully accountable in terms of physical causes. This seems to leave no "room" for mental causation to operate. If our bodily movements were caused by the preceding state of our bodies and our decisions and intentions, they would be overdetermined. Mental causation in this sense is not the same as free will, but is only the claim that mental states are causally relevant. If emergentists respond by abandoning the idea of mental causation, their position becomes a form of epiphenomenalism. In detail: he proposes using the chart above (which was originally drawn with the $