Physical Causal Closure Thesis
"No physical event has a cause outside the physical domain."
The physical causal closure thesis can take many forms, but in its simplest form the thesis states that if a physical event has a cause, then it has a physical cause.
A stronger and probably more widely held version of the thesis holds that all physical events ultimately have first-order physical causes. In other words, this thesis (unlike the more general thesis above) excludes the possibility of there being novel, irreducible, second(higher)-order physical causal powers. The stronger thesis requires complete causal reducibility to first-order physical properties and their relations.
The physical causal closure thesis is primarily a metaphysical framework to which materialists and physicalists are committed. Jaegwon Kim has emphasized in several articles and books that this thesis has significant implications for the philosophy of mind and the topic of mental causation. In particular, the thesis plays an essential role in the problem of mental exclusion: what causal role is left for the mental if each physical event has a physical cause? Kim goes so far as to argue that the physical causal closure thesis leads one to reject the reality of the mental in favor of some version of mental irrealism. It may be that one is left with only two options: either reject the physical causal closure thesis or reject the reality of the mental.
Web Resources On Physical Causal Closure Thesis
Book Resources On Physical Causal Closure Thesis
The Mind in a Physical World by Jaegwon Kim by