Abstract

In this article, I present a Leibnizian cosmological argument to the conclusion that either the totality of physical beings has a non-physical cause, or a necessary being exists. The crucial premise of the argument is a restricted version of the Principle of Sufficient Reason, namely the claim that every contingent physical phenomenon has a sufficient cause (PSR-P). I defend this principle by comparing it with a causal principle that is fundamental for physicalism, namely the Causal Closure of Physics, which says that every physical effect has a sufficient physical cause (CC). I find that the evidence for Causal Closure is weaker than the evidence for PSR-P, which means that physicalists who take CC to be justified must concede that PSR-P is also justified, and to a higher degree. Since my Leibnizian cosmological argument succeeds if PSR-P is granted, I conclude that physicalists must either give up CC and thereby physicalism, or accept that a necessary being exists.