 Swinburne notes that “a cosmological argument argues that the fact that there is a universe needs explaining” (2004: 9–10). However, he emphasizes that his approach differs from those we have already considered in that he rejects the Principle of Sufficient Reason understood as “everything not ‘metaphysically necessary’ has an explanation in something ‘metaphysically necessary’” (2004: 148), for the PSR leads, as it does in Leibniz, to a being that is logically necessary, and such a being cannot explain the logically contingent. From the logically necessary only the logically necessary follows. In place of using the PSR to construct a deductive argument, he employs a “basic theorem of confirmation theory”, Bayes’ Theorem, to construct an inductive argument (2004: 67). (In making this claim about the need for an explanation of the universe, however, it is hard not to see that he invokes some formulation of the PSR.)