The principle of sufficient reason (PSR) says every fact has an explanation. But van Inwagen argues the PSR is false—otherwise all facts are necessary facts. Consider the conjunction of all contingent facts, which we can call the Big Contingent Conjunction. If every fact has an explanation, then presumably the Big Contingent Conjunction had better have an explanation too. But what fact could explain its truth—is the Big Contingent Conjunction explained by a necessary fact or a contingent one? Trouble ensues either way. If the Big Contingent Conjunction is explained by a necessary fact, then it is hard to see why it should be contingent. (After all, if something follows from what is necessary, it too would seem to be necessary.) On the other hand, if the Big Contingent Conjunction is explained by a contingent fact, then the explanation appears circular since the explanans itself is among the facts it explains in the Big Contingent Conjunction. This paper explores an assumption of this argument rarely subjected to scrutiny—namely, the distribution principle, which asserts that if a fact explains a conjunction, then it explains each of its conjuncts. Though superficially plausible, close consideration of this principle reveals some reasons to reject it, potentially saving the PSR from van Inwagen’s challenge.