A Mereological Slingshot

Abstract I examine a package of views about facts: (1) the mereological sum of two facts is their conjunction, (2) the sum of facts obeys the laws of classical mereology, (3) facts are closed under disjunction and (4) facts are identical when they necessarily co-obtain. I show that this package of principles collapses: they jointly entail that there is at most one fact. I discuss four possible solutions, each consisting in the rejection of one of the principles.