 Whether this argument for the contingency of the universe is similar to that advanced by Aquinas in his Third Way depends on how one interprets Aquinas’s argument. Aquinas holds that “if everything can not-be, then at one time there was nothing in existence” (ST I,q.2,a.3). William Rowe (1975: 160–67) argues that what looks like a similar argument in Samuel Clarke for the contingency of the universe is fallacious, for even if every contingent being were to fail to exist in some possible world, it may be the case that there is no possible world that lacks a contingent being (on Aquinas, see Plantinga 1967: 5–6; Kenny 1969: 56–66). That is, although no being would exist in every possible world, every possible world could possess at least one contingent being. In such a case, although each being is contingent, something must exist. Rowe gives the example of a horse race. 