 Rowe’s example will work only if it is necessary that some horse will finish the race, for otherwise it is possible that all the horses break a leg and none finishes the race—a condition he notes in that “it is necessary that there exists at least one member of the collection”. So why should we think that something must exist, even if it is contingent? Rowe does not say why, but one argument given in defense of this thesis is that the existence of one contingent being may be necessary for the nonexistence of some other contingent being. However, although the fact that something’s existence is necessary for the non-existence of something else holds for certain relational properties (for example, the existence of a spouse is necessary for a man not to be a bachelor), it is doubtful that something’s existence is necessary for the non-existence of something else per se, which is what is needed to support the argument that denies the contingency of the universe.