 The ontological argument goes back to St. Anselm (1033/34–1109), but this section shall explore a current version relying heavily on the principle that if something is possibly necessarily the case, then it is necessarily the case (or, to put it redundantly, it is necessarily necessary). The principle can be illustrated in the case of propositions. That six is the smallest perfect number (that number which is equal to the sum of its divisors including one but not including itself) does not seem to be the sort of thing that might just happen to be true. Rather, either it is necessarily true or necessarily false. If the latter, it is not possible, if the former, it is possible. If one knows that it is possible that six is the smallest perfect number, then one has good reason to believe that. Does one have reason to think it is possible that God exists necessarily? Defenders of the argument answer in the affirmative and infer that God exists. There have been hundreds of objections and replies to this argument. Perhaps the most ambitious objection is that the same sort of reasoning can be used to argue that God cannot exist; for if it is possible that God not exist and necessary existence is part of the meaning of “God”, then it follows that God cannot exist.