If necessary existence is part of the meaning of 'God' and it is possible that God does not exist, then God's existence is not necessary and therefore impossible.

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