hy should this thought disturb us? That than which a higher cannot be conceived cannot exist merely as an idea, because what exists merely as an idea is inferior to what exists in reality as well as in idea. The idea of a highest Being which exists merely in thought, is the idea of a highest Being which is not the highest even in thought, but inferior to a highest Being which exists in fact as well as in thought.' The argument merely assumes that be who denies that there is a God must have an idea of God. There is also no force, as Anselm showed, in the objection of Gaunilo, that the existence of God can no more be inferred from the idea of a perfect being, than the existence of a perfect island is to be inferred from the idea of such an island. The argument is that a certain thought of God is found necessarily to imply His existence. The objection that existence is not a predicate, and that the idea of a God who exists is not more complete and perfect than the idea of a God who does not exist, is, perhaps, not incapable of being satisfactorily repelled. Mere existence is not a predicate, but specifications or determinations of existence are predicable. Now the argument nowhere implies that existence is a predicate; it implies only that reality, necessity, and independence of existence are predicates of existence; and it implies this on the ground that existence in re can be distinguished from existence in conceptu, necessary from contingent existence, self-existence from derived existence. That the exclusion of existence --which here means real and necessary existence --from the idea of God does not leave us with an incomplete idea of God, is not a position, I think, which can be maintained. Take away existence from among the elements in the idea of a perfect being, and the idea becomes either the idea of a nonentity or the idea of an idea, and not the idea of a perfect being at all. ...
