The idea of God, by Anselmian definition, implies that God exists, for to exist in reality is greater than to exist in the understanding alone. But if that is so, then what of God’s idea of himself? As a perfect being, God’s idea of himself must be of a perfect being. But if to exist in reality is greater than to exist in the understanding alone, would not the object of God’s thought be greater if it existed in reality than if it existed in God’s understanding alone? If so, then Anselm’s argument might be an argument not just for one perfect being, but an infinite number of perfect beings. Or you might see this as a reductio against Anselm’s argument.
Objection: “That’s trivial; of course God’s idea of himself entails his existence. Have you ever heard of Descartes’ Cogito?” Of course it’s true that God’s thinking of himself entails that God exists. But it’s unclear to me that the worry here can be dismissed so easily. The idea God has of himself is not strictly identical to God. There is a difference between the thinker and the object of thought. So if existing in reality is greater than existing in the understanding alone, then God’s thinking of himself does not merely trivially entail his existence (as the thinker), but the existence of a qualitative duplicate (as the object of God’s thought).
Objection: “There is no difference between existence in God’s mind and existence in reality, so the parallel doesn’t work at God’s level.” Two problems. First, this seem to imply a kind of radical idealism according to which we are all just ideas in the mind of God, which is absurd. Second, surely there is such a difference for God, unless we are willing to say there are no unrealized possibilities even for God; no possibilities God thought of but chose not to actualize. But that seems just as absurd. If there aren’t, is it because God cannot think of any, or maybe because God’s nature compels him to actualize all ‘possibilities’? Either case seems to collapse into a kind of divine necessitarianism: there is one and only one way things could be.
Objection: “The difference between existence in the understanding and existence in reality for us is not the same as it is for God. So the parallel doesn’t work at God’s level.” Again, two problems. First, granted, the difference might not be the same, but so long as there is a difference it seems there is a parallel. Instead of the usual difference between existence in the understanding and existence in reality that is true of us, we can just talk of existence in the understanding* and existence in reality* true of God. Second, while it seems true that existence in our understanding is different than existence in God’s understanding, do we really want to say existence in reality for us is different than existence in reality for God? Here ‘existence in reality’ just means existence simpliciter. Some want to say God’s mode of existence is different from ours, but I don’t. One reason is because every argument for the conclusion “God exists” would then be rendered invalid on account of equivocating on “existence.”
Maybe a closer look at a more detailed version of Anselm’s argument would turn up other premises where the parallel doesn’t work. Has anyone written about this before?