The Greatest Conceivable Being

A being that only exists in your mind is not as powerful as one that exists in reality, for instance. So the parody objection that you've just put up is this argument, this I imagine the greatest conceivable being and then if it exists only in the mind, it can be improved upon so it must exist in reality. You ask about the greatest conceivable spiderman or the greatest conceivable pizza, or it's going to put it the greatest conceivable island. And Selm des cartes, maybe. It wouldn't be improved on as a coffee cup, but it might be improved upon as a thing.