Gaunilo of Marmouthiers
On Behalf of the Fool
Gaunilo is unconvinced by Anselm's Ontological Proof and offers several counter-arguments. One of these counter-arguments concerns Anselm's claim that there are two ways in which a thing can exist, solely in the mind and outside the mind. Specifically, Gaunilo questions whether the analogy Anselm draws between a painting and other objects is accurate. He points out that an artist's work, before the artist actually begins painting, sculpting, or building, "belong[s] to the very nature of the mind itself" whereas other sorts of things are distinct from "the understanding that grasps" them. Gaunilo's point is that art is inextricably tied to the mind that creates it; intent to create is a necessary condition for art. In contrast, other things exist independently of the mind; the mind is not necessary for them to exist at all. Thus, while there is a sense in which an object of art exists in the mind and a sense in which that same work of art exists in the mind of the artist, there is no parallel for things that exist independently of the mind. Where the existence of something is independent of mind, Gaunilo argues, the understanding of that thing is a distinct entity from that thing itself. Thus, there are not two ways in which something-than-which-no-greater-can-be-thought exists. Rather, there really are two distinct things: the idea of something-than-which-no-greater-can-be-thought and that thing itself.
A different criticism concerns Anselm's claim that we have an understanding of something-than-which-no-greater-can-be-thought. Gaunilo distinguishes two ways in which one might have a conception of something that one has never encountered. First, one might have a conception of something never encountered on the basis of having encountered other things like it. In this sense one can have an idea of a person never encountered because one has encountered other persons and understands general human characteristics. Second, one might have a conception of something encountered by "the verbal formula.” In this sense one has some notion of the meanings of words describing the unknown, but merely "tries to imagine what the words he has heard might mean.” Since the something-than-which-no-greater-can-be-thought is unlike anything we have encountered, one cannot have a conception of it in the first sense. Thus, if one has a conception at all, it must be in the second sense. But if one only understands something-than-which-no-greater-can-be-thought in this sense, it doesn't really seem that the conception is in one's mind at all.
A third criticism, explained in more detail by Professor Rowe in the subsequent selection, is that one might apply Anselm's reasoning to other objects in order to "prove" that they exist. Gaunilo argues that we can imagine an island than which no greater island is possible. If we suppose that this island does not exist outside the mind, and since such an island would be greater were it to exist, we can think of an island greater than the island than which none greater can be thought. Thus, the claim that the island does not exist outside the mind must be false. Clearly there is no such island, Gaunilo argues, and the Ontological Proof must therefore be defective.