Anselm's Ontological Argument

February 2007

Can we conceive of a being so great that to disbelieve its existence only leads to absurdity? St. Anselm thinks that we understand “something greater than which nothing can be thought,” and he argues that our understanding of this being is such that we contradict ourselves upon thinking that such a being does not exist. Anselm arrives at his conclusion only by befuddling object language and metalanguage, blurring the distinction between “a being that exists” (meta) and a being that exists (object). Regardless, we see that if we take care in our interpretation of his argument, Anselm delivers sound reasoning for the possibility of such a being and a reaffirming argument for those who already believe in such a being.

Anselm’s first premise is that (A) we understand what is meant by “something than which nothing greater can be thought”1 when we hear it. (B) That which is understood exists in the understanding, and by the elimination of the universal quantifier in B and modus ponens with antecedent A, we infer that © God exists in our understanding. Now Anselm gives a reductio on the assumption that (D) God exists only in our understanding. Under this assumption, since (E) that which exists in reality is greater than that which exists merely in our understanding, (F) we can think of a being even greater than something than which nothing greater can be thought. This is absurd, and modus tollens propagates the absurdity to the assumption. Therefore, Anselm concludes (~D) it is not the case that God exists only in the understanding; God exists in reality.

Anselm first begins to blur the distinction between object language and metalanguage when he claims that (B) that which is understood exists in the understanding. This is the moment at which the often criticized leap from concept to being occurs. What exactly would it mean if I told you that upon hearing “eight-legged platypus” that an eight-legged platypus came into existence in your understanding? This seemingly small shuffling of words has nontrivial ontological implications, giving a conjuring of our understanding a hint of independent existence.

In the reductio, Anselm compares the God existing in our understanding (“God”) ̶what was previously just a concept ̶to an existing God. The comparison favors the existing God, and this is where we find the absurdity of the reductio. But this is not the greatest absurdity in the argument. Instead of comparing one concept to another, Anselm makes an absurd comparison between a concept of a being and the being itself. This comparison is invalid because it imports a predicate from the metalanguage to the object language in order to compare “God” to God. Clearly objects of our understanding do not exist in the same way that things do.

Notwithstanding the objection, Anselm has shown that to understand what is meant by “God” yet to think that such a being would not exist is absurd; clearly, when we conceive of God we conceive of God that exists. But how much is this worth? Does this only work for “something than which nothing greater can be thought,” or does it work for “eight-legged platypus” as well? When you conceive of the latter, does your concept include “that it exists?” If not, it sure is funny looking for something that does not exist! These questions are meant to suggest who and what Anselm’s argument is for: the argument is meant to convince people who already believe that God exists that they are correct. The fact that this argument is still in contention after a millennium suggests that Anselm was successful in this respect, and unsuccessful in giving a definitive proof for the existence of God.

  1. Henceforth referred to as “God” for abbreviation.