Ontological Arguments for God's Existence

St. Anselm, the 11th Century theologian and philosopher (who also served as archbishop of Canterbury), is best known for two things. Among theologians, he is principally associated with his deeply influential understanding of the Atonement--that is, his account of how Christ's crucifixion is to be understood as securing salvation for sinners. But among philosophers Anselm is better known as the author of the so-called "ontological argument" for God's existence (this name for the argument originated with Kant, who is also credited historically with formulating the most telling objection to the argument).

Until fairly recently it was generally assumed that, in his Proslogion,  Anselm offered a single "ontological argument" for the existence of God based on his distinctive formal definition of God as "that than which a greater cannot be thought." Certainly, there is only one "ontological argument" that comes under Kant's scrutiny and becomes the target of his famed (well, famous among philosophers) objection.

That argument runs roughly as follows: Taking "God" to mean "that than which a greater cannot be conceived," let us assume that God in this sense is only an idea in our heads and doesn't actually exist. On this assumption, we can conceived of something that is greater than God--because we can conceive of this God as actually existing, rather than as being nothing more than an idea in our heads (and a God that actually existed would be greater than one that did not). So, on this assumption, it follows that we can conceive of a being greater than that than which a greater cannot be conceived. But, of course, that is impossible. Hence, our assumption has led to a logical impossibility and so has to be rejected. It is not the case that God is only an idea in our head and doesn't exist in reality. Rather, God really exists.

This is the argument that Richard Dawkins, in The God Delusion, calls "infantile" and frames in terms of a school-yard conversation in which one smarmy kid "proves" God's existence by playing with words in a way that makes the argument sound truly silly. Now it is true that most philosophers look at this argument and think there is something fishy going on. But I think it's also true that most philosophers are grateful that the history of reflection on the argument was shaped by serious engagement. In wrestling seriously with this argument (which is formally valid), critics and defenders alike were forced to refine their understanding of what it means to say that something exists, as well as how this kind of statement differs from saying that something is blue or round. One might even wonder about whether the emergence of formal predicate logic as we know it owes something to the lessons of engaging with Anselm (in the symbolic language of predicate logic, an entity's existence is expressed through the use of what is called the existential quantifier, as opposed to being attributed to the entity as a predicate).

In any event, this ontological argument was criticized by Kant on the grounds that, in his terms, "existence is not a real predicate." Put another way, when we say of something that it exists, we don't add to our idea of a thing. Rather, we say that this idea (described in terms of the "real" predicates), has an instance in the world. Thus, to say of God that He exists is not to add to our concept of God. Since positing existence adds nothing to our concept, an existing God is not conceptually different from a nonexistent one. And so there can be no conceptual incoherence with respect to the latter that doesn't also attach to the former.

(Interestingly, I suspect that Anselm would have some sympathy with Kant's objection, because Kant is describing what existence means in its ordinary usage as applied to ordinary things--and Anselm insisted that "God exists" has to mean something very different from "Eric Reitan exists," insofar as God is taken to be the source of existence--or, in Anselm's language, "that through which" things exist, or from which things derive their being. Very roughly, to say that I exist is to say that I participate in existence itself, which is that through which I derive my being; whereas to say that God exists is to say that God is existence itself, that through which other things derive their being. Anselm furthermore attempted to show that existence itself must also be goodness itself, and by implication must be Godlike in the ways that theists have traditionally thought. Whether this element of Anselm's theology can be developed into an answer to Kant, however, is something I won't explore here.)

In any event, many if not most philosophers after Kant found his objection compelling, and the objection has since been expressed in numerous ways--including by Richard Dawkins in The God Delusion. While Dawkins makes no serious effort to carefully articulate this line of objection, he does at least quote part of one philosopher's articulation of it. Unfortunately for Dawkins (at least if he cares about his credentials as a scholar), the philosopher he appeals to for this quote is Norman Malcolm. Even more unfortunate for Dawkins, the quote comes from an article, "Anselm's Ontological Arguments," that is justly famous in the history of discussion about Anselm and his case for God. Since (according to his endnotes) Dawkins extracted the quote from an online encyclopedia article, Dawkins apparently doesn't know that this quote comes from an article in defense of Anselm. As such, Dawkins doesn't know that his dismissal of the ontological argument is, we might say, premature. To put the point more bluntly, Dawkins succeeds in completely ignoring the version of the ontological argument that is still alive today (in the sense of having active defenders) largely by virtue of the efforts of the philosopher Dawkins invokes to justify his dismissal of the argument.

It is true enough that Malcolm accepts the Kantian objection to Anselm. But what Malcolm then does (which is what makes his essay historically important) is to point something out about Anselm's original text that philosophers had historically overlooked. If one looks at that text, one sees Anselm wording his argument in a couple of ways, and it reads as if his second version is intended to be just a different way of saying the same thing. In fact, on a cursory reading it looks like the same argument restated slightly differently.

What Malcolm does in "Ontological Arguments" is show that this cursory reading is a mistake. The two arguments aren't different ways of saying the same thing, but different arguments. While there are important similarities, there is a crucial difference as well. And the difference makes a huge difference: By virtue of that difference, Malcolm argues, Kant's famous objection to the ontological argument doesn't apply. Whereas philosophers had widely assumed that Kant had dealt the death blow to the ontological argument in the 18th century, Malcolm not only showed that there was a version of the argument that avoided Kant's challenge, but he then proceeded to develop the argument in an effort to show that it was, in fact, a powerful and compelling argument for the existence of God--far more compelling, in fact, than the version for which Anselm became famous. Others have followed Malcolm's lead (including Alvin Plantinga) in developing so-called "modal ontological arguments" that trace their lineage to Anselm's second argument.

In addition to these arguments that trace back to Anselm (by way of Malcolm's discovery of the second argument), there are various ontological arguments sketched out by Gödel in his notebooks, especially in terms of the notion of "positive properties," that have come under discussion. Interestingly, however, Malcolm's development of Anselm's second argument develops themes that are also found in Gödel's argument. For these reasons I think Malcolm's version of the argument is especially deserving of closer attention. In my next post, then, I will outline Malcolm's argument.