Daniel Dennett on The ontological argument
Dennett regarded the ontological argument as a fascinating logical curiosity that fails to establish anything about reality.
Dennett engaged the ontological argument with the curiosity of a philosopher who found it intellectually stimulating but ultimately unconvincing. He acknowledged that the argument has a peculiar power — it seems like it should work, and identifying exactly where it goes wrong is more difficult than it first appears. But he was clear that it does go wrong.
His primary objection was that the argument conflates logical possibility with real possibility. The ontological argument shows that if a maximally great being is logically possible, then it exists. But logical possibility — the absence of contradiction in a concept — does not establish that the concept corresponds to anything in reality. A logically possible unicorn is not a real unicorn.
Dennett also argued that the argument has a troubling feature: it works equally well for a maximally great anything. If the logic of the ontological argument is sound, it establishes the existence of a maximally great island, a maximally great pizza, and a maximally great evil being — all of which are absurd. The fact that the argument proves too much is evidence that its logic is flawed, even if the flaw is subtle.
“The ontological argument is the philosopher's equivalent of a magic trick. It seems to produce something from nothing — and like all magic tricks, the secret is that something was hidden in the setup.”