In the eleventh century, Anselm of Canterbury wrote the most influential version of the Ontological Argument for the existence of God. Basically, it goes this way. Imagine the greatest being that can be conceived. Anyone can. Even the person that says, “God doesn’t exist,” can conceive such a being: she’s just uttered a sentence about that being. But the greatest being that can be conceived can’t exist in the mind alone; if it did, we could conceive of that same being having real existence, which would be even greater than the being that exists only in our minds. That would mean a being exists that is even greater than the greatest being that can be conceived. Greater than the greatest? Nonsense. Since we have reached a contradiction, we must reject our supposition, namely our supposition that God only exists in the mind. Ergo, He exists in reality.
Alvin Plantinga believes that God exists but doesn’t think that this argument proves it. But he doesn’t like any of the published refutations, either, including the famous refutation by Kant. His long, detailed analysis in chapters 2 and 3 of God and Other Minds involves a lot of experiments with multiple variations of particular lines in order to try to make either the argument or one of the refutations work, and I definitely didn’t follow it all. But his own refutation seems to hinge on a problem with the supposition that this greatest possible being (oh, by the way, one of his alternatives talks about the greatest possible being instead of the greatest conceivable being, a distinction that cuts away a lot of underbrush by removing the implied minds that have to conceive all these beings) can be conceived of in two varieties – one existing in the imagination only and one existing in reality – and that the two varieties can be compared. The existing one can’t be exactly the same as the imaginary except with the added property of existence: we defined the original being as the greatest possible being, so they would each have to be the greatest possible being, which is impossible from the outset.
In my previous post, I mentioned an experience that keeps occurring as I read this book: I’ll start to think of a problem, something it seems that Plantinga is missing, and then a few pages later find him mentioning it himself. In this section of the book, the prime example involves intensional objects. Plantinga explores the sentence “Dragons don’t exist” for quite a while without mentioning intensional objects. If dragons don’t exist, he says, then what are we talking about? What exactly is the subject of the sentence? The sentence isn’t nonsense, so we aren’t talking about nothing. Hey, I say to the book, I know the answer: dragons are intensional objects. And sure enough, after the turn of a leaf or two, Plantinga finally brings the topic up.
An intensional object is an object that resides in our conception. We know what a dragon is and would know one when we saw one. In fact we do see them – in movies – and recognize them as dragons. So something exists, and yet what exists isn’t exactly a dragon. It’s not just an idea of a dragon either, though. Several years ago I read a book by Nicholas Wolterstorff that helped me straighten this problem out. In it, he explored the ontology (the mode of existence) of a fictional character. Let’s use Ebenezer Scrooge for our example. Does he or did he exist in real life? No. But we can talk about him: we know what job he has (money lender), what kinds of things he says (“Bah! Humbug!”), where he lives (top floor), who he knows (Bob Cratchit), and what he eats (gruel). We even know things about him that Dickens doesn’t tell us. We know for instance that he has two legs, even though Dickens never counts them for us. But what is the nature of the being that has these two legs? He isn’t a real man. But he can’t exactly be a thought either, because thoughts don’t have legs. So he is an object with existence in our thoughts: an intensional object.
Now I don’t know what Plantinga would say about this next idea; maybe I’ll run across it in the next few pages. But I wonder if the subject of any statement with the verb “exists” is actually an intensional object. Maybe if “Dragons don’t exist” is really about an intensional object, so is “God exists.” Maybe that sentence really means, “The idea I have of God in my mind corresponds to an entity that has real existence.” But then we get into the area of adequate conceptions: how detailed does my idea have to be in order to correspond meaningfully to a real-world entity? Plantinga mentions the topic of adequate conception but doesn’t go into it very far, and I’m not skilled enough to say much about it. But I know that I can think true, valid things about real-world objects without knowing a lot about those objects. I didn’t know anywhere near as much about Rutherford B. Hayes before I read his biography as I do now. And yet I’m sure that I read a book about the person I wanted to read about; my conception was adequate enough to have read about the right person. But what if my thought had been “ I want to read about that bearded president who did interesting things” and then I had found a biography of Benjamin Harrison? Or what if I did found a biography of Hayes with that hazy conception? Wouldn’t it have been only an accident, since I didn’t have a clear enough idea of the person I was looking for? How much information is needed in a conception to adequately point to a given real-world object? I don’t know. My conception of adequate conception is inadequate.
As long as we’re on weird logic, I’ll mention one more subargument explored by Plantinga: a medieval argument indicating a problem with contradictions. The Law of Noncontradiction, a fundamental principle of logic, says that both A and not-A (written as ~A) cannot both be true (at the same time and in the same way). Suppose, the argument goes, that both are true. To any true proposition P, you can join any proposition you’d like (OK, I know Plantinga could point out some technical exceptions) with the conjunction “or” and still have a true sentence. “My computer is on at this moment” is true. So is “Either my computer is on or I was born on Mars.” But now let’s suppose both P and ~P, the contradiction. So since “My computer is on” (P) is true, “Either my computer is on or I was born on Mars” is true. But then by our supposition “My computer is not on” (~P) is also true. Now if one of these two possibilities is true – either my computer is on or I was born on Mars – and my computer is not in fact on, then I must have been born on Mars. Accepting a contradiction implies that any crazy proposition you can dream of is true! An infinite number of monkeys are typing Hamlet right now! Green is actually the color red in disguise! My high school education was the greatest possible education! Casually crossing the streams is a good idea! Pluto is not a planet! Positing a contradiction opens up a Pandora’s box of madness.
Dragons do not exist. Komodo dragons do exist. Oh, no. What have I done?