The Q&A discussion begins with a reader's inverse take on the the argument:
When I think about the concept of God --a maximally great being-- it seems clear that God, if he exists, exists necessarily. So if God exists in the actual world, then there is by definition no possible world in which God does not exist. But the problem is this: there seem to be a nearly infinite number of possible worlds in which God does not existI'll let you read the full question for yourself, but the gist is that to accept the modal ontological argument, one has to accept that there is no possible world in which God does not exist; to reject it, one merely has to accept that there is only one possible world in which God does not exist.
Craig's response is that imagining a possible world in which God does not exist "begs the question by assuming that the concept of maximal greatness is incoherent. Just because we can imagine a world in which a single particle (or whatever) exists gives no reason for thinking that such a world is metaphysically possible".
Le sigh. "Maximally great"? "Possible world"? "Metaphysically possible"? Half of the chore of addressing these arguments is deciphering the bizarre and often nebulous terminology. So let's look at the terms:
1) I don't think it's readily apparent that the concept of "maximal greatness" is coherent, because 'maximal' denotes a quantitative property, and 'greatness' denotes a qualitative one. In other words, there is no universally accepted definition of what constitutes 'greatness' in the first place, much less how greatness could be quantified as 'minimal' or 'maximal'.
2) "Possible world" is just philosopher slang for 'possible'. It seems to me then that it's utterly superfluous. If you're trying to reason about whether something is possible, just say "it's possible" or "it's not possible".
3) It's impossible to know what is or isn't "metaphysically possible" because the term 'metaphysically' is nebulously defined. Indeed Craig himself tacitly admits this in an old Q&A when he concedes, "What we take to be metaphysically necessary/possible depends on our intuitions about such matters."
The "possible world" semantics can be seen for how ridiculous they are simply by looking at one of the key premises in Alvin Plantinga's version of the argument:
4. If a maximally great being exists in every possible world, then it exists in the actual world.In other words, "If it is possible that a maximally great being exists, then a maximally great being exists".
What? There has to be some sort of hidden premise here, because it's obviously a non sequitur to simply say "It is possible that a exists, ergo a exists". The hidden premise is embedded in the idea of a so-called 'maximally great' being. Namely, these theologians conceive of a maximally great being who exists as being greater than a maximally great one who doesn't. Confused? You ought to be. Here's Craig's explanation:
When you think about it, anything that exists must have the property of existing in every world in which it exists! So you're right that you, I, and everyone else has existence as part of his or her essence in that sense. Rather the claim here is that God exists in every possible world. What God has that we don't, then, is the property of necessary existence. And He has that property de re, as part of His essence. God cannot lack the property of necessary existence and be God. Of course, if something has the property of necessary existence, it can't lose that property, since if it did, there would be a possible world in which it lacked necessary existence and so it was never necessarily existing in the first place!And here we find the elephant in the room: the property of existence. From the SEoP:
There is a long and distinguished line of philosophers, including David Hume, Immanuel Kant, Gottlob Frege, and Bertrand Russell, who followed Aristotle in denying that existence is a property of individuals, even as they rejected other aspects of Aristotle's views. Hume argued (in A Treatise of Human Nature 1.2.6) that there is no impression of existence distinct from the impression of an object, which is ultimately on Hume's view a bundle of qualities. As all of our contentful ideas derive from impressions, Hume concluded that existence is not a separate property of an object. Kant's criticism of the ontological arguments for the existence of God rested on a rejection of the claim that existence is a property of an object. Proponents of the ontological argument argue that the concept of God as an entity with all perfections or a being of which no greater can be conceived entails God's existence, as existence is a perfection and a being that exists is greater than a being that does not exist. Kant objected (in his Critique of Pure Reason, A596/B624-A602/B630) that existence is not a property. “Thus when I think a thing, through whichever and however many predicates I like (even in its thoroughgoing determination), not the least bit gets added to the thing when I posit in addition that this thing is. For otherwise what would exist would not be the same as what I had thought in my concept, but more than that, and I could not say that the very object of my concept exists” (A600/B628). Finally, both Frege and Russell maintained that existence is not a property of individuals but instead a second-order property—a property of concepts, for Frege, and of propositional functions, for Russell.What these philosophers were getting at is that conceptual abstractions do not have literally real properties; their properties are, themselves, conceptual abstractions. I can say for example that a unicorn (an abstraction) has the property of looking like a horse, having a horn, being delicious when canned, etc. But these properties are nothing more than conceptual abstractions — representative processes in the human brain. I cannot claim that by adding the property of "existence" to a unicorn, a unicorn is now a real thing. It's the other way around: something has to exist in order to have properties in the first place. To put it more plainly, imaginary things have imaginary properties.
This means that just because I can conceive of a being who is 'maximally great' — however I choose to define maximal greatness — I don't have any reason to think such a being actually exists. All I've done is conjure up some imaginary thing, and its actual existence still needs to be demonstrated independently of my ability to conceive it.
|Some properties of Equinas Unicornus|
What strikes me about all these arguments is the peculiar way in which they bandy about commonly used terms. For example, Aquinas' argument relies on a concept of 'pure being'; God, in whatever ineffable way, is not an amalgamation of properties but rather a being in which all his properties have somehow melded together and are indistinguishable from existence. It's bizarre because we've never seen anything like this, and we don't have any reason to believe that distinct properties can meld together in that way, somehow becoming identical to each other. I think Hume's argument, above, is appropriate here: there is no impression of 'existence' that is distinct from the impression of an object, which is (more or less) a bundle of qualities. We don't have any reason to think that 'pure being' is even coherent (it seems obviously paradoxical to me), but even if we did we've only conjured up a conceptual abstraction — the coherency of a concept is necessary, but not sufficient, to show that it corresponds to reality.
Why do these semantic 'proofs' of God rely on such nebulous and equivocal terms like 'metaphysical necessity', 'perfection', 'maximal greatness', and 'pure being'? Sean Carroll nicely captures the allure of this type of convoluted thinking:
If you have God intervening in the world, you can judge it by science and it’s not a very good theory. If on the other hand God is completely separate from the universe, what’s the point? But if God is a necessary being, certainly existing but not necessarily poking into the operation of the world, you can have your theological cake without it being stolen by scientific party-crashers, if I may mix a metaphor. The problem is, there are no necessary beings. There is only what exists, and we should be open to all the possibilities.