From: William Lane Craig <firstname.lastname@example.org>
Subject: Question of the Week – Misunderstanding the Ontological Argument
Good Day from Nepal. We badly need apologetics in Nepal so please keep in your prayers. I work in translating apologetic material in the language of Nepal where secularism and Hinduism are quite strong. Thank you for your work Dr. Craig. My question is on the ontological argument and I do not fully understand it. Can you help clarify? I recently asked a philosopher here and was told the following exchange:
My question to the professor:
…question concerning the reading packet in our resouces on Descartes and the Ontological argument. Most non-philosophers seem to think the argument is not credible while most philosophers do not it seems – could you help me by offering your own insights to its merit? For example – Alvin Plantiga seems to have developed the folowing:
The version below comes from Alvin Plantinga, one of America’s premier philosophers. It’s formulated in terms of possible worlds semantics. For those who are unfamiliar with the terminology of possible worlds, let me explain that by “a possible world” one doesn’t mean a planet or even a universe, but rather a complete description of reality, or a way reality might be. To say that God exists in some possible world is just to say that there is a possible description of reality which includes the statement “God exists” as part of that description.
Now in his version of the argument, Plantinga conceives of God as a being which is “maximally excellent” in every possible world. Plantinga takes maximal excellence to include such properties as omniscience, omnipotence, and moral perfection. A being which has maximal excellence in every possible world would have what Plantinga calls “maximal greatness.” So Plantinga argues:
1. It is possible that a maximally great being exists.
2. If it is possible that a maximally great being exists, then a maximally great being exists in some possible world.
3. If a maximally great being exists in some possible world, then it exists in every possible world.
4. If a maximally great being exists in every possible world, then it exists in the actual world.
5. If a maximally great being exists in the actual world, then a maximally great being exists.
6. Therefore, a maximally great being exists.
Premises (2)-(5) of this argument are relatively uncontroversial. Most philosophers would agree that if God’s existence is even possible, then He must exist. The principal issue to be settled with respect to Plantinga’s ontological argument is what warrant exists for thinking the key premiss “It’s possible that a maximally great being exists” to be true.
The idea of a maximally great being is intuitively a coherent idea, and so it seems plausible that such a being could exist. In order for the ontological argument to fail, the concept of a maximally great being must be incoherent, like the concept of a married bachelor. But the concept of a maximally great being doesn’t seem even remotely incoherent. This provides some prima facie warrant for thinking that it is possible that a maximally great being exists.
Would you agree that premises 2-5 are relatively non-controversial? In other words if premise 1 is “true” then would you say all 5 premises must therefore be logical true? Any thoughts/comments would be greatly appreciated.
Number 2 is not uncontroversial.
Just because it is possible for something to exist doesn’t mean that it does or must exist. Essentially no. 2 is stating “If it is possible, then somewhere it must be.” Not only is that not practical, it doesn’t even follow logically. Possible things do not automatically translate into actual things. I’d also dispute item no. 3, on the grounds that an example in one possible world doesn’t translate automatically into every possible possible world — were that the case, then all possible worlds would have to be identical, and full of mutually exclusive elements. Unless, that is, there is something special about the “maximally excellent” being that makes it unique and unlike other things, in which case, logic falters again.
This goes back to Anselm for the greatest formulation, and back even further than that. It has always been problematic.
I recall a professor of mine saying once that every philosopher sooner or later comes to the conclusion that the proof is right, but we don’t know how, and later comes to the conclusion that the proof is wrong, but we don’t know why.
Would you say he is mostly correct Dr. Craig? There are a lot of apologist who struggle with the ontological argument so any help would be greatly appreciated.
Dr. Craig responds:
Kamal, receiving a letter from a Christian brother in a place as far-flung and as hostile to Christian belief as Nepal made my day! So even though your professor’s objections are based on pretty elementary misunderstandings, I wanted to share your letter with others.
I’m afraid that your professor is mostly incorrect in what he says, Kamal. Your prof errs in thinking that the ontological argument goes back earlier than Anselm and in thinking that Anselm’s version is the best version of the argument. As Plantinga (as well as Leibniz) has explained, Anselm’s version needs reformulation; moreover, Plantinga’s version is not susceptible to your prof’s objections.
For example, his objection to (2) is based upon an apparent unfamiliarity with possible worlds semantics. To say that some entity exists in a possible world is just to say that such an entity possibly exists. It isn’t meant that the entity actually exists somewhere. Look again at my explanation: “To say that God exists in some possible world is just to say that there is a possible description of reality which includes the statement ‘God exists’ as part of that description.” Only if that description is true will the entity, in this case God, actually exist. So (2) is definitionally true.
Again, (3) is virtually definitionally true. A maximally great being is one that has, among other properties, necessary existence. So if it exists in one world, it exists in all of them! In that sense, such a being is different than contingent beings, which exist in only some possible worlds. A unicorn, for example, exists in some possible world, but not in all of them, for its existence is possible but not necessary. So your prof is right that there is something special, not about a maximally excellent being (which, you’ll recall, is defined to be a being which is all-powerful, all-knowing, and all-good), but about a maximally great being, which is defined as a being which has maximal excellence in every possible world. If such a being exists in any world, that is to say, if it is possible that such a being exists, then it exists in every possible world, including the actual world.
Logic doesn’t falter here. It all hangs on whether you think that (1) is true. (2)-(5) are true whether or not (1) is true. But if all the premisses are true, the conclusion logically follows.
There is a lesson to be learned in this. Students rightly have respect for their professors. We should learn from them in humility. But the fact is that many professors, both in the Anglophone world and especially outside the Anglophone world, are nearly clueless when it comes to Philosophy of Religion. I have been mortified by the simplistic and misconceived refutations of theism and theistic arguments that students often share with me from their Intro to Philosophy classes. You are well-advised to be quite critical about what your professors say about this subject, especially if they do not evince familiarity with the philosophical literature and are not interacting with other philosophers in the field who do not share their positions.
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