Posted: Apr 05, 2011 5:39 pm
by Paul Almond
The modal ontological argument deserves to be taken seriously in one respect: it is an ingenious and contorted piece of dishonesty to cause confusion in the gullible and philosophically naive. It works on multiple levels. First, there is the basic “proof” which tries to suck you into a detailed discussion about modal logic. After that there is a whole meta-argument, containing the original argument, about intuition and how all this is supposed to establish the rationality of what the argument just failed to show.

One thing I want to clarify - when I talk of an intuition about modal possibility being justified, that may seem strange. Isn't the whole point of intuition that it isn't justified - that there is no formal argument behind it? Really, by "justified" I mean "explainable by some kind of process that produces the intuition" or "having characteristics similar to other kinds of intuition" or "there is a plausible source of the information" involved in the intuition. The point here is that the possible worlds in Plantinga's possibility premise don't seem to give anyone anything more than that which a single world - this world, or the actual world - gives. The idea that we sometimes have intuitions about possibility is misleading.

Mick, if I claimed to have intuitive knowledge that it is modally possible that the Goldbach conjecture is true, do you think this could be a plausible claim - and how would you differentiate it from the claim of someone else who simply claims to know, intuitively, that the Goldbach conjecture is true? In each case, the person having the intuition is claiming to know something about mathematics. In the first case, someone (I) is claiming to know something about the disposition of mathematics in all possible worlds - and it is identical mathematics in each possible world. Saying that I somehow, intuitively, work out that something is the case in one possible world, and then extend this to all of them via S5 is just a distraction: I would actually know from the start that anything that I say is necessary in one possible world is possible in all of them. (Of course, you can attempt to refute this by raising the idea of possible worlds which are mathematically inconsistent with each other - but you really don't want to go there as a Plantinga advocate.) It should be apparent here that any mathematical intuition I have is not about "the existence of a possible world" in which some mathematical truth applies - it is about the disposition of the entire set of possible worlds. If I claim to know, intuitively, that a mathematical statement is modally possibly true, I am actually just claiming that it is true - assuming that mathematical statements are necessarily true (and they seem about as close to necessity as we can expect to get). Plantinga's claim of intuitive knowledge of the "possible" existence of a God is not just a claim about "possible" existence: it is a claim of modally possible existence. Regardless of what Plantinga says (and I don't value that highly) the general public associate this with our everyday idea of "possibility" and think that this is a fairly reasonable claim - one hardly needing support. In fact, it is a super-strong claim: it is a claim that the entire set of possible worlds have some feature.

If I were to claim to you, now, that I intuitively know that it is modally possible that the Goldbach conjecture is true, while also claiming that I am not claiming to know intuitively that it is true - but that the actual truth of the Goldbach conjecture follows from my intuition that it is true and the fact that mathematics is necessary - would you find this plausible?

There is one way in which someone might try to evade this. Suppose we say that intuition may come to us in ways that we cannot understand - and we should not view intuition in terms of any kind of processing of any information that comes to us from an external source. I am saying, here: suppose we avoid thinking that we must have any kind of "mechanism" in mind to justify the intuition. Someone claims to have an intuition that X, which is necessary if true, is true in a possible world. When challenged that he is simply claiming that X is true in all possible worlds, and therefore is actually true, he looks at us surprised. He explains that S5 did not occur to him, that it did not even occur to him that what is necessary in one possible world is the case in all of them. In fact, before our discussion, this person did not even realize that his intuition, if correct, means that X is actually true! Now, that person may feel that is unfair that we say that his claim to know intuitively that X is modally possibly true is just a claim to know intuitively that X is true: after all, until now he did not even know that his intuition implies that X is actually true! Does this help at all? Does it make his intuition any more plausible? No. All that is going on here is that we are imaging a very naive person, who can have an intuition in such a specific way that something else that should clearly be seen as part of that intuition goes over his head. The idea that X is true in a possible world and the idea that X is true are so closely related - so philosophically similar to each other - that any distinction is hardly relevant. None of this matters unless we are expected to infer something from this person's intuition - and he now tries to persuade us that his intuition of X's modally possible truth, together with the argument extending this to make X true in all possible worlds, somehow makes belief X rational. How does it do this? This can only make sense if we take the person's intuition seriously. We don't necessarily have to be convinced that he is right - but we may somehow think that his intuition has a good chance of being right - and that this translates into a good chance that X is true in all possible worlds, and is therefore actually true. But why should we take this any more seriously than if he had just said, "I intuitively know that X is true" - if he had said that, and we took it seriously, we could similarly view that as making belief in X more rational. Why should an intuition that X is modally possible be any more persuasive than an intuition that X is true - in the sense that we should think that the first intuition is more likely to be correct than the other? The "power" of the intuition is the same in each case. One intuition is supposed to be about what is true in a single, actual world, while the other intuition is supposed to be about what is true in some possible world which, with regards to what is being argued about here, is exactly the same as every other possible world. There is nothing about appealing to possible worlds that makes the reliability of the intuition any more likely. Again, I refer to my Goldbach conjecture analogy: someone who claims to know intuitively that the Goldbach conjecture is true should be no less persuasive, all else being equal, than someone who claims to know intuitively that the Goldbach conjecture is modally possibly true. In both cases, an intuitive ability of similar power is being claimed. We would generally say that the two claims are equivalent, but even if we accept some difference (and it would really be nothing but pedantry) it would not matter because in any important respect they are the same kind of claim.

Plantinga could have made his argument much shorter and easier to follow if he had done it this way:

S1: I intuitively know that God exists.
Conclusion: Therefore, it is rational to believe in God. Even if you aren't convinced by my intuition, the fact I am having it shows that my belief is rational.

People would have laughed at this - because it all hinges on this intuition which cannot be supported at all. In making the modal ontological argument, Plantinga has merely replaced this intuition with an intuition that "God's existence is modally possible". People get confused by this in two ways. Firstly, they conflate it with everyday possibility - this is probably how most theists view this argument - and then the whole train-wreck gets put into operation - or they recognize it as a modal claim, distinct from a claim of everyday possibility, but think that it is somehow weaker than a claim of God's actual existence - that it is more plausible to think that someone could have had this kind of intuition - that it is a more limited kind of intuitive process - however it happens or wherever all this is supposed to come from (I imagine some magical Platonic realm which looks like a Beatles album cover)- that could produce such an intuition. I should have shown here, by analogy with claims about mathematical intuition, that it is wrong to think this - that claims of intuition about possible necessity are as extreme as claims about necessity.

As an analogy for all this:

Suppose the police were looking for a serial killer. I go into the police station and say, "Look! I'm a genius. See my posts on Rational Skepticism? I won all these Orsons. I have a fantastic intuition about things - and I want to use that intuition to help you catch this murderer. I think I know where he is! I know because of my intuition! The killer is in Covent Garden, London."

The police officer who talks to me is sceptical, and ask how I know this. I explain that it is intuition. Do I really know where the killer is? the police officer wants to know. "Oh, sure I do," I reply. Every bit of the killer is in Covent Garden. His eyes are in Covent Garden, his nose is in Covent Garden, his ears are in Covent Garden, his fingers are in Covent Garden. Get the picture? Go and arrest him before he gets away!"

The police officer is not persuaded, and he throws me out. He thinks I am making an extreme claim, and he doesn't view my intuition as helping to make it rational to believe that the killer is in Covent Garden. I seem to be claiming a massive degree of intuition and he just can't plausibly see how I can do that.

The next day, I go back to the police station. The police officer reluctantly agrees to talk to me again. I now tell him that I have had another intuition. "Not another one!" he exclaims in dismay, "Are you going to make another implausible claim to have intuitive knowledge about something, even though there is no reason to think you could have come by this knowledge and that it is reliable? Is this another extreme claim that you possess some intuitive knowledge?"

"Oh, no," I say, "I'm sorry about yesterday. I realize now that my intuition wasn't to be trusted. I was claiming something very extreme- and it was hubris to think I could actually know where the killer was intuitively."

"So what is your intuition today?" the police officer ask me.

"Well, you know that yesterday I claimed that every bit of the killer was in Covent Garden: that his eyes were in Covent Garden, that his nose was in Covent Garden, that his ears were in Covent Garden and that his fingers were in Covent Garden?"

"And?"

"Well," I continue, "today I just know that the killer's ears are in Covent Garden."

"His ears are in Covent Garden?" the police officer asks me. "Why is that any more plausible than your claim yesterday?”

"Yesterday I was claiming intuitive knowledge that every bit of the killer's body was in Covent Garden. Today, I'm only claiming intuitive knowledge of where his ears are. Don't ask me how I know this: it is intuition. Have you ever lost something, and you just kind of know where it is, and you look, and it is there? Same thing. But with ears."

"Why would we want to arrest just a pair of ears?" is the reply.

"Don't you see?" I reply. "Simple human anatomy tells us that all the other parts of the killer are in the same place. Given that we now know that his ears are in Covent Garden, we can appeal to simple anatomical theory (and a reasonable belief that he has not been dismembered since his last murder), to say that all his other body parts - his eyes, nose, mouth, arms, legs, etc, are in Covent Garden. He's there right now - probably having a coffee and watching the mine artists. If you go there now, you don't just get to arrest the ears - you get to arrest the entire murderer!"

"That is one of the most stupid things I have heard!" says the police officer. "You came here yesterday with an implausible intuition that the murderer was in Covent Garden, and we didn't take you seriously. Today you have come here claiming to know that his ears…”

“and, by logical implication and appeal to anatomy, the rest of him!”

“Whatever,” Says the police officer. Why should we take you any more seriously today than yesterday?”

“Well,” I respond, “Yesterday I was claiming intuitive knowledge of where every part of the killer’s body was. Today I’m only claiming to know where his ears are!”

“You’re not!” exclaims the police officer. You’re still claiming to know where the killer is through intuition!”

“No!” I answer. “I am only claiming to know where his ears are. That is a less extreme claim of intuitive knowledge. The rest follows from human anatomy.”

“You’re still claiming intuitive knowledge of where the killer is!” says the (by now) very impatient police officer.

“I think that is a bit unfair,” I reply. “Can’t you see that a claim of intuitive knowledge about there whereabouts of every part of the killer’s body and a claim of the whereabouts of his ears are different things?”

“But you haven’t given any explanation of how you came by this intuitive knowledge!” says the police officer.

“It’s intuition!” I answer. “Of course I don’t know how I know. I just know.”

“So you want us to accept,” says the police officer, “that your claim to intuitively know where the killer’s ears are – and therefore from knowledge of human anatomy, the rest of his body – is more plausible than your claim, yesterday, of knowing where the entire killer was intuitively?”

“Yes, you’ve got it!” I answer.

“Why should the claim about the ears be any more plausible?”

“Well, I’m not claiming as much am I? Even if you aren’t sure that I’m right, don’t you see that my intuition about the killer’s ears makes it rational to believe that he is in Covent Garden?”

“What intuition could you possibly have about the killer’s ears that you wouldn’t also have about the entire killer? None of this makes sense. For example, your intuition that the killer is in Covent Garden might be based on meeting him, or someone who knows him, in the past. Maybe you went to Covent Garden and saw him there sometimes? Maybe you’ve worked out that he likes coffee? But what could you possibly be expected to find out, in any easier or more plausible way, about ears? What exactly is going on that delivers knowledge about serial killer ears to you that it is more reasonable to believe in than some process that delivers knowledge about serial killers in general?”

“Please phone the local hospital,” I say.

“Wanting to commit yourself to a psych ward?” the police officer asks.

“No, but it occurs to me that you are out of your depth here, officer. There are complex matters of human anatomy involved, and I’m not sure that you fully appreciate the way in which the presence of the killer’s ears at Covent Garden would imply the presence of his other body parts, and therefore the presence of the killer. There has been a lot of investigation about the relationship between the different parts of the body, and I think we need to ask a surgeon to come here so he can explain it to you. It isn’t your fault. Police officers can’t be expected to know about anatomy, so don’t feel bad.”

At this stage, I get thrown out again.

What I described myself as doing in that story is exactly what Plantinga is trying to do when he suggests that an intuition about the modal possibility of a necessary truth counts for anything. The claim that the killer’s ears are in Covent Garden is equivalent to the claim that Plantinga’s being exists in a possible world. My intuition that the killer’s ears are in Covent Garden is equivalent to Plantinga’s intuition that his being exists in a possible world. My claim that the entire killer is in Covent Garden is equivalent to the claim that Plantinga’s being actually exists in the world. My intuition that the entire killer is in Covent Garden is equivalent to any intuition (which Plantinga is allegedly not claiming) that his being actually exists in the world.

It should be obvious what the problem is in my story – and the same problem exists with any intuitive support of Plantinga’s modal possibility premise. The modal possibility premise is so powerful, and requires so much knowledge about Plantinga’s being, that it may just as well be direct knowledge about the existence of this being. If we can imagine any process by which intuitive knowledge could come to us that the modal possibility premise is true, it should be no less plausible to imagine intuitive knowledge that the actual conclusion of the argument is true – except everyone would just laugh if we said that. There is no plausible process, mechanism or source of knowledge for the intuition in either course.

I actually regard Plantinga’s modal ontological argument as reality-trolling on a massive scale.

EDIT - NOTE: in the story above, I referred to "Orsons." In case anyone does not know what they are, they are awards that are given out on the Rational Skepticism website (the website you are on now) for excellent posts or series of posts. If someone made a post, or number of posts, that represented very high quality work in refuting an irrational position (for example, by explaining why an argument by a famous argument by a well-known Christian apologist is wrong), then that person would be awarded an "Orson". I am just saying that in case I confused anyone who is new here.