Taken in isolation, this would not seem an unreasonable assumption. But it is not taken in isolation. This problem is true of many assumptions – alone they may be reasonable, but taken in conjunction with other assumptions, they may become unreasonable.
Then the word “possibly” is redundant under modal logic – and so serves no purpose other than to confuse or obscure. So why is it included in in the argument?
Take the original proposition:
There is a possible world W in which there exists a being with maximal greatness.
Remove the redundant “possible” and substitute in the definitions for “maximal greatness” and “maximal excellence”, and you are left with the real proposition that:
In every possible world there exists a being with omniscience, omnipotence, and moral perfection.
You left out the option that God is in fact not a necessary being. I’m not sure if this is logically coherent (carefully avoiding using the fraught words “possibility” and “possible”), but it would seem less catastrophic than logic not being true.
But even if there are only your three options, it leaves me in a linguistic, and potentially logical, ‘no man’s land’. I can conceive both the idea that God exists in all possible worlds, and the idea that he exists in no possible worlds, and I cannot a priori rule out either conception. How do I express this uncertainty in terms of modal logic?
(In common English I would express it as he possibly exists in all possible words and possibly doesn’t exist in all possible worlds – but modal logic would appear to preclude me from using “possibly” in this sense.)
Yes, but it’s use in the P1 you quoted, given the definitions contained in P2 & P3, would seem closer to the former than to the latter. When “a possible world W” is definitionally overridden by “every possible world”, it serves no informational purpose, so one has to ask why it is there (other than to mislead)?
If so, however, the obvious conclusion would be that modal logic is barking mad. That, and/or that trying to treat possibility and necessity as though they were real attributes of real things, and then to perform logical operations thereon, is basically a logical divide-by-zero error.
Existence can be formalized as a predicate, but that buys us all sorts of ridiculous sounding nonsense, like things that have the property of existing but do not actually exist, or a subset of possible worlds where contradictions are allowed, appropriately called “impossible worlds”.
The much easier way out is to say that existence is just not a predicate at all (but a quantization, rather). In that case, however, things like the modal ontological argument can no longer be written in formal notation. It is a string of words that cannot be correctly or fully represented in a formal language. We make of that what we will…
As I understand it, that is the issue under dispute. God, by definition, is a “necessary being.” As such, he must exist in every possible world.
The question, then, is: If it is not impossible that such a being exists, then is it necessary that it exists? If so, then it does exist.
It seems logically straightforward to me that, if it is possible that such a being exists, then it must exist. By the same logic, if it possible that 2 + 2 = 4, then it is the case that 2 + 2 = 4. That is to say, if we start from the (reasonable) premise that mathematical truths are necessary truths, then once we have determined 2+2=4 could be true, we have determined that it is true in all possible worlds.
Here is the rub, I think: In that case we are talking about metaphysical possibility. That is to say, it is possible as a result of the nature of the concepts under discussion. To illustrate, consider a more complicated example. Is it possible that the billionth digit of pi is 6? Without looking it up, I would say it is possible. There are ten possibly correct answers, and 6 is one of them.
However, I then look it up and find the billionth digit of pi is actually 9. Therefore, it is not possible that it is 6.
How could the same thing be both possible and not possible? Because we are talking about two different modalities of possibility. The first mode ("It is possible that the billionth digit of pi is 6) is epistemic possibility. That is, based on everything I know (before I have looked up the answer) it is possibly true.
However, it is not metaphysically possible that the billionth digit of pi could be 6. Metaphysical possibility refers to the nature of things as they are, and such possibilities are independent of whether or not one knows them to be the case.
So part of the difficulty with the modal ontological argument is that it is not always clear which mode one is using. If we say it is possible that God exists, I suspect we are generally using epistemic possibility. But if we are dealing with the question of whether he actually does exist, we are then talking about metaphysical possibility. In that sense, it could be (and IMHO most probably is) the case that God does not possibly exist. If the modal ontological argument is valid (and it seems to be) that is the only option available to the atheist.
The trick apologists will often play is to confuse these two senses of possibility by allowing the atheist to make the quite reasonable concession that the existence of God is (epistemically) possible, and then proceed to argue from God’s metaphysical possibility. That is why the atheist is often left with the feeling that he has been the victim of a shell game. In a sense, he has been.
That would appear to be an absurdity – you cannot define something into existence.
Otherwise I could define unicorns as necessary, and then they’d have to exist in every possible world.
I do not accept that God is necessary.
I can conceive of a world in which he exists. I can conceive of a world in which he doesn’t exist. Unless and until somebody can demonstrate either world’s impossibility, I view both as “possible worlds”. Therefore God does not exist in all possible worlds, and God does not not exist in all possible worlds. Therefore God is not necessary.
You have not demonstrated that God’s existence is analogous to 2 + 2 = 4.
You have failed to explicate metaphysical possibility. All that I can ascertain from your explanation is (i) that it is different from epistemic possibility, and (ii) that it is not metaphysically possible that the billionth digit of pi could be 6. Is it possible that it is 1? 2? … What digit is metaphysically possible? Any of them? Or do you mean that only one digit is a metaphysical possibility, but we don’t know which digit that is – as the digit is deterministic across all possible worlds, but is unknown?
Assuming that this is in fact what you mean by “metaphysical possibility”, are you arguing that my two conceivable worlds above are merely epistemic possibilities, not metaphysical possibilities?
If so, then how do you demonstrate that they cannot both be metaphysical possibilities?
Please note that I will not accept Classical Theism’s definition of God as “necessary” as a reason, as I do not accept Classical Theism, so am under no obligation to accept their definitions unless I choose to.
Yes, but all this does is earn the apologist (i) a fleeting ‘gotcha’ moment and (ii) permanent distrust thereafter. It seems more than a little counter-productive.
And that’s where understanding the role of definitions comes in. All that tells you is that a being that does not exist in every possible world fails to qualify for the label “God”.
Further for any definition adding a clause can only make it less likely that something exists, not more likely.
Therefore it cannot be more likely that a maximally great being exists than a maximally excellent being does. So if you do not accept that a maximally excellent being actually exists then you should not accept that a maximally great being even could exist.
Thus arguing from the definition is mistaken - necessity must be shown, not simply assumed on the basis of the definition. If it is possible that a maximally excellent being does not exist it is impossible that a maximally great being exists.
I would say that is so only in modal logic where “possible” differs from more usual uses. You are absolutely right to raise the issue of epistemic possibility - the premise of the modal ontological argument invites such a reading and is often defended by such a reading even though it is - as you say - wrong.
From my points above I’d say that necessary existence will often be impossible in modal terms. In fact if it turns up in a definition we should consider it very likely that it is impossible for anything to meet the definition. And that is so even when the other parts of the definition are easily met, which is certainly not the case for a maximally great being.
You could try, but then you would have to defend the position that necessary existence is part of what defines a unicorn as a unicorn.
I do not believe it is just an arbitrary add-on, intended just to win arguments, that necessary existence is included among God’s attributes. It seems as much part and parcel as omniscience, omnipotence, perfect moral virture, etc.
They are analogous here only in the sense that if they are true in one world, they are in all worlds. However, it is much simpler to demonstrate that 2+2=4 is true in one world.
I mean that only one digit is metaphysically possible and that is the correct one (9). And that is the case regardless of whether anyone, anywhere, in any world actually knows what the correct digit is. That is because, by its nature, there is only one possibly correct value for pi, and this will be the same in all possible worlds (if we accept the intuitive
premise that mathematical truths are necessarily true in all possible worlds.)
Well, sure, that is one approach: To simply deny necessary existence as one of God’s attributes. But that doesn’t address the problem of whether, if we do accept it as one of his attributes, are we then committed to also accepting his existence.
Did you watch the video from Joe Schmid I posted above? If so, what did you find unconvincing about his explanation?
Yes, the argument assumes modal logic. And another possible counterargument is to reject modal logic itself. But, given how widely accepted this is, one would need a better argument for such rejection than the fact that it seems to support the existence of God. Really, I don’t think calling basic logic into question is a good approach in any debate.
No, I very rarely watch videos. Very rarely. In what way does he disagree with my point?
I don’t. I do insist that modal possibility should be understood as modal possibility and certainly never confused with logical or epistemic possibility. I don’t believe that it is identical to metaphysical possibility either.
I’ll use the example he gives, but change it so that, instead of “A necessary being exists” I will use the premise “2+2=4”.
If we say that it is possible that 2+2=4 is true, that means there is a possible world, W, in which it is true that 2+2=4.
However, let’s also stipulate that if 2+2=4 is true, then it is necessarily true. This entails that, if it is true in world W, then it is true in all possible worlds, including ours.
The only way to avoid the conclusion that 2+2=4 is true then, is to assert that it cannot be true in any possible world.
Now, for “2+2=4”, substitute “a necessary being (God) exists”, and the same argument applies.
The whole idea of necessity only makes sense in the context of being necessary for something else. It’s necessity must follow from something. Otherwise how does it make sense to say it is necessary? You can’t just define something to be necessary full stop. You must provide an account of it’s necessity. It is necessary for what? It has to exist, because otherwise some contradiction is implied, or something else known to exist is proved to be contingent on it.
If brute necessity can just be declared, then so can superfluence. God is by definition superfluous to requirements. What are you gonna do now but stamp your feet?
I agree. But it’s necessarily true in virtue of what every symbol in that equation means. 2, +, =, and 4. Properly understood, each of those makes the equation necessarily true.
What is it that makes God’s claimed necessity, actually necessary? What is the relation that demands this conclusion that God is necessary? Necessary in virtue of what? I simply don’t understand the concept of a thing necessarily exists. Why would it if it is not because something else contingent on it existing, is already known to exist?
I don’t think that’s as problematic as you do. By all ordinary definitions of “possibility,” (which really means something akin to Hume’s notion of things not dismissable a priori: something which can be distinctly conceived and involves no contradiction in terms) this sort of outcome is just wrong:
So, by all ordinary usages, if modal logic does indeed result in such a connection, modal logic IS wrong. I have no idea whether it actually does. And if modal logic requires a usage of the word “possible” which is entirely inconsistent with ordinary usage, then we really need not claim it is right, given a completely asinine definition of possibility: the best outcome is that those who are misusing the word ought to invent a novel term to describe what they are presently misusing “possibility” to describe, rather than raiding ordinary language to render it silly.
But the sense I am left with is that when the theist asks the atheist whether, within the scope of imagination, a god or “maximally smelly/perfumey, maximally rough/smooth, maximally conductive/resistive, maximally large/small” being is something one can regard as possible, he really means to ask the atheist whether this God/Max-a-million EXISTS, not whether it is possible that it exists. If so, the whole thing collapses to: “if we assume God/Max exists, then God/Max exists.”
And again: doesn’t all of this just show that what is involved here is mere word-shuffling, having no relation to the external world? Text, unaided by anything except untenable definitions, cannot demonstrate a fact about the world.
I would add that in law, anyone who grapples with linguistic ambiguity, as one inevitably must, is left somewhat with the feeling that there is no language in our lungs adequate to the task of describing the world. But law being a rubber-meets-road discipline, we are thrown out of the purely philosophical and theoretical and into the practical, however roughly we may land. Philosophy, sadly, has no process of ejection like that, to force the philosopher to render his notions useful.
That would be a different argument from Plantinga’s.
Also, your stipulation would be redundant for “A necessary being exists”
But most importantly it does not clash with my points at all. Indeed I give reasons that a necessary being - by it’s necessity - should be considered very unlikely to exist in any possible world.
