it must have some basis in reality — Wayfarer

but is there any argument saying if it was there then we couldn't have missed to pick it up?
Arguments stay debatable for ever. Agnosticism is right to a certain extent.

There are many versions of it, some intensely complicated. The OPs version is Anselmian, and those arguments typically run:

(1) If God exists then God necessarily exists. (G -> nG) [Partial Definition of God]
(2) If its logically possible that God exists then God exists (pG -> G) [From (1)]
(3) It is logically possible that God exists. (pG) [Premise]
(C) God exists (G) [From 1-3]. — PossibleAaran

This doesn't really have much to do with Anselm's argument, other than being a species of an a priori "ontological" argument, one that, in a way of magical thinking, attempts to reify logical constructs.

Imagine a being, such that it cannot fail to exist.
Therefore, it exists. — SophistiCat

You see I don't think so. None of the premises of the argument say 'imagine a being such that it cannot fail to exist'. — PossibleAaran

I glossed possibility as conceivability - perhaps not quite what Plantinga was trying for. In his version he actually breaks the premise into two in order to obfuscate his meaning. It goes something like this:

First he asks us to accept that a Super-Duper Being is at least within the realm of the possible (not his exact words, of course, but that doesn't matter, since he doesn't explain what the words mean in this premise). Hopefully, a charitable and careless reader will not ask what a Super-Duper Being is and will grant this premise for the sake of an argument.

Then he spring the trap: a Super-Duper Being is one that, among other things, exists necessarily (cannot fail to exist). And he further stipulates that the words "possible" and "necessary" were being used in a technical sense of the S5 modal logic, where stacked modal operators collapse into one.

In the possible world semantics, a Super-Duper being is such that, if it exists in one possible world, it exists in all possible worlds. So the premise then is simply that it does exist in at least one possible world. Of course, stated this way, no one who does not independently believe the conclusion would go along with such an argument (and those who do ought not go along with it either).

But necessary existence is a property, and is immune to the criticism which Kant makes. — PossibleAaran

It is illegitimate to predicate existence in all possible worlds, just as it is illegitimate to predicate existence in some possible worlds. And @Michael's argument neatly shows why it makes no sense to predicate existence.

Perhaps we could argue that the world is the necessary thing, as it seems tautological to say that the world exists in every possible world. — Michael

Possible worlds for the World are just all the ways in which the World could possibly be (where the sense of "possibility" is left open).

It's premiss 2.

From the fact that we can imagine something, nothing follows about its existence. Imaginability and existence are logically distinct.

We would need another premiss, e.g.:

2a. Something that exists is greater than something that is merely imagined.

That's a dubious premiss. Of course, if there were a real God, then a real God would be far greater than a merely imaginary God. But if there is no real God, then the imaginary God (being the only God there is, ex hypothesi) is the greatest God of all. So 2a begs the question. And it's needed to comlete the argument.

I don't know. I read that passage you linked to from the Summa, and I really don't think Aquinas does succeed in refuting Objection 1. And I think subsequent history has borne out the argument that the existence of God cannot be 'demonstrated scientifically'. — Wayfarer

The point is just that Aquinas (and the traditional Catholic church) claimed that it could be. They rejected fideism.

The point I was making was more specific - it was about the sense in which something like ‘the ontological argument’ can be regarded as persuasive. After all, none of those particular philosophers would concur that it is (granting that the first two were historically prior to it.) What I’m saying is, in order to regard it as conclusive, or to understand the terms of the argument in such a way that it seems to be, already indicates a pre-disposition to believing it; I think, perhaps, it is that very pre-disposition that is really meant by the term ‘belief’. (But I do quite agree that it’s a very delicate question.) — Wayfarer

Yes, though the defenders could claim the same about those who reject the arguments (and the Catholic church did!) However it's worth noting that not all Scholastics accepted the proofs. For example Aquinas himself rejected the Ontological argument and Ockham rejected all contemporary arguments for God's existence including Aquinas' Five Ways (he was a fideist).

I think it is fair to argue that the existence of scientific laws suggests an Author, but that whether that is so, must be a matter forever beyond scientific demonstration or (I suppose you could say) mundane certainty. That's why I said before, I think it's important to always have a sense of the unknown-ness of whatever is claimed to be ultimate or absolute; so, to say that God can be demonstrated or known scientifically seems hubristic to me. — Wayfarer

Sure, but part of that may just reflect a difference in philosophical outlook (for example, you seem to hold that such demonstrations are impossible in principle). Presumably from the Scholastics' point-of-view, their arguments seem sound to them. As they see it, those that disagree just need to critique the arguments. One's prior dispositions to belief or unbelief aren't relevant to that.

So the ontological argument doesn't defend its assumption that the necessary thing (assuming there is one) has those other properties posited of God. — Michael

I think you are right about this. While the assumption is defended by defining God as 'the most perfect being', this defence is objectionable on the grounds that what is and is not perfect is entirely subjective and context dependant. If this is right, then the argument can at best show that there must be something which necessarily exists. But what is it? Who knows.

(2) If it's logically possible that a necessary thing exists then a necessary thing exists — Michael

Although saying that, I find 2 troublesome. To be logically possible is to exist in a possible world and to be necessary is to exist in every possible world, and so the second premise states that if a thing which exists in every possible world exists in a possible world then a thing which exists in every possible world exists. It defines a necessary thing into existence. — Michael

I am not sure that 2 'defines a necessary thing into existence' if this is meant to be a bad thing. If a necessary being exists in one possible world (it need not be the actual one. Suppose it isn't), then it must exist in every possible world, including the actual world. The point of 2 is that, from the assumption that a necessarily existent being is logically possible, it follows that a necessarily existent being exists. It doesn't define anything into existence. You might accept 2 and deny that a necessarily existent being is even logically possible, and thereby avoid the conclusion.


All of this is quite uncharitable to Plantinga.

First he asks us to accept that a Super-Duper Being is at least within the realm of the possible (not his exact words, of course, but that doesn't matter, since he doesn't explain what the words mean in this premise). Hopefully, a charitable and careless reader will not ask what a Super-Duper Being is and will grant this premise for the sake of an argument. — SophistiCat

He does define his 'super-duper being' very carefully. He defines a maximally great being as one which is maximally excellent in every possible world, and maximal excellence is defined as entailing omnipotence, omniscience and moral perfection. To wit, the first two premises of his argument from the Nature of Necessity, page 214:

" (34) The property has maximal greatness entails the property has maximal excellence in every possible world.
(35) Maximal excellence entails omniscience, omnipotence, and moral perfection. "

You are right that he asks us to accept that it is possible:

"(36) Maximal greatness is possibly exemplified. "

He doesn't explain what 'possibly' means in these passages, but it is uncharitable to say that he 'springs the trap' revealing that 'possible' was being used in the technical sense of modal logic. The argument is discussed in detail in The Nature of Necessity, which is a book entirely about the possible and the necessary, in the technical sense of modal logic. So when he comes to discuss the Ontological Argument, he takes it that people who have read him thus far will know that he is still using the words in the same way he was using them throughout the book. Hardly a sprung trap.

Of course, stated this way, no one who does not independently believe the conclusion would go along with such an argument (and those who do ought not go along with it either). — SophistiCat

This is a criticism which Plantinga himself makes of the argument, and he makes it in the Nature of Necessity. Nonetheless, I think he should not have made it, because its a poor criticism which rests on ambiguity. It is true that if I look at the argument, and I am utterly convinced that God does not exist, then I won't grant Plantinga's 36, once I see that 36 entails God's existence. Obviously I will reject it. But that's just a fact about my bias, not a reflection of the worth of the Ontological Argument. If I am utterly convinced that the earth is flat, then even if you show me a photograph of the earth from space, if I understand that this being a photograph of earth entails that the earth is not flat, I will deny that it is really a photograph of earth. And again, that's a reflection of my own bias, not of the worth of the argument against flat earth.

But then, suppose I don't have this bias. Suppose that I am not such that, when I see that a premise entails that God exists, I will not accept that premise. Suppose I don't believe that God exists but if I were shown that God's existence follows from something that I do believe, I would accept it. Suppose I also believe that the concept of God is perfectly coherent. Plantinga might point out to me that the coherence of the concept entails the logical possibility of God's existence, and then further point out that the logical possibility of God's existence entails his actual existence. Wouldn't that be convincing for such a person?

You also say that it is illegitimate to predicate necessary existence. Why? You say that Michael's argument shows why. But which argument of Michael's do you mean? Do you mean the argument that we can tack 'necessary existence' onto any concept and then create an argument for its existence, regardless of what the concept is?

Best
PA

If a necessary being exists in one possible world (it need not be the actual one. Suppose it isn't) — PossibleAaran

How can a necessary thing exist in one possible world but not the actual world?

I can't quite put my finger on the actual logical misstep. There's something wrong about talking about the logical possibility of the logical necessary. I wonder if such talk requires something like Tarski's hierarchy of language, or different sets of possible worlds, and the argument above conflates the members of the hierarchy/conflates the sets.

It just isn't right to say that there must be a necessary thing because a necessary thing is defined as something that exists in every possible world (and so the actual world).

As I said, the only thing that could perhaps be said to exist in every possible world is "the world", which is just an abstract container.

How can a necessary thing exist in one possible world but not the actual world?

I can't quite put my finger on the actual logical misstep. There's something wrong about talking about the logical possibility of the logical necessary. I wonder if such talk requires something like Tarski's hierarchy of language, or different sets of possible worlds, and the argument above conflates the members of the hierarchy/conflates the sets.

It just isn't right to say that there must be a necessary thing because a necessary thing is defined as something that exists in every possible world (and so the actual world).

As I said, the only thing that could perhaps be said to exist in every possible world is "the world", which is just an abstract container. — Michael

It isn't that a necessary thing must exist because a necessary thing is defined as something which exists in every possible world. Rather, if the concept of necessary existence is coherent, there must be a necessarily existent thing, since coherence entails logical possibility. If there is something wrong here, my suggestion is that it is the concept of necessary existence. I could not prove that it is incoherent, but it does seem like a very strange concept - a thing which cannot fail to exist. Any logically coherent story of how things might be must contain this thing. Either the world of Harry Potter contains this thing or the entire story is incoherent. Either the world of Sherlock Holmes contains this thing or the entire story is incoherent. Either Lord of the Rings contains this thing or the entire story is incoherent. I suppose what is really strange about it is that any object which I can imagine is such that I can apparently give a perfectly coherent description of a world without that object. I cannot really imagine anything to have the property of necessary existence, and so I wonder, do I really understand that concept at all?

Sure, I can use possible world lingo to make it seem less obscure. "Imagine a being which exists in not just one possible world, but every possible world". I then picture all of these different spheres and the necessary thing is in not just one, but all of them. That's what necessary existence is, I tell myself. But its just a metaphor, and the fact remains that I can't imagine it at all in a particular concrete case. Nothing I can imagine is such that I can't also apparently imagine it not existing.

Best,
PA

Rather, if the concept of necessary existence is coherent, there must be a necessarily existent thing, since coherence entails logical possibility. — PossibleAaran

I think there's a fundamental problem with saying that a logical necessity is logically possible. I can't quite put my finger on what that problem is, though, but as I said before, my instinct is that it's related in kind to Tarski's hierarchy of language.

Sure, I can use possible world lingo to make it seem less obscure. "Imagine a being which exists in not just one possible world, but every possible world". I then picture all of these different spheres and the necessary thing is in not just one, but all of them.

The problem is that I can also picture a set of these spheres but not have one thing which exists in all them. So it's possible that there isn't a necessary thing? But a necessary thing, by definition, exists in every possible world, in which case it should be impossible for me to picture a set of all possible worlds that doesn't contain a necessary thing.

Who is to say that our world isn't part of my imaginary set of all possible worlds that doesn't contain one thing in common?

This is what I'm getting at with my reference to Tarski.

Also, I can picture a set of spheres of all possible worlds in which multiple things exist in all of them. So as I said before, the argument which depends on the necessity of God can be used to defend the existence of any number of things, like Flying Spaghetti Monsters or Zeus. So even assuming that one (or more) thing is necessary, it doesn't then follow that it (or one of them) is God.

I don't think you're picturing every possible world. Surely you can imagine that one of these spheres doesn't share this thing in common? I certainly can.

I can imagine a possible world without a God, and so God can't be necessary. It's ridiculous to think that you can just define him to be, just as it would be ridiculous for me to define the Flying Spaghetti Monster as being necessary. This is the problem with treating "existence" as a property.

Thank you.

Ge = a god that exists in reality
Gi = a god that exists in imagination

Ge is greater than Gi....sure

That doesn't mean Ge actually exists

I think we need to introduce the word ''that'' as below...

1. God is the greatest being imaginable.

2. If God is the greatest being imaginable then ''that'' God exists in reality.

Now we can see the flaw clearly because we can actually see how God is being moved from the imagination to the real world.

If god existed only in our imaginations, he wouldn't be the greatest thing that we can think of, because God in reality would be better. — Harjas

Kant is disagreeing with this premise (bold) — bloodninja

All we can say is that we imagine that a God that really existed, and thus was not nearly merely an imagined God, would be greater than a God that existed only in our imaginations. What does this reveal beyond what it may be able to tell us about the human imagination? How could it possibly tell us anything about what actually exists?

All of this is quite uncharitable to Plantinga. — PossibleAaran

He does define his 'super-duper being' very carefully. He defines a maximally great being as one which is maximally excellent in every possible world, and maximal excellence is defined as entailing omnipotence, omniscience and moral perfection. To wit, the first two premises of his argument from the Nature of Necessity, page 214 — PossibleAaran

Fair enough, I didn't read that book - my recollection is of his own gloss of the argument in a short paper that I no longer have at hand. So let's assume the more careful formulation as you present it.

In that case, he seems to be fairly laying his cards on the table (assuming the reader is paying attention!), thus severely handicapping the argument right from the start. His ontological argument is much weaker than Anselm's; he does not just beg the question: the premise that he asks us to accept is much stronger than the conclusion of the argument. Thus, even those who already believe the conclusion independently may not accept his starting premise. (You seem to be of that opinion, judging by what you said concerning the issue of necessary existence.)

I think there's a fundamental problem with saying that a logical necessity is logically possible. I can't quite put my finger on what that problem is, though, but as I said before, my instinct is that it's related in kind to Tarski's hierarchy of language. — Michael

It is not problematic in the formal system to which Plantinga appeals. But that formal system (modal logic known as S5) basically ratifies your intuition: it posits as an axiom (or is it a theorem?) that adding the qualification of possibility to something that is already necessary changes nothing - it is an empty move devoid of any consequence, like multiplying by one or adding zero. (By the way, the same happens when you qualify possibility with necessity: necessity in that case does no work either.) So when that move is made and expounded on in a natural language formulation that seems to appeal to our informal intuitions concerning possibility, and yet in the end we are assured that "possibility" and "necessity" were used in their strict formal sense all along, you are right to be suspicious.

But then, suppose I don't have this bias. Suppose that I am not such that, when I see that a premise entails that God exists, I will not accept that premise. — PossibleAaran

I hope I explained why this is not the reason that neither I nor anyone who understands the argument that Plantinga is making - not in retrospect, but right as it is unfolding - would be likely to accept it.

You also say that it is illegitimate to predicate necessary existence. Why? You say that Michael's argument shows why. But which argument of Michael's do you mean? — PossibleAaran

It is what @StreetlightX and @Michael (and, no doubt, others who have criticized Anselm's argument) have said about predicating existence (necessary existence, as has been discussed, has even more severe problems). Having properties implies existence. So when we predicate a property of something, the qualification "provided that the thing exists" is already implied. When we define a unicorn as "a horse with a single horn," the same definition could be equivalently restated as "a being, such that if it exists, it exists as a horse with a single horn." The actual predicate here is still "being a horse with a single horn," nothing more. So when we "predicate" existence of a being, that is equivalent to saying "a being, such that if it exists, it exists" - which is just a tautology that applies to any hypothetical being.

Do you mean the argument that we can tack 'necessary existence' onto any concept and then create an argument for its existence, regardless of what the concept is? — PossibleAaran

That, too. Plantinga's argument is, if anything, even easier to parody than the original. Those attributes of Super-Dupeness Maximal Greatness do no work in the argument - they ride free and thus can be replaced with anything whatsoever.

The point is just that Aquinas (and the traditional Catholic church) claimed that [the existence of God could be demonstrated scientifically]. They rejected fideism. — Andrew M

But are there only two options here - fideism, acceptance on faith, or 'scientific demonstration?'

Aside from faith (doxa or pistis) and science (scientia), I think there is another mode of knowing - sapience or sapientia. The reason being, that investigating the reality of spiritual matters, is undertaken in the context of a relationship with a Person, not, like scientific matters, measurements made of an object of perception. It is a different kind of 'knowing' - more like sapience, or gnosis, or noesis, or one of those kinds of terms that denotes a different cognitive 'style' to that of science as now conceived. But is also not strictly speaking simply a matter of belief.

Ockham rejected all contemporary arguments for God's existence including Aquinas' Five Ways (he was a fideist). — Andrew M

He was also a voluntarist i.e. believed God to be forever beyond logic, and a nominalist. Some would argue that this is where the decline into materialism began. (See What's wrong with Ockham?)

Having properties implies existence. — SophistiCat

What if there were a widespread but fallacious belief in God, which served a functional purpose, namely that of being the object of faith amongst believers, and around which the entire corpus of religion had been constructed, even though there was no actual God (as atheists, in fact, believe). In such a case, God would not be real, therefore 'non-existence' would be predicated of God; God would then exist as a kind of collective delusion, much as what Richard Dawkins says is the case; a God that is believed in, but one that is not real. However were there really God, then this would be 'a real God'. So in this way, both 'existence' and 'non-existence' can be predicated of God. That is an objection to Kant's criticism of the ontological argument, I would be interested in hearing counters to it.

"Knowledge," says Clement, "is more than faith." "Faith is a summary knowledge of urgent truths, suitable for people who are in a hurry; but knowledge is scientific faith." "If the Gnostic (the philosophical Christian) had to choose between the knowledge of God and eternal salvation, and it were possible to separate two things so inseparably connected, he would choose without the slightest hesitation the knowledge of God." On the wings of this "knowledge" the soul rises above all earthly passions and desires, filled with a calm disinterested love of God. In this state a man can distinguish truth from falsehood, pure gold from base metal, in matters of belief; he can see the connexion of the various dogmas, and their harmony with reason; and in reading Scripture he can penetrate beneath the literal to the spiritual meaning. But when Clement speaks of reason or knowledge, he does not mean merely intellectual training. "He who would enter the shrine must be pure," he says, "and purity is to think holy things." And again, "The more a man loves, the more deeply does he penetrate into God." Purity and love, to which he adds diligent study of the Scriptures, are all that is necessary to the highest life, though mental cultivation may be and ought to be a great help.

Dean Inge, Christian Mysticism and Speculative Platonism

This is from Clement of Alexandria, around first-second century AD, when the idea of there being a 'higher knowledge', here presented as a 'scientific faith', was still in circulation; suffice to say it is from a different historical period, and reflects a completely different understanding, of what 'scientific knowledge' comprises than what is understood today, being more typical of what used to be called 'scientia sacra'. Nevertheless, I think this idea of there being a higher order of knowledge has dropped out of contemporary epistemology.

I don't think you're picturing every possible world. Surely you can imagine that one of these spheres doesn't share this thing in common? I certainly can. — Michael

I am sure you are right about that. I am only imagining at most five or six worlds. And not only do I think I can imagine that one of these six spheres has nothing in common with the other five, I seem to be able to imagine sets of possible worlds where no member of the set has any objects in common with any other member. But if the concept of necessary existence really makes sense, then I really can't do this, since all of the worlds must contain the necessarily existent thing. This is what I mean when I say that I can't imagine anything that is necessarily existent, and so I am not sure that I can really understand the concept at all.

I can imagine a possible world without a God, and so God can't be necessary. It's ridiculous to think that you can just define him to be, just as it would be ridiculous for me to define the Flying Spaghetti Monster as being necessary. This is the problem with treating "existence" as a property. — Michael

I think I can imagine a world without God, but what am I (you) really doing? I imagine some hills, trees and buildings. Perhaps I imagine a few people and an animal or two. I might imagine the earth as seen from space. The picture I paint doesn't have God in it, and so I conclude that I can imagine a possible world without God. But what I have imagined is at best a pathetically incomplete part of a possible world. 99% of the details about that world are left out, and all I have is a handful of images. Who knows, maybe if I did imagine the entirety of a possible world in all of its detail, I might discover that I can't coherently do so without including God. But then, maybe I discover that I can.

I am quite the sceptic about modal knowledge.

Best,
PA

the premise that he asks us to accept is much stronger than the conclusion of the argument. Thus, even those who already believe the conclusion independently may not accept his starting premise. — SophistiCat

The starting premise is that it is logically possible that a maximally great being exists. If someone believes that a maximally great being does exist, then they surely also believe that it is logically possible. Now consider someone who doesn't already believe the conclusion. Such a person might believe that the concept of a maximally great being is coherent. I think many people who deny the existence of God do believe that the concept is at least coherent. But then, it could be pointed out to them that this premise, which they believe, entails that a maximally great being exists. Why wouldn't that be an effective argument? I agree that most people always view the argument with suspicion when hearing it, but I think that is due to (1) the fact that people always view proofs of God's existence with suspicion, and (2) the Ontological argument is a priori, and people are always suspicious of a priori arguments.

I hope I explained why this is not the reason that neither I nor anyone who understands the argument that Plantinga is making - not in retrospect, but right as it is unfolding - would be likely to accept it. — SophistiCat

I am not sure you did explain that, or perhaps I missed it. Perhaps your thought is that once you see that the premise entails that God exists, you won't accept the conclusion. But isn't it true that every deductive argument is such that the premises entail the conclusion? If so, what exactly is wrong with the Ontological argument that makes it unpersuasive?

It is what StreetlightX and @Michael (and, no doubt, others who have criticized Anselm's argument) have said about predicating existence (necessary existence, as has been discussed, has even more severe problems). Having properties implies existence. So when we predicate a property of something, the qualification "provided that the thing exists" is already implied. When we define a unicorn as "a horse with a single horn," the same definition could be equivalently restated as "a being, such that if it exists, it exists as a horse with a single horn." The actual predicate here is still "being a horse with a single horn," nothing more. So when we "predicate" existence of a being, that is equivalent to saying "a being, such that if it exists, it exists" - which is just a tautology that applies to any hypothetical being. — SophistiCat

But this argument does not work against predicating necessary existence. I agree that the definition of unicorn as "a horse with a single horn" could equally be stated "a being, such that if it exists, it exists as a horse with a single horn". I also agree that when predicating existence of a being, it is like saying "a being such that if it exists, it exists", and this is to say nothing at all. But predicating necessary existence isn't a tautology and doesn't apply to any hypothetical being. Predicating necessary existence would be saying "a being such that if it exists, necessarily exists".

That, too. Plantinga's argument is, if anything, even easier to parody than the original. Those attributes of Super-Dupeness Maximal Greatness do no work in the argument - they ride free and thus can be replaced with anything whatsoever. — SophistiCat

I agree.

Let me make some general remarks first, just to make sure that we are on the same page (and to help those who are less conversant with the topic).

1. Modality is a way of thinking, talking, reasoning about the world. Modality can be a property of a proposition, but It makes no sense to talk about modal properties of a thing. Modality is a way of talking about things. So a "necessary being" is just a shorthand for saying that it is necessarily the case that such and such exists.

2. Modality can be understood and deployed in different ways. Those ways differ in their ground rules: what we hold to be fixed about the world, and what we allow to vary. Thus, an epistemic modality is where we reason from available evidence (presumably, also taking certain other things as given, such as known laws of nature). Nomic modality is where we hold just (some) laws of nature as fixed. Metaphysical modality is where we hold certain metaphysical constraints as fixed. And so on. Any set of constraints generates its own modal framework. As a limiting case, a priori (or logical) modality is where only the rules of inference are fixed.

For example, if I need to make my way from my office on the second floor to another office on the fifth floor, there are different ways in which it is possible for me to accomplish this. I can take different corridors, take different turns, use the stairs or the elevator, etc. But whatever I do, I have to contend with certain necessary facts: the fact that there are walls that I can neither move nor destroy (they are necessary beings in this context - they always exist in the same way, whatever course of action I take). I also cannot fly or teleport, there is a limit to the speed of my movement, etc.

3. There are different mathematical theories of modality, or modal logics. A theory is agnostic about the world on which it operates; it is agnostic even about the meaning of modal terms. All it does is it establishes certain rules for manipulating modal propositions. Defining the world and giving meaning to the modal operators gives a particular interpretation to the theory. As long as the rules of the theory are obeyed throughout, you are entitled to make use of its theorems to make meaningful inferences.

Now, returning to Plantiga's argument:

The starting premise is that it is logically possible that a maximally great being exists. If someone believes that a maximally great being does exist, then they surely also believe that it is logically possible. Now consider someone who doesn't already believe the conclusion. Such a person might believe that the concept of a maximally great being is coherent. I think many people who deny the existence of God do believe that the concept is at least coherent. But then, it could be pointed out to them that this premise, which they believe, entails that a maximally great being exists. Why wouldn't that be an effective argument? — PossibleAaran

You want to make use of the so-called S5 modal logic. In this theory, stringing several modal operators together has the same effect as taking just the last of those operators. So, something that is possibly necessary is just necessary. Any model (i.e. true interpretation) of this theory has to respect that rule. So when you propose that "it is ... possible that a ... being [necessarily] exists," that has to be understood as just proposing that "a ... being [necessarily] exists." Whatever interpretation you give to this proposition - however you interpret possibility and whatever properties your proposed being possesses - what I wrote above has to be the case, or else this is not a model of S5.

Yet, the way you want to reason, there seems to be a difference between the following two propositions:

(1) God exists as a matter of necessity,
(2) It is at least logically coherent to think of God as a necessary being.

One is a very strong proposition that obviously entails the conclusion of the argument, and thus it is no good as a premise. The other sounds like a much weaker proposition, one that we could accept without committing to the first proposition. Whether that is actually a reasonable reading of these sentences is not even the point - the fact is that you are trying to equivocate on the meaning of your modal terms. You are insinuating a meaning that is not consistent with the theory whose theorem you then want to use in order to reach the conclusion of the argument. You are not arguing in good faith.

Hi

Thanks for the detailed criticism. I agree with all of the background remarks.

The first premise of the Plantingan argument is:

(3) It is possible that a maximally great being exists.

Say that a maximally excellent being is one that is omniscient, omnipotent and morally good, like Plantinga does. We can then say that (3) is equivalent to:

(3*) It is possible that it is necessary that a maximally excellent being exists.

You rightly point out that the argument seeks to use the S5 model and so (3*) is really just tantamount to:

(3!) It is necessary that a maximally excellent being exists.

Thus, from (3), it follows that (3!). This just is the whole argument really; that God's existence follows from the logical possibility of his existence.

Your objection is that the argument trades on an ambiguity in the premise. Either the premise is:

(1) God exists as a matter of necessity,
or
(2) It is at least logically coherent to think of God as a necessary being.

You say that (1) obviously entails the desired conclusion, but as you point out, it is worthless because (1) just is the conclusion. So we have to understand the premise as (2). I am not sure what would be wrong with (2). You have said it is too weak, but I'm not sure why. Perhaps if I spell out my thinking directly, you could show me:

(2*) The concept of a being that necessarily exists is logically coherent.
(4) Therefore, it is logically possible that there is a being that necessarily exists.
(5) Therefore, there is a being that necessarily exists.

The inference from (4) to (5) is just collapsing the modal operators in accord with S5. The inference from (2*) to (4) assumes that if a concept is logically coherent, it is logically possible that it is instantiated.

Best
PA

But are there only two options here - fideism, acceptance on faith, or 'scientific demonstration?'

Aside from faith (doxa or pistis) and science (scientia), I think there is another mode of knowing - sapience or sapientia. The reason being, that investigating the reality of spiritual matters, is undertaken in the context of a relationship with a Person, not, like scientific matters, measurements made of an object of perception. It is a different kind of 'knowing' - more like sapience, or gnosis, or noesis, or one of those kinds of terms that denotes a different cognitive 'style' to that of science as now conceived. But is also not strictly speaking simply a matter of belief. — Wayfarer

Fair enough (and I'll check out your link on Christian Platonism). But in the normal sense, a relationship with a person presupposes that the person exists and is demonstratively known to exist. And that presupposition, with respect to God, was just what was at issue for the Scholastics as with now.

He was also a voluntarist i.e. believed God to be forever beyond logic, and a nominalist. Some would argue that this is where the decline into materialism began. (See What's wrong with Ockham?) — Wayfarer

Yes, with the other side of the coin being the decline of Scholasticism (and Aristotelianism).

I found this quote interesting: 'Louis Dupré, for instance, has complained that “nominalist theology effectively removed God from creation…. The divine became relegated to a supernatural sphere separate from nature… thus making God largely inaccessible to reason.”'

While the writer finds that baffling, I think it accurately describes the transition from Aquinas' more holistic Aristotelian perspective to a more dualistic understanding of the world.

I found this quote interesting: 'Louis Dupré, for instance, has complained that “nominalist theology effectively removed God from creation…. The divine became relegated to a supernatural sphere separate from nature… thus making God largely inaccessible to reason.”' — Andrew M

Totally agree. I read a really significant book in around 2010, Michael Allen Gillespie, The Theological Origins of Modernity. It depicts nominalism in the same terms, tracing it back to Franciscan theology, Bacon and Ockham. It features many interesting debates for example between Erasmus and Luther, and Hobbes and Descartes, among many others. An important study for understanding the present state of culture and philosophy.

I think it accurately describes the transition from Aquinas' more holistic Aristotelian perspective to a more dualistic understanding of the world. — Andrew M

I see Aristotelian Thomism as being one of the last outposts of a truly 'perennial philosophy' in Western culture. I have been reading some of Feser, and also some Jacques Maritain (who is on a much higher level altogether.) So in some ways, Catholicism is one of the few existing cultural forms in which that traditionalist understanding is kept alive. It is not the only instance, although it is almost the only instance that still has a significant voice in "Western" culture.

in the normal sense, a relationship with a person presupposes that the person exists and is demonstratively known to exist. — Andrew M

But, 'the divine person', as is often stated in philosophical theology, is 'beyond being' - actually the way I put it is, beyond existence or non-existence [e.g. here). That is because a fortiori, the Divine cannot come into and go out of existence, as has no beginning or end in time, even though (somehow) mysteriously manifesting in the finite realm (an archetypical example being Jesus.)

But this is why I keep saying that it is a mistake to think of God as 'something that exists'. He/she/it is not 'an existing thing, entity or being' at all. But the problem for modern thought, is that we can only conceive of things existing in that way - things either exist, or they don't, they're either real, or they're not. But remember that in philosophical theology, the student or aspirant actually has to 'ascend' to the knowledge of the Divine - it is something that natively, s/he doesn't know, as the vision is occluded by sin and/or ignorance. So the whole discipline of philosophical theology is the 'ascent' through praxis, theoria, metanoia, and so on, to the vision of the One - about which see, for example, Jacques Maritain The Degrees of Knowledge.

But it is exactly that 'vertical dimension' which has been collapsed or lost in the transition to modernity.

Modality is a way of thinking, talking, reasoning about the world. Modality can be a property of a proposition, but It makes no sense to talk about modal properties of a thing. Modality is a way of talking about things. So a "necessary being" is just a shorthand for saying that it is necessarily the case that such and such exists. — SophistiCat

I think for pre-modern philosophy and even for Descartes, there are ‘modes of being’, in other words, different kinds of things exist in different ways. As the 'mode of being' of humans is different to the mode of being of animals or of inorganic things, so there are 'degrees of reality':

Degrees of Reality

In contrast to contemporary philosophers, most 17th century philosophers held that reality comes in degrees—that some things that exist are more or less real than other things that exist. At least part of what dictates a being’s reality, according to these philosophers, is the extent to which its existence is dependent on other things: the less dependent a thing is on other things for its existence, the more real it is. Given that there are only substances and modes, and that modes depend on substances for their existence, it follows that substances are the most real constituents of reality.

17th Century Theories of Substance, IETP.

So, in this understanding, the origin or ground of being is 'God' which is unmade and uncreated. The reason the soul is 'nearer to God' is that it is created directly by God; whereas things, objects, and so on, are more remote, or less real, because they're manufactured, or at the end of a longer causal chain.

Materialism tried to preserve the foundation of the 'uncreated' by depicting the atom as the 'first cause' - the reason being that 'the atom' is eternal and undivided so is plausibly a mode of the 'unborn and uncreated'. However, as has now become abundantly obvious, there actually is no 'atom' as such, hence the current state of physical cosmology which is (charitably) a 'work in progress'.

This is from Clement of Alexandria, around first-second century AD, when the idea of there being a 'higher knowledge', here presented as a 'scientific faith', was still in circulation; suffice to say it is from a different historical period, and reflects a completely different understanding, of what 'scientific knowledge' comprises than what is understood today, being more typical of what used to be called 'scientia sacra'. Nevertheless, I think this idea of there being a higher order of knowledge has dropped out of contemporary epistemology. — Wayfarer

The problem is there is no way to explain how such "higher states" actually constitute anything that could rightly be termed 'knowledge'. If you want to say that such states are "higher" it would be better to refer to them as higher states of feeling or conviction.

You’ve asked me that a number of times. I mentioned that I did a degree in comparative religion, which encompassed a lot of anthropological studies of religion. From that I learned that there is abundant documentary evidence of such higher states. You generally insist that even if they’re real, they must be ‘private’ or ‘subjective’ but I really think this is simply a reflection of the way that current culture categorises them. (Actually now that I think of it, one of the first books I read about such things was Timothy Leary’s Politics of Ecstacy - not that I now think much of Leary, but the title says something!)

So, no, I don’t agree that they’re matters of ‘feeling or conviction’ only, but they’re also not matters for the natural sciences. That is why they’re referred to as ‘higher knowledge’ in the various traditions. And what I’m saying is that, this sense of there even being such a thing has generally dropped out of philosophical discourse, but that is it at least preserved in some aspects of the Thomist tradition.

I've reformatted the original post into a standard syllogism.

1.God is the greatest thing we can think of.
2. Things can exist only in our imaginations or they can also exist in reality.
3. Things that exist in reality are always better than the things that only exist in our imaginations.
4. If god existed only in our imaginations, he wouldn't be the greatest thing that we can think of, because
5. God in reality would be better.
Conclusion: Therefore, God must exist in reality! — Harjas

1. Vague terminology. What is "greatest"?
2. False equivocation. Things that "exist" in the imagination do not exist as things in reality do.
3. Vague terminology. What is "better"?

So, no, I don’t agree that they’re matters of ‘feeling or conviction’ only, but they’re also not matters for the natural sciences. That is why they’re referred to as ‘higher knowledge’ in the various traditions. And what I’m saying is that, this sense of there even being such a thing has generally dropped out of philosophical discourse, but that is it at least preserved in some aspects of the Thomist tradition. — Wayfarer

I have studied religious traditions myself for more than forty five years; so I am well aware, as you already well know, that there is abundant evidence for higher (I prefer heightened) states. So, no need to play the "i have studied" card. The problem is you can't explain in what sense they are knowledge. It is only preserved in Thomistic tradition on the presupposition of the existence of God. Without that presupposition (which as presupposition must be taken on a faith, which is itself feeling or conviction based) there is no way of explaining how heightened states of consciousness could be counted as knowledge. Also, I have not said they are merely "matters of conviction or feeling only" I have acknowledged that they are matters of higher, or better heightened, feeling or conviction.

The problem is you can't explain in what sense they are knowledge. — Janus

Not for want of trying.

I have not said they are merely "matters of conviction or feeling only" I have acknowledged that they are matters of higher, or better heightened, feeling or conviction. — Janus

In which case, there is no reason why they can't provide a basis for qualitative judgements concerning metaphysical and epistemological questions, such as the topic of this thread.

Not for want of trying. — Wayfarer

Then you need to try harder, because I haven't seen any explanation from you beyond vague suggestions.

In which case, there is no reason why they can't provide a basis for qualitative judgements concerning metaphysical and epistemological questions, such as the topic of this thread. — Wayfarer

"Qualitative judgements" which would seem to be, by definition, not based on quantitative. inductive or deductive evidence cannot be counted as knowledge in any normal sense of the word. ('Knowledge' is a term generally reserved for reference to what can be intersubjectively corroborated). If you want to say they do count as knowledge, then give a definitive account of what you mean by "knowledge" in this context. That would be the philosophically rigorous thing to do; otherwise why would anyone accept your unsupported claim?

Judgements concerning the topic of this thread are based on logic, not quality. It is the deductive validity of the Ontological argument which is under scrutiny here.

Earlier in this thread I wrote:

"All we can say is that we imagine that a God that really existed, and thus was not nearly merely an imagined God, would be greater than a God that existed only in our imaginations. What does this reveal beyond what it may be able to tell us about the human imagination? How could it possibly tell us anything about what actually exists?"

I think this is a fair summation of what we are entitled to claim by deduction; inferences from the human imagination to existence would seem to be unsupportable and this is a matter of mere logic; it really has nothing to do with "quality", as far as I can tell.

you need to try harder — Janus

You provide no incentive.

Why do I need to provide you with incentive? I really can't understand why you are so touchy about having your claims questioned. Surely that is why we are all here?

(1) God exists as a matter of necessity,
or
(2) It is at least logically coherent to think of God as a necessary being.

You say that (1) obviously entails the desired conclusion, but as you point out, it is worthless because (1) just is the conclusion. So we have to understand the premise as (2). I am not sure what would be wrong with (2). You have said it is too weak, but I'm not sure why. — PossibleAaran

That the second premise seems weak is a point in its favor (whether it really is weaker than the first premise and whether it even makes sense is debatable) - it is what helps to sell it as a premise to someone who does not already believe the conclusion.

(2*) The concept of a being that necessarily exists is logically coherent.
(4) Therefore, it is logically possible that there is a being that necessarily exists.
(5) Therefore, there is a being that necessarily exists.

The inference from (4) to (5) is just collapsing the modal operators in accord with S5. The inference from (2*) to (4) assumes that if a concept is logically coherent, it is logically possible that it is instantiated. — PossibleAaran

Yes, and my point is that this interpretation of possibility makes it unfaithful to the underlying logic, because it suggests that there is some difference between (2) or (2*) and (1), whereas there should be none.

Actually, it is not all that clear what it means to say "The concept of a being that necessarily exists is logically coherent." I hold the same opinion as you regarding necessary existents: with no constraints on possible worlds other than the rules of logical inference, there should not be any. (I am bracketing off "things" like ideas, abstractions, logical and mathematical entities and the like - presumably, when we talk about the existence of God, we are interested in something more than a mere idea of God.) But then it follows that the concept of a being that necessarily exists is inconsistent with this proposition that I already hold to be true, given the rules. So how is it coherent? Of course, as I mentioned earlier, we could play by different rules, stipulating, for example, that the relevant possible worlds are only those in which God exists (in much the same way as in my earlier example, where all relevant possible worlds contained the same immovable walls in the same places). That idea would be coherent - but unfortunately, stipulating such rules begs the question.

But again, the reason I resent Plantiga's argument is that he seems to want to sidestep such close examination of the premise, encouraging the reader instead to accept the premise because it sounds so unassuming and innocent. And so seemingly different from the proposition "God exists in all possible worlds" contained inside it. It is as if we were just picking up that outrageous proposition and looking at it at arm's length. But that feeling is betrayed, once the meaning of possibility is switched in mid-argument.