None of the scholastic 'arguments' were intended as polemical devices to convert non-believers. Nor were the psuedo-scientific hypothesis purporting to demonstrate some scientifically intelligible causal chain. They were exercises in intellectual edification that drew on various themes in the tradition of philosophy. But Anselm, Aquinas, and the rest, would never have relied on a philosophical argument to ground the truths of revelation, as they were by definition matters of faith. Given faith in the basic tenets, then the arguments are meaningful, but without that faith, they can only be empty words - and they all would have agreed with that. — Wayfarer

I think you'll find that the Scholastics intended their proofs of God's existence to be valid for believers and unbelievers alike just as Aristotle did for his own cosmological argument. Here's Ed Feser's comments on this (italics mine).

QUESTION (Jonathan): I read once on a blog post that the proofs for God were not intended as rhetorical or polemical proofs, in the sense of being intended to persuade unbelievers. They were more like edifying exercises for the faithful, but medieval theologians would not say that such philosophical arguments were sufficient to instill faith. Is this true?

DR. FESER: That is not true, and I suspect that the writers you read who said this misunderstand what “faith” means for a medieval theologian like Aquinas. The proofs were indeed meant to be completely rationally convincing even to someone who is initially coming to the question as an atheist. No faith is required at all.

The reason is that faith, as a thinker like Aquinas understands it, is a matter of believing something because it has been revealed by God. But before you can do that, you first have to establish that God really does exist in the first place and that he really has revealed something. And that requires evidence and argumentation. — Proofs for the Existence of God (#AMA with Dr. Edward Feser)

I disagree with Feser on that, at least in part because I think there were hardly any atheists in Aquinas' day, as belief in God was practically universal (In fact, I think I was the 'Jonathan' who asked him that question.) The question was based on another blog post, long since vanished off the Internet. But a further question I have for Feser is that if those proofs are as apodictic as they purport to be then how is there any room for disagreement, when there clearly is? Unless you share the basic presuppositions, then you're not going to be persuaded by such arguments, in my view.

Besides which, it degrades the concept of deity. It's the very unknowability of the answer that makes it a vital question. We need to be baffled by it, not to believe that we've worked it out.

There's an interesting essay about Gabriel Marcel's view of the 'five proofs' in Gabriel Marcel and the Existence of God.

Marcel has been concerned with the question of how we know God from the time of his earliest writings. At the beginning of his Metaphysical Journal, he expresses Kantian thoughts which, with some modification, persist throughout his later works. At this point he is concerned to show that since God does not exist in space-time, he cannot be known as an object of the world is known. Consequently, he makes the typical existentialist statement that God “ is” but does not “ exist.” “ God does not exist,” he asserts; “ He is infinitely above existence.”

But before you can do that, you first have to establish that God really does exist in the first place and that he really has revealed something. And that requires evidence and argumentation. — Proofs for the Existence of God (#AMA with Dr. Edward Feser)

Also, I don't believe that people were generally persuaded to believe that in the Bible by evidence and argumentation. There might have been some exceptions but on the whole, people generally believe in the Bible because their forbears and those around them do so. Of course it suits Feser, being a philosopher of religion, to say that his kinds of arguments are persuasive, but I think you could count on one hand the number of contributors on this forum who would agree.

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To better explain this:

1. We imagine this thing G₁
2. If G₁ doesn't exist then some real G₂ is greater

But what's the difference between imagining G₁ and imagining G₂ – a difference that the argument depends on? Presumably in both cases we imagine the thing to be real. So it's not entirely clear what the argument means by saying that if G₁ doesn't exist then we can imagine something greater (G₂).

We imagine this thing to be all-powerful, all-knowing, all-good, and real. If it isn't real then we can imagine something greater that is imagined to be all-powerful, all-knowing, all-good, and ... really real? The argument doesn't make any sense.

I disagree with Feser on that, at least in part because I think there were hardly any atheists in Aquinas' day, as belief in God was practically universal — Wayfarer

True, but there were theists of different types so articulating and defending the church's traditional position was seen as necessary.

The Scholastics were not fideists or truth relativists. On their view, if a proof fails, then it should be rejected by believers as well. There is nothing particularly edifying about a failed proof.

For example, Feser himself (following Aquinas) rejects the Ontological argument (see http://edwardfeser.blogspot.com.au/2010/11/anselms-ontological-argument.html).

But a further question I have for Feser is that if those proofs are as apodictic as they purport to be then how is there any room for disagreement, when there clearly is? Unless you share the basic presuppositions, then you're not going to be persuaded by such arguments, in my view. — Wayfarer

Sure and I don't think Feser denies that these arguments require considerable effort to learn and understand. That's just philosophy for you. But for anyone in the Aristotelian tradition, as Feser is, such presuppositions aren't merely subjective, they are as open to rational scrutiny as anything else. Perhaps on this, the Aristotelians anticipated Aumann's agreement theorem.

there were theists of different types so articulating and defending the church's traditional position was seen as necessary. — Andrew M

Indeed, but that is consistent with what I said - that the 'proofs of God' were scholastic arguments, intended for a scholastic audience. I don't think they were preached from the pulpit. And I don't think there were atheist opponents in medieval times at which these arguments were directed as polemical or rhetorical arguments. Certainly there were antagonists - Muslim and Jewish amongst them - but while they weren't Christian, they were also not atheist. ( I seem to recall that the Kalaam Cosmological argument was of Islamic origin.)

I don't think Feser denies that these arguments require considerable effort to learn and understand. That's just philosophy for you. But for anyone in the Aristotelian tradition, as Feser is, such presuppositions aren't merely subjective, they are as open to rational scrutiny as anything else. — Andrew M

True, but what would it take to make the effort? Do you think a conscientious atheist would be interested in making the effort? And what would such an effort consist of? How would they get into a kind of mental space where such Aristotelian ways of thinking would be meaningful to them?

I recall a couple of threads here from late last year on Feser's 'Five Proofs' book, and from what I could see, most of the 'modern' objections to Feser's logic, were on the basis that the Aristotelian definitions that are required for the argument to be meaningful, are themselves not tenable. For instance:

if one accepts the Aristotelean view of the world, in which notions like 'potential, 'essence' and 'directed' are believed to have meanings beyond their everyday pragmatic meanings, then the OP argument has some bite, and if one doesn't, then it has none. — andrewk

I think the same can be said for many, or all, of the classical arguments. And the upshot is, to really be prepared to entertain such arguments on their own terms already requires an element of belief.

Again, interesting to note Gabriel Marcel's objection to the 'proofs':

Speaking of these five classical ways, he notes that these arguments presuppose that we have “already grounded ourselves on God.” They attempt to bring to the level of discursive objectivity “an act of a wholly different kind.” Accordingly, he states his conviction that these arguments “are not ways, but blind ways, as one can have blind windows.”

One notes in such statements an echo of Kierkegaard’s assertion that what is known by faith cannot be explained by reason. Yet Marcel’s argument goes further than Kierkegaard’s: proofs are not only ineffectual, they are scandalous word-games about what cannot be voiced: The proofs are ineffectual precisely when they would be most necessary, when, that is, it is a question of convincing an unbeliever; conversely, when belief is already present and when, accordingly, there is a minimum of agreement, then they seem to serve no useful purpose.

If [a] man has experienced the presence of God, not only has he no need of proofs, he may even go so far as to consider the idea of a demonstration as a slur on what is for him a sacred evidence.

I don't know if I wholly agree with that, either, but I think it makes an important point; which is that I am finding Feser's style of argumentation a little too, well, scholastic for my liking. Especially because it presents certain 'articles of faith' as proven axioms. (Personally I am more drawn to the apophatic 'way of un-knowing'.)

The explicit form of the argument is given below:

1. God is the greatest being imaginable

2. If God is the greatest being imaginable then God exists — TheMadFool

One thing essential to understand is that in ancient philosophy, it was always assumed that 'being' -
to be real, to actually exist - is or has an inherent value. That is behind the ancient notion of the 'pleroma' (the 'divine fullness') and also the related intuition that 'nature abhors a vacuum'. The obverse is that non-existence or non-being is itself a defect or privation, the lack or absence of a real good, namely, that of 'being'. There was also, in ancient philosophy, the idea that there is an hierarchy of being, within which there are greater and lesser degrees of being or reality (sometimes referred to as the ‘great chain of Being’). Within that kind of schema, 'God' is 'being itself' or 'the most real' (which in Christian thought, was basically derived from adapting neoPlatonic philosophy) whereas matter is usually consigned to the lowest rung of the hierarchy. (Humans are in the middle, above animals, below angels.) Needless to say, that understanding is profoundly different to the modern point of view (which relegates humans to the animal kingdom and everything to matter).

Now I'm not saying that in support of 'the ontological argument' but only to illustrate the way in which the meaning of the idea of being has been changed, and the consequence of that for understanding the argument (and nor am I claiming any particular expertise in these ideas in saying that, simply pointing to a factor that I think is often overlooked in respect of this discussion).

Thanks for the illuminating post.

I tried arguing against the ontological proof in terms of a hidden premise viz. E=Existence (being) is greater than nonexistence. I then realized that, ceteris paribus, everyone actually does believe that E is true. What I didn't know is that this was/is a central belief in religion.

However, there seems to be an inconsistency in believing E. Religion talks of heaven, enlightenment, etc. which are supposedly better places to live in. Said otherwise that means human existence is unsatisfactory. It then isn't completely wrong in thinking that existence itself, whether in heaven or not, is unsatisfactory. Like a snake the notion of existence being better wraps around and bites you in the back.

What do you think?

That is really not an idea that is exclusive to religion as such, although the demarcation between religion and philosophy in such questions is problematical.

But there’s an idea that springs to mind, that is somewhat related. This is the idea of ‘a good that has no opposite’. Normally ‘what is good’ is opposed to ‘what is not good’, as if one is equal but opposite to the other. But the idea of there being ‘a good which has no opposite’ undercuts that. In this understanding, reality itself is actually a real good. Now of course in our scientific age this idea is incomprehensible because reality itself is assumed to be value-free or essentially devoid of anything qualitative. But again in ancient philosophy, there was the (often tacit) understanding that to perceive the real nature of things was essentially liberative. (This is the meaning of the Buddhist term, Yathābhūtaṃ.) The problem lies with our perception of things, which is contaminated or impure or occluded by self-interest. Again that is an understanding which is remote from the current zeitgeist but it helps to understand ontology because it provides a more effective interpretive framework for ontological questions.

In any case, in various traditional philosophies, ‘the sage’ is ‘one who sees what is’ in a way that the normal person (the hoi polloi) cannot, due to their own lack of discernment and self-interest which instinctively interprets every experience in terms of ‘what’s in it for me’. It is the transcendence or overcoming of that instinctively self-interested perspective or frame of reference which allows the sage to perceive reality as it actually is. (That is the original meaning of ‘detachment’ which is the traditional counterpart to what moderns understand by the term ‘objectivity’.)

This is actually preserved in science in the sense that scientific method attempts to eliminate ‘the subjective’ by concentrating exclusively on what can be objectively validated and measured. However, in so doing, scientific method routinely eliminates the qualitative as well, which is the profound lack or absence in most modern philosophies.

Fine post. I see some interesting connections there. Thanks.

Certainly there were antagonists - Muslim and Jewish amongst them - but while they weren't Christian, they were also not atheist. ( I seem to recall that the Kalaam Cosmological argument was of Islamic origin.) — Wayfarer

Yes but nonetheless the Scholastics would have regarded their arguments to be applicable to atheists. Aquinas held that God's existence was demonstrable via natural experience and logic alone (without recourse to faith or special revelation). As he put it:

Whether it can be demonstrated that God exists? Reply to Objection 1: The existence of God and other like truths about God, which can be known by natural reason, are not articles of faith, but are preambles to the articles; for faith presupposes natural knowledge, even as grace presupposes nature, and perfection supposes something that can be perfected. Nevertheless, there is nothing to prevent a man, who cannot grasp a proof, accepting, as a matter of faith, something which in itself is capable of being scientifically known and demonstrated. — St. Thomas Aquinas - The Summa Theologica

True, but what would it take to make the effort? Do you think a conscientious atheist would be interested in making the effort? And what would such an effort consist of? How would they get into a kind of mental space where such Aristotelian ways of thinking would be meaningful to them? — Wayfarer

You could ask the same questions about philosophy generally. Why read Plato, Aristotle, Hume, Kant, Wittgenstein or anyone at all?

Interestingly Aquinas' answer was, "the study of philosophy is not about knowing what individuals thought, but about the way things are." And he found Aristotelian ways of thinking useful for that end.

So one motivation to understanding the arguments could be simply to find out whether they succeed or not (independently of one's prior dispositions towards theism or atheism - which I think answers Marcel's objection). Or, more broadly, whether Aristotelian ways of thinking provide insights into modern philosophical problems (e.g., mind-body, ethics, the relationship between science and philosophy and so on).

All fair points, but it's worth noting that Aquinas says the existence of God remains 'a matter of faith'. And I think it's demonstrably not the case that the 'existence of God' can be demonstrated scientifically - although I suppose a Thomist could answer that in light of the very many great unknowns that the natural sciences are grappling with, it might be yet!

scientific method attempts to eliminate ‘the subjective’ by concentrating exclusively on what can be objectively validated and measured. — Wayfarer

This statement made me think about something that I have been chewing on for a long time. On the one hand, the mission of science to arrive at truth sees the observer (subject/subjective) as a contamination to the objective study at hand. This is why, to have total “objectivity”, we have double/triple blind tests. This scientific method has proven to work extremely well when dealing with the outer, quantitative, material order. I for one am extremely grateful to science for its extraordinary success.

On the other hand, we have the philosophies of the “perennial traditions” asking the enduring questions of life. Their primary concern is the inner, subjective, immaterial order (psychological). They hold that these are also studies of importance, meaning and value. The difference is that the object of study is also the subject/observer doing the looking. This is called self-inquiry by some traditions. With such topics as “the unexamined life is not worth living” or “to know thyself”. They are aphorisms to remind us of the human task at hand, that there is more to life than mere material goods.

The basic rules and dynamics seem to change drastically between the two orders of inquiry. Science does not seem to be interested in the latter because of this perceived contamination.

All fair points, but it's worth noting that Aquinas says the existence of God remains 'a matter of faith' — Wayfarer

In the above Aquinas says, "The existence of God ... are not articles of faith". However he also says there is nothing wrong with accepting it on faith, as long as it is scientifically demonstrable. Which is like accepting that Quantum Mechanics is true on faith rather than investigating it for oneself.

And I think it's demonstrably not the case that the 'existence of God' can be demonstrated scientifically - although I suppose a Thomist could answer that in light of the very many great unknowns that the natural sciences are grappling with, it might be yet! — Wayfarer

Keep in mind that Aristotelians have a broader conception of science than the conventional modern view. This includes the four causes (not merely a Humean efficient cause), realism about universals and substance hylomorphism. (Note: Aristotle's conception of science is actually very similar to Charles Sanders Peirce's conception that apo often describes.)

The initial problem is really one of translation. To show that the proofs do succeed or fail as scientific demonstrations in the Aristotelian sense requires familiarity with that world view (as you alluded to earlier).

This reminds me of Kuhn's thesis in his book The Structure of Scientific Revolutions which I think is just as applicable to our understanding of the Scholastic (and Aristotelian) proofs.

Kuhn wanted to explain his own experience of reading Aristotle, which first left him with the impression that Aristotle was an inexplicably poor scientist (Kuhn 1987). But careful study led to a change in his understanding that allowed him to see that Aristotle was indeed an excellent scientist. This could not simply be a matter of literally perceiving things differently. Kuhn took the incommensurability that prevented him from properly understanding Aristotle to be at least partly a linguistic, semantic matter. — Thomas Kuhn (SEP)

In the ↪quote above Aquinas says, "The existence of God ... are not articles of faith". — Andrew M

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'.

I don't buy the 'conflict thesis' - the idea that there is a fundamental conflict between science and faith - but that is mainly because I believe that the subjects of religious cognition are of a different order to those of the phenomenal domain. As the Gabriel Marcel essay puts it:

Marcel argued ...that one cannot validly think of God as an existing object independent of ourselves, because this mode of thought would place him within the ambit of the world. When we think God as an object, we fail to distinguish him from the world or from ourselves. An 'objective God' reflects a Kantian conception of existence as limited only to space-time relations. Marcel expresses this in the following terms: When we suppose we are positing (in existence or still only objectively) the absolute independence of God, we are really on the contrary only binding up God with immediate consciousness.

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.

Why read Plato, Aristotle, Hume, Kant, Wittgenstein or anyone at all? — Andrew M

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.)

On the one hand, the mission of science to arrive at truth sees the observer (subject/subjective) as a contamination to the objective study at hand. This is why, to have total “objectivity”, we have double/triple blind tests. This scientific method has proven to work extremely well when dealing with the outer, quantitative, material order. I for one am extremely grateful to science for its extraordinary success. — Pneuma

Welcome, and a great post.

I don't think that there ever can be perfect or total objectivity. That is actually one of the main implications of the Critique of Pure Reason, but one that is often overlooked or forgotten. There’s a book by Thomas Nagel called The View from Nowhere, which is very much about the tension between the ideal scientific view (the ‘View from Nowhere’) and our lived experience as subjects. (Although all that said, I too am extremely grateful to what science does for us every day.)

The basic rules and dynamics seem to change drastically between the two orders of inquiry. Science does not seem to be interested in the latter because of this perceived contamination. — Pneuma

A lot of this question is historical rather than strictly speaking simply philosophical. It has to do with the complex interplay between philosophy, science and religion in the Western tradition. Volumes could be written, but the basic outline is covered in another Nagel book, Mind and Cosmos:

The modern mind-body problem arose out of the scientific revolution of the seventeenth century, as a direct result of the concept of objective physical reality that drove that revolution. Galileo and Descartes made the crucial conceptual division by proposing that physical science should provide a mathematically precise quantitative description of an external reality extended in space and time, a description limited to spatiotemporal primary qualities such as shape, size, and motion, and to laws governing the relations among them. Subjective appearances, on the other hand -- how this physical world appears to human perception -- were assigned to the mind, and the secondary qualities like color, sound, and smell were to be analyzed relationally, in terms of the power of physical things, acting on the senses, to produce those appearances in the minds of observers. It was essential to leave out or subtract subjective appearances and the human mind -- as well as human intentions and purposes -- from the physical world in order to permit this powerful but austere spatiotemporal conception of objective physical reality to develop.

(pp. 35-36)

So this makes ‘mind’ essentially subjective, internal, private - which is one of the things that now seems so obvious that it is hard to even notice it. So everything is either ‘out there’ - objectively real, according to science - or ‘in here’, a matter of conviction or closely held belief. That is the way we nowadays carve up experience. So in this landscape, ‘what is real’ is what is objectively measurable, and what transcends what is objective real is to all intents a matter of private conviction.

Whereas, as you say, the perennial philosophy points to that which is at once real but also transcendent, a category for which I think our naturalistically-oriented culture lacks even an appropriate lexicon.

Science does not seem to be interested in the latter because of this perceived contamination. — Pneuma

What about neuroscience, sociology, evolutionary biology, psychology? Science is extremely interested in understanding subjective experience, it just does it on a presumption of physicalism, a perfectly valid presumption (among others). To say it's not interested is just wrong.

Science is extremely interested in understanding subjective experience, it just does it... — Pseudonym

...by treating it as an object of experience.

...by treating it as an object of experience. — Wayfarer

Of course, under the presumption of physicalism, that's what it is. That doesn't make it any less real, doesn't mean that science isn't interested in it. Science would love to explain subjective experience just like any other form of truth-seeking investigation would. It has its own methods and underlying axioms, just like any other philosophy. I don't see why it's being excluded from the discussion.

That doesn't make it any less real, — Pseudonym

Except for being no longer subjective, i.e. no longer what it actually is. Which is the ‘hard problem of consciousness’ in a nutshell, and another topic altogether.

And what really means 'the greatest thing we could ever think of'? What makes something great? What would be the greatest thing? How could we know or tell? And who is 'we'?

Here is what Kant said, that existence is not a real predicate or property of a concept. Which is to say that existence is not analytically contained in concepts but is synthetically added to concepts. I think he is right. Saying something exists is saying something different to describing the properties of a thing.

"A hundred real dollars contain no more than a hundred possible dollars. For, as the latter indicate the conception, and the former the object, on the supposition that the content of the former was greater than that of the latter, my conception would not be an expression of the whole object, and would consequently be an inadequate conception of it. But in reckoning my wealth there may be said to be more in a hundred real dollars than in a hundred possible dollars—that is, in the mere conception of them. For the real object—the dollars—is not analytically contained in my conception, but forms a synthetical addition to my conception (which is merely a determination of my mental state), although this objective reality—this existence—apart from my conceptions, does not in the least degree increase the aforesaid hundred dollars." (Critique of Pure Reason "Of the Impossibility of an Ontological Proof of the Existence of God")

God is the greatest thing we can think of. Things can exist only in our imaginations or they can also exist in reality.
Things that exist in reality are always better than the things that only exist in our imaginations.
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.
Therefore, God must exist in reality! — Harjas

Kant is disagreeing with this premise (bold)

Except for being no longer subjective, i.e. no longer what it actually is. Which is the ‘hard problem of consciousness’ in a nutshell, and another topic altogether. — Wayfarer

Yes, but only if you have already rejected physicalism before you start the investigation. Our experience is what it is, it's just that we don't know 'what it is' yet. If 'what it is' is nothing more than the firing of neurons, then scientific investigation reveals the whole of it, there is nothing more to investigate. If we reject this possibility by saying that scientific investigation is inevitably missing something, then we have simply prejudiced the investigation. Without prejudice, it remains a possibility that science is actually investigating all there is to be investigated.

Without prejudice, it remains a possibility that science is actually investigating all there is to be investigated. — Pseudonym

It’s not a matter of ‘prejudice’. It is simply the case that ‘the nature of experience’ has an intrinsically first-person aspect, which is excluded from scientific analysis as a consequence of the very methodology that makes science what it is. This is, as I said, precisely what David Chalmer’s seminal paper, Facing Up to the Hard Problem of Consciousness, is about:

The really hard problem of consciousness is the problem of experience. When we think and perceive, there is a whir of information-processing, but there is also a subjective aspect. As Nagel (1974) has put it, there is ‘something it is like’ to be a conscious organism. This subjective aspect is experience. When we see, for example, we experience visual sensations: the felt quality of redness, the experience of dark and light, the quality of depth in a visual field. Other experiences go along with perception in different modalities: the sound of a clarinet, the smell of mothballs. Then there are bodily sensations, from pains to orgasms; mental images that are conjured up internally; the felt quality of emotion, and the experience of a stream of conscious thought. What unites all of these states is that there is something it is like to be in them. All of them are states of experience.

Another point is that when you talk about ‘the firing of a neuron’, you’re speaking of an isolated event akin to the discharge of a spark plug. But such an event has no meaning - if you are to interpret it as meaningful, then that requires an act of interpretation, to say ‘it means X’, which is not something you will see in the objective trace of such an event. And then, as well as that, the single firing of a neuron means nothing - neurons act in conjunction with vast numbers of other neurons (actually there are said to be more neural pathways than stars in the sky). But even then, to understand what all of that means, inevitably requires acts of rational inference, which are internal to the operations of thought itself. They are never ‘in’ the data, but always inferred on the basis of the data. So logic is not strictly speaking ‘objecitve’ either, but transcendental, i.e. required in order to understand experience, but not actually the object of experience.

There are so many ways in which neural reductionism can’t work, but none of that is actually the least germane to ‘the ontological argument’, so we ought to leave it for another thread.

The Ontological Argument is given a bad time in this thread. I think a study of the Ontological Argument has taught us more about logic than almost any other philosophical argument. Its certainly a very fruitful piece of Philosophy in that sense.

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].

The first premise is supposed to be part of the definition of God. God is, by definition, an absolutely perfect being. He is omnipotent, omniscient, wholly good, eternal and if he exists, exists necessarily. I do myself wonder whether the notion of 'perfection' isn't merely subjective, and so cramming all of these properties into one definition is a little arbitrary. Still, I don't think this undercuts the argument in any serious way.

The second supposedly follows from (1), given that p(nX) -> nX (if its possible that X necessarily exists then X necessarily exists). I don't deny that this is controversial, but I've yet to see anyone argue against it in this thread.

The third premise claims that God's existence is logically possible. I don't think I have ever seen a 'proof' of this. But many people do in fact believe it, even people who are Atheists might be inclined to think that God's existence is at least logically possible. The argument would then be of some value, even if it couldn't prove God's existence to someone who doubted (3). Proofs don't have to be proofs to everyone no matter how sceptical, in order to be valuable, do they? At any rate, all one can do to illustrate logical possibility is try to explicate the concept clearly and carefully, remove confusions and reply to anyone who argues that it is incoherent.

Let me take a closer look at some of the objections in this thread.

All the argument can show - all every such ontological argument can show - is that if God existed, the argument would hold true. — StreetlightX

Every 'ontological argument for God' engages in this slight of hand: beginning with a material conditional and then silently dropping it along the way. — StreetlightX

I do not believe that the material conditional is silently dropped away in this reconstruction. The point can be made in possible world lingo, for illustrative purpose. If God exists at all then he exists in every possible world. From this, it follows that If God exists in at least one possible world then he exists in all of them. If we assume that God exists in some possible world, it follows that God exists. I stress that the possible world lingo is only illustrative. One shouldn't be lead to think that 'possible worlds' are some how real and the proponent of the argument is assuming God to exist somewhere off in some far away land! In any case, I don't see the masked 'if' which you describe.

There exists a being, such that, it exists.
Therefore, it exists. — StreetlightX

I stress again that the first premise is that If God exists then he necessarily exists. There is room to 'escape' the argument by denying (3).

Or,

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

(That's Plantinga's version, only he obfuscates it a bit.) — 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'. The first premise defines God as necessarily existing if existing at all. It doesn't say that God necessarily exists. The second premise is entailed by the first (yes, given axiom S5 in modal logic). The 3rd premise merely says that its logically possible that God exists. So I cannot see that the argument I have sketched (which is Plantinga's, just simplified) amounts to the bad argument that you give here.

We imagine this thing to be all-powerful, all-knowing, all-good, and real. If it isn't real then we can imagine something greater that is imagined to be all-powerful, all-knowing, all-good, and ... really real? The argument doesn't make any sense. — Michael

For the argument to work, we must imagine something that if it did exist, would exist in every possible world (or necessarily). If you imagine something that, if it exists, exists merely in one possible world, or five possible worlds, or even 9000 possible worlds, but not the actual world, then you have not imagined an absolutely perfect being, have you?

Here is what Kant said, that existence is not a real predicate or property of a concept. — bloodninja

Indeed, and Kant was right. But necessary existence is a property, and is immune to the criticism which Kant makes. It really does add something to the description of a thing to say that it necessarily exists, rather than just exists.

Best,
PA

For the argument to work, we must imagine something that if it did exist, would exist in every possible world (or necessarily). If you imagine something that, if it exists, exists merely in one possible world, or five possible worlds, or even 9000 possible worlds, but not the actual world, then you have not imagined an absolutely perfect being, have you? — PossibleAaran

This doesn't seem to address my objection, which is that when we imagine God we imagine it to exist, and so to argue that if God doesn't exist then we can imagine a greater being which does exist doesn't make any sense.

(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].

The first premise is supposed to be part of the definition of God. God is, by definition, an absolutely perfect being. He is omnipotent, omniscient, wholly good, eternal and if he exists, exists necessarily. I do myself wonder whether the notion of 'perfection' isn't merely subjective, and so cramming all of these properties into one definition is a little arbitrary. Still, I don't think this undercuts the argument in any serious way. — PossibleAaran

We can replace "God" with anything that has "necessary" as a property, and so use the argument to argue for any number of different things, e.g. the (necessary) Flying Spaghetti Monster.

But it really just amounts to this:

(1) If a necessary thing exists then it necessarily exists.
(2) If it's logically possible that a necessary thing exists then a necessary thing exists
(3) It is logically possible that a necessary thing exists
(C) A necessary thing exists

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

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. But this "world" is a purely abstract thing.

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.

it just does it on a presumption of physicalism — Pseudonym

I agree - and that is my main point.

any kind of 'proof' or rhetorical argument, will always fail. — Wayfarer

yes, proofs of either way. It's beyond human knowledge capability for sure, specifically if we know our limits at all. I think even none of famous scientists can bravely be honest on this subject instead of hiding behind the falsifiability shields.
"The safest conclusion seems to be that the whole subject is beyond the scope of man’s intellect; but man can do his duty." (Darwin - 1873)

The ontological argument is, basically, in order for us to have an idea of a perfect being, such as God, then it must have some basis in reality, as if it wasn’t real, then it wouldn’t be perfect. So where did this idea come from? If we merely dreamed it up, then it would be a mere fantasy, but fantasies are deficient in the sense that they are unreal.

Sure as hell ain’t any answer from Darwinian theory to an argument of that kind, as I’m sure that neither the argument nor its criticisms have any utility from the Darwinian viewpoint.

Kant is disagreeing with this premise (bold) — bloodninja

I am a Kant fan, but I can’t help but feel he’s wrong in this case. Can’t quite put my finger on why, but it has to do with the fact that I can indeed imagine something that is actually not real. Therefore that ‘imagined being’ - let’s say, Superman, or Donald Duck - does not actually exist, even though if I say those names, you and I both know straight away what is meant. So they ‘exist as characters in fiction’, but they don’t really exist. In which case it is fair to say that ‘existence cannot be predicated of them’.