Atheism, Burden of Proof, and Plantinga's Modal Ontological Argument

[punkforchrist]

There are a great many resources on this argument already, but I’m interested in exploring it some here.

Plantinga’s version of the OA states this:

1. There is a possible world in which maximal greatness is instantiated.
2. A maximally great being necessarily possesses maximal excellence in every possible world.
3. A maximally excellent being is necessarily omnipotent, omniscient, and perfectly good.
4. Hence, a maximally excellent being exists in every possible world.
5. Therefore, a maximally excellent being exists.

It may surprise some that premises (2) - (4) are relatively uncontroversial. If one accepts the so-called S5 axiom (if p is possibly necessary, then p is necessary), then the only premise under contention is (1).

So, let’s ask ourselves: is it even possible that God exists? If it is at least possible, then it seems to me that weak atheism is untenable, and that a proof must be offered in support of the claim that God cannot possibly exist. This theoretically can be done by demonstrating the contradiction inherent in the divine attributes, or that the problem of evil is inconsistent with such a being. Neither of these arguments has gained much support among philosophers (the evidential problem of evil is now most popular among atheologians).

Of course, (1) also appears to beg the question. One wouldn’t accept the premise, unless he or she already accepted the conclusion. This puts us at a bit of an impasse. However, if there are no compelling reasons to accept ~(1), then (1) can very well be rationally justified, even if it is itself not compelling.

Thoughts?

 

[warpspeedpetey]

There are a great many resources on this argument already, but I’m interested in exploring it some here.

Plantinga’s version of the OA states this:

1. There is a possible world in which maximal greatness is instantiated.
2. A maximally great being necessarily possesses maximal excellence in every possible world.
3. A maximally excellent being is necessarily omnipotent, omniscient, and perfectly good.
4. Hence, a maximally excellent being exists in every possible world.
5. Therefore, a maximally excellent being exists.

It may surprise some that premises (2) - (4) are relatively uncontroversial. If one accepts the so-called S5 axiom (if p is possibly necessary, then p is necessary), then the only premise under contention is (1).

So, let’s ask ourselves: is it even possible that God exists? If it is at least possible, then it seems to me that weak atheism is untenable, and that a proof must be offered in support of the claim that God cannot possibly exist. This theoretically can be done by demonstrating the contradiction inherent in the divine attributes, or that the problem of evil is inconsistent with such a being. Neither of these arguments has gained much support among philosophers (the evidential problem of evil is now most popular among atheologians).

Of course, (1) also appears to beg the question. One wouldn’t accept the premise, unless he or she already accepted the conclusion. This puts us at a bit of an impasse. However, if there are no compelling reasons to accept ~(1), then (1) can very well be rationally justified, even if it is itself not compelling.

Thoughts?

ive always liked Platingas argument but it ignores a basic priciple of G-ds qualities, namely that G-d is pure existence, the act of being. what then do all “possible” worlds share in common? the one trait that each must have in order to be a possible world? they must exist!

so, in that G-d is the ground state of existence, no world is “possible” without existing or the ability to exist.

so it sounds great to the philosophy department, but it falls to a little common sense.

 

[punkforchrist]

I suppose if we did a little bit of metaphysical work, we could connect necessary existence with pure actuality. However, that would require an emphasis specifically on causal relations, since abstract objects have necessary existence but are not pure actuality. The difference, then, is that abstracta are causally inert, whereas the necessary being stands in a causal relation. Hope I’m making sense.

 

[James_S_Saint]

I’m afraid I would have to kick Plantinga out of my Logic class.

“1. There is a possible world in which maximal greatness is instantiated.”

This statement is typical of a non-thinker attempting to apply logic (as are his others).

Given the possibility of possible worlds (which in itself is a bit naive), without defining what “maximal greatness” actually and realistically means, he has not really said anything other than “there is a possible world where I can claim the existence of ‘maximal greatness’”.

This is relevant because as you examine what that phrase actually means, you see that it is a subjective comparative. And that means that in that possible world, there would have to be a person who judges things in terms of “greatness” and to him there would be a maximum to such assessment.

That person’s assessment of greatness and maximum could be totally unrelated to God and probably would be. This means that the premise, even if accurate and true, is still quite unrelated to the existence of God.

And that is just in consideration of his first statement.

 

[AntiTheist]

1. There is a possible world in which maximal greatness is instantiated.
2. A maximally great car owned by me necessarily possesses excellence in every possible world.
3. A maximally excellent car owned by me is necessarily actually owned by me and not merely possibly owned by me.
4. Hence, a maximally great car owned by me actually exists.

Where’s my car?

 

[James_S_Saint]

In his **second **premise, he merely exchanges the word “greatness” with “excellence” otherwise stating nothing.

In his **third **premise, he merely defines “excellence == omnipotent, omniscient, and perfectly good.” A mere definition.

His **fourth **statement is a non-sequetor presumption relating only to his first premise, unrelated to the existence of God. He asserts that merely because there is a possible world where excellence can be assessed, every possible world must have such a quality.

His **fifth **statement of conclusion is derived merely from his non-sequetor fourth assertion. He has merely stated that "because every possible world must have a maximally excellent being, a maximally excellent being exists. This statement intended to be a logical conclusion, yet void of logical argument, is also a non-sequetor assertion.

In short, he proposed nothing logical at all and implied that God == your assessment of maximal excellence. Which just happens to be false. :ehh:

 

[James_S_Saint]

1. There is a possible world in which maximal greatness is instantiated.
2. A maximally great car owned by me necessarily possesses excellence in every possible world.
3. A maximally excellent car owned by me is necessarily actually owned by me and not merely possibly owned by me.
4. Hence, a maximally great car owned by me actually exists.

Where’s my car?

 

[gearhead]

Plantinga’s version of the OA states this:

1. There is a possible world in which maximal greatness is instantiated.
2. A maximally great being necessarily possesses maximal excellence in every possible world.
3. A maximally excellent being is necessarily omnipotent, omniscient, and perfectly good.
4. Hence, a maximally excellent being exists in every possible world.
5. Therefore, a maximally excellent being exists.

Between premises 1 and 2, the notion that “maximal greatness” implies “a being with maximal greatness” is slipped in without support.

Premise 3 seems to be a subjective opinion. Why is a “maximally excellent being” necessarily “omnipotent, omniscient and perfectly good”? Why isn’t such a being omni-crunchy, perfectly blue, and perfectly ornery? I see no compelling reason to select one set of “perfect” attributes over some other set, yet it would be possible to pick a set of attributes that conflicts with another, just-as-valid set.

I see no reason why premise 4 limits itself to the singular. If one “maximally excellent being” is great, presumably 2, 3, or *an infinite number *of “maximally excellent beings” would be even greater, implying that a single “maximally excellent” being is not “maximally great”.

Also, premise 4 seems to me to either be completely unfounded or a false equivocation based on the word “necessarily”. In premises 2 and 3, it seems to me that “necessarily” is used in the sense that if this thing exists, it must have these properties. In premise 4, it seems that this is re-interpreted to say that these properties must exist, therefore the thing that has them must also exist. These two claims are definitely not equivalent.

 

[NowAgnostic]

There are a great many resources on this argument already, but I’m interested in exploring it some here.

Plantinga’s version of the OA states this:

1. There is a possible world in which maximal greatness is instantiated.
2. A maximally great being necessarily possesses maximal excellence in every possible world.
3. A maximally excellent being is necessarily omnipotent, omniscient, and perfectly good.
4. Hence, a maximally excellent being exists in every possible world.
5. Therefore, a maximally excellent being exists.

It may surprise some that premises (2) - (4) are relatively uncontroversial. If one accepts the so-called S5 axiom (if p is possibly necessary, then p is necessary), then the only premise under contention is (1).

Correct, though I prefer a different version of the MOA, there might be a problem here. Here I think that “maximal greatness” needs to be more clearly defined to more clearly make the connection between maximal greatness and a necessary being. Otherwise you may have a problem with 2), as your “maximally great” being might not exist in every possible world, and it can’t “possess maximal greatness” in a world if it doesn’t exist in that world. I think this version of the MOA gets it backwards - it’s easier to argue from the concept of a necessary being that it must be maximally great than the other way around.

So, let’s ask ourselves: is it even possible that God exists? If it is at least possible, then it seems to me that weak atheism is untenable, and that a proof must be offered in support of the claim that God cannot possibly exist.

Let’s not confuse epistemic possibility with logical possibility. If God is “at least” logically possible, then He exists, period. That’s what the Modal Ontological argument (and in fact all ontological arguments) show. If God is “at least” epistemically possible, that shows nothing. There may be some reason we are unaware of that makes Him logically impossible (just like a complicated math equation that to us non-mathematicians is epistemically possible (true for all we know) which is yet logically impossible). And that’s why ontological arguments can never be a proof a God’s existence, without a formal proof of God’s logical possibility.

This theoretically can be done by demonstrating the contradiction inherent in the divine attributes, or that the problem of evil is inconsistent with such a being. Neither of these arguments has gained much support among philosophers (the evidential problem of evil is now most popular among atheologians).

(Just as an aside, I do not believe the quality of arguments can really be accurately assessed by the current popularity they have among philosophers. The Five Ways of Aquinas don’t have much current popularity. They used to have lots of popularity. It’s impossible that the quality of those arguments changed over time.)

What you suggest here would be a formal proof of God’s impossibility. But lack of a formal proof of God’s impossibility does not prove His possibility any more than lack of a formal proof of His possibility proves His impossibility.

In the lack of any proof either way, one is reduced to a posteriori arguments. The cosmological argument attempts to argue that something about our world is impossible without God’s existence - therefore He exists. The argument from evil does just the opposite - attempts to argue that something about our world is impossible with His existence.

If neither of THESE work, then we’re really up a creek. I don’t buy any sort of “evidential” (meaning falling short of proof) kind of argument. You need to know likelihoods of what worlds could exist with and without God, and there is no basis whatsoever for objectively finding these, people are just pulling numbers out of a hat.

Of course, (1) also appears to beg the question. One wouldn’t accept the premise, unless he or she already accepted the conclusion. This puts us at a bit of an impasse. However, if there are no compelling reasons to accept ~(1), then (1) can very well be rationally justified, even if it is itself not compelling.

Thoughts?

Well it could be, but it might not be. I disagree that accepting a premise is **necessarily **rationally justified just because there are no compelling reasons to accept its negation (it **can **be justified in that instance, but might not be). Would you accept the premise “it will rain on December 10th in your area” as rationally justified when it is impossible for meteorology to predict that far out? Yet what compelling reasons are there to deny it? And, you have shown no compelling reasons to accept (1), so then ~(1) could be rationally justified by your epistemology.

 

[James_S_Saint]

Yeah, what He said.

 

[hatsoff]

There are a great many resources on this argument already, but I’m interested in exploring it some here.

Plantinga’s version of the OA states this:

1. There is a possible world in which maximal greatness is instantiated.
2. A maximally great being necessarily possesses maximal excellence in every possible world.
3. A maximally excellent being is necessarily omnipotent, omniscient, and perfectly good.
4. Hence, a maximally excellent being exists in every possible world.
5. Therefore, a maximally excellent being exists.

It may surprise some that premises (2) - (4) are relatively uncontroversial. If one accepts the so-called S5 axiom (if p is possibly necessary, then p is necessary), then the only premise under contention is (1).

So, let’s ask ourselves: is it even possible that God exists? If it is at least possible, then it seems to me that weak atheism is untenable, and that a proof must be offered in support of the claim that God cannot possibly exist. This theoretically can be done by demonstrating the contradiction inherent in the divine attributes, or that the problem of evil is inconsistent with such a being. Neither of these arguments has gained much support among philosophers (the evidential problem of evil is now most popular among atheologians).

Of course, (1) also appears to beg the question. One wouldn’t accept the premise, unless he or she already accepted the conclusion. This puts us at a bit of an impasse. However, if there are no compelling reasons to accept ~(1), then (1) can very well be rationally justified, even if it is itself not compelling.

Thoughts?

First of all, it is not the case that, for some claim Q, lack of justification for ~Q constitutes justification for Q. It could be that neither claim has justification, forcing us to withhold judgment if we wish to avoid irrationality.

Second, I think we have plenty of reason for accepting ~(1), that being the enormous superfluity and utter lack of evidence for the God hypothesis.

Finally, as you rightly point out, (2)-(3) are relatively uncontroversial to those familiar with possible worlds semantics, and (4)-(5) follow from (1)-(3). So, (1) is more or less the same as saying that God exists, hence begging the question.

 

[punkforchrist]

I’m actually not impressed with the many parodies of the OA. A “maximally great” car could always have a little more nitro. A “maximally great” island could always have a few more palm trees, or dancing girls, or whatever. It seems to me that any time we plug in a physical object and try to maximize it, we are left with something incoherent. Yet, a maximally great being, per the MOA, is not descriptive of some kind of physical entity, so I don’t see the parity between this argument and the usual parodies (Gaunilo’s Island, etc.).

NowAgnostic, I agree with most of your thoughts on the MOA. I agree that both (1) and ~(1) may be rationally justified; neither are necessarily compelling, at least prima facie. I also agree that, in order for the MOA to be sound, it need only be logically possible for God to exist, which is distinct from epistemic possibility. Hence, I agree that the MOA doesn’t constitute a “proof” in any strict sense. Plantinga, in fact, says the very same thing:
Alvin Plantinga:

Since I believe in God, I think the following argument is sound:

Either God exists or 7 + 5 = 14
It is false that 7 + 5 = 14
Therefore God exists.

But obviously this isn’t a proof; no one who didn’t already accept the conclusion, would accept the first premise. The ontological argument we’ve been examining isn’t just like this one, of course, but it must be conceded that not everyone who understands and reflects on its central premise–that existence of a maximally great being is possible–will accept it. Still, it is evident, I think, that there is nothing contrary to reason or irrational in accepting this premise. What I claim for this argument, therefore, is that it establishes, not the truth of theism, but its rational acceptability. And hence it accomplishes at least one of the aims of the tradition of natural theology.

This sums up quite nicely my own position on the MOA. I don’t think we can prove (1) or ~(1) to be true, but one may be justified in believing either premise. Of course, I’m open to any purported demonstrations of one or the other.

 

[Spock]

The concept of “maximally great” is undefined and incoherent. From that point the argument goes downhill.

 

[punkforchrist]

hatsoff:

First of all, it is not the case that, for some claim Q, lack of justification for ~Q constitutes justification for Q. It could be that neither claim has justification, forcing us to withhold judgment if we wish to avoid irrationality.

There’s really no alternative to (1) and ~(1). One might withhold judgment, but that doesn’t affect one’s belief with respect to one premise or its negation. I’m not saying that lack of justification of ~(1) means that (1) is true, but that barring any proof of ~(1), the theist may be rationally justified in accepting (1).

Second, I think we have plenty of reason for accepting ~(1), that being the enormous superfluity and utter lack of evidence for the God hypothesis.

That’s doesn’t really bolster the likelihood of ~(1), since God need only exist in just one possible world in order for (1) to be true. Moreover, I think you’re begging the question with respect to the evidence aspect. Theists offer many a posteriori arguments for God’s existence. You may not accept the reasoning of these arguments, but they would have to be dealt with nonetheless.

Finally, as you rightly point out, (2)-(3) are relatively uncontroversial to those familiar with possible worlds semantics, and (4)-(5) follow from (1)-(3). So, (1) is more or less the same as saying that God exists, hence begging the question.

Yes, I agree that it begs the question. However, ~(1) begs the question just as much as (1) does. ~(1) is virtually identical to ~(5): “Therefore, God necessarily does not exist.”

Thanks to everyone for your thoughts. Keep 'em coming.

 

[punkforchrist]

The concept of “maximally great” is undefined and incoherent. From that point the argument goes downhill.

Lol well, that incoherence has to be demonstrated in order for ~(1) to be literally preferred to (1).

 

[punkforchrist]

Allow me to qualify the “burden of proof” aspect as relating to epistemic justification.

 

[Spock]

Lol well, that incoherence has to be demonstrated in order for ~(1) to be literally preferred to (1).

How can incoherence be “demonstrated”? I will substitute “maximally great” with “maximally wheuxeos”… and ask you demonstrate its incoherence. Greatness as a concept is a compound attribute. Different people will consider “greatness” differently and subjectively. There is no absolute “greatness” apart from some criteria - greatness in relation to something. Should I continue? To say that something is “maximally great” is meaningless proposition. The OA does not even get off the ground.

 

[NowAgnostic]

Allow me to qualify the “burden of proof” aspect as relating to epistemic justification.

I don’t know how it is meaningful to discuss any sort of “epistemic justification” without evidence. Assume a belief B and a set of evidence E. If the likelihood P(E|B) >> P(E|~B) then I can accept there’s epistemic justification to believe B. Without the evidence, it’s a matter of the prior P(B) which is just pulled out of a hat except in the case of tautologies and contradictions. But it’s if a matter of evaluating likelihoods we’re back to cosmological arguments.

 

[punkforchrist]

How can incoherence be “demonstrated”? I will substitute “maximally great” with “maximally wheuxeos”… and ask you demonstrate its incoherence. Greatness as a concept is a compound attribute. Different people will consider “greatness” differently and subjectively. There is no absolute “greatness” apart from some criteria - greatness in relation to something. Should I continue? To say that something is “maximally great” is meaningless proposition. The OA does not even get off the ground.

The difference between “maximally great” and “maximally wheuxeos” is that the latter is undefined. Saying that this is subjective is an entirely different claim than saying it’s meaningless. And, of course, it cannot be meaningless when a definition is provided in the syllogism itself.

 

[punkforchrist]

I don’t know how it is meaningful to discuss any sort of “epistemic justification” without evidence. Assume a belief B and a set of evidence E. If the likelihood P(E|B) >> P(E|~B) then I can accept there’s epistemic justification to believe B. Without the evidence, it’s a matter of the prior P(B) which is just pulled out of a hat except in the case of tautologies and contradictions. But it’s if a matter of evaluating likelihoods we’re back to cosmological arguments.

The sentence in bold, I think, is key to one’s epistemic justification for (1). Nevertheless, I agree that this would result in just as much begging of the question as one’s acceptance of ~(1).

I also don’t see any reason that a posteriori considerations cannot be used to bolster one’s justification for (1) or ~(1). Of course, we still wouldn’t have any proof for either premise, but it would lend itself to epistemic justification. So, I do think we can use evidence; I just don’t think one’s evaluation of the evidence necessarily falsifies another’s warrant.