What do you think of this argument for God?

[RoadRunner79]

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First I was curious about your referenceing ipse dixit in regards to premise 3  and citing Plantinga as conceding this.   I would just like to see it in context.

I mentioned this in my first in-depth dissection post, but for full reference:

Alvin Plantinga is a Christian apologist (I don't say this to disparage him, just to make it plain that this is the explicit basis that he uses for all of his positions) with a particular interest in the various ontological arguments. In 1974, he authored the version of the modal ontological argument that I showed in my previous post - the one that makes use of the S5 axiom set to define God as necessary. He published this argument in his book The Nature of Necessity, wherein it was presented as a reformulation of Saint Anselm's original argument.

In the conclusion of that same book (page 221, specifically, which can be found on Google Books if you're curious), he stated:

"Our verdict on these reformulated versions of St. Anselm's argument must be as follows. They cannot, perhaps, be said to prove or establish their conclusion. But since it is rational to accept their central premise, they do show that it is rational to accept that conclusion. And perhaps that is all that can be expected of any such argument."

The "central premise" that he refers to is that it is possible for a being with maximal greatness to exist. And, as I have pointed out, while Plantinga asserts that acceptance of this premise is rational, he cannot actually show how or why this would be so. As such, the premise is bare assertion (it is his attitude towards it being bare assertion, his attempt to simply tell people to accept it anyway, even though he knows it's faulty, that leads me to use the label "ipse dixit" here). And, again as even Plantinga himself admits, this is the best that can ever be expected from any version of the ontological argument.

And this is entirely without getting into all of the other potential issues with the argument, such as incoherent definitions (as "goodness" is subjective) and misuse of axioms. As I mentioned previously, while S5 is valid, it is not the only set of axioms that modal logic can make use of, and each set of axioms has very specific limitations and applicability. Modal logic is not my particular specialty, so I haven't taken the time to sit down and work out whether or not Plantinga should have been working under S4 or another set of axioms instead, but I suspect that he might have - and, under those other sets, he would not be able to pull the sleight-of-hand trick with "possibly necessary" that his argument rests on.

But, as I said, I haven't actually verified that personally, because it doesn't really matter. Whether or not S5 applies, the central premise of the argument remains bare assertion, by Plantinga's own admission.

As such, the argument is discarded.

It uses the modal form of the argument that I have normally heard used

Yes. That is Plantinga's argument, slightly rephrased to put the language of modal logic in layman's terms. You can swap the phrases "exists in every possible world" and "is necessary" without changing anything, mechanically speaking.



Correct, but with the slight quibble that it is entirely possible for both of these objections to be true.

It is also demonstrable that the latter objection is true; we have no idea whether or not the existence of a god is possible. That is why the argument fails to establish its conclusion. It is precisely the premise that both Plantinga and myself have pointed out as being unsupported. If we knew that the existence of this necessary being were possible, we really wouldn't need to have this discussion - but since the concept cannot even be coherently defined, let alone be established as possible, the argument is a non-starter.



I'm not sure I would call it a great argument for establishing that the concept of God includes the fact that he is necessary. An important definition, maybe, and something that might influence someone's thoughts on God, but the argument itself is just kind of dead on arrival.

I have also heard William Lane Craig mention a similar two conclusions to the argument

As a general rule, I would discourage listening to anything that William Lane Craig has to say. He's an idiot.

And I don't mean to say that he is an idiot because he is a theist. Plantinga is a theist, and while his formulation of the ontological argument fails to establish its conclusion, he is at least an intelligent man who can build a coherent argument within the laws of modal logic. He understands how prepositional calculus works, and how to employ sets of axioms, and so on. He is an intelligent man who just happens to let his beliefs color his thinking a bit farther than is advisable (and, admittedly, doesn't understand the theory of evolution and mouths off about it more than he really should). I don't agree with much of what he says, but he does at least have some legitimate grounding as a philosopher, and he is at least honest about the failings in his formulation of the ontological argument.

Craig is an idiot of the highest caliber. I am honestly surprised that he possesses the necessary brain function to walk and chew gum at the same time. His one and only talent is as a bullshit artist. Do not be fooled by the "Doctor" in front of his name; while he does technically possess a Ph.D. in Philosophy, this is only because the institute that he went to did not offer doctorate degrees for anything more specific. He has always and only ever studied philosophy of religion, and without any actual critical eye turned towards any of it.

Again, I'm not just saying this to try and be dismissive (I mean, obviously I'm dismissing Craig, but you get what I mean). If you actually want to learn anything about philosophy, logic, or really anything at all, you would be best served by ignoring Craig and everything that he says or does. Even if he were an atheist, and arguing against the existence of God, I would say the same thing. The man simply has zero understanding of logic as a system, and any argument that he advances can be safely thrown into the garbage bin without a second glance, as it is guaranteed to be full of more holes than a sieve.

Anyway. I'm more than happy to carry on this discussion, though I admit to being slightly hazy on what particular part of the quoted section you wanted my thoughts on. I picked out what appeared to be the most important points and gave a brief rundown of each, but if I missed anything, just let me know.

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NonPareil,

Perhaps it is a result of when I grew up, and some of the changes I have seen and always hearing quotes like those below, but from my view of the semantics in modal logic, I think that possible is the more neutral and default term.   It is possible, if and only if; it is not necessarily false.  This is independant of whether it is actually true or false.   It is saying, that the claimant doesn't find any reason to find it logically impossible.  How would you go about showing that something is possible in this sense?

 

I have learned to use the word impossible with the greatest caution. – Wernher von Braun
The positive thinker sees the invisible, feels the intangible and achieves the impossible. – Anonymous
When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. – Arthur C Clarke

Now you main objection as I see it, is that you consider the definition of maximally great in the premise to be incoherent.  I am assuming (from what you have stated thus far) that you mean incoherent in an ambiguous sense, and not that it is logically incoherent.  From this, at best, I think that the best that you can say is that you cannot comment on it, because you do not know what it means.   In one view, this may make it a bad argument because people may come at it with different views.  Christians certainly have a longstanding view of what constitutes greatness concerning God, and I don't think that most of it would be considered controversial.  However; I don't think that most would argue that nothing is greater in an objective sense.  Is Love and self sacrifice greater than hate  and self serving?  Is greater potential in power greater than weakness?  Even if different people disagree on what is considered greatness.  They can be incorrect, and it doesn't make it subjective.   This has to do with epistemology not ontology.  And with this argument even if we differ greatly, only one attribute is needed for agreement in the area of greatness.

As to what you are unsure of that I quoted and you mentioned at the end of the post.   Would you agree, that apart from simply not taking a view on the argument (which is equivalent to pleading ignorance on the topic); that the argument makes the concept of God either impossible or necessary?  That God is either possible, or logically incoherent.   I think that is a pretty tall order to support the latter.   It's possible, that we are simply not smart enough or lacking knowledge to articulate reasons to why it is impossible.   However I think that it's the science nerd in me, that say's I need a reason for why not, and not to default to impossible, simply because I don't know.

(Note:  I do see an issue with the argument I quoted.  I think that this particular form of the argument, somewhat assumes that the hearers are familiar with previous forms of the argument; and doesn't show how it moves from existing in some possible world, to existing in every possible world.   However this could easily be corrected.  I could see some other issue that could arise, but they don't really deal with the argument itself and are really off topic)