As far as I understand St. Anselm doesn't make the claim that God is essentially understandable. God being understood as the Cause of causes (and thus definitionally beyond human understanding) should be sufficient for the argument to work.

I also saw an IEP article on Plantinga's version of the ontological argument, and it seemed pretty sound to me. I prefer the cosmological argument, but I see the ontological as a viable alternative.

@Mysterious Brony,
Thanks for the recommendation and I will check them out!
(BTW are you an actual Brony?)

I'd like to hear about Godel's version too.

Here are a few links that might be of interest to some of you folks.

The Ontological Argument: Therefore God Exists

The Ontological Argument: Question Begging?

And yeah, someone would need to totally walk me through this kind of argument and help me see how they don't beg the question. But I do like such arguments a lot!

The Ontological Argument, at least in its modal formulations, is one of my favourite articles of Natural Theology. I don’t consider it the most indubitable proof but I do think it’s the one which gets us closest to the very nature of God; indeed, its emphasis on the essence of beings brings it closer to the sphere of pure logic than most of the other proofs. 

Thomist and particularly Neo-Thomist criticisms of the OA have long been a bug-bear of mine. So many of the criticisms given in the manuals attack grotesque strawmen, ‘the argument implies we have intuitive access to the essence of God’, or even defy coherence (see Hartshorne for examples). That Thomists persist in this knee-jerk attitude to this day both astounds and depresses me. To give one glaring example in Real Essentialism David Oderberg hastens to reassure people that the Real Distinction does not imply the truth of the OA – when I first read that I was very tempted to send him a sarcastic email asking him to further reassure readers that the Act/Potency distinction wouldn’t imply anything nasty like the existence of a being which is Pure Actuality! 

Here’s rough break down of the various versions: 

The Epistemic Version: Anselm’s ‘first argument’, found the second chapter of the Proslogion, states that existence in re is greater than existence in the understanding alone. This version is vulnerable to the famous Kantian contention about Existence not being a property, as well as worries about the coherence of something ‘existing in the understanding’. Katherine Rogers and Yujin Nagasawa have defended modern reformulations of this version as has Brian Leftow, who gets around my later worry by appealing to Free Logic. 

The Modal version: this is the version we are all familiar with from the Plantinga onwards. Whilst Anselm presented a modalised formula for the OA in Pros 3 it probably wasn’t until Scotus and Leibniz that the true modal nature of the proof was realised (although Descartes arguably reverts to a modal formulation in his respond to Gassendi’s Kantian criticism). After being eclipsed by Kantian confusions over the epistemic argument this stronger version of the proof was only rediscovered in the last century by Norman Malcom in his famous article 'Anselm's Ontological Arguments'. Of course it gained fame and mainstream acceptance when Alvin Plantinga formalised it in terms of Possible Worlds and Great- Making Properties.

The Modal Version proves that if God is possible, exists in one possible world, then God is actual (on the logical frameworks in question a merely possible necessary being is a contradiction in terms), exists in all possible worlds. Here most opponents of the argument will try to counter by arguing that God is impossible due to one or more of the Great Making properties being incoherent or incompatible with the others. 

They might also- and this is where Plantinga lets himself down- try a sceptical approach and ask the proponent of the argument to justify the possibility and compossibility of the Divine Attributes in question. Here I say: bring it on! If by conceptual analysis we can make a positive case for the coherence of the attributes against criticism (and such criticism will amount to an ontological disproof of God as traditionally conceived anyway) and further elucidate what they entail it means that we have de facto provided a stronger case for the possibility and thus actuality of God. All in all WLC's approach is preferable to Plantinga's own. 

The following are all developments of the Modal Version: 

The Deontic Version: This version is equivalent to the normal modal version but with an additional limb which purports to support the controversial possibility premise with reference to the deontic axiom 'Ought implies can'. Despite being an interesting advance in the possibility direction there is remarkably little work on this version - for a more in-depth overview and critique see this article by Bill Vallicella. 

The Godelian Argument: The mechanics of this argument date back to Scotus and Leibniz (from whom Godel developed it), and revolve around the concept of a ‘pure perfection’, from which it is proved via analysis that no property which is a pure perfection entails the negation of another property which is a pure perfection, ergo all perfections are compossible ergo God is possible ergo God is actual. As it happens Godel’s own formulation of said argument is false, in that it entails a problem known as ‘modal collapse’ wherein all truths become necessary truths. This was proved by J.H. Sobel in an excellent early article on the argument. Fortunately C.A. Anderson and others were very quickly able to show that by slight tweaking it’s possible to reformulate the argument in such way as to avoid this, Cotempoary proponents of this argument include Thomists Pruss and Koons. 

The Modal Perfection Argument: an enhanced version of the Godelian Argument first put forward by Robert Maydole in an article for Philo. This argument, which has attracted a great deal of academic attention, is ridiculously complicated (it may commit us to uncomfortable modal accounts). There used to be a simplified explaination of it floating around onn the internet (on a blog?) but unfortunately it appears to have vanished.

For resources on the OA I would recommend Brian Leftow’s article, ‘The Ontological Argument’, in The Oxford Companion to Philosophy of Religion as well as Maydole’s [url=https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjbupbq4vLJAhVFaRQKHVbqAA8QFggiMAE&url=https%3A%2F%2Fappearedtoblogly.files.wordpress.com%2F2011%2F05%2Fmaydole-robert-22the-ontological-argument22.pdf&usg=AFQjCNHyshPxAYmiFcCPrs8n3u_5QzmrTQ&bvm=bv.110151844,d.ZWU]mammoth paper on the subject[/url] previously mentioned by Mysterious Brony. 

I would also suggest less Analytically minded readers check-out Charles Hartshorne’s Anselm’s Discovery, which provides a nice history of the argument centring around the rediscovery of its true modal nature. Hartshorne is a Process Theist and thus has his own peculiarities, but overall the volume is highly accessible and packed with interesting insights; if one’s main exposure to philosophical theology has hereto been Neo-Scholastic manuals this is the place to start.

Last edited by DanielCC (12/23/2015 3:02 pm)

@DanielCC
Yes, besides the parody objection, philosophers use the famous Kantian objection against the OA. However, I have some questions regarding the Kantian objection. What does it mean when someone says "Existence is not a property"? Also, I remember Yujin talks about this objection in the article you sent me. I quote "For in order to defend it, one has to prove not only that the ontological argument presupposes that existence is a predicate, which itself is controversial, but also that existence is indeed not a predicate, which is even more controversial, independently of the debate on the ontological argument." He goes on to say, "Thus in order to refute the ontological argument by relying on the Kantian objection, one needs first to solve the very difficult problem regarding the nature of existence."