Thomas Keating has a lot of nerve!

[HarryStotle]

HarryStotle:

Except that for Aquinas God’s essence is existence. God is the Pure Act of Being Itself or Actus Purus, Ipsum Esse Existens.

That’s the Thomistic reasoning…I happen to think it’s spot-on.

Ergo, your point that “ knowing that something exists does not entail that you know its nature” does not apply to God at all. The more that you understand God’s nature the more you understand that he exists

I’m not sure what you’re trying to argue here. My claim was that a judgment that something exists doesn’t entail that you know its nature with precision. That’s not a bold claim. This is true for every being that we ever come to know about, including God (though He’s not a “thing,” not another being among many in the universe).

Moreover, although St Thomas affirms that there are many truths we can know about God, he’s also cautious. See his entire Q.12 of Part 1 of the ST. Within the articles of that section, Aquinas says things like, “it is impossible for any created intellect to see the essence of God by its own natural power.” (Art 4) And, “it is impossible for any created intellect to comprehend God.” (Art 7) And, “God cannot be seen in his essence by a mere human being, unless he be separated from this mortal life.” (Art 11). He’s optimistic about knowledge of God but simultaneously very cautious.

That is why the ontological argument has traction when speaking of God but not with islands and such.

Eh, maybe. Some thomists are impressed with the ontological argument (eg, Bishop Barron). Thomas himself wasn’t impressed by it…

It isn’t quite true that he wasn’t impressed by it. He didn’t think it could persuade someone who didn’t think God exists, but that would be because such an individual does not properly understand what it is that is being discussed. That is what Aquinas thought the Five Ways accomplished - giving a clearer picture of what is being spoken of when the word God is being used. It is pointless to argue from the ontology behind the idea when the idea isn’t being grasped by the person you are trying to persuade.

 

[Magnanimity]

It is pointless to argue from the ontology behind the idea when the idea isn’t being grasped by the person you are trying to persuade.

I think Aquinas agrees with this, but it’s also his objection to the ontological argument.

He says, “Perhaps not everyone who hears this word “God” understands it to signify something than which nothing greater can be thought, seeing that some have believed God to be a body. Yet, granted that everyone understands that by this word “God” is signified something than which nothing greater can be thought, nevertheless, it does not therefore follow that he understands that what the word signifies exists actually, but only that it exists mentally. Nor can it be argued that it actually exists, unless it be admitted that there actually exists something than which nothing greater can be thought; and this precisely is not admitted by those who hold that God does not exist.” -ST Ia, q. 2, a. 1, ad 2.

 

[HarryStotle]

Given that Objection 2 concerns the question of whether or not the proposition God exists is self-evident, Aquinas’ answer ought to be taken as addressing that question alone.

Therefore the proposition “God exists” is self-evident.

Ergo, the answer does not necessarily imply that the ontological argument doesn’t hold up but that the argument would be convincing if the proposition God exists were self-evident. Since it isn’t to those denying God’s existence Aquinas is arguing that the ontological argument doesn’t work as a compelling argument to persuade those people.

That isn’t quite the same thing as claiming the argument is false or untrue.

That, I think, is the gist of this statement by Aquinas.

Therefore I say that this proposition, “God exists,” of itself is self-evident, for the predicate is the same as the subject, because God is His own existence as will be hereafter shown (I:3:4). Now because we do not know the essence of God, the proposition is not self-evident to us; but needs to be demonstrated by things that are more known to us, though less known in their nature — namely, by effects.

Basically, Aquinas is stating that the proposition God exists is self-evidently true in itself, even if it is not so for those who do not accept it.

 

[Magnanimity]

Given that Objection 2 concerns the question of whether or not the proposition God exists is self-evident, Aquinas’ answer ought to be taken as addressing that question alone.

Therefore the proposition “God exists” is self-evident.

Aquinas criticizes the reasoning for the conclusion in ob 2, which is an ontological line of reasoning. That’s why his entire response to objection 2 is a criticism of an ontological argument. It’s not accidental. So no, it’s not simply to the conclusion that God exists to which he offers a response. That would be an odd, non-contextual reading not justified by the text.

Again, as I said above, Aquinas’ opposition to the ontological argument is well-known. The briefest of internet searches will reveal this. He gives arguments against it in many places of his major writings—ST, SCG, On Truth and elsewhere.

If it helps you to come to terms with this, I quote below Aquinas’ extended criticism of the ontological argument (a la Anselm) from the SCG, I, 11:

1. Nor is the existence of God necessarily self-evident as soon as the meaning of the name God' is known. First, because it is not evident, even to all who admit the existence of God, that God is something greater than which nothing can be conceived, since many of the ancients said that this world was God. Then granting that universal usage understands by the name God’ something greater than which nothing can be conceived, it will not follow that there exists in rerum natura something greater than which nothing can be conceived. For thing' and "notion implied in the name of the thing" must answer to one another. From the conception in the mind of what is declared by this name God’ it does not follow that God exists otherwise than in the mind. Hence there will be no necessity either of that something, greater than which nothing can be conceived, existing otherwise than in the mind; and from this it does not follow that there is anything in rerum natura greater than which nothing can be conceived. And so the supposition of the nonexistence of God goes untouched. For the possibility of our thought outrunning the greatness of any given object, whether of the actual or of the ideal order, has nothing in it to vex the soul of any one except of him alone who already grants the existence in rerum natura of something than which nothing can be conceived greater. [21] 2. Nor is it necessary for something greater than God to be conceivable, if His non- existence is conceivable. For the possibility of conceiving Him not to exist does not arise from the imperfection or uncertainty of His Being, since His Being is of itself most manifest, but from the infirmity of our understanding, which cannot discern Him as He is of Himself, but only by the effects which He produces; and so it is brought by reasoning to the knowledge of Him.