Kant, as you may or may not know, objects to the cosmological argument in the first critique (starting around KRV, B 631). His objection is that the cosmological argument relies on the ontological argument (which is false) but adds an a posteriori step.

His objection to the ontological argument (contained in the previous chapter of the first critique) is that existence adds no new conceptual content. St. Thomas Aquinas, who proposes the cosmological argument (following Aristotle) makes the same assertion as Kant in his commentary on Aristotle's Metaphysics. Thomas (and his Thomist henchmen today) obviously still thinks the cosmological argument holds; Kant doesn't.

My term paper is going to be working with Kant's objection to the cosmological argument, which I haven't exactly decided my opinion on yet(scholarship seems to side against Kant so far), but I'm being drawn to side against Kant so far.

Anyways, I decided to open up the floor to discussion on the topic.
Does the cosmological argument rely upon the ontological argument?
Is there a pro-Kant argument out there? Will someone take to his defense?

Here's my formulation of the ontological argument:

Definition: God is “that which nothing greater can be conceived.”
Axiom: It is greater for something to exist than for something to not exist.

Reductio:
I.God does not exist.
II.Concept 'A' contains all of the properties of God and existence.
III.By the axiom, 'A' is greater than God.
IV.Proposition III contradicts the definition of God.
V.By the law of contradiction, I. Is false.
VI.By the law of excluded middle, God must exist.

And here's the cosmological argument from Stanford Encyclopedia of Philosophy:

1. A contingent being (a being that if it exists can not-exist) exists.
2. This contingent being has a cause of or explanation[1] for its existence.
3. The cause of or explanation for its existence is something other than the contingent being itself.
4. What causes or explains the existence of this contingent being must either be solely other contingent beings or include a non-contingent (necessary) being.
5. Contingent beings alone cannot provide an adequate causal account or explanation for the existence of a contingent being.
6. Therefore, what causes or explains the existence of this contingent being must include a non-contingent (necessary) being.
7. Therefore, a necessary being (a being that if it exists cannot not-exist) exists.

Before you consider what Kant said,
Definition: God is “that which nothing greater can be conceived.”
Axiom: It is greater for something to exist than for something to not exist.

To make these meaningful,

Definition:
Can God be "that" which is conceived (is God a thing?)? Can God be conceived by man? Is God bounded by human conception?
Greater in what sense? bigger? most potent? most qualities? most preperties? if all of these, then is that logically consistent?

Axiom:
Is this "greater" the same as the previous "greater"?
Can God be "something"? Or is something limited to things, either imagined or actual?

"Can God be "that" which is conceived (is God a thing?)?"

Obviously He can be an object of our consideration since we are considering Him. Yes, God is a "thing," whether real or imagined.

"Can God be conceived by man?"
If by God, you mean "that which nothing greater can be conceived," it seems conceivable to me.

"Is God bounded by human conception?"
I'm not sure exactly what you mean by this but if you mean "within the bounds of human conception," if you can conceive the definition, yes.


""Greater in what sense? bigger? most potent? most qualities? most properties? if all of these, then is that logically consistent?""
The typical conception is for him to be omnipotent and omniscient (St. Thomas describes God as "the act of all acts and the perfection of all perfections), which is superfluous to the definition. All that is relevant to the definition is that, whatever "greater" means, he is the "greatest."

"Is this "greater" the same as the previous "greater"?"
Yes. It is the only qualification of the word "greater" relevant to the argument.

"Can God be "something"? Or is something limited to things, either imagined or actual?"
Can "that which nothing greater can be conceived" be a thing? I think you're underestimating how vague the word "thing" is (recall "Sense Certainty"). God, by definition, is a thing.

In that case, I no longer understand what you might mean by "exists". The concept of ontological existence has a tortuous history from Aristotle through Aquinas to Descartes and Locke, and from Berkeley through Hume to Kant. What I mean might be seen in plato.stanford.edu/entries/existence/ with an interlude from www.ditext.com/broad/bdms.html

The difference is whether we're trying to prove that God has "essence" or properties. To Berkeley, we only perceive material properties, never an object. Hume agreed that "existence" adds nothing to a distinct impression. Then Kant says By whatever and by however many predicates we may think a thing — even if we completely determine it — we do not make the least addition to the thing when we further declare that this thing is. … If we think in a thing every feature of reality except one, the missing reality is not added by my saying that this defective thing exists.(CPR)

If God is a thing, then it's quite different to work from Aquinas or Kant. But I think the original argument might have been more directed at trying to bridge the gap from the idea of God to a material existent. I can't see how that can be done. Boethius ~ finite ... may in a sort be compared one with another, but a finite and an infinite never That something be greater or less can be compared within finite things or within infinite things, but not between finite things and infinite God.

I don't know the exact history of the cosmological arguments at the time of Kant, but I can suggest that Kant wasn't offering up a refutation of an argument formulated by Aquinas, but more likely one formulated by the Leibniz-Wolff et al., or one of the other traditions he was more closely considering in his time.

I'll review these sections of the Critique again, anyway, if I have time (hopefully) and try to say something more constructive.

When Kant says that the cosmological argument (CA) depends on the ontological argument (OA) to prove a divine reality, he means that the CA only proves that something is necessary, which transcendental theologians go on to claim (by way, surreptitiously, of the OA) to be something divine. But by itself, the CA doesn't tell us what, exactly, the attributes of a necessary existence are (save that it's not contingent), and so doesn't establish divinity.