What are some good checkmate arguments against religion?

[Rampant.A.I.]

Plantinga himself admits the modal ontological argument is unconvincing and flawed: One must presuppose the conclusion to allow the premises.

What one presupposes in Plantinga's argument is that 1) modal realism is true and 2) God's existence is possible. If those 2 are true, then God would exist. That's no more circular than saying 1) modal realism is true, 2) the existence of ETs is metaphysically possible, 3) Therefore ETs exist (in some possible world, not necessarily ours). You're confusing circularity with entailment. The assumptions I mentioned do entail the conclusion, but that's true of all arguments.

For example, Kalam assumes that actual infinities are impossible and that the A-theory of time is true. These entail the conclusion that the unuverse has a cause for its existence. But that doesn't make Kalam circular.

I'm unsure why you would provide four examples of circular reasoning when I asked you for a logically sound ontological argument, but judging from past responses and your post here, you simply fail to understand why circular reasoning is logically invalid.

I DO understand why circular reasoning is bad, but you're actually wrong. Circular reasoning is not, strictly speaking, logically invalid; it's just unconvincing because it can support any proposition. I'm lazy, so I'll just quote Wikipedia's article:

Circular reasoning is a logical fallacy in which the reasoner begins with what they are trying to end with. The components of a circular argument are often logically valid because if the premises are true, the conclusion must be true. However, the argument is useless because the conclusion is in the premises. Circular logic cannot prove a conclusion because, if the conclusion is doubted, the premise which leads to it will be doubted.

http://en.wikipedia.org/wiki/Circular_reasoning

Regardless, what YOU don't seem to understand is that the arguments aren't anymore circular than any other logically valid argument. Take the classical syllogism:

All men are mortal;
Socrates is a man;
Therefore Socrates is immortal.

The first premise entails the conclusion already, but we clearly don't see this as a problem.

Now, you'd have to be a fuckwit if you think I'm supporting circular reasoning. What I am doing is questioning your claims about ontological arguments (esp. Plantinga's) being circular.

Worse, you seem to be confusing validity with circularity. I've never said I thought any ontological argument was sound (I'm an atheist, dumbass), but plenty of them have been valid, i.e the conclusion follows from the premises.

You should learn not to describe presuppositional arguments as "logical proofs," and then condescend to anyone who disagrees with an invalid ontological argument being defined as a "logical proof" like an arrogant 21 year-old suffering from the Dunning-Kreuger effect.

Oh boy, the old standby of "Can't beat the argument, so let's talk about my spurious claims regarding their psychology!"

Anyway, Plantinga's argument is not presuppositional, it's an argument from natural theology. It is almost never disputed as being logically valid (I can only find claims that philosopher Michael Martin disputes this) because, again, it just follows from its premises. Yes, they ARE proofs because given the premises, the conclusion NECESSARILY follows; that's basically what a logical proof IS. That tells you nothing of the soundness however.

The argument is indeed presuppositional, as it presupposes God's existence in order to define necessary existence as a characteristic of God in the opening premises.

It relies on an equivocation between subjunctive possibility and epistemic possibility.

Plantinga's argument has indeed been challenged, and has all the shortcomings of other historical ontological arguments which have been categorically challenged and shown to be invalid.

http://en.m.wikipedia.org/wiki/Ontological_argument

The introduction of "necessary existing being" is problematic. If something exists necessarily, is existence a property of something existing contingently?

If I replace the necessarily existing God with Necessary Unicorn, is the argument still valid as proof of any supernatural entity? What makes a being "necessary," saying it's necessary? You'd have to accept an ontological argument, or assume God's existence for such a concept to even appear coherent in the first place.

I'd rather like to know what my apparent condescension and arrogance has to do with the argument at hand.

It's because you're the douchebag who sits in the front row of Philosophy 101 classes, presenting "new original thoughts of your own" covered in the first few chapters of course material you didn't bother to read.

I can show why you're wrong - and have - but as with many when shown you're wrong, you shift into non sequiturs and ad hominems.

This is because you continue to repeat like a broken record that ontological arguments are logically valid, without even bothering to glance at the historical objections posted in the same Wiki pages you're copying the arguments from.

Most are just content to criticize arguments for bad (or at least badly stated) reasons and call it a day. Which always surprises me from a community which generally trumpets its rationality, intellectual capabilities and skepticism. Disagreeing is fine, but accepting bad responses to arguments we reject is just silly.

If you'd bother to look in to the objections to the arguments instead of claiming "no one disputes them" and "they're logically valid," this wouldn't be an issue.

Instead you dismiss objections and continue to introduce largely debunked arguments as "logically valid," and then go on to lecture about rationality, critical thinking and skepticism?