Unconvinced as yet. If God is defined as per the original argument, then God is "the greatest conceivable being". If I already accept premise 2, then existence is required as a property of God. I don't see how it's an optional attribute. This is begging the question, surely. To even agree with your definition of God we must presuppose the following:

1. Existence is greater than non-existence (premise)
2. Any non-existent being would be made greater by existing. (from 1)
2. God is defined as the greatest conceivable being (definition)

So your definition sneaks in the premise you are trying to prove.

The basic idea of the ontological argument is that a proper understanding of the concept of god would show that we cannot coherently conceive of god as not existing. This is supposed to just be a matter of the conceptual framework of the universe. So, if you think that in fact there is no god, you have to either show that the concept of god I'm putting forward is incoherent, or that it doesn't imply that god actually exists. Telling me that I'm begging the question, or sneaking in premises isn't very helpful.

Remember, the form of the argument I've put forward here is a reductio. Do you agree that the argument is valid? If not, show me where. If it is valid, then one of the premises must be false. Which one?

but why is existence greater than non existence?

That's one the main problems I have with this argument is that it gets into very subjective areas, where when challenged on some of these things you basically have to say: "oh cmon, clearly this is greater than that."*

(I dont mean "you" as orp, specifically, just anyone defending the argument)

It's not valid because the definition contains the premise you want to prove. It's no different from saying "God is defined as a deity that exists".

Babe Ruth had different sets of skills, abilities, and accomplishments then Einstein, so that doesn't explain why one is greater than the other. You then said it was about value or importance, well okay this is a new metric but is NOT the bolded metric you just stated. It is looking more and more like you cannot come up with a well defined ordering of "greatness" comparing simply humans, so I don't know how you think it is obvious that there is such a well defined ordering for every possible being.

Reading your other comments you are also starting to talk about comparing "the idea of nonexistence" or "typwriters" or any number of things. So it isn't just humans, or animals, or even "beings" but it seems to be "all concepts" of which you want some ordering on all of that to which you will claim we can easily understand this entire picture and see so obviously that it is a premise that god is greater than all of these. Heck, it seems to me that the only being that COULD actually conceive of this monstrous ordering is the type of thing you want God to be!

It is entirely appropriate to question whether one of the premises of the argument is true, which is what I am doing. I said "I am not convinced" not "I am certain it is false", so it is again entirely appropriate for me to question whether there is this meaningful and welldefined partial ordering.

Ok fine so as I understand it you have shown that

If there exists <a being X say that satisfies that it is false that a being greater than X can be conceived> then such a being X exists.

In other words in 6 you effectively assume that your god exists, then show logically that if follows that that god exists.

Effectively proof by assertion with lots of logical babble to try and hide that that is what you have done. Still I have to admit that proof by assertion is the best argument for a god's existence.

Look, maybe you think the argument fails. Fine. Simply telling me that it is "logic babble" doesn't tell me how. The argument is all there. Either show that one of the premises is false or that it is invalid. Otherwise I don't see how you are making a serious response.

As for the claim that it is proof by assertion--presumably this means that you think one of my premises is false. Which one?

Nah. Arguments that beg the question are still valid arguments. For instance, this is a valid argument:

1) God exists.
---------------
2) Therefore, God exists.

In other words, if you think I'm begging the question and you think my conclusion is false, then you must think that one of my premises is also false. Which one and why?

I think we can probably agree that there will be a lot of difficulty and squishiness in developing a complete theory of what it means to be greater than something else. However, that doesn't mean that there can't still be clear examples. For instance, there is (arguably) no clear distinction between being bald and not being bald. Yet we can still all agree that Patrick Stewart is bald and Mitt Romney is not.

So maybe you don't think that a god that actually exists is greater than just the idea of a god. However, I would like to see you support that claim, as it is certainly counter-intuitive. If you are going to hang your rejection of the ontological argument on this point, then I think theists can rightly think that this argument advances their case.

" to say Einstein is greater than babe ruth in this sense is you making a value judgment. Perhaps I think being the greatest baseball player among literally thousands( perhaps tens thousands) is a bigger accomplishment.

Not only do I think that example fails,To be perfectly honest, no I don't think we can agree that there are clear examples of "greater", because it depends on a number of different factors. Firstly, we would need to agree on a metric on which to judge, which,i imagine will be pretty difficult to do

Forgetting my problems with "greater" for a second and turning my attention to the bolded. It seems to me that it actually could be said that something in my mind can be greater than the something in reality simply because in my mind i can ascribe whatever attributes i want. consider a woman. for example. In my mind I can construct what i believe to be the ideal woman, complete with all the physical features my perverted mind can come up with (two mouths, thinks im the sexiest man alive, what have you) However, this woman would not exist in reality, and so from my perspective the woman in my mind who is sexually optimized and constantly wanting to please me is greater than a woman in reality.

A circle is greater in the mind than in reality, as in reality there can never be a perfect circle. On this basis, almost any thing of which I conceive is greater in my mind than existing in reality (nothing is perfect in reality, but I can conceive of perfect things).

Therefore we change your premise 2 to the more reasonable "Existence in the understanding alone is greater than existence in reality" and conclude that God only exists in the mind. This also applies to "the greatest conceivable X", but not to "non-greatest conceivable X" so there is no contradiction.

(x-post with Sommerset)

jinx!

I'm not going to get into the OA in any deep way because I don't like it and even if some form of it was a good argument it wouldn't be very useful to general apologetics.

Briefly, then, I seem to remember Russell pointing out the problem with the OA hinges on the equivocation of the word "exist", and I tend to agree. I may be a fool, but I think the weak part of the argument is (8). I think at least a robust definition of "exist" is required for the argument to work.

Both you and Sommerset are making a similar error here. The question is not whether anything that exists in reality is greater than anything that exists in the mind. So maybe you think the idea of the calculus is greater than the reality of a particular hydrogen atom. That's not the point. The idea is that of anything that exists as an idea, it would be greater if it also existed in reality. In other words, existing in reality is a "great-making" quality. So you shouldn't be comparing the idea of Marilyn Monroe to the reality of someone you find boring and sexually uninteresting. Rather, it is the idea of Marilyn Monroe to the reality of Marilyn Monroe. Similiarly with perfect circles, which of course can exist in reality.