The Ontological Argument is Sound

I'd like to thank Ramshutu for accepting this debate. It's a pleasure to debate you on this topic. As mentioned in the intro, the ontological argument is formulated like this:

In philosophy, there are 3 types of beings:

Likewise, there are 3 types of worlds:

To illustrate, numbers and logic are both necessary beings; they exist necessarily in every possible world and their existence is impossible. 2+2=4 is a true saying in every possible world and A=A in every possible world. The ontological argument thus makes the claim that God is a necessary being and His existence is impossible in every possible world. 

In this context, God is defined as a maximally great being. Indeed, if there was a being greater than God, then that thing would be God! To be maximally great, one would need to be all-powerful, all-knowing, morally perfect, etc. in every possible world, thus existing in the actual world. 

Steps 2-6 are relatively uncontroversial among philosophers. Indeed, one gets from 2-3 from S5 modal logic which states that:

S5: If possibly necessarily P, then necessarily P.

When I first looked at the ontological argument, I thought it was rather laughable and easy to laugh off. However, once I seriously engaged in the argument, I found that it was nearly irrefutable. The idea of God is perfectly coherent, thus He must exist in some actual world. I look forward to your rebuttal. 

Thank you for your speedy reply! To keep things simple, I'll use the same heading that Ramshutu uses. 
 
1.) Equivocation Part 1
 
The first thing to note is that the fallacy of equivocation is an informal fallacy and not a formal fallacy. There's a significant difference between an informal and a formal fallacy. Informal fallacies in deductive reasoning can still be valid (though not necessarily sound). With that said, let's look at the argument itself to see whether or not it commits this fallacy. 
 
1. It is possible that a maximally great being exists.
2. If it is possible that a maximally great being exists, then a maximally great being exists in some possible world.
3. If a maximally great being exists in some possible world, then it exists in every possible world.
4. If a maximally great being exists in every possible world, then it exists in the actual world.
5. If a maximally great being exists in the actual world, then a maximally great being exists.
6. Therefore, a maximally great being exists.
 
Con accuses the argument of defining "exists" in two different ways: 
 
 Exists(a) - definitely and absolutely exists. Virtuoso, Myself, voters, trees, Owls definitely exist.
 
Exists(c) - exists contextually contingent on something else existing. Neo from the matrix exists - only in the context of the matrix universe. He only Exists(a) if that matrix universe exists(a)
This is far from the truth. Rather, the word "exist
 
This is absolutely false. Throughout the argument, the word “exists” means “have objective reality or being.” To prove this, let’s plug in this definition instead of the word “exists:”
 
1. It is possible that a maximally great being have objective reality or being.
2. If it is possible that a maximally great being have objective reality or being, then a maximally great being have objective reality or being in some possible world.
3. If a maximally great being have objective reality or being in some possible world, then it have objective reality or being in every possible world.
4. If a maximally great being have objective reality or being in every possible world, then it have objective reality or being in the actual world.
5. If a maximally great being have objective reality or being in the actual world, then a maximally great being have objective reality or being.
6. Therefore, a maximally great being have objective reality or being.
 
There is no equivocation going on here.
 
1.2) Equivocation Part 2
 
The next equivocation charge is also false. “In every possible world” means that a MGB exists in every world that is logically possible. By definition, our world is a logically possible world and thus is included in the possible worlds.  
 
Had he read my opening argument, he would have known that this is simply the result of modal logic which states:
 
S5: If possibly necessarily P, then necessarily P.
 
My opponent drops this point.
 
2.) Question begging
 
This is the more serious objection to the argument. The first premise states that “It is possible that a MGB exists.” The first premise essentially states that such a being is logically coherent. However, as we have seen above, the question begging is an informal fallacy and not a formal fallacy. Begging the question is when the conclusion of the argument is considered to be proven without any new information other than what is given in one premise. The ontological argument does not do this thus is not question begging.
 
So, what is actually meant by “maximally great being”? A MGB is a being with the maximum great making properties. For example, it is greater to exist than not to exist; it is greater to be morally perfect than not morally perfect; it is greater to be all-knowing than lacking certain knowledge etc.
 
3.) Conclusion
 
As I have shown, my opponent’s arguments rest on a faulty understanding of the argument and a faulty understanding of the equivocation fallacy. The ontological argument remains unbloodied and unbowed. The same cannot be said of Ramshutu’s rebuttal. 

An interesting reply!

1.) Equivocation PT1

Pro contests the charge of equivocation, and reframed his argument, I’ll focus on his P2:

The reframing made the issue more obvious: A maximally great being only has objective reality or being in some possible world if that possible world actually exists. 

It’s somewhat hard for a being to objectively exist if the world it exists in doesn’t exist.

The problem can be reframed too: as a possible world may or may not exist we can split P3 into those two possible options to make the issue more obvious. 

There are two possible outcomes from this clarified P3 - one that proves the conclusion, one that doesn’t. 

The OA does not eliminate P3.2 as a possibility, it only uses equivocation between exists(a) and exists(c) to mask that there are actually two options.

This logical error renders the OA unsound.

2.) Equivocation PT2:

To clarify - this is not a separate equivocation charge, but showing how the initial equivocation is used to bestow existence on something that is not shown to exist. 

This step is basically showing that the MGB exists - once further steps are accounted for.

When you substitute this, and the unequivocated definitions, P3 is essentially stating, essentially, that because the MGB exists(c) it exists(a).

This is the logical error on the OA, it manufactures existence through equivocation. P2 introduces the equivocates term, and P3 realizes the it.

3.) Modal S5 Logic.

As pro claims I dropped this argument, I feel I need to address this.

Pro made a logical argument that is inherently flawed due to the issues I raised above.

Nothing mentioned about S5 modal logic is instructive or even relevant in solving the logical error, and no argument was offered in pros opening as to the relevance of S5 in resolving the issues I raised.

As pro is not specific in how S5 was inherently used in P2 or P3 in any detail, nor is it clear how that reasoning ties into my objections: there isn’t really a valid contention to drop, nor any impact to the validity of the specific claims I made even had I done so.

Pro should explain how S5 logic contradicts the point I am making, or undermines the accusations of equivocation. If not, pros usage of S5 logic is largely irrelevant.

4.) Informal vs Formal fallacy.

If the OA commits an informal or formal fallacy - the conclusion cannot be said to follow from the premises. Thus in either case, the OA is un-sound, even though it’s conclusion - that God exists - may still be valid.

In this respect the distinction pro makes between formal and informal fallacies is largely irrelevant. If a fallacy exists of either type, the argument is unsound as the conclusion does not follow.

5.) Begging the Question

Pros definition is mostly correct: Begging the question is where the conclusion of the argument must be presupposed as true in the premise.

In the case of the OA “An MGB is possible” is a bottomless pit of potential assumptions.

What makes an MGB possible? What would make it impossible? What things can and can’t exist in the universe in general? 

It’s not possible to guess, assert or assume what is metaphysically possible - or not- in the universe. We simply don’t have the data, knowledge or information; there is inherently no real basis for pro to claim that P1 is valid as I alluded to.

For example - if we assume that the laws of physics are supreme : God invalidates these laws, and is impossible. Thus, claiming God is possible, implicitly assumes that the laws of physics are not supreme. We don’t know whether they are or not - and yet pro requires the assumption that they are not.

There are many of these metaphysical assumptions the OA makes. Going any other way than pro does would render God impossible, and the OA fails.

What the OA does therefore, is to make all of these assumptions with the inherent goal of allowing God to exist, and is therefore inherently assuming the conclusion.

To highlight this issue, I can reframe the point I raised a few paragraphs ago as a question for my opponent:

If the laws of physics are supreme over everything: we can agree that a MGB could not exist: this would be an impossible being by pros description. This would invalidate P1.

If the laws of physics are not supreme over everything: let’s assume that MGB is a possible being. (For the moment, let’s ignore other similar assumptions that can raise questions like this one). This would be consistent with P1.

If P1 may be untrue - does that not mean the OA is unsound? And if not - on what basis can this inherent assumption on the lack of primacy of physics be justified?

That’s inherent where the begging exists: the assumptions are chosen with the predicated conclusion existence.

Conclusion

As shown; the OA clearly uses equivocation of the word exists. This is obvious with pros reframing - and the underlying logical error I pointed out in R1 is fully exposed.

As shown, the OA is forced to make unsupported assumptions for P1, that are implicitly hidden behind the simply statements it makes. To allow the OA to work, these unsupported assumptions made are inherently required in the conclusion that an MGB exists.

I extend all my arguments.

I would also like to invoke pros rule #1: No forfeits, and ask all voters award arguments based on this rule.

Well, that’s a bit of a let down.

I extend my arguments and encourage everyone to vote based on pros no forfeit rule,