Sorry the response to this week’s challenge is a day late. I talked way too much and had about 30 minutes of video to go through and edit (and if you know anything about video editing, you know that’s a lot)!
UPDATE: NonStampCollector has offered his thoughts on my video response, in the comments section on YouTube.
STR Place Blog 
Thanks Brett! Very good video.
I already said what I thought about applying Ockham’s razor to this challenge, so I won’t repeat that.
I’m not totally convinced that your argument from omnipotence is sound. The reason is because omnipotence is the ability to do all things logically possible. If you had two beings who were equally powerful, it would be no strike against the power of either of them that they couldn’t overpower the other. The idea that an all-powerful being could over-power another all-powerful being would entail a logical contradiction, so isn’t a strike against the power of either of them that they couldn’t anymore than it’s a strike against their power for not being able to microwave a burrito so hot that an all-powerful God couldn’t eat it. So I don’t see why it couldn’t be possible for two all-powerful gods to exist.
Another reason I don’t think think the all-powerful argument is sound is because if you press the argument far enough, it would also disprove the Trinity. If the Trinity is true, then your argument is unsound. Lemme explain why. If God is three distinct persons, then each person has an independent faculty of volition. The faculty of volition is the will, and to will something is to exert. So power originates in the will. The will is the origin of any exertion. The Father, Son, and Holy Spirit are each all-powerful, but they each have their own will. That means they cannot over-power each other, but that in way entails that they can’t all be omnipotent. If it’s possible for three distinct persons to be all-powerful, then it’s possible for three distinct beings to be all-powerful.
I understand the law of identity, but let me clarify my argument since Elliot didn’t seem to understand what I was saying either. According to the indiscernibility of identicles, if A and B have every property in common, then A and B are the same entity. So if there anything true about one that is not true about the other, then they are not the same entity.
It’s possible to have two animals who have every mental and physical property in common except location. They could have the exact structure down to the quark with the exact same memories and everything and still not be the same person.
Of course with immaterial beings, like gods, you couldn’t appeal to “location” as the one property two gods did not share in common since, strictly speaking, neither god has any property of physical location. But it seems at least possible for two gods to have all the same properties except their “personal identity.” By “personal identity,” I don’t mean exactly the same thing by “identity” as I mean when I say, “law of identity.” By personal identity, I mean the “who” or the “ego” or the “I.” If two distinct persons exist, then they will have two distinct selves, egos, etc. Each will have his own first person subjective point of view. It’s possible for these two perceivers to perceive exactly the same things–same personality, thoughts, memories, perceptions, etc., and still not be the same person.
Imagine that God wants to create two immaterial spirits. It seems at least possible that he could create them to have every property in common, including their abilities, their thoughts, personality, memories, etc. But as long as they each have their own distinct first person point of view, they are not the same person.
That’s just one part of my argument. I only mean to establish with this one argument that as long as two entities have one thing that they do not share in common, then it’s possible for them to be two distinct beings and not the same being. I offered their own center of consciousness or personal identity as that one thing. If two gods had everything else in common, and it’s no better to be one than the other, then both can be as great as it’s possible to be.
Now to the second part of my argument, I made the point that not all properties are great-making properties. You and Elliot both argued if there are two distinct gods, then “The differences between the two would have to be greater in one as compared to the other,” which I think is mistaken since it’s possible for two gods to have some difference between them that is not relevant to greatness. Obviously, there are some properties, such as powerful, benevolence, knowledge, etc., that are great-making properties. But there are other properties, such as non-moral preferences, that are not great-making properties. It’s possible for two gods to share every great-making property in common, but differ in some property that is not a great-making property. So it’s possible for two gods to have maximal greatness and still be two distinct gods since they might differ in some property that is not a great-making property.
I have a third argument that I haven’t brought up yet. Remember that we are working with the definition of God that says he is the greatest possible being. Now just imagine for a second that you have two imperfect beings. You begin to add greatness to each of them in equal proportions. One of two things can happen if you keep doing this.
The first possibility is that there is no limit to the greatness you add to them. But if that were the case, then there could never be a greatest possible being. The only way it’s possible for there to be a greatest possible being is for there to be a limit to how great it’s possible to be. That’s the only way that “greatest possible” is even coherent.
The second possibility is that you will eventually reach a limit to how much greatness you can add to the two. Once you reach that limit, they will both be the greatest possible beings since it’s not possible to add anymore greatness to them.
By the law of excluded middle, there either is a limit to how great it’s possible to be, or there is not a limit to how great it’s possible to be, so these two scenarios exhaust the possibilities. Since the first possibility doesn’t work, the second possibility must be true. That entails that it’s possible for two distinct beings to be the greatest possible being.
The only way I can think to get around this third argument of mine is to imagine that once you reach the limit of how great both beings could be at the same time, there’s some great-making property it’s possible to add to one but not possible to add to the other. I’m open to suggestions.
I just have one last comment to make, and it’s about the last point that you made. We should always ask, “What follows from this?” if the challenger is right. In this case, we want to know what follows if there are multiple gods. I agreed with everything you said does NOT follow. But I think what WOULD follow is that Judaism, Christianity, and Islam are false religions. So while multiple gods would defeat atheism, it would also defeat Christian theism.
Unless you’re a Mormon. 😉