As we saw in the previous blog, if the modal ontological argument had nothing else going for it, it would at least be logically valid. Logical validity is more than many arguments can boast, and the only remaining condition is that the premises be true. If both of these conditions are true then the argument will be sound, and the conclusion will be true. In this blog, we will look at the really controversial premise.
For reference, the modal ontological argument is set out below:
- It is possible that a maximally great being exists.
- If it is possible that a maximally great being exists, then this being exists in some possible world.
- If a maximally great being exists in some possible world, then this being exists in every possible world.
- If a maximally great being exists in every possible world, then this being exists in the actual world.
- If a maximally great being exists in the actual world, then a maximally great being exists.
Therefore, a maximally great being exists.
The Real Controversy
Part 3 of this series demonstrated that premise 3 was not controversial if we properly understand what is meant by a maximally great being. After all, a being who didn’t even exist in half of the possible worlds would not be very maximal. Indeed, a maximally great being would have to exist, by definition, in every possible world. In addition, premises 2-6 are relatively straightforward. Premise 2 follows by way of terminology – to possibly exist is to exist in some possible world. Finally, premises 4-6 take the time to walk us through the final steps that follow from this being’s existence in every possible world.
The only serious question remaining is of premise 1: It is possible that a maximally great being exists. After all, if a maximally great being is possible, the remaining dominos of the argument fall with relative ease. If this being’s existence is not possible, then the argument fails before it even begins. Therefore, the only controversial premise of the argument is really premise 1. This being the case, it becomes important to develop a definition of a maximally great being and test it for logical coherence.
Defining Maximal Greatness
By a maximally great being we mean a being who possesses all great-making properties to the highest degree in every possible world. These properties would include, but not necessarily be limited to, omnipotence, omniscience, and moral perfection.
Note also that this being would have to possess these traits in every possible world. A being who is morally perfect in ten possible worlds and morally compromised in the rest is vastly inferior to the one who is morally perfect in every possible world. The same is also true of the other two properties.
To object to the possible existence of a maximally great being, one would have to find something logically contradictory or else incoherent in the possible existence of such a being. Is there anything implied by this being’s properties which precludes this being’s possible existence?
- Omnipotence is sometimes misunderstood as being the ability to do anything. Instead, omnipotence is better understood as having all power, and therefore having the ability to accomplish anything that requires power. Omnipotence, therefore, does not give a being the ability to do things that are logically impossible. No amount of power can make a box that is bigger on the inside than the outside, because a thing like that is logically incoherent. Another example is that omnipotence cannot force a free creature to act or feel in a certain way. Forcing someone to freely love another, for instance, is logically incoherent. “For if it is free, it is not forced. And if it is forced, then it is not free”.  Properly understood, then, omnipotence is not incoherent.
- Omniscience is defined as, “knowing the truth value of every proposition.”  It is important to clarify that omniscience does not entail experience, else omniscience would imply the personal experience of all sorts of moral atrocities that would be incompatible with moral perfection. Further, it would imply the experience of the absence of omnipotence and omniscience in order to “know” what it was like. But then this being would not be maximally great. To be omniscient, then, is to know the truth or falsity of every proposition, including past, present, future, and potential events.
- Moral perfection, for non-Christians in general, and atheists in particular, can be controversial. Because of this, we will delay our discussion of it until the next blog.
Since the modal ontological argument is logically valid, the only other condition for soundness is true premises. Further, premise 1 is really the only controversial premise. Therefore, an examination of the logical coherence of maximal greatness is imperative, and has yet to present any difficulty for such a being’s possible existence.