What happens when an unstoppable force meets an unmovable object? Or more properly phrased, what happens when an unstoppable object collides with an unmovable object? This question seems like a bit of a logical stumper, until one realizes that it is sheer nonsense. An unmovable object and an unstoppable force cannot simultaneously exist. Within in the bounds of the laws of physics and of mathematics, neither object can exist, for an unmovable object would necessitate an infinite amount of inertia, and thus infinite mass; and an unstoppable object must have an infinite amount of momentum, which is possible only if the object has infinite mass or is traveling with a speed of c, that is, at the same speed as light traveling in a vacuum.

The former, an unmovable object, would constitute the actual physical realization of a simultaneously infinite quantity, and that in the literal sense. This is, of course, different than an "uncountable" quantity which is counted for all eternity, but it is literally impossible to have a simultaneously infinite quantity in a single locality--which is precisely what an "unmovable" object must be, at least within the realm of our physics.

Similarly, an unstoppable object must meet the requirements of having both an infinite amount of momentum and an infinite amount of energy--thus, such an object would be the actual realization of an infinite quantity which is simultaneously contained in some locality. This is mathematically impossible, and thus cannot exist, at least not according to the laws of physics.

Thus, it is impossible for an unstoppable object to meet with an unmovable object because neither can exist in the universe. But what about as just a logical problem? Suppose there exists a place where the laws of physics or mathematics do not apply, or can be re-written so that it is possible to have both an unstoppable object and an unmovable one? Can both simultaneously exist? I would answer again with a negative. At the very least, the two objects cannot interact: the unstoppable object would pass through the unmovable object, or else they could never cross paths. If there was any interaction, then either the unstoppable object must stop, or the unmovable object must move. Thus, it is impossible for the two to collide, even if the laws of physics and mathematics were re-written so as to accommodate the existence of either, because collisions are necessarily a type of interaction.

Where does omnipotence come into this picture? An omnipotent (all-powerful) Being--God--could will the existence of the unstoppable object, or of the unmovable object. He may have to alter the laws of physics and mathematics to do so, but He could create either object. Yet, even God cannot create both simultaneously; for, as C.S. Lewis has noted, there is only one limit to omnipotence, and that limit is nonsense. God cannot create an irreconcilable contradiction; He cannot, for example, will Himself out of existence, or create a rock so large that eve He cannot lift it, or will Himself to be both inside and absolutely not inside of a wall (for example). Thus, even God, who is all-powerful, cannot will the collision of an unstoppable object with an unmovable one.

Why do I spell so much virtual ink writing about this limit to God's power? Because this fundamental limit places a second limit on the existence of God as opposed to gods. Because an unstoppable object and an unmovable object cannot both exist, there cannot exist more than one God. If that conclusion seems hard to follow, then please forgive me for leaving out a few logical steps, which I shall explain below.

If God is really to be God, then He must be omnipotent. Thus, if there were two gods, then both must be omnipotent. But omnipotent means all-powerful, and thus neither god can be more powerful than the other. If the two were to struggle with each other, then neither could win, and that's true in both the general and the particular sense. Suppose now that god A wants to make an unstoppable object, and God B wants to make an unmovable object. Who wins? To argue that they both get their way doesn't really work, because there is no way for this to happen.

You might propose that both objects are created such that the unmovable object is not in the path of the unstoppable object. This seems a victory at first, but then suppose that God A desires to place the unmovable object in the path of God B's unstoppable object? Then God A's power is negated by God B, and so God A is not really God. The converse is true if God B desires to aim His unstoppable object at God A's unmovable object.

This objection can, however, be taken a step farther with the caveat that perhaps the unmovable object passes through the unstoppable one, without any interaction. Very well, but now consider this: an omnipotent Being Who desires to be unmovable becomes unmovable, and an omnipotent Being who desires to be unstoppable becomes unstoppable (He cannot, of course, be both simultaneously). If God A desires to be an unmovable object and God B desires to become an unstoppable one, then the two cannot interact.

More generally, if the two desire any contradictory result, then they cannot interact. If God A desires that the earth exist and God B desires that it doesn't, one of the two Gods must win; the earth either exists or it doesn't. If the earth comes into existence, then God A is more powerful, so then God B is not really omnipotent, and thus is not God. If the earth does not exist, then God B is more powerful, and so God A is not omnipotent, and thus is not God.

Therefore, the only way for multiple Gods to exist is if they share a common will--and it must be totally common. But if This Will directs both God A and God B, then both are subordinate to this divine Will, and so the person with this divine Will is really God, or perhaps I might say that this divine Will is itself God. For a truly omnipotent Being cannot truly be subordinate to anything save Himself. Ergo, there can be only one God, and not many.

UPDATE: Mr Phil Carter, author for the blog Of Cabbages and Kings and a friend of mine, has an interesting response to this essay which asks about the Mormon concept of God as a being Who is divine in His own universe, but existing separate of other universes which have their own Gods. It's worth hte read.