In the third step of our series on the existence of God, we turn to the question of whether there can be more than one unconditioned reality. In Step 1, we saw that there must be at least one unconditioned reality. In Step 2, we saw that any unconditioned reality must be absolutely simple, outside space and time, immutable, and infinite. In Step 3, we will show that there is only one unconditioned reality.
Any unconditioned reality must be absolutely simple, without any incompatible states with other realities. (2.10) Thus, if there are multiple unconditioned realities, each must be absolutely simple and none incompatible with any of the others. (2.5 and 2.10) Furthermore, they cannot be distinguished by having different boundaries, for unconditioned realities have no boundaries. (2.5 and 2.10)
3.1 Unconditioned realities cannot be distinguished by having distinct boundaries.
But this deprives us of any way of distinguishing between different unconditioned realities.
Think of how we distinguish between things. One way to distinguish between iron and posies is that the boundaries of the former give rise to an incompatible state with the latter (inanimate as opposed to animate). Iron is a different kind of thing than a flower. Even among flowers, there are different kinds: posies are distinct from roses. These distinctions in kind arise from distinct boundaries, which gives rise to incompatible states. But we cannot distinguished unconditioned realities this way, for they have neither boundaries nor incompatible states. (2.5 and 2.10)
3.2 There are not multiple kinds of unconditioned realities.
But things of the same kind can have distinct instantiations. Say that one has two iron spheres of precisely the same size. In kind, they are the same. Nevertheless, the spheres still differ by having distinct physical boundaries: one is here, another there. Furthermore, they differ by being made of up different materials. One has these atoms, another those. Yet we cannot distinguish unconditioned realities this way, for they are not in space (2.2), nor are they material, for then they would be conditioned by the materials. (This is just another way of saying they lack boundaries.) But distinct instantiations are distinct by virtue of being in different places, composed of different entities, or otherwise having distinct boundaries. Thus we can conclude:
3.3 There are not multiple instantiations of unconditioned realities.
Yet we know that there is at least one unconditioned reality. (1.10) Thus we can conclude:
3.4 There is only one unconditioned reality.
The basic tenets of theism is that there exists a reality that is one, that is unlimited by space or time, that is eternal and immutable, absolutely simple, infinite, is unlimited by the laws of physics, and is the continuous creator of all other realities.
You will have noticed a certain pattern: at this point, the argument I have presented has demonstrated that there exists one, and only one, unconditioned reality that is not limited by space and time, is infinite and eternal, is absolutely simple, is immutable, and is not limited by the laws of physics. There remains only one more step: to show that this reality is the continuous creator of all that is.