This is a post discussing the objections to Step 2 in the ongoing series setting forth a proof on the simplicity of any unconditioned reality.
In the First Step of the argument for the existence of God, we established that if there exists any reality, there exists an unconditioned reality. That step established that if anyone asserts that something exists, but denies the existence of an unconditioned reality (i.e., a reality that is utterly independent of any other reality), one is caught in self-contradiction.
The Second Step of the argument establishes than an unconditioned reality, considered in itself, must be 1) without parts, 2) absolutely simple (i.e., it possesses no intrinsic or extrinsic boundaries and has no actual or potential incompatible states with any other reality) and 3) infinite. From the necessarily simple and infinite nature of an unconditioned reality, several other features--eternity, independence of the laws of physics, and immutability--followed.
Can an Unconditioned Reality be Spatial?
The only sustained criticism of the second step concerned the argument that an unconditioned reality cannot be composed of parts. The original post did not define the notion of a part, but a subsequent edit added that definition. The addition of the definition renders the objections raised superfluous. I do believe, however, that a quick reformulation of the argument as it relates to spatial extension will be useful.
Extended Spatial Realities Have Parts
A part is defined as:
any aspect belonging to a reality that is distinct in any way from any other aspect of that reality. (2.1a)
The question, then, is does a spatial reality necessarily have parts?
If a spatial reality is extended, it has parts. For if A is a spatial reality, it means that some aspect of A has a distinct location from some other aspect of A. If A had no aspects that were distinct in terms of location, A would be a non-extended point. Thus, if a reality is extended, it is composed of parts.
Pure Unconditioned Reality Has No Parts
Can an unconditioned reality be composed of parts? We can distinguish two types of parts: parts upon which a reality depends and parts upon which a reality does not depend. Take a trivial example: my existence currently depends upon my brain. However, my existence does not depend upon my hair. I can go on existing if I shave my head, but I cannot go on existing without my brain. We can break the question down into two parts: can an unconditioned reality have parts upon which it depends? And can an unconditioned reality have parts upon which it does not depend?
An unconditioned reality clearly cannot have parts upon which it depends, for an unconditioned reality cannot be dependent upon any other reality. (1.1 and 1.3) Remember that a reality is defined as broadly as possible: if you can say of x either, "there is an x ..." or "it is not the case there's no such thing as x ...", x is a reality.
Can an unconditioned reality have parts upon which it does not depend? We've left the answer open: possibly it can. However, when we speak of "pure" unconditioned reality or an unconditioned reality considered in itself, we mean the unconditioned reality as it is independent of such parts. Thus, while we leave open the possibility that it might be in some sense true that an unconditioned reality might possess non-essential parts, we speak of unconditioned reality in itself as it is independently of these parts.
(Christians will obviously want to maintain that an unconditioned reality can take on non-essential parts, as it opens the way for the Incarnation.)
We can conclude from the above that an unconditioned reality, considered in itself, does not have parts. Thus, pure unconditioned reality is not spatially extended. (Note that nothing new from Step 2 has been introduced, the premises have just been shuffled to deal specifically with the issue of spatiality.)
What of Non-Extended Spatial Realities?
Yet there is one final possibility: though an unconditioned reality cannot be spatially extended, can it be a non-extended spatial reality? That is, can it be a point? We again answer no; for a non-extended reality to still be spatial, it must be in some way located spatially. It must be here instead of there.
Yet for this to be true, such a reality depends upon the space in which it can be located here instead of there. A reality that is non-extended and not located in space would be extra-spatial. Thus, such a reality is necessarily conditioned. But no unconditioned reality can be conditioned. Therefore, no unconditioned reality can be a non-extended spatial reality.
We have established that pure unconditioned reality cannot be an extended spatial reality, and it cannot be a non-extended spatial reality. We must conclude, then, that if a reality is unconditioned, it is neither extended, nor located in space. To be neither extended nor located in space is to be extra-spatial. Therefore, a pure unconditioned reality is extra-spatial.
An Alternative Argument for Immutability and Extra-Temporality
Step Two offers an argument for the non-temporality and immutability of any pure unconditioned reality. However, there is an alternative proof that is, to my mind, even more effective.
One could rearrange the immutability and temporality premises and make the argument differently. A reality, to be mutable, must be able to change (by definition). To be able to change, a portion of the reality must be in a state of potentiality—i.e., not x but able to become x. Yet any reality, to exist at all, must be actually in some state.
Therefore, a reality, to be changeable, must be in some respect actual and in another respect potential. Potentiality and actuality are two distinct aspects of a reality, distinguished by modality. It follows that any mutable reality has parts. But no unconditioned reality, considered in itself, has parts. Thus, no unconditioned reality is mutable. (2.4)
Now, time is either a reality independent of other realities or an aspect of those realities. No unconditioned reality can have time as a condition. Therefore an unconditioned reality cannot essentially be in time. Nor can time be said to be an aspect of an unconditioned reality in itself, for unconditioned realities, in themselves, do not change. (2.4) An unconditioned reality is non-temporal in the sense that it does not depend upon time, does not change in time, and does not have its own time (in terms of a sequence of states).