Friday, April 22, 2022

Arguing for divine simplicity

I want to defend this argument:

  1. If God is not simple, then some of God’s parts are creatures.

  2. If some of the parts of x are creatures, then x is partly a creature.

  3. God is not even partly a creature.

  4. So, God is simple.

I think (2) is very plausible. Premise (3) follows from the transcedence of God.

That leaves premise (1) to argue for. Here is one argument:

  1. If God is not simple, then God has a part that is not God.

  2. Anything that is not God is a creature.

  3. So, if God is not simple, then God has a part that is a creature.

Premise (5) is true by definition of “simple”. Premise (6) follows from the doctrine of creation: God creates everything other than God.

But perhaps one doesn’t believe the full doctrine of creation, but only thinks that contingent things are created. I think we can still argue as follows:

  1. If God is not simple, then God has contingent parts that are not God.

  2. Anything contingent that is not God is a creature.

  3. So, if God is not simple, then God has a part that is not God.

Why think (8) is true? Well, let’s think about the motivations for denying divine simplicity. The best reasons to deny divine simplicity are considerations about God’s contingent intentions or God’s contingent knowledge, and the idea that these have to constitute proper parts of God. But that yields contingent parts of God.

Now, what if one rejects even the weaker doctrine of creation in (9)? Then I can argue as follows:

  1. If God is not simple, then God’s contingent thoughts are proper parts of God.

  2. God is contingently the cause of each of his contingent thoughts.

  3. Anything that God is contingently the cause of is a creature of God.

  4. So, if God is not simple, then God has a part that is not God.

Again, the idea behind (11) is that it flows from the best motivations for denying divine simplicity.


Unknown said...

It seems to me that the person who denies divine simplicity would want to say, instead of (6), (9), or (13), something like "Anything that is outside of God is a creature of God" where by "outside of God" one means "not God and not a part of God". Or perhaps even more modestly "Any substance which is not God is a creature of God".

Walter Van den Acker said...


Or perhaps one argue that God's 'parts' are not contingent but necessary.

Wesley C. said...

I wonder how this relates to God's free act of creation. If we assume God has indeterministic self-motion as the principle of contingent actions like creating the world, would this fall into the category of contingently caused thoughts or whatnot, thereby making them parts of God and creatures in this sense?

How would you interpret the contingency of God's act of creating the world (especially if it's logically prior to the world's existence, or internal to God as an action on His part)?

Alexander R Pruss said...


Yeah, but the best arguments against divine simplicity have to do with contingent parts.


I think what is contingent is the effect of the action, while the action itself is necessary (and identical with God). The intentional content of the action then is partly grounded in the effect.

Alexander R Pruss said...


This is hardest to do for (13), since it seems analytic that if God contingently causes something, that something is a creature.

Daryl said...

Isn't a wholesale denial of any proper parts, ala WLC, an easy way out of this argument?

Alexander R Pruss said...


I don't follow. That's what the conclusion is: God is simple, i.e., has no proper parts.

Wesley C. said...
This comment has been removed by the author.
Wesley C. said...

Alex: A couple of questions come to mind - if God's act of creation itself is necessary, does this mean that the existence of some creation is necessary, just not the specific creation that comes about?

As for the intention to create being constituted by the effect, couldn't one object that this gets the logical hierarchy wrong as intentions are supposed to be logically prior to the effects that are intended? So saying the effect is logically prior to the intention ends up basically saying that God didn't intend creation initially, and it somehow was just...caused?

About the intention being partially based in the effect, an intention by itself seems not to be indeterministic in the sense that an effect can obtain completely different from the intention, and since God is omnipotent, nothing He intends internally in Himself can fail to obtain.

What do you think?

Alexander R Pruss said...

God's act of creation, A, is identical to God. It is not necessary that A be an act productive of anything external to God.

Walter Van den Acker said...

Then God does not have to be personal, because a quantum vacuum can work in the same way.
It doesn't have to be productive of anything external to it either.
God's act of creation A can be productive of a,b,c ...or nothing at all. Whatever is the result of A is purely random chance.
This is one of the best arguments against a personal God. I have ever encountered.

Trevor Giroux said...

Dr. Pruss, I was wondering what you thought of Aquinas argument for God in his De Ente Et Essentia? It seems that he is arguing that because a things essence is distinct from its existence it needs to be caused to exist by something that has no distinction between its essence and existence. It seems that if this argument is successful it would be a good reason to accept divine simplicity as well as the need for God to concurrently cause anything that creatures do.

Alexander R Pruss said...

I defend a version of the argument in my PSR book. I think the difficulty with the argument is that the atheist may say that some finite things have an existence distinct from the essence, and with all three of existence, essence and their conjoining being uncaused. In the PSR book I try to argue against this. I can't remember exactly how.

How do you think the argument establishes the need for concurrence?

Trevor Giroux said...

I believe the idea is that some properties come from the essence of creatures while others do not. Humans have the power to have children and this power does not rely on the previous generations of humans still existing because the creature has the power in itself. Existence however is not something that comes from the essence of the creature in itself because the essence would already have to exist in order to cause its existence. Because the existence does not come from the essence of the creature it is naturally nothing and would require existence to be given for any moment it exists. It would seem that if successful this would require God to conserve our existence and concur with our actions in order for them to exist at all.

Alexander R Pruss said...

That would be an argument for conservation, but I don't see how it would be an argument for concurrence. Suppose that I break a window with a stick. The argument might show that God's sustenance of me, the window and the stick is needed. But I don't see that it shows that God's concurrence with the stick's actualization of the causal power for a broekn window is needed.