Don't be ridiculous. The thread title is "Demonstration of God's Existence I: an Aristotelian proof", and the OP is a modified version of Aristotle's so-called proof with some of the language changed.

Any argument that purports to prove the existence of God could be called a demonstration of God's existence. That doesn't mean the person detailing the argument believes the conclusion of the argument, nor does it mean that the demonstration is successful.

So what do you mean by god?

It does mean it is important to say what god is in the context of the "proof".

Well, again, I am not a theist, I am presenting an argument in favor of theism so we can discuss it. God is said to be the purely actual actualizer, and is unified, immutable, eternal, immaterial, incorporeal, perfect, good, omnipotent, and omniscient. That are common characteristics attributed to God. Nobody in their right mind actually believes in the mythological notion of an invisible fairy or whatever bullshit the new atheists manufacture for the masses.

"God is said to be the purely actual actualizer, and is unified, immutable, eternal, immaterial, incorporeal, perfect, good, omnipotent, and omniscient."

Well that is one version. Was that so hard to type?
To be omniscient and omnipotent it would have to be omnipresent too.
Here's one problem omnipresent and good would mean that no evil can exist.
Here's another: it cannot be incorporeal AND actual.
It cannot be immutable and an omnipresent, since there is such a thing as change.
In fact it cannot be an actualiser and immutable.

Have you god a more usable version of god?

Well that is one version. Was that so hard to type? — charleton

I put it in the OP, literally copy-pasted it into the previous reply.

To be omniscient and omnipotent it would have to be omnipresent too.
Here's one problem omnipresent and good would mean that no evil can exist.
Here's another: it cannot be incorporeal AND actual.
It cannot be immutable and an omnipresent, since there is such a thing as change.
In fact it cannot be an actualiser and immutable. — charleton

Lots of assertions, no arguments though.

To be omniscient and omnipotent it would have to be omnipresent too. — charleton

Why? God exists outside of space and time. This isn't an argument for pantheism.

Here's one problem omnipresent and good would mean that no evil can exist. — charleton

Well, according to this argument, evil is a privation of goodness and has no positive existence itself.

Here's another: it cannot be incorporeal AND actual. — charleton

Why?

It cannot be immutable and an omnipresent, since there is such a thing as change. — charleton

But it doesn't have to be omnipresent, it just has to sustain everything that exists.

In fact it cannot be an actualiser and immutable. — charleton

Why?

Stop wasting your breath, charleton is a joke on two feet >:O

You and I need to learn to adopt Sappy's stoicism and let such things go >:O

Now, on a different note... I had a quick skim through them, and they're really well set out. Which argument did you find the strongest?

I liked the Neo-Platonic proof the most. Though I've always favored Plato over Aristotle anyway so that might just be a bias of mine.

I'd rather see what conception of God is engendered by the assumptions than attempt to shoehorn in a totally irrelevant conception for the sole purpose of refutation. — fdrake

We can conclude that only an illogical god is engendered by the proof.

just be a bias of mine. — darthbarracuda

Yes a bias that has no respect for logic.

I liked the Neo-Platonic proof the most. Though I've always favored Plato over Aristotle anyway so that might just be a bias of mine. — darthbarracuda

Hah! Interesting. I thought the Augustinian one was the strongest, though I've always favored Aristotle over Plato :P

Yes a bias that has no respect for logic. — charleton

It's more of an aesthetic bias than an argumentative one. Stop grasping at straws, you fool.

Yes, doing philosophy without biases! We are androids after all - that sort of thing is possible.

I mean, I do dream of electric sheep.

I will be making several threads in the near(-ish) future about the general proofs of God's existence argued by Edward Feser in his new book, Five Proofs for the Existence of God so we can discuss them and hopefully learn something. First up is his "Aristotelian" proof. — darthbarracuda

The following section of the proof (from Feser's book) is interesting:

• 19. In order for this purely actual actualizer to be capable of change, it would have to have potentials capable of actualization.
• 20. But being purely actual, it lacks any such potentials.
• 21. So, it is immutable or incapable of change.

But why should this actualizer be purely actual and thus immutable? The argument (where A is the initial actualizer and S is a substance being actualized) is:

• 9. A’s own existence at the moment it actualizes S itself presupposes either (a) the concurrent actualization of its own potential for existence or (b) A’s being purely actual.

Feser reasonably argues against (a) and concludes (b):

• 14. So, there is a purely actual actualizer.

But the implication of 9(a) being false is simply that A's existence is necessary for S to be actualized. That doesn't imply the absence of potentials for A and, consequently, doesn't imply A's pure actuality or immutability. And so the subsequent conclusions that assert specific attributes of A (immaterial, omniscient, etc.) don't follow since they require that A be purely actual and immutable.

So the key premise is 9 and it seems to me to be false.

Feser has a response to exactly this criticism (why does the actualizer have to be purely actual and not simply have unrealized potentials?) on page 66:

Effectively, Feser argues that if the actualizer had parts of itself that were unactualized potentials, then the actualized parts are what are really the purely actualized actualizer.

Feser has a response to exactly this criticism (why does the actualizer have to be purely actual and not simply have unrealized potentials?) on page 66: — darthbarracuda

On that page Feser says, "So, suppose this first actualizer had some potentiality that had to be actualized in order for it to exist." But this misses the criticism. It is already granted that the first actualizer A necessarily exists and so does not have unactualized potential for its own existence. But it may nonetheless have unactualized potential for, say, causing substance S to exist.

If A subsequently does cause S to exist, then it has actualized a potential and thus has changed per premise 2:

• 2. But change is the actualization of a potential.

But it may nonetheless have unactualized potential for, say, causing substance S to exist.

If A subsequently does cause S to exist, then it has actualized a potential and thus has changed per premise 2:

2. But change is the actualization of a potential. — Andrew M

I don't think this is true. Just because change requires the actualization of a potential doesn't mean causing the actualization of a potential requires change. Indeed it would lead to an infinite regress if we tried to explain change by reference to something that, itself, changes.

Just because change requires the actualization of a potential doesn't mean causing the actualization of a potential requires change. Indeed it would lead to an infinite regress if we tried to explain change by reference to something that, itself, changes. — darthbarracuda

It would, but that doesn't describe the scenario. Causing substance S to exist just is the actualization of a potential.

So, for example, suppose Alice has the potential to construct a chair (i.e., to cause a chair to exist). If Alice subsequently does construct a chair then she has actualized a potential. Thus, per premise 2, she has changed.

Sure, but that's because your body is a material substance. God is not a material substance.

Any potential must be separate, or independent from the pure actualizer because the pure actualizer cannot have any potential. If that separate potential were prior to any actual substance it would be pure potential. Pure potential is proven impossible by Aristotle's cosmological argument, so potential must exist as an aspect or property of an actual substance. This means that the act of creation, which is carried out by the pure actualizer, which creates actual substances, that have potential, is an act of separation. Something actual is separated from the pure actuality, and this act of separation is the creation of potential.

Sure, but that's because your body is a material substance. God is not a material substance. — darthbarracuda

The proof, from premise 9 onwards, is about the nature of the first actualizer and isn't assumed to be immaterial. It could be a hylomorphic substance that necessarily exists and has potentials for causing other hylomorphic substances to exist. Premise 9 doesn't eliminate this possibility and Feser's discussion on p66 doesn't consider it.

I'm confused by what you mean. A purely actual being cannot change and thus cannot exist in time, which means it cannot be material. Are you implying it has not been shown that God must be immaterial?

A purely actual being cannot change and thus cannot exist in time, which means it cannot be material. — darthbarracuda

Sure, but what I'm saying is that the proof fails to demonstrate that the first actualizer is a purely actual being. As I argued initially, the problem is with premise 9 of Feser's proof.

What notably distinguishes the first actualizer from other substances is that it necessarily exists. But there is no reason why it can't be material and mutable and have potentials just as other substances do.

In Aristotelean metaphysics matter is potency. Therefore, something that is purely actual is immaterial by definition. Furthermore, change is defined in that system as the transition from potency to actuality. So something that is purely actual is also immutable by definition.

That said, I would hazard to suggest that the argument as presented by Darth is not quite right (no offense Darth). For instance, I can't imagine that Feser would accept premise 6 as stated, because it implies that a purely actual substance cannot exist.

As others have noted, this argument is not about temporal causation. What Feser seems to be saying is that at any moment every substance is either dependent for its actualization on something else that is "lower" in the existential hierarchy, or it is not. A coffee cup could not exist as it does (i.e. "in act") without the molecules that make up the styrofoam existing in the way that they do, and those molecules could not exist without the atoms that make up the molecules, etc. He is arguing that there must be something purely actual at the "bottom" of this hierarchy that does not depend for its actuality on anything else, otherwise the hierarchical chain of existential dependency relations that are necessary for the actualization of being in each moment could never be "instantiated". In other words, "being" could never get off the ground if the actualizer at the bottom had any potency that needed to be actualized by something more fundamental.

That said, I haven't read the book, so my interpretation may be off. Perhaps Darth can point out how what I've said differs from Feser's intent.

What notably distinguishes the first actualizer from other substances is that it necessarily exists. But there is no reason why it can't be material and mutable and have potentials just as other substances do. — Andrew M

This is going in the the neo-Platonic demonstration, but if this material being had both actuality and potentiality, then it would be a complex composite with parts, and a composite necessitates the existence of a simpler entity. This is again meant in the stronger hierarchical sense. It seems that by the nature of composites, they cannot be necessary. The fact that there are contingent composites leads the way to the existence of a non-composite, simple entity.

Though I do agree with you to some extent, I think Feser did not explain this well enough/failed to consider this particular objection.

In Aristotelean metaphysics matter is potency. Therefore, something that is purely actual is immaterial by definition. Furthermore, change is defined in that system as the transition from potency to actuality. So something that is purely actual is also immutable by definition. — Aaron R

Yes. So the pivotal issue is whether the first actualizer is purely actual. Feser doesn't assume it, he concludes it in statement 14. I argue why I think that conclusion doesn't follow from its premises .

That said, I would hazard to suggest that the argument as presented by Darth is not quite right (no offense Darth). For instance, I can't imagine that Feser would accept premise 6 as stated, because it implies that a purely actual substance cannot exist. — Aaron R

Yes, to avoid any interpretational issues I've been directly referencing the argument statements in Feser's book which Darth links to in the OP.

In other words, "being" could never get off the ground if the actualizer at the bottom had any potency that needed to be actualized by something more fundamental. — Aaron R

Agreed. So I reject the idea that the first actualizer has potential for its own existence which is why I've said that it necessarily exists. However it doesn't follow that it doesn't have potentials for the existence of other substances.

Basically it's not clear to me how anything else could come into existence if there weren't potential for them to exist in the first actualizer.

This is going in the the neo-Platonic demonstration, but if this material being had both actuality and potentiality, then it would be a complex composite with parts — darthbarracuda

I agree with the rest of your analysis, but I think this conclusion assumes dualism. A hylomorphic substance has both form and matter without being ontologically separable into form and matter. I would argue the same for actuality and potential. So the first actualizer could be a hylomorphic and mutable simple.

A potential cannot be actualized except by something already actual.

But there are several concrete ways around this:

• The universe could itself exist by logical necessity.
• Physical laws (modern, not Aristotelian physics) could be the sole cause an occurrence, such as the appearance of virtual particle pairs in a vacuum, or near the edge of a black hole, especially in combination with a logically necessary universe.
• A potential could be actualized by the object of the change itself.