Does the God of classical theism exist? The principal reason for thinking that God fits the profile defined by classical theism is this: we have good metaphysical grounds for believing both that some entity that fits this profile exist, and we have good theological grounds for believing that, if such an entity exists, it must be identical to God, that is, to the God of the Bible, the God of Abraham, Isaac, and Jacob. 
 
So, what is the profile of the God of classical theism? There are four crucial characteristics:
 
1.God is absolutely the first cause of all causable things.
2.God is atemporal.
3.God lacks any intrinsic, passive potentiality.
4.God has no distinct nature and no distinct act of existence: He is identical to His own act of existence, which is also His nature or essence.
 
It is noteworthy that this list does not contain any of the traditional omnis: omniscience, omnipotence, or omnibenevolence. I haven’t included personality on the list, nor such properties as having knowledge or will. I haven’t included God’s infinity or perfection or uniqueness. This is not because classical theism is silent on any of these points, but because, in the classical-theist tradition, all these divine characteristics follow from the four that I have listed. They are, from an epistemological point of view (that is, in the order of human understanding), secondary characteristics of the God of classical theism. These secondary characteristics are not points of controversy between classical and non-classical theists; in contrast, all of the primary characteristics on the list are quite controversial.
 
There are, therefore, two tasks which the classical theologian must complete: first, to argue successfully that some entity satisfies the four primary characteristics, and, second, to demonstrate that any being with the primary characteristics must also have the familiar secondary characteristics.

This is a revised version of my argument in this earlier blog:

If God is a necessary a being and uncaused, then He must lack all passive potentiality. Whatever intrinsic properties He has (qua God), He must have necessarily. Here's the argument.

First, I will need the concept of a logical moment. If agent A causes some effect E, then we can identify two logical moments, even if the action and the effect are temporally simultaneous. If agent A causes E, then agent A acts at one logical moment M1, and the effect is first in actuality at a posterior moment M2. The relation of priority/posteriority between logical moments is transitive and asymmetric. No logical moment is prior to itself, and no moment is prior to any moment that is prior to it.
 
We have proven that there are absolutely uncaused facts. These facts must belong to logical moments that are absolutely primal—i.e., logical moments that are posterior to no logical moments.
 
Second, I need the concept of a full complement of intrinsic properties. A substance x has a full complement of intrinsic properties at moment N with respect to its nature if and only if every property P is such that, if x has P intrinsically at some logical moment in some possible world, then x has either P or its negation intrinsically at N (with respect to that same nature).
 
Now I’m in a position to propose a basic principle about causality:
 
The Completeness of Agents (COA). Necessarily, if agent x acts at logical moment M to produce some effect, then x has a full complement of intrinsic properties at M with respect to its nature.
 
The rationale for COA is this: in order to act at a logical moment, an agent must actually exist in that moment. But an agent cannot actually exist at a moment without possessing a full complement of properties at that moment. If it didn’t possess such a full complement, it would fall short of actuality and would thereby be disqualified from acting.
 
I need one further principle:
 
The Groundedness of Intrinsic Properties. Necessarily, if an individual x has property P intrinsically at logical moment M, then there are some properties Q1 through Qn such that: x’s being P at M is wholly grounded by x’s having Q1 through Qn at M, and for each Qi, x’s having Qi at M is a basic, positive fact.

Let’s suppose that God is one of the agents acting at a primal moment M. Suppose for contradiction that God has some intrinsic property P at M contingently. By GA, there must be some basic properties Q1 through Qn possessed intrinsically by God at M, and God’s having P at M is wholly grounded by His having Q1 through Qn at M. We can assume that grounding is a necessitation relation. Consequently, God must have at least one property Qi contingently at M. If He had all of them at M necessarily, then He would have to have P at M necessarily as well.
 
Since it is a basic, positive, contingent fact that God possesses Qi at M, then this fact (by the PSR or principle of causality) must have a cause. But that is inconsistent with our assumption that M is a primal moment, and so no fact at M can have a cause.
 
Hence, God cannot possess any contingent intrinsic properties at logical moment M.
 
If it is necessary that God possess P intrinsically at M, there must be some explanation of this necessity. A logical moment is not a thing in its own right, but simply a node in the causal network of the world. So, if it is necessary that God possess P intrinsically at M, this must be a result of God’s essence, and a result of God’s essence alone, since there are no prior facts to appeal to. But if God’s possessing P is a result of God’s essence alone, then He must possess P necessarily at ever logical moment in every possible world, and not just at M.
 
Suppose that God has an intrinsic property P at moment N. Since God has a full complement of properties at the primal moment M, God must either have P or its negation at M. So, God qua God must have P necessarily at all logical moments in all possible worlds. Hence, God has all His intrinsic properties necessarily at every logical moment.
 
Here’s another way to look at this. Why can’t God lack some intrinsic property P at primal moment M, such that God could gain P in some subsequent logical moment? For a thing x to lack a possible intrinsic property is for it to have an intrinsic character of a certain kind. This intrinsic character must be a positive fact about x. Either the absence of P is grounded by x’s having some contrary intrinsic property Q, or else there is some totality property T [1] of x that encompasses the fact that x’s total complement of intrinsic properties does not include P. In either case, there is a basic, positive fact about x that must be causally explained (given the PSR).

When God lacks a particular intrinsic property (with respect to His divine nature), this absence is not a mere absence but a kind of privation. Contingent privations are causable facts, and so the PSR requires that they all have actual causes (see Haldane 2007). Consequently, God cannot have (qua God) any contingent privations in the primal moment M. It is not possible for Him to subsequently gain intrinsic properties in His divine nature, since He has with necessity a full complement of intrinsic properties.
 
Since God has every intrinsic property essentially, He must be a being of pure actuality, with no passive potentiality. Consequently, He must be timeless.
 
[1] A totality property is a constituent of what David M. Armstrong (1997) called totality facts. A totality fact about some particular substance would entail that the substance lacks any intrinsic property not contained in some totality C. Totality facts are basic, positive facts that ground truths about privations.

I have argued that we can deduce that God is a being of pure actuality, without passive potentialities, from the fact that He is absolutely the First Cause. Joe Schmid has challenged me on this inference, rightly pointing out that the implication is not immediate. I will try here to make the connection more nearly evident.
 
To do so, I will have to introduce some technical machinery. First, I will need the concept of a logical moment. If agent A causes some effect E, then we can identify two logical moments, even if the action and the effect are temporally simultaneous. If agent A causes E, then agent A acts at one logical moment M1, and the effect is first in actuality at a posterior moment M2. The relation of priority/posteriority between logical moments is transitive and asymmetric. No logical moment is prior to itself, and no moment is prior to any moment that is prior to it.
 
We have proven that there are absolutely uncaused events. These events must belong to logical moments that are absolutely primal—i.e., logical moments that are posterior to no logical moments.
 
The second technical device that I need is the definition of a nature-constituted disjunction of properties. Let D be a (possibly infinite) disjunction of monadic properties. Then D is a nature-constituted disjunction for individual x if and only D is a minimal disjunction such that it is essential to x to have some property in D. That is, there is no disjunction D* whose disjuncts form a proper subset of the disjuncts of D and such that it is essential to x to have some property from D*.
 
Let’s say that an individual x has a full complement of properties at logical moment M just in case x has at M every property that is essential to x, and, for every nature-constituted disjunction  D of properties for x, x has a property from D at M.
 
Now I’m in a position to propose a basic principle about causality:
 

• The Completeness of Agents (COA). Necessarily, if agent x acts at logical moment M to produce some effect y, then x has a full complement of properties at M.

 
The rationale for COA is this: in order to act at a logical moment, an agent must actually exist in that moment. But an agent cannot actually exist at a moment without possessing a full complement of properties at that moment. If it didn’t possess such a full complement, it would fall short of actuality and would thereby be disqualified from acting.
 
I need one further principle:
 

• The Groundedness of Accidents (GA). Necessarily, if an individual x has property P as an intrinsic, natural property, then there is some nature-constituted disjunction D of x’s essence such that P is one of the disjuncts of D.

 
In order for a property to be an intrinsic and natural property of a thing, it must be determinate of some determinable property that is essential to that thing. A thing can’t just take on intrinsic properties willy-nilly. An intrinsic property must fulfill some essential role dictated by the thing’s nature. The requirements of a thing’s nature lay out the possibilities for a thing’s intrinsic character.
 
Let’s suppose that God is one of the agents acting at a primal moment. Suppose for contradiction that God has some intrinsic property P contingently. By GA, there must be some disjunction D such that D is a nature-constituted disjunction for God, and P is a disjunct of D. If D were a trivial disjunction (with only one disjunct), then P would be an essential property of God and so not contingent. So, D must be a non-trivial disjunction.
 
Let M be a primal moment at which God acts. By COA, we know that God possesses a full complement of properties, relative to the divine nature, at that primal moment M. So, God must possess some member of D at M. But every member of D is such that, if God possesses it at M, He must possess it contingently. Consequently, God must have some contingent intrinsic property at M. Call this property Q.
 
Now, either it is necessary that God possess Q at M, or it is contingent that He do so. Both are impossible.
 
If it is necessary that God possess Q at M, there must be some explanation of this necessity. A logical moment is not a thing in its own right, but simply a node in the causal network of the world. So, if it is necessary that God possess Q at M, this must be a result of God’s essence, and a result of God’s essence alone, since there are no prior facts to appeal to. But if God’s possessing Q is a result of God’s essence alone, then He must possess Q necessarily and not contingently.
 
There is a second reason for ruling out this first horn of the dilemma: a reason based on St. Thomas's First Way. Suppose that it is necessary for God to have Q at the primal moment M. Then, since Q is contingent, it must be possible for God to have some contrary property at some posterior logical moment. If so, this would mean that God is intrinsically changeable. But an intrinsically changeable being exists within time, not outside it. And a being that is inside time cannot be causally responsible for the propagation of time, as the Prime Mover must be.
 
If, alternatively, it is contingent that God possess Q at M, then this fact (by the PSR or principle of causality) must have a cause. But that is inconsistent with our assumption that M is a primal moment, and so no fact at M can have a cause.
 
Hence, God cannot possess any contingent intrinsic properties at any logical moment. He must be a being of pure actuality, with no passive potentiality.
 
There is a complication that is introduced by the fact of the Incarnation. The Second Person of the Trinity has two complete natures, one divine and one human. Hence, we must distinguish between the properties that God the Son has qua God and those He has qua man. Qua God, the Son cannot have any contingent intrinsic properties, for the reason given above. Qua man, the Son has many contingent intrinsic properties. In fact, having a human nature is one of those contingent properties that the Son has qua man. So, in this sense, and only in this sense, God can have contingent intrinsic properties, namely, by assuming a second nature.

In the Summa Theologiae Q4, a1, Thomas gives just one simple argument for concluding that God is perfect: namely, the fact that imperfection always implies some lack of actuality, and God is actuality in its absolute fullness. His reply to objection 3 is also noteworthy. Objection 3 observes that ‘existence’ seems radically imperfect, since things can exist no matter how far they are from perfection. Since God’s nature is simple, unqualified existence, He would have to be the most imperfect thing of all.
 
In the Reply, Thomas rejects this greatest common factor conception of ‘existence’. It is true that the formula ‘X exists’ can be true, no matter how minimal X’s grip on existence may be. (Thomas calls this the ‘formal principle of existence’, by which he seems to mean its logical or semantical role.) However, Thomas urges us to focus instead on the metaphysical role that is played by acts of existence (actus essendi). It is the act of existence that gives each thing whatever degree of being it has. The act is limited by the nature or essence of the thing, not vice versa. Acts of existence are the source of reality and actuality. Hence, God, as the supreme act of existence, must contain eminently every possible degree of being, so that He can give to each individual act of being all the actuality it needs to do its work, given its associated essence.
 
In article 2, Thomas argues that God possesses all the perfections had by creatures. This is the crucial point at which we depart from purely negative theology. He gives two arguments: one from God’s place as First Cause, and the other from God’s essence being His pure existence. First, since God is the cause of all the perfections in any creature (not only in the actual world, but also in any alternative possibility), God must possess in an eminent form each of those perfections. This is an appeal to the principle of proportionate causality which we’ve seen repeatedly since the First Way. As Thomas explains, the fact that the sun is the cause of heat does not entail that the sun is formally hot. But it does entail that it contains heat eminently—that it has some attribute that is, by virtue of its greater nobility of being, capable of making other things formally hot. Similarly, God is the cause of all heat, but He is not himself formally hot. How, then, is He eminently hot? He is so, as we shall see, by being an Intellect, knowing the form of heat as one of His possible creations. This is the same sense in which an architect is eminently a house.
 
So far, we have not really moved very far from a negative theology, since to say that God is eminently F is really to say little more than that He is the cause of F-ness. The second argument is, I think, the more fruitful. God’s existence is unlimited by any distinct form or essence. He is thereby a case of pure, unqualified existence. For the moment, let’s define a perfection as a property that doesn’t explicitly entail that its bearer is not God (not the First Cause, not identical to its own act of existence). So, for example, being finite, being created, having a nature, having passive potentiality—none of these would count as perfections, since they all entail explicitly that their bearer is not the First Cause. In contrast, being powerful, loving, knowing things—none of these explicitly rule out being God.
 
Say that F is such a perfection. If God lacked the possibility of being F, then being itself would lack this possibility. If F were not absolutely impossible, and if F does not explicitly rule out being God, then it would have to be possible for God to be F. There could be then no explanation of the impossibility of God’s being F: F itself does not rule this out, and God has no nature but existence, so if His nature rules it out, there must be a fundamental incompatibility between existing and being F. So, God must be possibly F.
 
But God lacks all passive potentiality. Hence, it is impossible for God to be merely potentially F. If He can be F, He must actually be F. Consequently, God must possess every perfection.
 
The basic premise of this second argument is that impossibility must have some explanation. If F and G are both purely positive, then there could be no logical inconsistency between them. Hence, is must be possible for F and G to be combined. Existence as such is purely positive. Hence, existence can be combined with any purely positive property. Since God’s nature is nothing but existence, it must be possible for God to have any purely positive property. Since God is a being of pure actuality, He must have in actuality every purely positive property.
 
We saw, when considering the Third Way, that Thomas seemed to assume that the possible existence of something that doesn’t actually exist needs to have an explanation. There is some prima facie tension between that principle and the principle relied on here. Suppose that there is no explanation for the possible existence of p, and no explanation for the impossibility of p. Is p then possible or not? The Third Way would say No, and the argument from perfection would say Yes. But p can’t be both possible and impossible.
 
The two principles can be reconciled in the following way. The Third Way appeals to the Nihil ex Nihilo principle:
 
(NEN) If x does not actually exist, then x’s existence is possible only if there is something that actually exists with the actual power to cause x to exist.
 
The second perfection argument depends on the principle that logically consistent combination is always possible:
 
(LCC) It is impossible to combine two properties only if there is some logical inconsistency between their essential internal structure or definition.
 
Are the two principles consistent? Consider some x that does not actually exist. Now consider two properties: actually existing, and being x. These are clearly not logically inconsistent in their internal structure or definition. So, by LCC, it must be possible to combine them. This means that x’s existence is possible. By NEN, it follows that something has the power to cause x to exist. But this is true: God exists and has this power. What’s interesting is that these two principles by themselves seem to entail that in every possible world, something exists with the power to cause the existence of anything that doesn’t exist in that world. This isn’t quite a proof of God’s existence, but it’s close. This does suggest that many atheists will find either NEN or LCC implausible. One could mitigate this problem by restricting LCC in such a way that it doesn’t apply to properties like being x (some particular thing). We might limit LCC to potentially general properties, properties that could in principle be instantiated by more than one thing. Then the atheist could consistently accept both principles.

A central thesis of Thomas’s natural theology is the claim that God is a being of pure actuality—meaning that God is utterly lacking in passive potentiality. This follows quickly from the fact that God is absolutely the first cause, in the sense of being the cause even of other necessities. God is the only being that is necessary in Himself. In order to act as first cause, God must be in His very essence fully equipped with a complete complement of intrinsic properties. If He were not, then there would be a component of contingency or at most conditional necessity in His intrinsic state as the first cause, but any such component would require a still more primary cause, contradicting God’s status as absolutely first.
 
God lacks only passive potentialities: He possesses active potentialities (i.e., active powers) to the greatest possible degree. God can cause anything that is metaphysically causable—His active power is without limit. If it were limited, then this limit would require some cause, again contradicting God’s status as first cause.
 
God is, moreover, maximally free. He was free, in particular, to create nothing at all, or to create any cosmos that would be a fitting expression of His nature. There are many such possible cosmoses. Ours is just one. Hence, our cosmos is thoroughly contingent.
 
How is the contingent exercise of active power on God’s part consistent with His lack of passive potentiality? In Aristotelian metaphysics, there is no conflict, since the exercise of active power is an action, and an action takes place in the patient, not in the agent. God does not have to modify Himself in order to exercise His active power. He does not have to deliberate or plan, and His intentional action requires no internal representation in His mind. The truthmaker for God’s intentionally creating creature x is simply the existence of x itself. No difference internal to God is required to differentiate worlds in which God creates x from worlds in which He does not.
 
But, a critic may respond, isn’t God identical to His own action, given Thomas’s strong doctrine of divine simplicity? If so, the objection goes, since God exists necessarily, His action must exist necessarily, in which case everything that God creates must also exist necessarily.
 
It is true that Thomas embraces the thesis that God is identical to His own action. In Summa Contra Gentiles, I, chapter 45 and in Summa Theologiae I, Q14, article 4, Thomas argues that God’s act of understanding is identical to His essence. Since He is identical to His own essence, God is identical to His act of understanding. In Part II of the Summa Contra Gentiles, Thomas claims both that God’s power is identical to His own substance, and that His action is identical to His power.
 
Ordinarily, the act of a power is distinct from that power. So, if I whistle a tune, my particular act of whistling is obviously distinct from my power of whistling. However, in God’s case, His act of understanding is identical to His power of understanding, and both are identical to God Himself.
 
The act of a power is the perfection of the power. A power that isn’t exercised is imperfect. So, if God’s act were distinct from His power of understanding, then that act would perfect His power. Furthermore, the perfecting of this power would be the perfecting of God’s essence. Hence, God’s perfection would depend on something other than God, which would contradict the fact that God is infinitely perfect. God’s act must be identical to God, so that it is God who perfects Himself.
 
An act stands to a power as actuality to potentiality. So, if God were not identical to His act, then His power of understanding would have a potentiality that is actualized by His act. But God has no passive potentiality. He doesn’t stand as potential to anything else. So, He must be identical to His own act.
 
The Modal Collapse Argument
 
Many critics of Thomas argue that he is committed to God’s willing necessarily everything that He wills, because of Thomas’s strong doctrine of divine simplicity. The argument typically goes something like this:
 

1. God exists necessarily (Third Way)
2. God is identical to His act of willing (Divine simplicity – SCG I.45 and II.9)
3. God’s act of willing is identical to His act of willing to create this universe.
4. So, God’s act of willing to create this universe exists necessarily. (From 1, 2, 3 by the law of identity)
5. So, God necessarily wills to create this universe. (From 4?)

 
The argument is guilty of a fallacy of equivocation. Understood in one way, the term “God’s act of willing to create this world” picks out something that exists necessarily, namely, God Himself. Understood in a second way, the term picks out something that exists only if this world exists. On either meaning, conclusion 5 does not follow from sub-conclusion 4. On the second meaning, the phrase “God’s act of willing to create this universe” is actually a kind of quantifier: “There is something that is uniquely an act of willing by God to create this universe and…”
 
To make clear why 5 does not follow from 4 using the first meaning, the inference to 5 on that reading requires an additional assumption:
 
4b. God’s act of willing to create this universe is essentially God’s act of willing to create this universe.
 
On the first reading, assumption 4b is false. God’s actual act of willing (which is in fact an act of willing that He create this world) could have been an act of willing that He create a different world, or no world at all. Consider, for example, a parallel proposition:
 
BD. Ben’s father is essentially Ben’s father.
 
Not true—although I am in fact Ben’s father, there are possible worlds in which I have no children at all.
 
Critics of Thomas will complain that the cases are not parallel. Assumption 4b just must be true, because every act of willing has its own object essentially. My choosing a chocolate cookie for a snack could not have been my choosing an oatmeal cookie. Different objects necessarily imply different acts of will. However, this is wrong, for two reasons. First, because God is different from creatures. God does not have to undergo any kind of process of deliberation in order to make a choice. Hence, He and His act of will are exactly the same in every possible world. They have different objects in different worlds, but this difference is merely a Cambridge difference in God—it doesn’t require any internal modification. The objects of God’s choosing are immediately present to God as chosen by Him—they don’t have to be re-presented within God as chosen.
 
Second, even in the case of human actions, it is possible for the same act of human willing to have different objects in different worlds. I’m thinking of a case of spontaneous but voluntary action—acts taken without any prior deliberation, but which are nonetheless guided by the human will. Consider, for example a musician who is improvising as he plays, or a speaker who is speaking very rapidly. The notes or words that are chosen are chosen by will, and yet there need be no prior mental event guiding the action. The action has “voluntariness”, as Elizabeth Anscombe puts it, without being the product of some internal volitional event. In a different possible world in which the person chooses a different note or different word, there may be no internal difference despite the fact that a different choice was made. Consequently, there is no reason to deny that the very same act of will could exist in both worlds.
 
Let’s return to the argument and consider using the second meaning. On that interpretation, steps 4 and 5 look like this:
 
4c. There is something that is uniquely an act of willing by God to create this universe, and that thing exists necessarily.
5c. There necessarily exists something that is uniquely an act of willing by God to create this universe.
 
Again, 5c does not follow from 4c, unless we assume that anything that is in this world an act of willing by God to create a certain universe must be an act of God to create that same universe in every possible world in which it exists. Again, we have to assume that God’s act of willing is essentially an act of willing to create this universe specifically. And that Thomas will deny.