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#729 Divine Simplicity

April 25, 2021

Dear Dr Craig,

You recently answered my question about religious language in the Reasonable Faith podcast (March 22, 2021) and I wanted to try to reformulate my question in a more understandable way. I admit that my formulation of the question was very choppy and muddled in thought, so I want to take the time to try to re-articulate it because I am genuinely seeking answers.

Basically, what I think I am trying to ask is this: on your view of God, how can God be qualitatively infinite and absolutely unique? On the Thomistic perspective, since God is not any particular being but is instead Being Itself Subsisting, then God would have to be qualitatively infinite and unique for the simple fact that creatures could not possibly comprehend such a reality, even throughout all eternity. That is why I and other Thomists believe that for all eternity in Heaven, we will constantly be "learning" new things about God and there will never be a moment when we reach the "final" fact about God. Since you seem to believe that God is indeed a particular being and not Being Itself, then it seems that on a very basic metaphysical level, you have a finite view of God and, therefore, we could theoretically reach a "final" fact about God in Heaven. This seems very problematic because God, as the ultimate reality, should not be a finite reality. As David Bentley Hart puts it, God is that great "Ocean of Being" from which all finite being derives from. I hope this makes more sense.

Thank you for reading and I look forward to a reply. God bless.


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Dr. craig’s response


I’m glad for your question, Anthony, because it connects with my current research for my projected systematic philosophical theology. I have now embarked on the section on the Doctrine of God and am exploring what philosophers call the coherence of theism, or how best to make sense of the various attributes of God. Having written first drafts of the sub-sections on divine necessity and divine aseity, I am now working through the prodigious literature on divine simplicity.

The doctrine of divine simplicity holds that there is no composition or complexity in God. The doctrine has been variously understood throughout church history. Everyone agrees that God is not composed of material parts, since He is not a physical object. But at the other end of the spectrum, followers of Thomas Aquinas claim that in God there is not even a distinction between essence and existence. Rather God just is the pure act of being. 

In order to understand this claim, we need to have some prior understanding of Thomistic metaphysics. For Thomas, finite beings are one and all composed of essence and existence. A thing’s essence is its individual nature, where the nature of a thing is given in answer to the question, “What is it?” For example, a horse has a certain nature that makes it a horse rather than, say, a man or a lion. A thing’s existence is given (or not) in answer to the question, “Is it?” By considering the essence of a horse, we cannot answer the question as to whether it exists. Its essence is distinct from its existence.

It is crucial to understand that for Thomas this is not merely a conceptual distinction which we make in our minds. Rather it is a metaphysical or real distinction within creatures. Creatures are metaphysically composed of essence and existence. By “existence” Thomas means an act of being which instantiates the essence. Existence is not a property which is added to a thing’s essence; rather it is the instantiating of that essence. Thomists like to emphasize the verbal nature of the word “being” or “to be” (in Latin esse). Being is not a property but an act of instantiation. So if some creature is to exist, being must be conjoined to its essence in order for that creature to be a real thing.

So the claim that God is absolutely simple entails (given the real distinction between essence and existence) that God is the pure act of being. It is unacceptable to hold that God has a certain nature, say, deity (not to speak of the various essential properties normally ascribed to God such as holiness, aseity, omnipotence, omniscience, eternity, and so on), to which the act of being is necessarily conjoined. An essence serves to restrict being to this or that sort of being, say, a man or a horse. But since He is simple, God’s act of being is not constrained by any essence. He just is the pure act of being unrestricted by any nature. He is, as Thomists like to say, being itself subsisting (ipsum esse subsistens).

Now it is to your credit, Anthony, that you see clearly the radical implications of this doctrine. It entails that God is literally incomprehensible. For the way that the human intellect grasps a thing is via its nature or essence. That’s how we come to know what it is. The human intellect therefore has no way of grasping the pure act of being. Not conjoined to any essence, it is incapable of being thought. Aquinas’ doctrine thus leads to a profound agnosticism about who or what God is. We can say only what He is not: not physical, not temporal, not spatial, etc. We can have no positive knowledge of God.

Thus, it is false that for Thomists “for all eternity in Heaven, we will constantly be ‘learning’ new things about God.” On the contrary, if Aquinas is right, we will constantly be learning nothing about God—ever! If the saints in heaven do come to have a “beatific vision” of God’s essence or being, it will have to be an ineffable, mystical, non-cognitive experience.

Such a doctrine is so unbiblical—not merely in the sense that it is not taught in the Bible, but in the sense that it is contrary to the teaching of the Bible, which instructs us that God is loving, personal, holy, almighty, eternal, and so on and so on—, that one wonders how any biblical Christian could be attracted to so pernicious a doctrine. Thomas’ God is more like the ineffable Absolute of Hinduism, which is also without distinctions, than the God of the Bible, Who reveals Himself to us as this and not that.

You offer as justification for the doctrine of divine simplicity the claim that without this doctrine God is finite, which is clearly theologically unacceptable. But I don’t see this at all, Anthony. Even if simplicity were a sufficient condition for God’s infinity, why think that it is a necessary condition? Why can’t a complex being be infinite? God is qualitatively infinite in multifaceted ways: He is metaphysically necessary in His existence, He exists a se as the sole uncreated reality, He is omnipotent, omniscient, eternal, morally perfect, the very standard of goodness, and so on. Such attributes are entailed by God’s status as the greatest conceivable being. I see no reason at all to think that a non-Thomistic God cannot have such a constellation of properties.

On the contrary, in fact, it is the Thomistic God that cannot have these properties. Indeed, it’s not at all obvious in what sense the Thomist can affirm that God is infinite in any positive sense. All we seem to get is that God is the pure act of being not received or contracted by any essence, as it is in creatures. This is at best the thesis that God is not finite, but that is a purely negative concept. Why think that the pure act of being is a great Ocean of Being rather than just the great Unknown?

What, you ask, makes God absolutely unique? Well, He is the sole uncreated reality for one thing, plus the only necessary, eternal, omnipotent, etc., being. As the Lord said to Isaiah, “I am God, and there is no one like me” (Isaiah 46.9). No one else has such attributes. I see no reason why such an infinite being cannot exist alongside finite beings as their existential cause.[1]

A final wrinkle to add to this debate: as an anti-realist about properties, I don’t think that God is metaphysically composed of any constituents. You don’t need properties as metaphysically existing things in order to make true predications about God. In that sense, I actually agree that God is simple! But that’s not of any theological significance because we are also simple in that sense! I reject constituent ontologies. On the other hand, as an anti-realist I also reject relational ontologies, which take properties to be abstract objects to which things stand in a relation of exemplification. I find that in the literature on divine simplicity it tends to be assumed that one must be a realist about properties either in the sense of a constituent ontology or a relational ontology. The anti-realist escapes this dilemma by simply rejecting properties altogether.


[1] You might want to take a look at my article “Pantheists in Spite of Themselves? Pannenberg, Clayton, and Shults on Divine Infinity,” https://www.reasonablefaith.org/writings/scholarly-writings/christian-doctrines/pantheists-in-spite-of-themselves-pannenberg-clayton-and-shults-on-divine-i/


- William Lane Craig