The responses to my original essay on divine simplicity have been interesting to read. I am grateful to Theopolis for the opportunity to contribute to this conversation, and I appreciate all of my dialogue partners to this ongoing debate over the doctrine of divine simplicity. There are several themes that I wish to comment on below.

The Argument

            The first theme that I wish to comment on is the argument that I developed in my first essay. Here is the argument once again.

1) If God is free, then God can refrain from acting to give grace.

2) God is free.

3) Therefore, God can refrain from acting to give grace.

4) If God’s act to give grace is absolutely necessary, then God cannot refrain from acting to give grace.

5) God can refrain from acting to give grace.

6) Thus, God’s act to give grace is not absolutely necessary.

7) God’s existence is absolutely necessary.

8) Anything that is identical to God’s existence must be absolutely necessary.

9) All of God’s actions are identical to each other such that there is only one divine act.

10) God’s act to give grace is identical to God’s one divine act.

11) God’s one divine act is identical to God’s existence.

12) Therefore, God’s one divine act is absolutely necessary.

13) If God’s one divine act is absolutely necessary, then God’s act to give grace is absolutely necessary.

14) Therefore, God’s act to give grace is absolutely necessary. [Contradicts 6.]

15) Therefore, God cannot refrain from acting to give grace. [Contradicts 5.]

16) Therefore, God is not free. [Contradicts 2.]

In my first essay, I pointed out that most Christian theologians and philosophers accept (1) through (8). Then I explained that premises (9), (10), and (11) are only affirmed by proponents of divine simplicity. From there, I derived 3 contradictions related to divine freedom and divine grace. I have repeated the argument because it is not clear that my dialogue partners have adequately attempted to engage with the argument. As I explained in my first essay, anyone wishing to defend divine simplicity will need to remove the three contradictions by pointing to premises in the argument that she rejects, and offer a justification for why she rejects those premises. My dialogue partners have not been entirely forthcoming about which premises they reject.

For example, consider Edward Feser’s reply. Feser comments on my argument from divine simplicity to the necessary existence of the world. This is curious because none of the premises in my argument even mention the necessary existence of the world. This leaves me to wonder if Feser read my original essay closely. To be fair to Feser, he does at least attempt to identify which premise in the argument that he rejects. Feser says,

Now, what the doctrine of divine simplicity claims—contrary to what Mullins supposes (in what he labels premise (9) of his argument)—is not that all of God’s properties are identical and thus are necessary as he is, but rather that all of his real properties are.

Feser then goes on to say that he rejects premise (9) because of a distinction between real properties and Cambridge properties. According to Feser, God is identical to His real properties, but God is not identical to His Cambridge properties.

I find this reply from Feser curious for several reasons. First, it is curious because my premise (9) does not even mention the word property. What my premise (9) actually says is, “All of God’s actions are identical to each other such that there is only one divine act.” My actual premise (9) is something that proponents of divine simplicity explicitly endorse.[1] By this one act, God is said to will Himself and everything else that He has made.[2] Moreover, I intentionally avoided any mention of properties in the premises of my argument. I avoided this because, as I explained in my original essay, proponents of divine simplicity explicitly deny that God has any properties, forms, immanent universals, or tropes.[3] As the proponent of divine simplicity, Katherin Rogers, makes clear, the simple God does not have any properties. Instead, God is simply act.[4]

Second, I find this reply from Feser curious because it appears that Feser is rejecting some other premise from some other argument from some other philosopher. It seems as if Feser has taken material from pages 195-196 of his book Five Proofs for the Existence of God and assumed that it addresses the argument that I offered. In this book, Feser is responding to an argument from the philosopher Thomas Morris, who offers an argument from the identity of God’s properties to the necessity of the created world. (Which again, is not the argument I offer in my original Theopolis essay.) It appears that Feser has taken this material and replaced “Morris” with “Mullins” for his blog post. This would explain why Feser’s essay does not actually address my argument, and why he skips over premises (10) and (11).

Third, I find this reply from Feser curious because it is not a legitimate reply to Morris’ argument from simplicity to the necessary existence of the universe. Feser’s response to Morris’s argument is to appeal to the distinction between real properties and Cambridge properties. According to Feser, God is identical to all of His real properties, but God is not identical to any of His Cambridge properties. (How God can lack all properties and yet have Cambridge properties seems to be a confusing notion, but I digress.)

This distinction between real and Cambridge properties has nothing to do with Morris’ argument. As T.J. Mawson points out, God’s act of creating the universe is nothing remotely like a Cambridge property.[5] Divine actions are intrinsic to God. Given divine simplicity, divine actions are identical to God. Divine actions like creating the universe or giving grace are not Cambridge properties because they are intrinsic to God, and identical to God. As Thomas Aquinas makes clear, “The manifold actions ascribed to God, as intelligence, volition, the production of things, and the like, are not so many different things, since each of these actions in God is His own very being, which is one and the same thing.” (Summa Contra Gentiles II.10) I have emphasized the production of things because it is important to note that God’s causal activity of producing the universe and of producing grace in sinners are actions which are identical to God given divine simplicity. Any mention of Cambridge properties from Feser here is quite simply a category mistake. It is nothing but hand-waving. Morris’ argument, and others like it, are far more serious than Feser lets on.

On Appeals to Mystery

Joe Lenow’s essay mentions several interesting ideas that require more thought than a blog post can do justice. For example, Lenow mentions an argument that I have previously published elsewhere that seeks to show that divine freedom and pure actuality are incompatible. Lenow refers to a forthcoming paper of his where he develops a response based on the metaphysics of powers. Lenow’s work on the metaphysics of powers is intellectually stimulating, and demands more thought. However, since it is in reference to a different argument from the one I presented in my original essay for Theopolis, I shall have nothing more to say about here.

In reply to my Theopolis essay, Lenow says that there are different ways to think about the doctrine of divine simplicity. One could look at divine simplicity as a substantive metaphysical thesis, as I have in my original essay. Alternatively, one could look at divine simplicity as a consequence of a more fundamental claim about God—i.e. God’s essential unknowability. Since God is essentially unknowable, Lenow says we must deny all distinctions of God. Lenow claims that the unknowability of God is deep within the Christian tradition. He even says that God’s essential unknowability has a biblical basis in passages like Isaiah 55:8-9, which proclaims that God’s thoughts and actions are higher than our own.

I have several things to say in reply to this. First, the notion of essential unknowability is self-contradictory on its surface. One simply cannot know that God is unknowable. The very notion of knowing the unknowable is incoherent. If one knows X, then X is such that it is potentially knowable. If X is essentially unknowable, it is impossible to know anything about X including knowing that it is unknowable.

Perhaps one might complain that I have not properly captured the notion of essential unknowability. In one place, Lenow says that God’s essential unknowability is “one of the defining attributes of the divine life.” Lenow explains that it is an apophatic thesis that “every theological concept or claim must fail to describe God as God truly is.” I think this is also self-contradictory. If the apophatic thesis is true, then it is false to say that essential unknowability is “one of the defining attributes of the divine life.” This is because essential unknowability is a theological concept, and thus fails to describe God as God truly is.

Second, divine simplicity does not follow from God’s essential unknowability. To start, divine simplicity is a theological concept or claim, and thus fails to describe God as God truly is. Moreover, if God is essentially unknowable, why should I think that I must deny all distinctions of God? If God is really unknowable, I am not in a position to say what can or cannot be denied of God. For all I know, God might be incredibly complex and have more distinctions than I can possibly imagine. Alternatively, God might have just two distinctions that are beyond my ken to know. Who knows? All bets are off if God is essentially unknowable. Any claim to know what the entailments are from God’s essential unknowability presuppose that one knows too much about the essentially unknowable God.

Third, I find it doubtful that God’s essential unknowability has its basis in a set of holy scriptures that explicitly claim to make God known to humanity. In Acts 17:23, the apostle Paul criticises the people of Athens for worshipping an unknown God. Why? Because Paul thinks that God has made Himself known through Jesus Christ. Are God’s thoughts above my own? Sure, but that does not tell me that God is essentially unknowable. Instead, it tells me that God is much wiser and more knowledgeable than I am. Isaiah assures me that I can know that God is very wise indeed. That is not an essentially unknown God.

What is the moral to draw from this? If divine simplicity rests upon the essential unknowability of God, this is not a great position for a proponent of simplicity to be in. The essential unknowability of God is self-contradictory, does not entail divine simplicity, and goes against the explicit teachings of scripture.

On Appeals to Analogy

Feser points out that the doctrine of analogy is about literal predication. I am aware of this fact, so I am not sure what Feser’s point is. Perhaps Feser is wishing to inform other readers, which is surely an important task. Also, I am not entirely sure what the doctrine of analogy does for divine simplicity with regards to my argument. Can analogical predication somehow remove a contradiction like “God is free and God is not free.” No. Classical theists are quite clear that God cannot be free if His actions are performed of absolute necessity.[6] No amount of analogical predication can make God’s free actions consistent with those actions being performed of absolute necessity. Can analogical predication somehow make God’s contingent and necessary actions identical? Of course not.[7] No amount of analogical predication can make necessity and contingency mean something completely different so as to remove the contradictions that I have pointed out. I think what Feser is really working with is equivocation.

In order for an analogical predication to be successful, one must be able to identify the sense in which the two predicates are being used in a similar way. In other words, one must find the univocal core of the analogical predication.[8] Otherwise, one is simply equivocating the terms, and changing the conversation. This is a point that Peter Leithart brings out in his essay. Despite all the appeals to analogical predication, proponents of divine simplicity have to rely on certain univocal concepts in order to establish their claims about the simple God.

On the Dire Consequences of Denying Divine Simplicity

Feser says that there are dire consequences if one denies divine simplicity. For example, if one denies divine simplicity then one has to give up on the uniqueness and ultimacy of God. Thus, if one denies divine simplicity, then one has implicitly denied the existence of God.

In reply, I say that there are some slippery slope arguments, and then there are some really slippery slope arguments. Feser’s assertion that denying divine simplicity leads to atheism is very slippery indeed. Feser’s claims assume an elaborate set of metaphysical theories that a Christian does not have to affirm in order to articulate a biblical doctrine of God. As I pointed out in my original essay, the doctrine of divine simplicity has no explicit biblical support. Instead, the doctrine has to be argued for on the basis of certain metaphysical assumptions, which also do not have any explicit biblical support.

The classical theist’s underlying metaphysical assumptions about mereology and what counts as a part are controversial and extravagant. The sort of merelogical assumptions that are at play in this argument are ones that I find implausible. As I pointed out in my original essay, proponents of divine simplicity assume that all properties, actions, and potentialities count as parts. Even existence counts as a part. I find it implausible that existence and actions count as parts. I find it implausible that the essential properties of an immaterial soul count as literal parts of a soul. I find it implausible that God’s accidental property of Creator counts as a part. I find it implausible that conceptual distinctions, like conceptually dividing God’s life up into conceptual temporal parts, count as literal parts.[9] I reject the mereological assumptions that are at play in many standard arguments for divine simplicity.

What happens if I deny divine simplicity along with its underlying mereological extravagance? I am left with a wide array of models of God and competing metaphysical positions. Let’s be clear about this fact. With debates over models of God, we are also considering debates over competing metaphysical claims.[10] Our options are not really Thomistic metaphysics or atheism. That is a false dichotomy. There are many other metaphysical theories that are available to the Christian who wishes to develop a biblical doctrine of God.  

Moreover, there are many alternative models of God that one can turn to if she denies divine simplicity. The options are not classical theism or atheism. Here are a few of the other options: neo-classical theism, open theism, panentheism, pantheism, and process theism.[11] To be sure, some contemporary classical theists, like Feser, caricature these other models as nothing more than superhuman deities. They even lump these quite distinct models into the incredibly unhelpful, and uninformative, category of “theistic personalism.” But this is nothing more than a caricature that does not reflect serious scholarship. It might turn out that, upon close examination, these other models of God are not viable options. (Personally, I would rule out a couple of these models of God on biblical grounds.) But a Christian who takes seriously the problems for divine simplicity ought to take seriously the available models of God instead of asserting that our options are classical theism or atheism. 

R.T. Mullins (PhD, University of St Andrews) specializes in philosophical theology. He has published on topics such as God and time, the Trinity, the Incarnation, disability theology, and the problem of evil. His book, The End of the Timeless God was released in 2016 by Oxford University Press. He has previously held research and teaching fellowships at the University of Notre Dame and the University of Cambridge. Currently, he is a research fellow at the University of St Andrews. His forthcoming book, God and Emotion is due for publication in 2020. He is the host of The Reluctant Theologian podcast. When not engaging in philosophical theology, he is often found at a metal show. Checkout more at

[1] Katherin A. Rogers, The Anselmian Approach to God and Creation (Lewiston: The Edwin Mellen Press, 1997), 40.

[2] Thomas Aquinas, Summa Contra Gentiles I.82.

[3] Michael Bergmann and Jeffrey Brower, “A Theistic Argument Against Platonism (and in Support of Truthmakers and Divine Simplicity” in, ed. Dean W. Zimmerman Oxford Studies in Metaphysics: Volume 2 (Oxford: Oxford University Press, 2006), 359-360. Cf. St Augustine

[4] Katherin A. Rogers, Perfect Being Theology (Edinburgh: Edinburgh University Press, 2000), 27.

[5] T.J. Mawson, The Divine Attributes (Cambridge: Cambridge University Press, 2018), 54.

[6] Aquinas, Summa Contra Gentiles I.88.

[7] William Hasker, “Is Divine Simplicity a Mistake?” American Catholic Philosophical Quarterly 90 (2016), 717.

[8] Cf. Thomas Williams, “The Doctrine of Univocity is True and Salutary,” Modern Theology 21 (2005).

[9] Hasker, “Is Divine Simplicity a Mistake?” 701-704.

[10] Keith Ward, Christ and Cosmos: A Reformulation of Trinitarian Doctrine (Cambridge: Cambridge University Press, 2015), 26.

[11] For more on these models see, eds. Jeanine Diller and Asa Kasher, Models of God and Alternative Ultimate Realities (New York: Springer, 2013).

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