The doctrine of divine simplicity is a doctrine that some philosophers and theologians love to hate. The doctrine is accused of being confusing, incoherent, unbiblical, and just plain muddleheaded. One prominent example of rejection of the doctrine is Alvin Plantinga’s lecture turned book Does God Have a Nature?. Although this book is somewhat dated now it has exercised a larger influence than its diminutive size would suggest.[i] Even when the doctrine of divine simplicity is not rejected outright it has been retooled to cohere with some notion of human rationality. Sometimes it has been like theological taffy and been stretched out of all recognizable shape. My goal here is simply (pun intended!) to offer a brief consideration of the doctrine. It is not all that we say about our great and glorious Triune God. But it is essential (yes, this pun is intended too).
Let’s formulate a simple doctrine of simplicity. The doctrine of divine simplicity affirms that God is not made up of more basic parts (or any parts whatsoever). Perhaps two illustrations will help us understand this. First, consider a brick wall. A brick wall is a single thing, right? Yes and no. Yes, it is one thing. It is a wall. But it is made up of more basic or primitive parts, namely: bricks and mortar. Second, my wife makes a wonderful Johnny Cake (cornbread). It is one thing: it is Johnny Cake. But as I watch my wife make the Johnny Cake I see that she uses many ingredients. She uses corn meal, eggs, butter, salt, sugar, etc. We say that the ingredients that go into making the Johnny Cake are more basic than the Johnny Cake itself. In like manner, bricks and mortar are more basic than the brick wall.
The doctrine of divine simplicity is formulated from biblical texts and the implications we can draw from them that God is not made up of more basic ingredients (for instance, Deuteronomy 4:15–16; John 4:24; and Luke 24:39). We cannot even think of the three persons that way. God the Father is not one third of the Triune Godhead, the Son a third, or the Spirit another third. Each person of the Godhead is wholly God and the full God due to the mutual interpenetration of the persons in one another (called perichoresis in Greek or circumincessio in Latin).[ii]
You may be wondering what the big deal is. Perhaps this all strikes you as so much abstract philosophizing. But it isn’t. Let’s consider some implications of the doctrine of divine simplicity and connections it may have with other aspects of what we know about God as revealed in the pages of Scripture and developed in systematic theology (see the Westminster Confession of Faith chapters 2, 5, and 8; the Larger Catechism Q&A 7, 10, and 12; and the Shorter Catechism Q&A 4).
The doctrine of divine simplicity is inextricably tied up with God’s other attributes. This should not surprise us since God is simple. Properly understood, God is his attributes. Divine simplicity articulates the truth that God is not made up of ingredients that are more basic than he. As the WCF 2.1 has it, “God is without body, parts, or passions…” There is no before or after with God. This is divine simplicity seen in terms of time. There also is no here or there with God’s location since he fills all space. This is what divine immensity is about. It is divine simplicity with regard to space. Also related is the doctrine of divine aseity. God is a se, from himself. As Cornelius Van Til was fond of saying, God is the “self-contained ontological Trinity.”[iii] That is, God is absolutely independent. Whereas we as creatures are dependent on God, he is never dependent upon us. God is also pure act(ion). He has no unactualized potential. God is an utterly immutable, simple dynamic perichoretic Triune being.
This ties closely into God’s omnipotence and omniscience. God could not be all-powerful or all-knowing if he is not a se or simple. If God was not simple he could get stronger or weaker. If God was not simple he could discover new truth he did not know before or he could forget knowledge he had once possessed. To say that God is simple is to affirm divine immutability. God does not change. Even the incarnation does not change this. God the Son united himself to a true human nature, a “true body and a reasonable soul” as the Westminster Shorter Catechism Q&A 22 has it. The Son as to his divine nature did not change in the incarnation. Yes, a human nature was added to the divine nature. But the person of the divine Logos was the person of the God-man Jesus Christ. That is, the Son as to his divine nature did not undergo change in the incarnation even though his human nature most assuredly did.[iv]
One concern with the doctrine of divine simplicity is that it destroys God’s ability to relate to his creation. God cannot enter into real relations with his creatures if he is simple (and immutable and eternal and impassible ad infinitum). One problem with this criticism is that it confuses the Creator with the creature or puts God and his creation on the same level. If we humans only relate to one another through the experience of change and the addition and subtraction of characteristics (say we lose or gain weight, our hair turns gray or falls out, and we learn something new or forget what we once knew) then it must be true of God too. If God is a person, and he is, then he too must undergo this same kind of addition or subtraction. But this fails to reckon with the fact that God is, as we have already had occasion to note, pure act(ion) and is a dynamic Triune fellowship of Father, Son, and Spirit. The relation between a simple God and his creatures undergoes change, but he does not. This is ultimately beyond us mere creatures because God is God and we are not.
I do not pretend to have wrestled with all the various challenges brought against this doctrine. But the doctrine is sound nonetheless. Let me close with these brief observations. If the Triune God of Scripture is not simple, then it is possible for him to disintegrate into a heaping pile of nothingness. Further, if our God is not simple then it is possible for him to change his mind on the plan of redemption. Perhaps God will decide that those who believe on Christ will all go to perdition. Even further, if God is not simple then his Word is no longer the sure revelation of his will for us and for our salvation. If God is essentially complex, then God could be wrong about the final outcome of his unfolding plan of redemption. It is one thing to recognize that God’s plan of salvation is progressive throughout history culminating in the person and work of Jesus Christ, but it is another thing for this plan to unravel. Finally, if God is not simple, then perhaps he is an evolving God who grows through self-awareness and self-actualization and becomes what he once was not. So much for God engraving us on the palms of his hands (Isaiah 49:16). So much for his knowing the end from the beginning. He may be the best guesser. But that may not even be true. What’s worse, perhaps God has evolved from an undifferentiated monad into a Triune God. If that’s the case, just maybe God will evolve even further. Do not fret. God is simple and none of these potential problems really reflect his nature. This is such a straightforward doctrine delivered from various and sundry texts of Scripture and arising from their interplay with one another, it is a real shame that this even has to be said. But it does need saying. Over, and over, and over again. It’s that simple.
[i] Alvin Plantinga, Does God Have a Nature? Aquinas Lecture 44 (Milwaukee, WI: Marquette University Press, 1980).
[ii] See Dr. Richard A. Muller’s Dictionary of Latin and Greek Theological Terms: Being Drawn Principally From Protestant Scholastic Theology (Grand Rapids, MI: Baker Academic, 2017).
[iii]See Cornelius Van Til’s Introduction to Systematic Theology and Defense of the Faith for this kind of language.
[iv] See the Chalcedonian Formula for an orthodox understanding of the hypostatic union of the two natures in one person of Jesus Christ. Each nature retains its proper characteristics while being joined together in one person, namely the eternal divine Logos.