The idea that God is simple has a long history in theology, and was expressed perhaps most notably in the writings of the theologians of the Middle Ages, especially Thomas Aquinas. Stated generally, the doctrine of God’s simplicity states that God is not composed of parts. Most importantly, it says that God does not have properties like humans have – such as love, righteousness, etc. – rather, he is those properties. God’s essence is his attributes, so that when we say with the Scriptures, for example, that God is love, we really mean it!

I think there are important theological reasons to accept some version of divine simplicity, but there are also philosophical problems with this doctrine, just as there are with many doctrines about God. A chief concern, raised by 20th-century philosophers such as Alvin Plantinga, is as follows, as I summarize it in an early paper from grad school: “If God is identical with his own properties, then each of his properties is identical with each of his properties, so that God has but one property. In other words, if God is identical with his properties, then we could not reasonably say that God has any properties distinct from his other properties, which seems clearly contradicted in Scripture (which asserts that God has, for example, both power and mercy). Second of all, if God is identical with each of his properties, then it would seem, says Plantinga, that God himself is a property; which would make it extremely difficult for God to be considered a person–especially one who could have made and sustained the world–and not a mere abstract object.”

In response to this, those who defend divine simplicity have sought various models for understanding how God relates to his properties, and these are understandably rather complex (ahem). Perhaps at this point you may be wondering why any of this matters, even a tiny little bit. And here it would be helpful to go back to one of Aquinas’s main concerns. For Aquinas, being faithful to Scripture was paramount; but he also wanted to make sure that we understand that God is different from humans. This way of doing theology was called “negative theology.” We cannot really know God as he is, the idea goes, so we must proceed by discussing what he is not. Understood in this way, I would argue, the doctrine of divine simplicity gains more credibility and importance. For when we consider the nature of human beings, it becomes clear that we are composed of parts in a way that God cannot be. For example, we certainly are not identical to our properties. We are not love itself; we may have love at times or show love, but sadly, there are also times when we do not have love. For God this is impossible. In philosophical terms, love is an accidental property of humans; we can be without it and still be who we are. But not so with God; in fact, God cannot have accidental properties (or so goes the traditional argument). All of his attributes, which of course are all perfectly good, are essential to him.

Still, questions remain. It is sometimes difficult, it turns out, to determine the difference between an essential and an accidental property, even in God. From my own point of view, such classic doctrines need always to be reassessed, especially if the issue is not exactly clear in Scripture (perhaps statements like “God is love” aren’t meant to be used as defenses of obscure doctrines). Problems, serious ones, do indeed result from the doctrine of divine simplicity. But since the Scriptures do present God as distinct from humans, especially regarding the divine attributes, doctrines like divine simplicity should not be casually dismissed either, especially if they have a long and respected history in the church. There is something wonderfully marvelous about God–this being who has no beginning or end, who depends on nothing else for his existence, and who is the pure and perfect exemplification of all that is beautiful and good. How he is so, perhaps we will one day discover more of. For now, there definitely is something to divine simplicity, but perhaps some defenders of this doctrine have been a bit too dogmatic. It is one thing to state how God is different from humans; it is quite another to claim to know something in detail about this greatest of all possible beings, whose essence ultimately lies far beyond our finite understanding.