The Doctrine of Divine Simplicity

According to the doctrine of Divine simplicity, God does not have parts. God is not a being who happens to possess various qualities. Rather, God simply is the Supremely Perfect Being, and His existence is His essence. Strictly speaking, God does not have various distinct properties; rather, the various properties of the Divine nature we speak of are just (from our limited, finite perspective) various aspects of the one, simple Divine nature.

This doctrine of Divine simplicity has been criticized by nontheists as incoherent. If divine simplicity is true, skeptics argue, then God cannot be known, since He is known only through His properties. But Christians have always believed that the Divine essence is ultimately incomprehensible and unknowable to finite human minds. Christians have always recognized that human language is ultimately inadequate to be used to define the Divine essence; we can only speak of what God is not (God is not limited in power, knowledge, etc.), or use analogical language to give us some idea of what God is like. But in spite of God’s essence being ultimately beyond our comprehension, we can know who God is, what He has done for us, and what we must do in order to be in right relationship with Him. 

Atheist John Loftus critiques the doctrine of Divine simplicity by arguing that, “if God isn’t identical with his properties, then he is either bound by these independently existing properties (extreme realism) or he doesn’t have a nature and can change his properties at will (nominalism).”^[1]John W. Loftus. Why I Became an Atheist: A Former Preacher Rejects Christianity, Revised and Expanded Edition (Amherst, NY: Prometheus Books, 2012), 99. But it does not logically follow that, if God is not bound by independently existing properties, then He must be able to change His nature at will. As the Supremely Perfect Being, God has a perfect will, and so cannot will Himself to be imperfect or other than who He eternally is. 

The doctrine of Divine simplicity has also been criticized as incompatible with the idea of a personal God. If God is simple, then how can He have a personality? If God has a simple mind, then how can God know particular things, think, or make choices? For human beings, all of these things require a complex brain and mind, so how can a simple being do these things?

Once again, it is important to stress that all human language about God can only speak of God by analogy. We speak of God being a “person” with a “mind” and “will,” but we cannot allow the definitions of these words when applied to human beings to determine our understanding of God. God is not a person like human beings are persons, and God does not have a mind or a will like human beings have minds and wills. 

Human minds are complex, but it does not follow from this that God’s perfect “mind” must be complex. Human minds make choices by wavering in uncertainty between two options, but it does not follow from this that God’s perfect “will” must function in such an imperfect way. Human minds gather knowledge in a complex manner, but it does not follow from this that God must know things in this way; instead, God knows all particular facts with a simple act of intellection. We know that God is “personal” in the sense that He loves us and has communicated with us regarding His will for us in ways that we can understand, but this does not mean that God must have a personality in the same way that human beings have personalities. Just because human minds, wills, and personalities are linked to complex brain structures, this is no reason to think that God, in order to be a “personal” God, must be complex in the same way.

The doctrine of Divine simplicity has also been criticized as being incompatible with the Christian doctrine of the Trinity. If God is three Persons, skeptics argue, then God cannot be simple; if God the Father, God the Son, and God the Holy Spirit are distinct, then God must have three parts.

However, the doctrine of Divine simplicity and the doctrine of the Trinity are not contradictory. Father, Son, and Holy Spirit do not each possess part of the Divine nature. Rather, Father, Son, and Holy Spirit each possess the entirety of the Divine nature. Everything that the Father is, the Son is. Everything that the Son is, the Holy Spirit is. Everything that the Holy Spirit is, the Father is. The only distinction between Father, Son, and Holy Spirit is a relational distinction: the Son is begotten of the Father, and the Holy Spirit proceeds from the Father and the Son. This distinction does not introduce division into the Being of God, since Father, Son, and Holy Spirit mutually indwell one another (the technical term for this is perichoresis). The Divine nature is simple and indivisible, even as God exists as Father, Son, and Holy Spirit. Thus, there is no contradiction between the doctrine of Divine simplicity and the doctrine of the Trinity.