One supposed implications of simplicity and its denial, according to Matthew Barrett

He is not a God made up of parts but a God without parts. There is in him no composition, nor can he be compounded by parts. If he could, then he would be a divided being (parts are divivisible by definition), a mutable being (parts are prone to change), a temporal being (parts require a composer), and a dependentent being (depending on these parts as if they precede him). [Matthew Barrett, Simply Trinity: The Unmanipulated Father, Son and Spirit (Grand Rapids, MI: Baker, 2021), 137]

The doctrine of simplicity of God, in its basic form, is the teaching that God is not made up of parts such that one can have a part of, or various parts of God. At its most basic form, it means simply this: One gets God, or no God; there is no in-between. In this basic sense, simplicity is a biblical doctrine, since the Scripture make it clear that one gets God, "warts" and all.

In the providence of God, God uses the metaphysics of classical theism, based as it is upon Greek philosophy, to express this truth for us Christians. Yet, philosophy, being invented by Man, is a mere tool for gaining knowledge. Being a creation of Man, philosophy was never meant to be infallible, and thus we must be free to critique philosophy and never treat any one particular philosophy as THE way to think about anything, both the philosophy of things or theology itself. This particular critical stance is important when we look at some of the ways the supposed recovery of the "creedal doctrine of God" has been working itself out, as seen in the above argument by Matthew Barrett.

In this particular argument, Barrett makes the following argument: If God is not simple, then he is divisible, mutable, temporal, and dependent. But is this statement true? We would certainly agree that if God is not simple, then he is divisible, since "divisibility" is opposite of "simplicitity." However, I would question what Barrett means by a "divided being." Next, according to Barrett, parts are prone to change, therefore a non-simple God would be mutable. However, why should parts be prone to change? Even in the material world, parts like atoms of hydrogen-1 are not prone to change over millions of years. Accordingly, the protons, neutrons, and electrons of Hydrogen-1 in interstellar space do not change at all over time. Thus, even in the material world, we can see that parts are not necessarily prone to change. Why then would a non-simple God be mutable at all? Obviously, I am not arguing against simplicity here, just showing that the argument here just does not follow. It is possible to believe in immutability and deny simplicity, for the simple fact that parts are not necessarily prone to change or even are mutable in any respect.

Barrett next claims that parts require a composer, and therefore a non-simple God is temporal. That likewise does not follow. Why should parts require a compser? Again, in the material world, if you accept the Big Bang Theory, then atoms come into being spontaneously without a composer. While agreeing that God is the ultimate cause of things, there are many things in the world that are self-organizing, from a material point of view. Salt solutions when left to themselve naturally compose themselves into salt crystals, with fixed crystalline structures depending on their chemical composition. There are autocatylytic reactions like the degradation of tin metal into grey tin, or the auto-excision of introns from RNA. Therefore, even things that have parts do not necessarily need a composer. It is possible for parts to auto-organize, and therefore parts do not necessarily require a composer. For a non-simple deity, it is possible to envision such a god being made of self-organizing and eternal parts, thus a non-simple deity is not necessarily temporal.

The last claim made by Barrett is that a non-simple God is dependent on the parts that precede him. Again, this is a non sequitur. Something made of parts could be made of parts because it could be divisible yet started as one whole (the whole is prior to the parts). There is simply no reason why parts must necessarily precede the whole. For example, the human body is made up of parts, yet the human body does not develop as parts which are then composed into the human body. Right from the start as a fetus, the human body develops as a whole. The human body is not like a car assembly line whereby parts are made separately then put together to make a car. Rather, the whole comes prior to the parts, as the parts develop from the whole. In fact, the parts of the human body depend on the whole human body for them to survive. Cut the hand out, and the hand dies while the rest of the body survives. In the case of the human body therefore, the part here is dependent on the whole.

Barrett is right to promote the doctrine of simplicity. However, there are biblical ways to argue for simplicity, and simply illogical ways stemming from outdated philosophy. In this particular case, Barrett's argument is unsound. God is simple because one cannot have a God that has only certain parts, the parts that any particular group likes. But denying simplicity does not lead to a mutable or temporal or dependent being.

When seeking to teach and defend biblical and confessional truths, a key point to note is that one ought to put foward arguments that are sound. Making unsound arguments only weakens one's position, and might lead some to reject the position altogether. The last thing anyone who is promoting simplicity as the biblical doctrine should be doing, is to repeat such unsound arguments. Keep to the basics, and leave the psuedo-intellectual arguments of classical theism behind.