God's immutability seems to be an entailment of his infinity. Anything actually infinite in being and perfection can neither lose a perfection it already possesses and remain infinite nor receive any additional act of being since it lacks no actuality; thus it cannot undergo change either by augmentation or diminution. (James Dolezal, God without Parts, 81; as cited in Charles J. Rennie, "A Theology of the Doctrine of Divine Impassibility: (I) Impassibility and the Essence and Attributes of God," in Richard S Baines, Richard C. Barcellos et al, eds., Confessing the Impassible God, 283)
Now, before interacting with this quote, let me just say upfront that I hold to divine impassibility, and the immutability, infinity and eternity of God. With that out of the way, let's look at the quote here. In this quote by James Dolezal and argued by Charles Rennie, the point is made that the various divine attributes are related to each other such that modification or rejection of any one attribute would undermine and result in the unraveling of belief in other divine attributes. To some extent, that is true, for a denial of divine immutability would entail denial of divine impassibility for example. But I am not so convinced that they are so related that every single doctrine is jeopardized by the denial of one of those attributes.
On the doctrine of divine infinity, what does infinity mean? It means that God is not finite, that God is beyond anything and everything. Divine infinity implies omniscience, omnipresence and omnipotence. But does infinity necessarily imply divine immutability, as Dolezal and Rennie argue? Now of course perfection understand as God being pure act (purus actus) does imply immutability, but does infinity itself imply immutability? I think not!
Dolezal and Rennie argue that changes would either augment or diminish one's being. If perfection is understood as pure act, then of course change would imply the presence of potentiality within God and thus God cannot be perfect and thus cannot be infinite. But we see here that the deduction from infinity to immutability has a few steps to follow.
- God is infinite which means He is perfect
- Perfection entails God having no potentialities
- Any change must result in either augmentation or diminuition
- Therefore, infinity implies perfection which implies immutability.
Now, if all 3 premises are true, then of course the conclusion (4) follows. But points 2 and 3 are not implications of infinity. In fact, I can't think of where they can be implications of any other attribute of God. It seems to me that points 2 and 3 are implications of immutability rather than the other way around. Apart from belief in immutability, why should we accept points 2 and 3?
Let's look at point 3. Why must any change be either augmenting or diminishing? What about horizontal changes, i.e. change from one state to another equal and alternate state? And since there is no reason why (apart from immutability) there cannot be equal and alternate states, point 2 is also called into question, for there can be an infinite number of perfect states. One can always posit an infinite, mutable God. Such a "God" would of course not be the God of the Bible, but I do not see why it could not be conceived without having its other attributes unraveled.
God is an infinite, immutable and impassible God. But we do the doctrine of God a disservice when we think we can articulate 17th century arguments and expect everyone to buy into unspoken and unproven premises. In the modern age when every single attribute of God might be questioned, and where Aristotelian metaphysics is hardly known and most definitely not embraced, arguments like these by self-professed confessionalists only serve to make classical theism look like dinosaurs by others. I guess they don't really care, but for those who are interested to be confessional and be intellectually honest and engaged, such a treatment of the doctrine of God is really disappointing.
[P.S.: Along similar lines, I do reject the ontological argument for the existence of God]