Why defining immutability according to Aristotelian categories is problematic

Those are all still changes. It takes a state, be it ontological or metaphysical, and changes it to something else. God does not change, even within the Godhead. If it's a simplistic view, it's because it's a simplistic concept. Divine Simplicity doesn't allow change whatsoever.

— Travis W. Rogers - author (@ReformedPhotog) November 25, 2021

In Aristotelian (meta)physics, "motion" is a change of state. A moving ball has motion, just as a piece of burning wood which is in motion from being wood to becoming ash. Basically, anything is motion is changing in some form or another. This use of the word "motion" is alien and confusing to those of us trained in the sciences, which presumably should include most educated people in this modern 21st century world. Nevertheless, one must conceptually split the word "motion" into is older, Aristotelian meaning, and the modern (and what I would think correct) meaning. I will use motion(A) for the Aristotelian sense of "motion" and motion(M) for the modern sense of motion. A moving ball has motion(A) because moving implies change. A moving ball has motion(M) because its displacement is changing over time. However, a moving ball according to Aristotelian metaphysics is constantly changing because it is moving (A). Whereas, a moving ball in the modern sense is not changing because it is in constant motion (M).

This concept of "motion" is important because much of classical theism draws upon Aristotelian philosophy and Aristotelian categories, even centuries after the modern world has consigned them to the realm of archaic history. It is therefore hard for the modern man to understand classical theism, seeing as how they have to learn not just a different philosophy but also to experience cognitive dissonance in the different definitions and concepts of terms. Grasping the Aristotelian notion of "motion" is like a gestalt switch—seeing things differently from how most people normally think. And for those who continue to want to live in the modern world and especially treasuring the sciences, even teaching the sciences, one has to learn how to hold two almost incommensurable concepts simultaneously, switching from one to the other when the situation demands it.

In classical theism, immutability is the doctrine that God does not change, and change is defined in terms of motion in the Aristotelian sense of the term. Thus, immutability is not the same as immotility (no movement (M)), since immotibility is built upon motion (M). That said, by sticking to the Aristotelian sense of the term, motion cannot do justice to the Scriptures, as I will show now.

We note in the beginning that for a moving ball, the ball is moving in both the Aristotelian and modern sense. However, the moving ball is changing according to motion (A), while not changing according to motion (M). The reason why the ball is not changing according to motion (M) is because there is no resultant unbalanced external force acting on the ball (assuming a ball moving at constant velocity). In other words, the ball continues to move because it does not change. For the ball to stop moving, it experiences a change. Since modern physics is a much better approximation of how the world works, we know that motion (M) is the correct notion of motion, and motion (A) is intesting conceptually but it does not reflect anything in the real world.

In the doctrine of God, the doctrine of immutability focuses on the fact that God does not change. But is Aristotelian physics, inadequate for the real world, adequate for one's doctrine of God? Since it is not applicable to the real world, we should be skeptical that it would be applicable here. But let's look further into the matter. Let us look at how immutability works in the Bible concerning God. Now, we say that God is love. Immutability as it is applied to God teaches us that God is always love. He does not change to be less loving, or more loving. That applies to all the attributes of God. But note one thing: "love" is an action attribute. "Love" is always to be expressed from the lover to the beloved. In other words, "love" is like a moving ball. As we remember, in Aristotelian physics, a moving ball has motion because it is moving. For a ball to not have motion, it must be stationary. But if love is like a moving ball, in that both are actions, then surely to asseert that there is no motion (A) in God is for God's love to cease? But if God's love does not change to be more or less loving, then there is no change in God's love according to motion (M). So which idea of "motion" is suitable when we deal with immutability and the love of God, if not the modern notion of motion, not the Aristotelian notion of motion?

Thus, we see here that definiting immutability according to Aristotelian categories is indeed problematic. While I will not claim that the immutability of classical theism is immotility, I will assert that the Aristotelian notion of "motion" is incompatible with the immutability of God's active atttributes. Aristotelian metaphysics, when applied to God's love, must say that God is immutable only when he has not love ad intra. Since that is not true, Aristotelian metaphysics about motion must be false, at least when applied to God's love.

Should we therefore change to the modern notion of motion and change? That is an interesting proposition to explore, but I will not claim that this is the path we should necessarily take. Rather, define immutability as God not changing, let the Bible informs us what change would be like if applied to God, and hold one's philosophy about what constitues "change" or "motion" at arm's length.

[Note: I know many classical theists believe God is love. This article is asserting that it is inconsistent to hold to Aristotelian metaphysics of motion and still believe God is love. So one has to decide whether to follow Scripture, or follow Aristotle. Thankfully, classical theists follow Scripture where it counts, however inconsistent that is with their Aristotelianism.]