Dmitry Chernikov’s Blog

I was so impressed with this post by Just Thomist the first time I read it that I thought of emailing it to my heathen physicist uncle. But then, on second thought, it occurred to me that my uncle might get pretty upset with me for not getting the basic physics right.

The comment I left was:

Motion is relative, so a thing may be moving from the point of view of one reference frame and stationary from the point of view of another reference frame. So, is an intelligence both moving and not moving it?

Motion has direction, but it is not “to something,” as if the moving thing wanted to get there.

Also, no cause is necessary for a thing to remain in constant motion. Hence there would seem to be no need for a power guided by an intelligence to keep moving it.

And these are due to Newton’s first law of motion.

Of course, Aquinas argues from God’s being unmoved to His not having a body. But isn’t using Aristotelian physics to argue for the existence and simplicity of God somewhat absurd? God may have set off the Big Bang (or something like that), and He may be sustaining all things in existence, but those are a far cry from saying that an object moving at constant velocity in an inertial frame is being pushed by God.

Now I am not averse to arguing that the reason why any cause A causes effect B (e.g., gravitational attraction causing accelerated motion) is that A, in a sense, loves B and wants to see it happen. So even natural causes act toward an end. But “whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence… Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.” (ST, I, 2, 3) Gravity, in other words, is low-level love. And love, if it is to succeed in attaining the end that it seeks, must know how to do so. Gravity’s “knowledge” of how to act is due to some transcendent intelligence guiding it. In other words, the love-knowledge-power Trinity permeates the entire causal structure of the universe. Or: if there are natural laws, then there must be a lawgiver who gives eyes to matter to obey the laws. And that’s the “fifth way.” I like the fifth way; fine. But constant-velocity (not “speed,” for it’s a scalar; velocity is a vector) motion in a reference frame that is neither rotating nor accelerating needs no cause in order to persist! And all inertial reference frames are equivalent. Nor, again, are inanimate moving things moving “to” anywhere; they are just moving.

So, Thomist’s argument also involves Aquinas’s first way. And I really don’t know how to rehabilitate the first way. Aquinas thinks that in order to move A may have to be kept in motion by B, B by C, …, but ultimately there cannot be an infinity of movers, so there must be a being which moves the first moved mover who is itself not only unmoved but unmovable, as well. (The motions of A, B, C, … are simultaneous.) But as we have seen, that’s not the case. What if we restricted our attention to forces? Here, too, dynamic systems are stable, because most forces cancel each other out. What role, then, is there for God?

Kreeft tries to salvage the first way by speaking of change rather than movement: “The universe is the sum total of all these moving things, however many there are. The whole universe is in the process of change. But we have already seen that change in any being requires an outside force to actualize it. Therefore, there is some force outside (in addition to) the universe, some real being transcendent to the universe. This is one of the things meant by ‘God’.” (Handbook of Christian Apologetics, 50) But if we were to ask for an example of a thing being moved directly by God, what would the answer be? Perhaps we could regress into the past and say that things are moving now because of some initial push billions of years ago. But that would rob the argument of much of its intuitively persuasive power.

Thus, the first way seems extremely fishy. I am not giving up on it completely, but I wish someone would rework it in light of modern physics.

Suppose that the unmoved mover argument works. Aquinas gives an example of a staff being moved by the hand. But the hand is moved by the soul. And the soul is moved by some perceived good. And the ultimate good is God. Hence, he can say, all motion is reducible to the unmoved mover either as the efficient or the final cause of motion.

Isn’t being immobile a defect (because you cannot move from a less comfortable place to a more comfortable)? No; God is unmoved, because He already extends everywhere, even in space, “by essence, presence and power”: “God is in all things by His power, inasmuch as all things are subject to His power; He is by His presence in all things, as all things are bare and open to His eyes; He is in all things by His essence, inasmuch as He is present to all as the cause of their being.” (ST, I, 8, 3) In addition, God is perfectly happy and is therefore already in the most comfortable place imaginable.