Chapter 3: The Existence of God: The Unmoved Mover
First of all, “movement” in this context really means change of any kind, not necessarily motion through space. Yes, I know this is annoying and confusing.
Feser introduces two kinds of causes: accidentally ordered and essentially ordered. (Here, “accidentally” doesn’t mean “by misfortune”, and “essentially” doesn’t mean “more or less”; they’re terms of art.) A father causes a son, but if the father dies, the son can keep going; so the father and son are “accidentally ordered”. But if your hand pushes a stick that in turn pushes a stone along the ground, the stone will stop moving when the stick stops pushing on it, and the stick will stop moving when the hand stops pushing it; so the hand, stick, and stone are “essentially ordered”. You can have an arbitrarily deep essentially ordered stack of things that depend on each other, each one depending on the previous item on the list:
These sorts of series paradigmatically trace, not backwards in time, but rather “downward” in the present moment, since they are series in which each member depends simultaneously on other members which simultaneously depend in turn on yet others, on so on. In this sort of series, the later members have no independent causal power of their own, being mere instruments of a first member. Hence if there were no first member, such a series would not exist at all. [p. 93]
The emphasis on “simultaneously” is Feser’s, and at first I thought he was using the word in some technical sense that doesn’t mean “in the same instant of time”, rather the same way that “accidentally” doesn’t mean “by accident”, above. But no, apparently he does, and that’s a problem.
Aquinas and his predecessors couldn’t have known this, of course, but nothing is instantaneous. The stick in the example acts more like a very fast spring: when the hand pushes on it, it compresses the top end of the stick a little bit; this causes a wave to travel very quickly down the length of the stick and push on the rock, so really the rock starts moving a tiny fraction of a second after the hand starts pushing on it (and likewise when the hand stops pushing).
And even if Feser didn’t know this, surely he has a driver’s license, which means he must have taken a test that required him to know about braking distance, which is a problem because it takes time for a nerve impulse to travel down from the brain to the driver’s hands and feet. So the rock will stop moving a larger fraction of a second after the person holding the stick decides to stop pushing.
Or consider a mountain stream that’s fed by a glacier, which in turn is built up by regular snowfall. If the weather patterns change and snow stops falling, the glacier will melt and the stream will stop flowing… eventually. A century might elapse between the cause stopping, and the effect stopping.
So simultaneity doesn’t work, here (and I’m not even bringing up relativity and the fact that two observers might not agree on whether two events are simultaneous). But perhaps it’s possible to salvage this idea: the big distinction seems to be between effects that get kickstarted by their cause, and ones that are sustained by their cause. So let’s go with that. More on this in a bit.
Another problem with the stick example is that the stone doesn’t stop simply because the hand stops pushing it: as Newton explained, four hundred years after Aquinas, a body in motion continues to move at a constant velocity, unless acted upon by an outside force. The outside force, in this case, being friction with he ground. It must be remembered that Newton’s first law was quite counterintuitive and revolutionary for its time, so we can forgive Aquinas for not counting the earth as an important actor in this example, but Feser ought to know better.
At any rate, we were talking about essentially-ordered series, where each element is sustained by the previous one.
How far can it go? Not that far, actually; certainly not to infinity. [p. 95]
Okay, why not? Feser doesn’t say. He uses the example of an infinitely-long train, where car 1 pulls the caboose, car 2 pulls car 1, car 3 pulls car 2, and so on, but there’s no engine at the head of the train.
Well, yes. Infinities are counterintuitive (see this short video about the Hilbert Hotel, which has an infinite number of rooms). And the idea of an inifinitely-long causal chain is unsettling (at least, I find it unsettling), but I see no reason a priori why there can’t be an infinitely-long causal chain.
Worse yet, since time does weird things at huge relativistic scales, and at tiny quantum scales, I can’t rule out the possibility of a closed loop of causes, where A causes B and B causes A.
But okay, maybe there’s something I’m overlooking. Where’s Feser going with this?
Now, a first mover in such a series must be itself unmoved or unchanging; for if it was moving or changing – that is, going from potential to actual – then there would have to be something outside it actualizing its potential, in which case it wouldn’t be the first mover. […] The series can only stop, that is to say, with a being that is pure actuality (or “Pure Act,” to use the Scholastic phrase), with no admixture of potentiality whatsoever. And having no potentiality to realize or actualize, such a being could not possibly move or change. [pp. 95–96]
[…] Aquinas goes on to say: “. . . and this we call God.” [p. 96]
So that was a long and bumpy road to say that “God” is the first cause.
For some reason, Feser never explores any cause-effect relationship other than chains. We saw above that the rock stopped moving for two reasons: the earth and gravity exerted friction, and the hand and stick were no longer applying sufficient force to overcome this friction. So an effect can have multiple causes, and those causes can in turn have multiple causes, and it’s not always as simple as A causes B causes C. Perhaps there are gazillions of uncaused causes all around us.
And now we see why Feser insisted that essentially-ordered causes and effects be simultaneous: he wants there to be a god now. Just having sustaining causes, as with the glacier and stream, would imply that it’s possible that God started and sustained the universe (like the snow on the glacier), but then disappeared, and the universe will eventually notice and stop running, but hasn’t done so just yet.
Of course, all this makes the unmoved mover sound rather abstract, more like an abstract principle than the sort of anthropomorphic deity who cures cancer when prayed to.
“Well, uh, OK, then,” you might be thinking; “but what does that have to do with God as the average person understands Him?” A lot, actually. For once we have this much in hand, we can go on to deduce all sorts of things about what a being of Pure Actuality would have to be like, and it turns out that such a being would have to be like the God of traditional Western religious belief.
How? Because Courtier’s Reply is how. Aquinas and other theologians have written thousands of pages on the subject — thousands! — therefore it must be so.
Okay, that’s not entirely fair:
Now recall the Aristotelian principle that a cause cannot give what it does not have, so that the cause of a feature must have that feature either “formally” or “eminently”; that is, if it does not have the feature itself (as a cigarette lighter, which causes fire, is not itself on fire), it must have a feature that is higher up in the hierarchy of attributes (as the cigarette lighter has the power to generate fire). But the Unmoved Mover, as the source of all change, is the source of things coming to have the attributes they have. Hence He has these attributes eminently if not formally. That includes every power, so that He is all-powerful. It also includes the intellect and will that human beings possess (features far up in the hierarchy of attributes of created things, as we will see in the next chapter), so that He must be said to have intellect and will, and thus personality, in an analogical sense. Indeed, he must have them in the highest degree, lacking any of the limitations that go along with being a material creature or otherwise having potentiality. Hence He not only has knowledge, but knowledge without limit, being all-knowing. [p. 98]
“And that, my liege, is how we know the Earth to be banana-shaped.”
What a remarkable reversal! At the beginning of the paragraph, Feser tells us that a lighter can cause fire despite not being itself on fire; at the end, he says that God caused intelligence, and therefore must be intelligent. Presumably the explanation is that God’s intelligence is eminent, i.e. God is intelligent in the same way that a car’s cigarette lighter is on fire, which is to say, it isn’t. We now see why Feser defined causation the way he did, using language that suggested that things have attributes inside them that they can release onto other things: he’s defined God to be an abstract principle, something perhaps akin to the Tao, but he also wants this god to have intelligence, benevolence, and so on. He squares this particular circle by playing word games, saying that a cause contains the effect “eminently”, where “eminently” means “doesn’t contain”.
Does this mean that the Unmoved Mover has what we would regard as negative or defective features too – blindness, disease, heroin addiction, etc., “eminently” if not “formally”? Not at all. For every such feature is what the Scholastics called a “privation,” the absence of a positive feature rather than a positive feature in its own right. [p. 99]
I suppose it follows that God does not lack a yeast infection, because that would be a privation. I guess it’s possible that “positive feature” here means “feature that someone wants; an asset”, but that would be begging the question. (Also, I thought addiction was basically poorly-tuned brain chemistry. How does it qualify as a “privation”?)
And while I’m sure the thousands of pages have an answer, it seems to me that the unmoved mover defined above isn’t the Christian God: Feser is quite insistent that the unmoved mover has no potentialities, i.e., it’s static; there’s nothing it can become that it isn’t already; no attribute it might gain that it doesn’t already have.
But Jesus’ life and resurrection is an important part of Christianity, or at least of Feser’s flavor of Christianity, Catholicism. According to the story, Jesus lived and was divine, and then died, at least his human body did. So God wasn’t incarnated, and then was incarnated, and then wasn’t. So incarnation must have been one of Yahweh’s original potentialities, which means that he can’t be the unmoved mover described above.
So maybe Muslims are right after all: Allah has no son.
 In a post on the subject, he had to reach into the depths of science fiction to come up with a non-simultaneous example.