Change and matter

Aristotle’s positing matter is driven by trying to respond to the Parmenidean idea that things can’t come from nothing, and hence we must posit something that persists in change, and that is matter.

But there two senses of “x comes from nothing”:

1. x is uncaused

2. x is not made out of pre-existing materials.

If “x comes from nothing” in the argument means (1), the argument for matter fails. All we need is a pre-existing efficient cause, which need not be the matter of x.

Thus, for the argument to work, “x comes from nothing” must mean (2). But now here is a curious thing. From the middle ages to our time, many Aristotelians are theists, and yet still seem to be pulled by Aristotle’s argument for matter. But if “x comes from nothing” means (2), then theism implies that it is quite possible for something to come from nothing: God can create it ex nihilo.

There are at least two possible responses from a theistic Aristotelian who likes the argument for matter. The first response is that only God can make things come from nothing in sense (2), and hence things caused to exist by finite causes (even if with God’s cooperation) cannot come from nothing in sense (2). But there plainly are such things all around us. So there is matter.

Now, at least one theistic Aristotelian, Aquinas, does explicitly argue that only God can create ex nihilo. But the argument is pretty controversial and depends on heavy-duty metaphysics, about finite and infinite causes. It is not just the assertion of a seemingly obvious Parmenidean “nothing comes from nothing” principle. Thus at least on this response, the argument for matter becomes a lot more controversial. (And, to be honest, I am not convinced by it.)

The second and simpler response is to say that it’s just an empirical fact that there are things in the world that don’t come from nothing in sense (2): oak trees, for example. Thus there in fact is matter. This response is pretty plausible, but can be questioned: one might say that we have continuity of causal powers rather than any matter that survives the generation.

Finally, it’s worth noting that I suspect Aristotle misunderstands the Parmenidean argument, which is actually a very simple reductio ad absurdum:

3. x came into existence.
4. If x came into existence, then x did not exist.
5. So, x did not exist.
6. But non-existence is absurd.

The crucial step here is (6): the Parmenidean thinks the very concept of something not existing is absurd (presumably because of the Parmenidean’s acceptance of a strong truthmaker principle). The argument is very simple: becoming presupposes the truth of some past-tensed non-existence statements, while non-existence statements are always false. Aristotle’s positing matter does nothing to refute this Parmenidean argument. Even if we grant that x’s matter pre-existed, it’s still true that x did not exist, and that’s all Parmenides needs. Likewise, Aristotle’s famous actuality/potentiality distinction doesn’t solve the problem. Even if x was pre-existed by a potentiality for existence, it’s still true that x wasn’t pre-existed by x—that would be a contradiction.

To solve Parmenides’ problem, however, we do not need to posit matter or potentiality or anything like that. We just need to reject the idea that negative existential statements are nonsensical. And Aristotle expressly does reject this idea: he says that a statement is true provided it says of what is that it is or of what is not that it is not. Having done that, Aristotle should take himself as done with Parmenides’ problem of change.

Augustine's problem

Augustine raises this problem: What was God doing for the infinite amount of time prior to creation? Why didn't God create the world earlier?[note 1] Augustine reports the joke answer that God was busy creating a hell for people who ask such questions, and then goes on to give his famous answer that God created the universe and time simultaneously.

Augustine's answer is a good one. The start of time is a non-arbitrary answer to the question of when to create the universe. However, Augustine's answer can only be adopted if God has an atemporal existence. So if Augustine's answer is the only one or the best one, we have an argument that God has an atemporal existence.

But could someone who takes God to be only a temporal being—say, an open theist—give an answer to Augustine's problem? If God is a temporal being, then time has infinite age, as God then does (the suggestion that God is a temporal being that has finite age is incompatible with divine eternity, even if it is compatible with the claim that God exists at all times). Hence no answer that depends on time's having a beginning will do.

One way to see a problem is to imagine God deliberating annually, say a million years before creation. God has good reason to create that year—after all it, is good that there be a created world. Maybe he has good reason not to create as well (maybe creation entails that there is imperfection; at least, creation makes reality less simple). But in any case, there intuitively should be some moderate probability, say 1/2, that he would create that year. But he doesn't. That's fine: he also had a probability of 1/2 that he wouldn't. But likewise he doesn't next year. He had probability 1/4 of creating in neither year. That's fine: events of that probability aren't very surprising. But keep on running this. He doesn't create in any of a 1000 years. That's much less likely. The probability of that is 2⁻¹⁰⁰⁰. So, it seems, on the assumption that God is in time and there is an infinite past, we have very good reason to expect that God would have created the world earlier than he did—no matter when he created it!

There are two difficulties with this line of thought. The first is that numerical probabilities can't be assigned too divine deliberation. That's fine: they are still heuristic and highlight the extreme unlikeliness of the scenario of God waiting for an infinite amount of time before creating. The second is that it presupposes a particular model of how God deliberates whether to create, namely that he continually deliberates whether to create there and then.

Can we solve Augustine's problem if, instead, we accept a model on which God from eternity (i.e., at every past time) decides on a particular time t at which to create? Well, if God is changeable, that still leaves open the question of why God didn't change his mind—why God kept on waiting, even though he had reason to change his mind (namely, the reason that creation could come earlier if he changed his mind). If he had probability one in a million of changing his mind in any given year, we'd expect that over a million years he'd have changed his mind, and a again an intuitive argument like before can be run. Maybe, though, a changing God can unchangeably determine his will (by making a promise to himself, maybe?), and at every time he always already had done so, given that he knew there would never be any new information becoming available? Or maybe God, while in time, is unchangaeble, and hence his decisions cannot change? Or maybe God, from eternity, efficaciously willed that creation should occur at t₀—God's efficacious willing need not be contemporaneous with what is willed.

So there are some things that can be said about the changeability subproblem. Our best model right now for a God-in-time story is that God from eternity has unchangeably decided that creation would come at t₀. It is tempting to say "And then God waited until t₀." But waiting is what you do when you have little else worth doing, and God is ever infinitely active in his intratrinitarian communion. So we shouldn't say that. Let's focus, however, on a different subproblem. Why did God eternally choose t₀, rather than say t₀−1 year, for the date of creation? Absent distinctions coming from notable events within creation, all times are, presumably, exactly alike. I suppose two answers are available. First, that it is a reasonless divine choice. Second, that there is a reason, in that there is a particular incommensurable value associated with each possible time for creation. I think these are tenable answers, but it must be noted that neither is uncontroversial. The subproblem of why God chose this time rather than another is a hard one.

There is another subproblem, however, related to the changeability subproblem. Take an answer to the changeability subproblem. Consider the proposition p_n which says that in year n B.C., God was decided that he would create at t₀. What explains p_n? Presumably it's p_n+1. I.e., God was decided in year n B.C. because he was decided in year n+1 B.C. But this generates a vicious regress.

All of this suggests that Augustine's answer is the best answer to Augustine's problem. And we have reason to reject views on which God is a temporal being.

This leaves two kinds of views. The first are ones on which God is solely atemporal (except in virtue of an Inarnation) and the second are ones on which God exists atemporally, but with creation comes to be omnitemporally present as well, as an aspect of his omnipresence. I do not know if either view is compatible with the A-theory. Certainly, I don't think presentists can make sense of atemporal divine existence. So theists (at least ones who, like Christians and most relevant scientists, think that the universe has finite age) shouldn't be presentists.