Tuesday, June 7, 2016

Molinism and the Principal Principle

Molinism says that there are non-trivial conditionals of free will and that God providentially decides what to create on the basis of his knowledge of them. I shall assume, for simplicity of examples, that what Molinism says about free will it says about other non-determined events. The Principal Principle says that when you know for sure that the objective chance of some future event is r, the epistemic probability you should assign to that event is r.

Suppose a dictator has set up a machine what will flip an indeterministic and fair coin. On heads, the coin will trigger a bomb that will kill almost everyone on earth. On tails, it will do nothing. Since the coin is fair, the objective chance of heads is 1/2. But suppose you are sure that Molinism is true. Then you should think: "Likely, God would only allow this situation to happen if he knew that the coin flipped in these circumstances would land tails. So, probably, the coin will land tails." Maybe you aren't too convinced by this argument--maybe God would allow the coin to land tails and then miraculously stop the bomb or maybe God is fed up with 99% of humankind. But clearly taking into account your beliefs about God and Molinism will introduce some bias in favor of tails.

This seems to be a violation of the Principal Principle: the objective chance of heads is 1/2 but the rational epistemic probability of heads is at least a little less than 1/2.

Not so fast! The "objective chances" need to be understood carefully in cases where foreknowledge of the future is involved. An assumption behind the Principal Principle is that our evidence only includes information about the past and present. If we know that a true prophet prophesied tails, then our credence in tails should be high even if the coin is fair. Given Molinism, the fact that God allowed the coin toss to take place is information about the future, since it indicates that the coin is less likely to land heads given the disastrous consequences.

So, Molinism is compatible with the Principal Principle, but it renders the Principal Principle inapplicable in cases where it matters to God how a random process will go. But everything that matters matters to God. So the Principal Principle is inapplicable in cases where the outcomes of the random process matter, if Molinism is true. This renders the Principal Principle not very useful. Yet it seems that we need the Principal Principle to reason about the future, and we need it precisely in the cases that matter. So we have a bit of a problem for Molinists.


IanS said...

Objective chance can be seen as a mechanical, soulless analogue of free will. Seen in this way, it raises similar issues. If there were circumstances in which God could know that the coin would land tails, would the coin flip be objectively fair? Would it even be objectively chancy?

We lack God’s knowledge, so we may have good reason to treat it as chancy. We may also have reasons to assign credence 1/2 to tails. But it is at least arguable that this is not a case of objective chance, and that the Principal Principle is irrelevant.

William said...

Perhaps we should not tie God to a false coin-flip dichotomy where it comes to larger events?

If God indeed has spoken as to guarantee an outcome where, as far as we know, part of the causal chain includes the random coin flip's outcome, I would surmise that half the time the causal chain will somehow manage to bypass the (wrong) outcome and half the time the causal chain may (up to God) include the coin flip outcome because it was "randomly" the right one.

So if the oracle is actually trusted, the principle can say that we go with the oracle AND still accept the coin flip itself as 50/50 if we've stipulated that.

Trevor Adams said...

Given the possibility that God may have an unforeseen yet morally sufficient reason for allowing some important event (an event that matters) to happen or not to happen I would imagine we aren't in a place to determine odds about the event anyway.

Heath White said...

I am not seeing the problem. If I had good insight into how God would do things that are matters of objective chance, I guess I could modify my credences somewhat. But I have no such insight, nor does anyone else AFAICT. So why does anyone need to give up the PP for practical purposes?

entirelyuseless said...

I don't see how this is specifically an argument against Molinism as opposed to a general argument against a common idea of providence.

For example, someone might say, "Yesterday I narrowly avoided a fatal car accident. I avoided it because a cat ran across the road and I swerved in order to avoid the cat. If I hadn't swerved, I would have hit a slippery place on the road and smashed into a concrete wall. So the fact that the cat was there at the time must have been especially providential, and the cat was there in order to save my life."

But we can directly test whether providence works this way or not. Here is a suggested experiment. Flip a coin 10,000 times. Each time you get tails, do nothing. Each time you get heads, kill an innocent person.

If providence carefully arranges events in order to avoid deaths, then we should get tails more than 50% of the time.

Of course, we don't have to do the experiment to know that we will get heads about 50% of the time. So providence just does not work that way.

Michael Gonzalez said...

Pruss: Correct me if I'm wrong, but I don't think Molinism has anything to do with non-agential matters. What God is supposed to have middle-knowledge of are subjunctive conditionals of creaturely FREEDOM, no?

That being said, things like fair coin tosses are actually purely deterministic to someone with total knowledge of all the causal forces at play. Your example might be better phrased in terms of quantum indeterminacy, but even that I think is probably deterministic (many of the live interpretations of QM are deterministic; the apparent indeterminacy being purely epistemic on the part of non-omniscient beings).

If you grant ACTUAL indeterminacy, then even God does not know how those events will turn out. There is NO view of foreknowledge (Calvinist, Molinist, simple, or Open) which allows God to have knowledge of that for which there is no fact of the matter at all (the truly indeterministic). On Molinism, He knows what a given free agent "would freely do" given a certain set of circumstances, because there is a fact of the matter about each possible free agent for each possible circumstance. But that is not analogous to an actually indeterministic quantum "coin-flip", which could turn out either way with equal likelihood given exactly the same circumstances.

Now, He could choose not to let that dictator come into existence; or at least He could create the circumstances in which that dictator never ends up leaving our fate to the quantum "coin-flip". But, if the "coin-flip" really is totally indeterministic, and there is no fact of the matter about it WOULD definitely do given a set of circumstances, then the Molinist God does not have knowledge of what will happen and should not allow such a circumstance to ever arise.