Friday, November 03, 2006

On the Force of "Possibly" in Plantinga's Free Will Defense (Slightly Revised)

Plantinga construes the key claim in his Free Will Defense as possibly true:

(TWD) Possibly, every creaturely essence suffers from transworld depravity.

According to Plantinga, if a creature suffers from transworld depravity, then *every* God-accessible world (i.e., every world *that God can create*)) is one at which the creature goes wrong at least once.

So if some free creature FC is transworld-depraved, then we have:

1) Necessarily, if God actualizes FC, then FC goes wrong at least once.


And if every creature is transworld-depraved, then we have:


2) Necessarily, for any x, if x is a free creature, then if God actualizes x, then x goes wrong at least once.


If so, then if Plantinga is using "possibly" in (TWD) in the metaphysical sense (as in (1)), then (TWD) amounts to:


3) Possibly, it's necessary that for any x, if x is a free creature, then if God actualizes x, then x goes wrong at least once.


But Plantinga accepts S5 modal logic. If so, then he accepts the following axiom of S5 modal logic:


(AS5) If it's possible that P is necessary, then P is necessary.


But if so, then by (3) and (AS5), (TWD) reduces back to (2):


2) Necessarily, for any x, if x is a free creature, then if God actualizes x, then x goes wrong at least once.

But this can’t be what Plantinga meant to assert, can it? For now we don’t just have a defense – we have a theodicy. For we have an account that’s not just possibly true, but necessarily true. And you can’t have a stronger theodicy than one that’s necessarily true.

The problem, though, is that it’s implausible to think that (2) is true: is there some shortage of souls, such that there is no possible creaturely essence, such that there is at least one possible God-accessible world at which it never sins? Plantinga grants that there are possible worlds at which free creatures never sin; it’s just that none of them are worlds that God can actualize. Is this really plausible?

I think that this problem (in addition to some things that Plantinga says) leads many to say that Plantinga's "possibly" shouldn't be construed as *metaphysical* possibility (i.e., that there is, as a matter of fact, at least one possible world at which it's true), but rather as *epistemic* possibiliity (i.e., *we can't rule it out*, given all our evidence, that it's metaphysically possible).


Now the relevant notion of epistemic possibility can be construed in at least two ways:

(Strong EP) We're not quite justified in thinking that P really is metaphysically possible; however, we're not justified in thinking that P is metaphysically impossible, either -- given our evidence, it could go either way.

(Weak EP) We're not justified in thinking that P is possible; however, although it's implausible to think that P is possible, we can't *conclusively* rule it out that P is possible.


Of course, the theist hopes that (TWD) is at least strongly epistemically possible; if it's merely weakly epistemically possible, one wonders how interesting the Free Will defense really is ("Sure, it's pretty far-fetched to think that every essence suffers from transworld depravity, but it hasn't been *conclusively* ruled out as imposssible -- hooray!")

The problem is that the same objections arise all over again for the strong epistemic possibility construal: it seems implausible that it's metaphysically possible. It seems that there are infinitely many free creaturely essences that God could actualize; are we to think that *every one of them* is such that *all* of the worlds in which they always freely do right are inaccessible to God? And as I’ve mentioned before, it looks to be a part of conservative Christian theology that angels exist, are free, and that some never sin. But if so, then it’s not necessarily true (because it's not *actually* true) that all free creatures are transworld depraved. Thus, it looks as though it might not be an option for theologically conservative Christians to believe it’s strongly epistemically possible. Even if the Old and New Testaments don't force belief in a doctrine of sinless angels, it needs to be pointed out (again) that Christians who endorse Plantinga's Free Will Defense have no choice but to reject such an idea.

What about weak epistemic possibiity: is it true that we can't *conclusively* rule it out that every creaturely essence would freely go wrong in all God-accessible worlds? Well, maybe for non-theists, some non-Christian theists, and some moderate and liberal Christians. But it doesn't seem to be weakly epistemically possible for theologically conservative Christians (recall the problem of angels who always freely do right).

What, then, does Plantinga's Free Will Defense really show? In light of the previous discussion, just this: for people who aren't theologically conseverative Christians, it's not conclusively ruled out as impossible that the Free Will Defense saves theism from the logical problem of evil; but for the theologically conservative Christians, it seems that it is.

9 comments:

Bill Curry said...

I am not that familiar with Plantiga's argument, so I will apologize in advance for being dense here. I do not understand why Plantinga says that is has to be possible that every creature suffers from trans-world depravity. I thought his goal was to merely show that it is logically possible that 1) An omnipotent and all good god exists and 2) evil exists. Couldn't he have said something like: "It is possible on every world that God can actualize, as subset of the creatures will encounter situations where they would choose to do wrong"?

For example, maybe if God didn’t create us, the angels who currently won’t sin would have ended up sinning because they didn’t see the consequences that happened to us or something like that. Anyway, I would appreciate you explaining again why it needs to be necessary for every creature to suffer TWD for Plantinga’ argument to work.

Thanks

exapologist said...

Hi Bill!

I think you're right to say that Plantinga is attemptiing to show that it's (broadly) logically possible -- i.e., metaphysically possible -- for God and evil to co-exist. I believe his strategy is to deflate the epistemic status of the claim that God can do anything that's (broadly) logically possible (he calls this claim "Leibniz' Lapse"). For if God can do any such thing, then since, prima facie, there are possible worlds in which free creatures always freely do what's right, there's pressure to explain why God didn't actualize such a world (as opposed to one like ours).

Thus, if it's possible that every creaturely essence suffers from transworld depravity, then Leibniz' Lapse is false: there are possible worlds that even an omnipotent God can't actualize, viz., worlds in which free creatures always act properly.

Your point about our sinfulness functioning as a greater good (serving as a warning for angels, right?) looks interesting, but I'm not sure I understand it fully. Could you please explain a tad more?

Anyway, thanks for your question!

Steven Carr said...

'For example, maybe if God didn’t create us, the angels who currently won’t sin would have ended up sinning because they didn’t see the consequences that happened to us or something like that.'

Let me explain what this means, and come up with a foolproof defense to the logical problem of evil.

Unlike Plantinga's defense, mine is immune from criticism.

But unlike Plantinga's defense, it cannot be sold to the general Christian public.

Plantinga needed not only a defense, but also one which appeared as if it was plausibly true to Christians, or else Christians would realise that finding a successful defense to the Logical Problem of Evil does not rescue Christianity.

Anyway, here is a defense , along the lines of Bill Curry's thoughts

Remember, all we need is a scenario where the existence of God is compatible with Mackie writng about the problem of evil in a book.

So here goes.

Satan and God are talking in Heaven one day.

Satan - You know God, you are such a loving, fair, wonderful being that I could never imagine rebelling against you.

God - But you could if you wanted to. I created you wth free will you know.

Satan - Why would I want to do that? The idea is absurd. But what would happen if I did? I'm curious to find out.

God - Do you want me to show you?

Satan - If you can.

God - Just look over there at that simulation I just created of a world where you rebelled.

Satan - Gosh, it's very good, isn't it? Even the flesh tones.

God - I am pretty amazing aren't I?

Satan - Are you sure it is a simulation? It looks very realistic to me. Even the simulants think it is real

God - Of course it is. Look. Simulation on. Simulation off. Simulation on. Simulation off.

Satan (drooling) Mmmmm... Omnipotence.

Satan. Oh look over there. That's very amusing. There is somebody called Mackie, writing a book claiming you don't exist! That is so ironic, because you are the ground of his being.

God - Well, the simulant doesn't realise that it is just a simulation. There's somebody over there called Plantinga trying to prove I cannot create a world where creatures love me enough not to rebel. A bit cheeky of him! I suppose that sort of denigration of my powers is what would happen if you had rebelled.

Satan (shudders) Thank God we live in a world full of happy, contented people and not those crabbed beings like Mackie and Plantinga who don't realise your awesome powers.

God - I accept your thanks.

Satan - Could you switch the simulation off now please? I've seen enough to realise just how much I would never rebel against such a wonderful being as you.

-----------------------------------

There you are. One perfect solution of the Logical Problem of Evil and , unlike theistic defenses, this one is waterproof.

Of course, Christian apologists could never sell it to their flock, which is why they rely on flawed defenses, which they are hoping the public will buy.

Bill Curry said...

Exapologist,

Upon further thought, I think I understand why Plantinga proceeded as he did. I was originally hung up on the TWD premise which I understood to imply that that every creature with significant moral freedom will eventually sin. That premise coming from a Christian is surprising. I think you rightly point out that acceptance of it is problematic for Christians. I wondered why Plantinga didn’t propose a more modest premise that Christians would accept that would still solve the logical problem of evil. But if his goal was more modest, and he was just trying to defend theism in general and not Christianity specifically, his approach makes sense. It may be much harder to formalize a possible solution that is palatable to Christianity. (Did he put his argument in a predicate calculus?) Maybe he considered the more modest premise an exercise for his students? I was trying to come up the start of a possible solution that may be acceptable to Christians and still solve the logical problem of evil. I am not sure it would work.

exapologist said...

Hi Bill,

I should point out that I've recently discovered that I've misinterpreted Plantinga (although, in my defense, I *inherited* the misunderstanding of TWD from theist and atheist philosophers, such as John Hick, R. Douglas Geivett and J.L. Mackie). It turns out that recent discussion in the literature has cleared up Plantinga's account (see Michael Bergmann's excellent paper that I mentioned in my previous post).

My mistake was to define 'transworld depravity' in an unqualified way, when in fact it's (what Plantinga defines as) a world-indexed property: the property of being transworld depraved *in (some) possible world w* (as opposed to being transworld depraved *per se*). This gets tricky, as the account involves the logic of counterfactuals and applies them to various possible worlds (contemporary work on two-dimensional semantics elucidates such talk nicely, but it's a pain to learn the syntactic and semantic machinery).

Now based on what I understand so far of the current literature on this clarification, the FWD is still problematic even on the correct construal (though I can't say so with any confidence yet). Still, it should be pointed out that I have attributed to him a popular misconstrual from the literature in the 80's. I hope and plan to post on the corrected construal of Plantinga's FWD when I get some free time in a couple of weeks or so (or during Christmas break at the latest).

Best,

exapologist

Steven Carr said...

How can a 'trans' world property be world-indexed?


And if there are worlds were creatures are not TWD, why doesn't God create those?

exapologist said...

Hi Steve,


I don't want to say too much yet, as I would be speaking before understanding, but a gisty way of putting the idea, I think, is this.

So suppose we number the possible worlds, and suppose that at possible world W238, you are transworld depraved. Then no matter what complete set of actual or counterfactual circumstances (i.e., no matter what *complete* world *counterfactual* to W238) God actualizes *with respect to W238*, you'll blow it at least once.

It's absolutely crucial to emphasize that the relevant worlds are *counterfactual* worlds -- not just any possible worlds are relevant. Rather, only worlds that are, so to speak, possible "offshoots" of *that* world.

Regarding your second question: at the moment,I think your worry is legitimate: this is a point that Heimir Geirsson makes in a couple of recent journal articles (and of which I and a colleague worry about). You and go to Geirsson's website (just google his name, and add "department of philosophy") and read his arguments on this.

Also, I can't recommend strongly enough the paper by Bergmann that I mentioned in an earlier post for a rigorous formulation of the interpretation of transworld depravity I (hastily and clumsily) describe above. Finally, I would take a look at the journal article (also online: just Google the name of the article) by Howard-Snyder and O'Leary-Hawthorne, "Transworld Sanctity and Plantinga's Free Will Defense"). All of these papers raise worries about the FWD on this interpretation of transworld depravity.

Best,

exapologist

Steven Carr said...

I still don't understand. If I am only transworld depraved at world 238, how am I 'trans' world depraved? What is 'trans' about that?

And suppose world 239 differs from world 238 only in two features

1) I am not transworld depraved.
2) God has created one extra electron , 90 thousand million light-years from Earth.

Wouldn't that solve God's problems?


----------------------
'Rather, only worlds that are, so to speak, possible "offshoots" of *that* world.'

I agree with that.

Suppose S is the alleged state where I choose evil.

Then are not these two logically possible worlds, 'offshoots' of world 238?

World 238-A) A world where I am in S and God knows I will use my libertarian freedom to choose evil

World 238-B) A world where I am in S and God knows I will use my libertarian freedom to choose good.

These are different worlds, and I think that both worlds are both logically possible 'offshoots' from world 238.

There is clearly a fact of the matter about how I will choose in world 238-A.

There is clearly a fact of the matter about how I will choose in world 238-B.

Both facts are 'counterfactual' facts, and so are known to God by his middle knowledge.

And God's middle knowledge does not cause me to choose the way I freely choose in world 238-A and world 238-B.

So how then can it be the case that there is a fact of the matter about how I will choose in situation S in all worlds which are logically possible offshoots of world 238?

exapologist said...

Hi Steven,

Your first objection doesn't seem to work, as far as I'm able to tell -- at least not if we accept the standard Lewis-Stalnaker account of counterfactuals. Thus, consider a counterfactual of the form P > Q, i.e.,

1) If P *were* the case, then Q *would* be the case.

Call the actual world 'W'. Now imagine all possible worlds as being ordered according to their degree of similarity to W, so that we have W in the center, and then concentric circles of possible worlds, with the worlds most similar to W being in the closest concentric circle, and outer circles containing worlds that are less and less similar to W.

Now the counterfactual conditional (1) is true *at W* just in case Q is true whenever P is true in all of the "nearby" worlds --the worlds relevantly similar to W.

Compare the semantics of counterfactuals to conditionals of other sorts:

Material conditionals (or indicative conditionals): the conditional "If P, then Q" is true just in case Q is true whenever P is true in the *actual* world.

Necessary conditionals: the conditional, "Necessarily, if P, then Q" is true just in case Q is true whenever P is true in *all* possible worlds.

With this brief sketch of the semantics of would-counterfactuals (as opposed to the semantics of the latter two sorts of conditionals) in place, consider
again your question:

"And suppose world 239 differs from world 238 only in two features

1) I am not transworld depraved.
2) God has created one extra electron , 90 thousand million light-years from Earth.

Wouldn't that solve God's problems?"

In light of the previous, we see that the counterfactual conditional implied by the above is *false* at W238, so it can't help here.

However, your other point about why God didn't just actualize a *different* world -- one that's not a counterfactual of W238, and at which creatures always freely do right -- is a great one. So far, I don't see how Plantinga's FWD (given the account of TWD we're now considering) solves this problem. Again, I'd look at the articles I mentioned by Geirsson (online at his website -- just Google him) for a fuller articulation of your point here.

Best,

exapologist