Wednesday, April 30, 2008

Truthmakers and Conceivability Arguments

In my last post, I discussed Lucas's presentist account of what grounds truths about the past. The upshot was that Lucas and his ilk must find someway of specifying those mental states of God which are supposed to be doing the grounding in their theory but without already presupposing that these states are memories (since that in turn already presupposes the very truths about the past which are supposed to be explained). But this gets us into a further problem.

Many presentist accounts of the grounding of past truths are susceptible to conceivability arguments against their proposed truthmakers. Consider a verificationist account, for instance, on which past truths are grounded in present evidence. If this account were correct, given the current evidence it would necessarily follow that we have exactly the past truths we in fact have. But this doesn't seem right. It is certainly conceivable that our universe have the evidence it in fact has yet have a completely different past (say, because God decided to miraculously make it so at this particular point in time, with no taking into account anything that came before). Russell seems right about this sort of thing. So it seems false that evidence is what grounds past truths since they seem to be only contingently related.

So a version of Lucas's view, reformed to take into account my last post, is going to say that there is some mental state S of God's such that it has the content p and that this is what makes it true that p (or that WAS(p), depending on how this gets spelled out). Now, one virtue of cashing this out in terms of memories was that it guaranteed the truth of p - no conceivability argument was possible against it. But now that we cannot specify S in terms of memories, it looks like this view is going to be susceptible to conceivability arguments perhaps after all - it seems likely that it will indeed be conceivable that God bear S to p and yet p not be true of the past. Indeed, it will be conceivable that S is not a memory at all.

Thursday, April 24, 2008

Presentism, Divine Memories, and Circularity

In A Treatise on Time and Space, J R Lucas - a (sometime) presentist and theist - posits the theory that it is God's memories that ground purported truths about the past (I think Alan Rhoda also subscribes to this view and has a paper on the subject but I haven't read through it carefully yet). There's a bit of trouble for this theory, though, that means such a theory needs to be restated.

First, let's take a step back - when we remember something, what do we remember? I take it that we remember something having occurred or having been the case - that is, that memory presents its contents as obtaining in the past. If we represent the situation as this: 'Memory(p)' the complete content of the memory will be 'it was the case that p'. We can cut out the tech-speak by simply saying 'I remember that such-and-such happened' or something similar, where the sentence falling under the that-clause is in the past-tense.

So if God remembers that p, 'p' is going to be past-tensed. But since it is past-tensed, it is in need of a truth-maker if presentism is true. This is what Lucas's account supplies: What makes it true that p is that God has a memory that p. But now we are in trouble. What makes something a memory in the first place? What makes something a memory that p - as opposed to some other attitude towards p - is that p is true and p's occurrence is responsible for that very memory. Leave aside the second, 'responsibility', clause - it offers its own problems, but I won't go into them here since the problems offered by the first are enough for now. The fact that p is one of the grounds for the fact that God has a memory that p. But, on Lucas's view, the fact that God has a memory that p is itself supposed to ground the fact that p. We clearly have a vicious circle that we somehow must break out of. If we want to keep something like Lucas's view, I take it that the only option is to come up with some other way of picking out the appropriate mental states which are supposed to be doing the grounding work - that is, other than as memories - and in such a way that we do not already presuppose what we are supposed to be explaining - that is, the truth of things like p. I don't know if that's going to be a difficult job or not - but if this sort of view is to be tenable, I think it must be done.

Monday, April 21, 2008

In the Meantime...

Busy working on a biographic presentation on Elizabeth Anscombe for FBC. Here's a funny political comic I found to tide you over until my next blog:

Tuesday, April 15, 2008

Can a Presentist Believe in Incompatibilist Freedom?

In my last post, I argued that the following was true:

Fatalist Contradiction (FC): ~((Incompatibilism & DF) & FP)

Since then, I noticed that this has certain other consequences for presentism (and growing block views too). Notice first that the following seems true (straightforwardly, via the principle that Truth Supervenes on Being):

Presentism and Indeterminacy (PI): If Presentism and Incompatibilism then FP.

A Molinist may deny this, but in doing so they run afoul of TSB or either DF or Incompatibilism (depending on how its spelled out). So it follows from FC and PI that

Incompatibility (I): If DF, then ~Presentism or ~Incompatibilism.

So if libertarianism is true, presentism is not. And if presentism is true, either we have no free will or we do but it is of a compatibilist nature.

EDIT (4/18/08): PI should probably be restricted in such a way that it is true only of future truths - that is, as far as facts about the future are concerned, if Presentism and Incompatibilism, then if these future things are determinate they are necessary.

Monday, April 14, 2008

Fatalism, Indeterminacy, and Power

Here's an interesting argument I came up with:

Many people (i.e., many (but not all) growing block theorists and presentists) don't believe in a real, concrete and determinate future because they think it leads to fatalism and hence a lack of freedom on our part. Here are some assumed (incompatibilist) assumptions:

Freedom Implies Power (FIP): If I am free to make it the case that p then I have the power to make it the case that p and I have the power not to make it the case that p.


Power Implies Possibility (PIP): If I have the power to make it the case that p then possibly (I make it the case that p).

These seem to be fairly straightforward incompatibilist beliefs - incompatibilists will accept them, even if others do not. Here's another principle:

Power Produces Determinacy (PPD): I have the power to make it the case that p iff I have the power to make it the case that determinately p.

This is pretty straightforward - it makes no sense to say that someone has the power to bring something about if they do not also have the power to make it determinately the case (and vice versa). So far none of this gives us fatalism when conjoined to a determinate, real future. But then, some no-future folks will also hold to the following controversial principle:

Fatalistic Principle (FP): If it is the case that determinately p then necessarily p.

FP in conjunction with FIP and PIP entails the relevant belief in no determinate future:

Openness Principle (OP): If I am free to make it the case that p then it is not the case that determinately p.

And so these folks will take it that there are instances where I am free to do something and hence where my doing it in the future is indeterminate. And, of course, I am not only free to do certain things, but I am determinately so (since really robust freedom requires us to be determinately free, not merely for it to be indeterminate whether we are so):

Determinate Freedom (DF): I am determinately free to make it the case that p.

From OP and DF, we can reasonably infer,

Determinate Indeterminacy (DI): It is determinate that it is not the case that determinately p.

Now here's where my real argument starts to get going: From DI and FP, we get:

Necessary Indeterminacy (NI): It is not possible that determinately p.

From NI and PIP, we get:

Power Failure for Determinacy (PFD): It is not the case that I have the power to make it the case that determinately p.

And now we finally get to use PPD which I mentioned earlier. From PFD and PPD we get:

General Power Failure (GPF): It is not the case that I have the power to make it the case that p.

So from GPF and FIP we get:

Unfree (U): I am not free to make it the case that p.

And so we have a contradiction, which means at least one major assumption must be false. The only real substantive premises that might be candidates for rejection, I would contend, are FIP, PIP, FP, or DF. Since FIP and PIP just follow from incompatibilism and DF is just a way of saying that we are free, we can put things this way: What this argument shows is that either incompatibilism is false, the Fatalistic Principle is false, or we have no free will. Contra the no-future folks who hold to all three of these, we must choose one of these options. In my opinion, a rejection of the Fatalistic Principle is the obvious choice.

Thursday, April 10, 2008

Tenseless Eternalism: Myths and Misconceptions

So, I've been reading a lot lately - in philosophy of time, mind, and language respectively (mostly for my dissertation) - and this has included quite a few books and articles by folks who reject eternalism, the tenseless theory of time, or both. Unfortunately, I've found that for a lot of these authors, their rejection of tenseless eternalism is based on one or more fundamental misconceptions about what the theory says or what its practitioners believe. Frankly, it's a bit frustrating to see such things over and over again. Not all the tensed theorists I've read fall into this camp - some seem to understand tenseless theory perfectly well - but the number who do fall into this group was somewhat overwhelming (of course, tenseless theorists do not always understand the nuances of opposing positions either). Even more unfortunate is the extent to which many people who have held to tenseless eternalism have themselves misunderstood the position and/or held to complimentary but unnecessary positions which might be mistaken for necessary corollaries for holding to such a theory. So it's no wonder that many tensed theorists have such misconceptions about tenseless eternalism given the statements and positions of many of the people who have historically held such a position.

Here are some of the myths or misconceptions about tenseless eternalism that I have in mind (not precisely in any particular order):

Time is static and unchanging.
There is no change or dynamism.
There is no passing away, ceasing to exist, coming to be, becoming, coming to pass, happening, flow, or presence.
All is at once.
All coexists.
All facts are fixed from or at the beginning of time.
All events or facts are eternal or endure through time.
Every time, including the future, is already there.
Temporal experience is illusory.
There is no past, present, or future.
Time is pretty much exactly like space (except maybe for those differences we find in physics).
Everything has temporal parts.
Tensed representation or thought is degenerate, not needed, or otherwise 'bad'.
The river of time metaphor is a fraud.
Causal determinism holds.

Saturday, April 5, 2008

BSD 2008

I just got back from the 2008 Berkeley-Standford-Davis Graduate Student Conference in Philosophy and it was a lot of fun (we here at Davis were the hosts this year). Unfortunately, I only got to go to talks in the morning sessions, but I did get to hang out at dinner and 'talk shop'. During the first session I commented on Patrick Todd's paper "Freedom, Presentism, and Truth Supervenes on Being". His paper was showing how the principle of the open future (OF) for the presentist was incompatible with the conjunction of truth supervening on being (TSB) and future semantic settledness (FSS). In my comments I argued that, as formulated, OF was directly incompatible with TSB. During discussion time, Patrick and I talked a little about how to amend the formulation of OF so that he wouldn't get that result. I think we came up with relatively similar strategies for how the revision would go. It was a good paper and Patrick's a cool guy - it was nice talking with him. It's nice to be around people who like both metaphysics and philosophy of religion stuff! (Not too many of those hereabouts)

During the second session, our own Jonathan Dorsey argued that our conception of the physical should not include a constraint against fundamental mentality (hence the title of the paper, 'Against the No Fundamental Mentality Constraint'). I was a bit weary at first, but the argument's growing on me.

Overall, it was a pretty good time.

Friday, April 4, 2008

Link: How to Solve the Paradox of the Incarnation? One word: Counterparts!

Click here for a very interesting post by Ross Cameron where a lot of the seemingly contradictory aspects of the doctrine of the Incarnation get explained via, of all things, counterpart theory. I suppose if Geach can try to explain the Trinity via the metaphysically exotic relative identity, why not put counterpart theory to work with the Incarnation? (Of course, I don't believe either metaphysical view, so...bummer)

Thursday, April 3, 2008

Presentism, Passage, and Time Density

Here's a quick argument I thought up. I don't really know whether it is a good one or not, so I hope if there's something wrong, someone who reads this will point it out to me. So here's the argument:

1. If time is dense, for any distinct given moments m1 and m3, there is a further distinct moment m2 that is between m1 and m3.
2. If a moment m3 is the next moment after a moment m1 then there is no further distinct moment m2 between them.
3. So, if time is dense, for any moment m1 there is no next moment.
4. If presentism is true, time irreducibly tensedly passes only if either first some moment m1 is present and then the next moment m2 is present or temporal passage proceeds in a non-continuous manner.
5. So if time is dense and presentism is true then either time does not irreducibly tensedly pass or temporal passage proceeds in a non-continuous manner.
6. Presentism is true only if time irreducibly tensedly passes.
7. So if presentism is true, time is not dense or temporal passage proceeds in a non-continuous manner.

I'm not sure of the mathematics, but I think if time isn't in fact dense, temporal passage will have to be non-continuous here too - in which case, it would follow that if presentism is true, temporal passage proceeds in a non-continuous manner. That is, there are going to have to be something like chronons for the presentist - smallest units of temporal passage with non-zero duration (that is, if the duration of the time segment which is present stays constant - otherwise we might have strange things like first one duration of 5 hours being present, then 1 minute, then 3 years, etc., which would be highly strange and hard to motivate). So the presentist is then, perhaps, committed to a temporally thick present which may be troublesome for some of the motivations that have been offered in its favor. In addition, we would need to come up with some non-arbitrary way of specifying the exact length of said interval, which may or may not cause trouble.