The B-theory of time, according to which the distinctions between past, present and future (possibly unlike the distinctions between earlier-than and later-than) are merely perspectival, is often accused of being a "static theory of time".
But it is clearly a sufficient condition for x to change with respect to a predicate P that x satisfy P at one time and not at another. I am not claiming here that this is what change is. I am only claiming that satisfying a predicate at one time but not at an another is sufficient for change. How could something be round at one time and not round at another without its having changed in respect of roundness.
But of course it is a part of a typical B-theory that objects satisfy predicates at some but not at other times. In other words, something that is sufficient for change is a part of the B-theory. So how can be the B-theory be accused of being static?
Well, it could be the case that a theory T is incompatible with some phenomenon C (say, change) but nonetheless posits a phenomenon A (say, objects satisfying different predicates at different times). Such a theory is metaphysically incoherent, but of course there are metaphysically incoherent theories. So my response to the staticness charge (not the same as a static charge!) against the B-theory is not complete. But I think it shifts the onus of proof. Given that the B-theory of time posits something that clearly entails the phenomenon of change, if the theory is incompatible with the existence of change, the theory is metaphysically incoherent—and that has not been shown by its opponents. And it is too much to ask the B-theorist to prove the coherence of their theory, since showing metaphysical coherence is very hard in metaphysics. (Of course, one can prove a particular formalization of a theory to be formally coherent. And it's not hard to do that with the B-theory or the A-theory. But the question we're interested in is metaphysical coherence, not formal coherence.)
31 comments:
Suppose God snuffs some static particle out of existence. If existence is a predicate, does satisfying 'exists' at one time and then failing to at another time count as change? If not, then perhaps your condition isn't sufficient, perhaps because changing requires that the changed survives? Then again, perhaps existence is no predicate. Hmm.
It seems OK to say that that would be a change with respect to existence, no?
But isn't it true that a B-theory must posit perdurantism, and on perdurantism no entity endures from t1 to t2. So there just is no 'x' at t1 & t2. There must be an 'x' at t1 and a 'y' at t2. Thus there is no change. What have I missed here?
"But isn't it true that a B-theory must posit perdurantism"
No, why would it have to? :-)
"on perdurantism no entity endures from t1 to t2"
True, but change in respect of a predicate requires that an entity persist from t1 to t2. How it persists, whether by perdurance or endurance, seems to be a different question.
I've been reading William Lane Craig's "The Tenseless Theory of Time", Chapter 9. Craig argues that, based on the Principle of the Indiscernability of Identicals, an object 'O' at t1 could only be 'O' at t2 if it has all the same properties. But this does not seem to be true given the B-theory, since the entity at t1 still exists and has different properties than the entity at t2. His conclusion is that there are two different objects, not one and the same thing that has undergone change.
Is there a good counter to Craig's view? Is it necessary to challenge the PII to do so?
Also, for your second comment, how should one understand something persisting given perdurance?
Thank you for your insight, Doctor.
1. Indiscernibility of identicals tells us that if x=y, and x has property P, then y has property P. This applies just fine to properties like "being green at t1" or "being non-green at t2". It's just that the B-theorist has to relativize changing properties to times.
2. According to perdurance, an object persists at times t1 and t2 provided it has temporal parts at t1 and at t2.
I myself am inclined towards neither perdurance nor endurance, but stageless worm theory. Ordinary objects are four-dimensional. They don't have temporal parts. An object persists at times t1 and t2 provided it is partly located at t1 and partly located at t2.
Can a stageless worm have a mind and thus be a person? If so, is it compatible with libertarian free will?
I don't see why not?
Isn't the future determined (already in existence) on a B-theory view? Doesn't this imply fatalism?
Not causally.
1) If something is extended four-dimensionally, and that is why it exists at t1 and t2, doesn't it follow that contradictory truths can hold about a given object? You say it has a certain property at t1, and then doesn't have it at t2, but if the substance really exists at both times, then it follows that it both has and doesn't have the property.
2) Craig's point seems to be that, since O at t1 and O at t2 are ontologically equivalent (they are both "as real" as each other), it follows that the very thing which you call "relativizing" is what makes them really different objects. It would be as if I and a perfect doppleganger of me both existed at the same time, and there was nothing different between us but our spatial location. We are identical, except when relativized spatially... but we are therefore not the same object!
3) A stageless worm couldn't deliberate and then freely choose among alternatives, could she? She would both already have chosen, and yet not have chosen, such that her choice is pre-determined even as she deliberates.
As to consciousness, can she really have a persisting, continuous consciousness, if all of her thoughts are concurrently real (not "concurrent" in terms of location along the t-axis; but ontologically equivalent such that one thought never "goes out of existence" to make way for the next thought, and so she must (if she is really extended as you suggest) continue to have all of the thoughts together)?
Ad 1: It has properties P1-at-t1 and does not have property P1-at-t2. No contradiction. Both properties are, however, indicated by the same predicate in a tensed language.
Ad 2: Suppose I am green on my left side and blue on the right side. That doesn't make me two objects.
Ad 3: A stageless worm can have an accident of deliberation located at t1 about an accident of action located at t2.
1) What about being dead or alive? Or conscious vs. unconscious? If we are extended along the 4th dimension, it seems to follow that only part of us is conscious/alive, while other parts are unconscious/dead.
2) That seems to be oversimplifying the matter. If you are a converted Christian (for example) at t2, but at t1 you're still an agnostic or an atheist, can it really be true of the same person that he is both a Christian and an atheist?
3) Doesn't that undermine the idea that the deliberation at t1 has any causal relation to the action at t2? For the deliberation at t1 to be legitimate, it seems to me that it should be capable of yielding either choice A or choice B. If the result is already set at t2 (and has been set forever, just as the deliberation has been occurring forever), how can it be that the deliberation causes the choice?
Forgive me if these are naive or ignorant questions. I am not a professional philosopher.
1. You're alive in this region of spacetime and not alive in that. For instance, I am alive in Waco in the early 21st century but am not in alive in Chicago or in 18th century or, unless the resurrection of the body comes relatively soon, in the 22nd century.
Being dead or alive can be relativized to spatiotemporal locations. Ditto for conscious/unconscious.
2. Likewise, being Christian and non-Christian can be relativized by spatiotemporal location.
3. At t1, I have the causal power to bring it about that I have property P at t2, and the causal power to bring it about that I have ~P at t2. That it is true that I exercise one, and not the other, of these causal powers does nothing to deny that I have the other causal power. We have lots of unexercised causal powers.
1&2) I suppose that makes sense. It just seems to me rather muddled to imagine being conscious of everything that you will ever be conscious of all at once. I suppose I have more reading to do on tenseless time philosophy.
3) But, doesn't the statement "I have causal power at t1, to produce either P or ~P at t2", require that whether or not P or ~P is instantiated at t2 be an open question? I mean, do I really have the power to make t2 different? It really looks like Libertarian free will goes out the window when there is a time, t2, such that my decision is already made, and so I never really could have chosen otherwise.
Forgive me for asking another (probably silly) question, but isn't there a problem with defining entropy (especially the increase of entropy over time, in accord with the second law of thermodynamics) in a Universe where all times are equally real? This is in line with your original point about "change", and that it should be sufficient to say "x satisfies P at t1, but not at t2". How does that work for a quantity that is supposed to build up over time accross the whole system? Wouldn't the entropy of the entire 4-dimensional block always be the same?
But you're not conscious of it all at once. You're conscious of it partially at different times.
I don't see why having a causal power to make ~P true at t2 is incompatible with P being actually true at t2. There doesn't seem to me to be anything problematic about the power to do something that you won't actually do.
The decision isn't already made--it will be made.
Entropy, by the way, is defined at a particular time, I believe.
With all respect (truly), what on Earth does it mean to be "partially conscious at a particular time"? Consciousness is the unity of my experience. I have no idea what it would mean to have the fragmented consciousness you imply.
But the decision is already made at t2, and has been true eternally (just as my deliberation at t1 is eternally true). So, unless I have the power to change that which is unchangingly and eternally true, I don't see how I have Libertarian free will. It's not just that we should have the causal capacity to change the fact of t2, but it should really be possible for us to do so. If, however, the fact of P at t2 is eternally and statically true, it doesn't seem to me that I could ever change that. That being said, I suppose an Aristotelian account of modality, such as you give in your book, would make these one and the same question....
Entropy refers to the distribution of matter throughout the entire system. If space-time is a static "block", it would refer to the distribution along all the dimensions of spacetime (be they 4, 11, 26, whatever). A static Universe also shouldn't seem to be "expanding", should it? If spacetime is a "block", then time is inextricably linked with space, and would "expand" with it (indeed, the relativistic effects on space, also effect time). I just think that matters like entropy and spacetime curvature/relativity will cause problems for the B-theory. General Relativity seems to sit much more comfortably with an A-theory, in which dynamical change (of physical space AND time) is possible.
1. Split brain patients appear to have consciousness without a unity of the experience. It also seems plausible that Christ's divine and human consciousness were not unified into a single set of experiences.
2. Sure, you can't change the future, since that would require that at t1 the future at t3 be one way and then at t2 the future at t3 be a different way. But what we need is the capacity to affect the future. Sure, it's eternally true that P obtains at t2. But it's eternally true as a result of my decision.
3. "Static" is a tendentious description. In any case, entropy is generally defined at a time.
Thank you for your responses. I'll think about these matters. With regard to libertarian free will (which seems to me essential for Christianity, and for morality in general), I really think there's a problem for the B-theory. You're saying that P eternally obtains at t2, but does so as the result of my choice at t1. However, the libertarian will not consider what happens at t1 to be a real "choice". It will be just like a tree growing a branch or some other such inevitable consequence. If I actually have no ability to make t2 different, then I do not actually make a libertarian choice at t1. Indeed, it seems to me that "choice" loses meaning in such a world. A tree does not "choose" to grow a branch, it is just the inevitable future that it will do so. But, a person does choose to murder someone, and their moral accountability depends crucially on whether or not they could have done otherwise. But, if it has eternally been true that they committed murder at t2, how can they really be culpable? They could never have done otherwise.
I agree about the important of libertarianism.
But I don't see the issue. They could have done otherwise, but they didn't. There is no causal inevitability. Of course given that at t2 one will choose something, one can't do otherwise, but that's just a matter of logic, rather than any kind of necessitation.
Isn't logical necessity a limiting factor on one's freedom? I mean, I can't draw a round square, despite having all the powers needed for drawing any possible shape. "Round square" isn't a possible shape. So it isn't a lack of power, it's just that it is a logically necessary truth: you cannot draw a round square.
So, if it is logically impossible that I should change what has eternally the case at t2, it follows that I actually can't do it (not for lack of power, but because it is logically impossible).
Even when the libertarian debates with the compatibalist, what often comes up is the "ability to do otherwise". However, if doing otherwise is logically impossible, it seems libertarian free will is an illusion.
It's logically impossible that: I do A at t2 and I not do A at t2.
But it does not follow that, assuming I do A at t2, it is logically impossible that: I do not do A at t2.
Hm... It isn't? As I said, I'm not a professional philosopher, nor is my modal logic anywhere near where it should be, but... you're saying: ◇(A&~A) is false, but A&◇~A is true? In other words, it's not possible that both A and ~A obtain, but if A obtains it is still possible that A not obtain?
Yes, certainly. :-)
On second thought, I guess that makes obvious sense. Any contingent fact A, will also be possibly not true. Only if it were necessarily true that A would it not be possible that ~A.... It still seems wrong to say that I ever have the ability at t1 to make t2 anything other than what it is. If which choice I'm going to make is already established, I don't see how it's a truly free choice. But I guess I'll have to wrestle with that some more.
Thanks for helping me out on this one!
I would quibble with the "already". It's true what it will be, but it's true in virtue of a future event.
But it is true at t1 that I "will choose" X?
Maybe. I am not sure it makes sense to talk of truths-at-a-time. Truth, like mathematics, just isn't the sort of thing to be qualified by times. But if we do allow "true at t" as a locution, then yes. But it's true at t1 that you will choose X only because you will choose X. This is no more, and in fact less, problematic than the case where you are in the year 100 BC because in 2014 AD you will choose to enter a time machine. Entering the time machine can still be free.
Mathematical truths are necessary truths. They are always true, and it doesn't make sense to qualify them at times. But contingent truths, it seems to me, are just the kinds of things that you yourself qualify with statements like "dead at t2, but alive at t1".
Your analogy actually shows why most people consider time travel impossible! People who think about temporal paradox seriously, usually come to the conclusion that, having created a temporal loop, you are not able to avoid getting into the time machine. It is impossible for you to do otherwise, since you were already there in 100BC. So, I think your analogy may just make matters worse (at least in my poor brain).
If I may, let me try to emphasize my problem by paraphrasing what Peter van Inwagen has said on this issue: "If choosing X rather than Y is possible, then it is reasonable to discuss what would happen if X were chosen. So, if it is true that I will choose Y at t2, despite it being POSSIBLE to choose X instead, then what would happen if I chose X?" In other words, calling something "possible" carries with it the question "what would happen if...?", and that seems to be what's so unsettling about the account you give.
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