Tuesday, May 13, 2008

"Thank goodness it's over!"

This post is another attempt to go over the same ground in a back post.

You are in pain, and then the pain ends. You exclaim: "Thank goodness the pain is over!" It is thought by some A-theorists (who think that there is an objective division between past, present and future) that B-theorists (who do not think there is an objective present and who think temporal determinations are relative) can make sense of the sentiment. After all, the sentiment is not a relative one. One is not exclaiming: "Thank goodness that the pain is later than this remark!" Rather, one is being grateful (implicitly to Providence?) that all the pain is, objectively, in the past.

But if time travel is conceivable, this is mistaken. Suppose I travel to the year 2200, and find myself with a horrendous headache. I decide to go back to 2008. Simultaneously with my return to 2008, my pain coincidentally goes away. I exclaim: "Thank goodness the pain is over!" This exclamation makes perfect sense. But if it does, then the A-theorist is wrong to think that the exclamation is an expression of joy at all the pain being in the objective past. For the pain is actually objectively in the future: the pain is 2200. But it makes no sense to dread that objectively future pain. For that objectively future pain is not in one's subjective future. It is in one's subjective past. Therefore, in the exclamation "Thank goodness the pain is over!" the word "over" refers to subjective time.

But subjective time is not the time that the A-theorist talks about. For instance, if there is time travel, then there may be no objective fact about what subjective time it is for some person x. For this person may now be twice-over present at the same time, having traveled back to this time, and so there are now two subjective nows for that person.

I am growing more and more convinced that subjective time, or more generally internal time (subjective time is only had by conscious substances; internal time can be had by non-conscious entities) is the logically primitive form of time. In those possible worlds where the internal times are appropriately correlated with causation, there is also external time—the time of the world—which supervenes on, and even reduces to, internal time. And both internal and external time is B-theoretic in nature.

7 comments:

Roman Altshuler said...

Very interesting. I am curious about two bits here. First, what is the difference between subjective time and internal time? Your suggestion seems to be that subjective time is just a species of internal time. But this seems to imply that subjective time is not dependent on consciousness, or that subjective time is just what we call the time internal to particular sorts of substances (i.e., conscious ones). Would persons then have two different internal times, given that there would be one internal time for them as bodies and another for them as consciousnesses?

Second, I am wondering about your last claim, that both internal and external time are B-theoretic. As far as I can tell, your argument here seems to show that the "thank goodness" argument for A-theory doesn't work, because the time it applies to is internal, rather than external time. While it is true that this is not what A-theorists generally want to establish, doesn't the "thank goodness" argument now--on your account--seem to establish that internal time is A-theoretic? (After all, what makes the "thank goodness" make sense is that the pain is in my subjective past, not that it is subjectively earlier than my utterance.) And if internal time is primitive (and on this I tend to agree with you), that seems to imply that the A-series is primitive.

Alexander R Pruss said...

Wonderful questions, thank you.

You may be right that it is possible for subjective and internal time to come apart. It may, in general, be that a substance has more than one internal time sequence (think of someone whose brain has two internal clocks running at different rates). In the case of humans, our subjective time has neural correlates, which suggest that the physical and mental times don't come apart too much.

Internal time can't be A-theoretic, because the A-theory claims an objective present. But I doubt it would make sense to say that there is an objective present relative to each person, would it?

Heath White said...

It seems to me that we could very well say there is an objective present relative to each person. Alternatively, we could just say there is a subjective present. The point is that the subjective A-theorist has a genuine past, present, and future in subjective time. I'm with Roman--I don't see how this shows that subjective time is B-theoretic. In fact I would think it shows that subjective time is A-theoretic.

Alexander R Pruss said...

Heath:

How would this subjective present relative to each person work?

Here's one proposal. For each person x, there is an objective fact about what time is now subjectively present to x.

What does the "now" mean here? If it's a B-theoretic now, then the claim is merely that at each time t, there is an objective fact about time is at t subjectively present to x. But if so, then it's not an objective fact what time is subjectively present to x, but a fact relative to the time t.

Suppose it's an A-theoretic now. Then we require a non-person-relative A-theory to make sense of the person-relative A-theory.

But in both cases we still have the following problem. Surely the right answer to the question: "At noon, what time is subjectively present to x" is noon. (The subjective present isn't just the time one believes to be present--one can be wrong about what time it is!) What sense could there be in saying that at noon, it is 1 pm for x? Would that mean that x is literally now in the future? No. So, at every time t, the time that is subjectively present to x is t.

But now it doesn't seem like we're talking of a subjective present any more. Maybe the past and future are still subjective, though.

Heath White said...

Ergggh. This is hard. This is why I don't do metaphysics.

I think it should be uncontroversial that time requires a sequence of events. Ordinarily we think of this as the "objective", external-world order. But with time travel, we may want to put them in a different order, and call it subjective time. The question then is whether there is a kind of "now" that is something beyond "simultaneous with this thought/speech act".

It won't do, as you say, to think of subjective time in terms of objective facts about now-ness for a subject. Rather, if we take subjective time seriously, I would say there just would be no objective facts about time at all. The earlier-than/later-than relation will be person-relative, and so will the now-fact if there is a now-fact, and there just wouldn't be any more to say about it.

I wouldn't swear all that makes sense. However, my general thought is that if we take subjective time seriously, then we could be A-theorists or B-theorists about it, and our debate will go on as before.

Roman Altshuler said...

My comment was coming out too long, so I put it up as a post (linked below). Basically, I agree with Heath White (if I read him right) that we cannot simply treat subjective time in the same way we treat objective time, because then the distinction falls apart: objective time just becomes the internal time of the universe as a whole, as opposed to the internal time of a particular entity or set of entities in that universe. And if that's really all there is to the distinction, I'm not sure what sense there is to the idea that subjective time is logically primitive: it seems, after all, to be logically identical.

Alexander R Pruss said...

I agree that the crucial move in what I'm doing is to equate subjective and internal time.

By "subjective time", I meant the time that is internal to us as subjects.

If, however, one understands "subjective" in a different (though related) sense, one tied to a form "subjectivism", then one does get a different view. This different view is one I can at present make no sense of (that doesn't imply that no sense can be made of it), but that's probably because I can make no sense of any properly subjectivist view.

I can make sense of relational and indexical views (e.g., an indexical view of beauty is that "beauty" is an indexical, whose content depends on the contextually relevant individual and her perceptions), but such a relational or indexical unpacking of a subjectivist A-theory would probably fail, perhaps for the reasons I indicated to Heath.

Here's a different way of putting my worry (or perhaps a different worry). Let's use parentheses to indicate the subject relative to whom a temporal term is used. Suppose I see you talking. Thus, unless my senses deceive me, you are now(ARP) talking. Is it now(RA) the case that you are talking? Well, that question is problematic, because it seems to suppose a cosmic time that connects the now(RA) with talking.

Rather, to stay subjectivist, the question I have to ask is this: Given that now(ARP) you are talking, is it now(ARP) the case that now(RA) you are talking?

Or, more generally, if E is occurring now(ARP), does it have to follow that it is now(ARP) the case that E is occurring now(RA)?

Suppose the answer is affirmative. Then the subjective nows all have to be correlated. For all x and y, whatever is happening now(x) is also happening now(y). (And ditto for what is happening in the future(x or y) and past(x or y).) If so, then now(x) = now(y). And we lose the subjectivity.

So suppose that there need not be a correlation. Thus, it is possible that now(ARP) you are talking, but now(ARP) it is not the case that now(RA) you are talking. I am not sure what sense can be attached to this. How can it now(ARP) be the case that you're talking but you're not talking now(RA)? Is the now(RA) somewhere off in the past(ARP) or in the future(ARP)? That doesn't seem to make sense.

OK, so the subjectivist A-theorist has to go back and reject the sensibility of the questions that led us to this point. Thus, either we have to reject the sensibility of the question whether you are now(ARP) talking, or the sensibility of the question whether it is now(ARP) the case that you are now(RA) talking. I think the subjectivist A-theorist should reject the first question (and the second, too, but the first is the obvious one). For subjective time measures only what is internal to one. So it makes sense to reject the question whether you are now(ARP) talking, though of course the question whether I am now(ARP) talking makes perfect sense, as does the question whether I am now(ARP) hearing you talk.

Alright. So, I cannot actually talk of what is now(ARP) happening outside me on this view. And ditto for the future(ARP) and past(ARP) determinations. So, on this view, I can only talk B-theoretically about what is happening outside of me. Thus, it makes no sense to ask whether you are talking now(ARP), but it does make sense to ask whether you were thinking before(RA) you were talking.

This is an odd combination of views: that we talk A-theoretically about ourselves and B-theoretically about others. I find it unattractive, in part due to this excessive complexity. I am also vaguely concerned about private-language related things here. The A-theoretic concepts only apply to me. But can I make sense of concepts that apply only to me?

I guess relativized versions of the A-theoretic concepts might apply to others. Thus, I might say that while you're speaking, it is now(RA) the case that you're speaking. But this doesn't give me much of a concept of "now(RA)", because I can just say more simply that while you're speaking, you're speaking.

Sorry, this is rambling. I'm just trying to come up with as good a statement of the position I'm opposing as I can, and I'm failing. Maybe you can do better. Thanks for these really thoughtful reflections.