Wednesday, November 07, 2007

Why Is This Time the Present?

My occasional metaphysical sparring partner, Ian Spencer, poses the following objection to presentism - the view that only what exists now exists simpliciter:
Here's a problem for most forms of presentism - on most versions, there's no good answer to the question of why this time is the present one. That is, why does the stuff at this time (and in its current arrangement) exist rather than that of some other? Why isn't some other time the present one?
What I find puzzling here is the fact that Ian thinks this is a problem for presentism. After all, for the presentist the present time is the only time there is - the past is no more and the future is not yet. So to ask "why is this time the present?" sounds to a presentist's ears like asking "why is the present the present?" Not a very interesting question.

What I think Ian has in mind is a somewhat different question: "Why does the present have the configuration it now does?" The obvious answer is to say that the present configuration of the world is as it is because it developed from an earlier configuration in accordance with the causal powers, dispositions, choices, etc. that were in effect at that earlier state.

Here's an analogy. Imagine a world with the same physical laws as ours in which there is only a single homogeneous lump of radioactive material that God has just created ex nihilo. According to physics, the atoms composing this lump have a certain disposition to undergo radioactive decay. The strength of this disposition is reflected in the radioactive half-life of the substance. The lump will also have a disposition to emit photons due to a phenomenon known as black-body radiation. Finally, the atoms of the substance and the electrons on those atoms have kinetic energy, which depends on velocity, which is an instantaneous directional tendency to be elsewhere. Now, given the inherent dynamic tendencies in the lump, it will not, indeed cannot, remain in its initial state. But the moment something, anything happens - decay, photon emission, electron motion, etc. we no longer have the same configuration. The radioactive lump system, due to its own internal tendencies and causal powers, has changed from one configuration to another. And with change comes time. At each moment in the evolution of the system it is in a different state. Each state is the consequence of previous states. And, unlike what B-theorists seem to think, there is no need for previous states to "stick around" as static parts of a tenseless block universe.

In my experience, I've found that many people, philosophers included, are held captive by a certain conceptual metaphor when it comes to thinking about time. The metaphor is that of the "timeline". According to this metaphor, time is "stretched out" along a dimension and consists of multiple events ordered by temporal relations like "earlier than" and "later than". It's a familiar picture from history books. But it's a picture that presentists (with the partial exception of ersatzist presentists like Bourne and Crisp) thoroughly repudiate. For presentists, time is not a line. It does not consist in "earlier than" relations between events. It consists, rather, in the intrinsic dynamism of reality, especially the tendencies of things to become other than they now are. Ian may find that picture "spooky". So be it. I'm inclined to say the same about his block universe. We may just have to agree to disagree on this issue.


At 11/07/2007 9:04 PM, Blogger Ian said...

Hi Alan, actually I would defend my wording of the question. Of course, "This time is the present one" is trivial if understood de dicto. But so understood de re - that is, if I'm picking out one particular time (some time in 2007) and asking why that one is present. That is, why out of all the possible temporal states of the universe, is this one the one that is actually realized? As you can see, this de re understanding of it is pretty much what you thought I meant (which it was). Since this is a perfectly natural understanding of what I said, I think the question, properly understood, is a perfectly good one and one of the actual semantic disambiguations of the words used. But that's just verbal stuff - it doesn't matter too much since you got what I was saying anyways.

I'm a bit puzzled by your response to me since I'm not really sure how it responds to anything I've said (that is, "responds" in the sense of "objects to"). For one thing, I didn't say all presentists have this problem - I only explicitly addressed certain kinds of presentism and gave arguments in each case for why they couldn't give the exact answer you give - that "the present configuration of the world is as it is because it developed from an earlier configuration in accordance with the causal powers, dispositions, choices, etc. that were in effect at that earlier state." I think that is a perfectly good answer and, as I said in my blog, the right one. I just think certain versions of presentism can't make good on that explanation since they get the explanatory direction backwards given what they think such facts about the past and its development into the future really are. So again, I'm a bit puzzled about how any of this is an objection to anything I said. Maybe it's not meant to be.

As for the metaphor, I freely admit to being "held captive" by it, but only because I think it accurately reflects what's really there. I do understand that most presentists do not view time in that way and I don't think I assumed this from the outset in anything I said (not that you were accusing me of doing so, since you didn't). As for the "block universe", if you mean just eternalism then you are right that I wouldn't find it spooky. But there are views that go by that name (as well as by names like "tenseless theory" or "B-theory") that I would probably find almost spooky as you. Too often, though, I think people hear about eternalism or tenseless theory and think it means or must mean one of these other, weird views (a problem not helped by many historic tenseless theorists and eternalists). That's not to say that you're doing it - it's just an observation from reading a lot of articles that mention these kinds of topics.

At 11/07/2007 9:18 PM, Blogger Ian said...

"I think that is a perfectly good answer and, as I said in my blog, the right one. "

Oops! Okay, I looked back at my post and realized I never made this explicit. My fault.

At 11/08/2007 6:41 AM, Blogger Ocham said...

Hi Alan. What I am about to say you will have heard me say in different ways, many times before. But anyway.

To me the question makes little sense. It's like asking 'why is this place here, and not somewhere else.' or 'why am I this person who is talking, and not someone else'.

Well, 'this place' and 'here' mean the same. Likewise 'I' and 'this person talking' mean the same. So they *would* be the same.

At 11/08/2007 6:46 AM, Blogger Ocham said...

I now see that Ian has addressed this trivial interpretation I mention. But what other interpretation is there? To talk about 'de re' versus 'de dicto' only confuses me more. What is a 'de re' interpretation?

I also detect the 'Mcguffin' - the expression or technical term that is always to hand in such cases. Here, it is 'all of the possible temporal states of the universe'. Also 'actually realised'. Once you translate these into English, you get back to de dicto, as before.

At 11/08/2007 9:14 AM, Blogger Alan Rhoda said...

Hello Ian,

Thanks for the response.

To be clear, I didn't intend this post as an objection against you, but only as commentary on an issue that you raised on your blog.

As you note, you were only targeting some versions of presentism. And here there is much that we agree on. We agree, for example, that ersatzism doesn't work. We also agree that Craig's account of tensed properties gets the explanatory order backwards. All I was trying to do here was to spell out in some detail what an adequate presentist response would have to look like.

On the timeline metaphor, it seems to me that what creates problems for ersatzist presentism is the fact that it partially buys into the metaphor and tries to combine it with presentism. I think that's a mix that just won't work. It reintroduces, after a fashion, the same types of problems that the "moving spotlight" theory does.

At 11/08/2007 9:23 AM, Blogger Alan Rhoda said...

Hi Ocham,

Like you, I'm a little confused on Ian's application of the 'de dicto'/'de re' distinction in this context.

In the quotation I gave from his blog entry he asks three questions, and they don't seem at all to me to be the same question restated, but rather three different questions.

At 11/08/2007 9:05 PM, Blogger Ian said...

Sorry - my first comment was another one written while tired and uncareful (shame on me). The basic idea I was trying to get across is that if we're using words how ordinary people use them (well, ordinary people wouldn't necessarily ask such questions, but hopefully you get the idea...), there are perfectly natural disambiguations of the questions I ask on which they mean pretty much the same or at least where there's some entailment between them going on. After all, if by "this time" I mean 2007 then it's not a trivial question at all to ask why 2007 is the present one (that is, assuming there's a privileged present - if one has a token reflexive sort of theory like ocham's then it does seem a lot more trivial, but most presentists probably would reject that understanding anyway). After all, on the views under consideration, it is certainly possible that 2006 could have been present. To avoid talking of times (which some presentists don't like) I rephrased the question to speak of what is the case at a time rather than the time itself (which is okay, since on some views this is just what a time is anyways). The last question is just a corollary of the first - why not some other time? I hope that helps sort out what I had in mind. I admit I wasn't very clear and hopefully I've been clearer here.

Ocham, as far as you analysis of indexicals goes, I'm afraid I wouldn't agree with all of your interpretations (though I used to hold such a view and am still somewhat sympathetic). For instance, I think it's wrong to think that I *means* "the person speaking" or something like that. When I say "I" I'm not talking about speaking at all - I'm referring to myself, period. "I" refers to the speaker but it doesn't *mean* that. Or at least, that's what I've been convinced of. (For one thing, when I say, "This person talking is my sister" it can be perfectly true whereas when I say, "I am my sister" that is definitely not!)

At 11/09/2007 2:42 AM, Blogger Ocham said...

Hi Ian. Yes, that was a bit sloppy and in the past I have criticised people for such sloppiness. "I" does not mean 'the person now speaking. Rather, it means, the person who says 'I', as is clear from the first of the three examples below. This has to be understood in the context of a more general theory of indexicality that I am working on. I claim all the following are similar.

"I am not amused" said the Queen
"This is it" said Derek, pointing at the box
"Now you must go to bed", said the nanny at 8 o'clock, to the children.

In each case there is an indexical in quoted sentence (I, this, now, you), which signifies the same thing as signified by a noun phrase in an unquoted sentence (the Queen, the box, 8 o'clock, the children). And it's clear from these cases at least, the sort of question you were trying to raise doesn't make any sense, i.e. "How come 'this' (pointing at the box) is a box, and not any of the other million things in the world?" – is an absurd question.

On the other hand (I thought about this last night) there is a sense – hard to express – in which I can ask why it was I ended up here, in this body, at this time in the life of the universe. The sort of question that occurs to us when we reflect on our own mortality.

At 11/09/2007 9:02 PM, Blogger Ian said...

Hi Ocham, I actually agree with you quite a lot. As I said before, things only change if you accept at least certain tensed view of time. Let me explain myself more clearly:

I think you and I would both agree that the question "Why is this time (where 2007 is referred to) the present?" is a silly one since the function of "the present" in this sentence is simply to refer to 2007 so that the question ends up just asking "Why is 2007 2007?" I don't actually dispute that, as you seem to suggest.

However, on some tensed views, talk of the present isn't trivial in that way - there is a privileged, concrete present that is specially present in a metaphysically robust way. After all, on presentist views x exists (or is real, perhaps) iff x is present. So the question "Why is this time (2007) the present?" is no longer weird or trivial since it entails the non-trivial question, "Why does 2007 exist?" But that's just on this sort of view - I never endorsed this. You might disagree with it, and I would agree with you whereas most(?) tensed theorists wouldn't.


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