Monday, April 29, 2013

Eternalism and presentism

Here is an argument against eternalism:

  1. If eternalism is true, times are like places.
  2. Times are not like places.
  3. So, eternalism is false.
There are a number of arguments for (2). Many, though not all, of them have something to do with the directionality of time, given that space lacks such directionality. Now consider this parallel argument against presentism, and hence for eternalism:
  1. If presentism is true, times are like worlds.
  2. Times are not like worlds.
  3. So, presentism is false.
There are a number of arguments for (5). Here's a fun one. If I am happy now and miserable at all other times, I'm really unfortunate. If I am happy in the actual world and miserable at all other worlds, I'm really lucky one. In general, misery at other times matters in a way in which misery at other worlds does not.

So how to break this impasse? One way would be to opt for a theory other than eternalism and presentism, say growing block. Another way is to keep on adding disanalogies between times and places or between times and worlds until one of the disanalogies ends up being much stronger. Yet another way, and I think the most promising, is to embrace both (2) and (5), but explain the disanalogy in a way that is compatible with presentism or eternalism (whichever is one's preference).

One should also note that arguments from analogy tend not to be the strongest.


Anonymous said...

So I've been wondering about something for a while now and its answer is slightly relevant to (5) in your post, so perhaps this is an appropriate place to ask it (apologies if it's malformed or misguided). Is it not possible for a presentist to hold that possible worlds are only individuated by tenseless propositions only? In that case the actual world would be all tenseless facts that ever have been true, those that are currently true, and those that will be true in the future. Not to say that there aren't irreducible tensed facts (as I suppose the presentist will have to say), but just that these don't factor into distinguishing between possible worlds like other idexical statements (like "a horse exists *here*", or "*I* exist") don't factor in.

Alexander R Pruss said...

Yes, Merricks says something like that here. So he thinks that tensed statements like "I am sitting" are not true at any world.

Unknown said...

What's the motivation for (1)? I ask because, as a guy who leans strongly to eternalism, I think of times as more like worlds than places.

Alexander R Pruss said...

Well, all places are equally real, and ditto for times.

Michael Gonzalez said...

As one who strongly leans toward presentism, I must say that I've never thought of time as being "like worlds". I think of time as keeping track of temporal becoming. If temporal becoming is real, then it seems to me that the actual world simply undergoes constant change, and that contingent statements about it go from being untrue to being true to being untrue again (or, at least, they need to be relativized to times).

One question: I don't know very much about "growing block", but doesn't it seem that the block itself is undergoing objective change, such that it would be accurate to say "it used to be such-and-such size, and it is now a greater size... but then the block cannot account for time (at least, not metaphysical time, in the sense of duration). I've often wondered if this isn't a problem for regular old B-theory too. I mean, if someone asks "how long has the static space-time block existed?" we have a ready response: "eternally" (right?). But, that response seems to be saying that the duration of the block is not relative to its t-dimension (any more than it's relative to any of the x,y,z dimensions), and that means that at least one temporal question has to be answered outside the only time framework that B-theory has to offer.

I don't know.... Just thought I'd throw some of that out there!

Martin Cooke said...

As a presentist, I agree with Michael; I think that possible world semantics is an eternalist device. There are many possible futures for the one world, and in each of them you, for example, exist, even though there is only one you. Transworld identity is trivial under presentism, because under presentism there is only the one world, a world that changes.

I would guess that an eternalist could say the same kind of thing about time not being like space, as we know it, because such space is something that we move through, whereas eternalist space is a projection of an atemporal spacetime, maybe.

Unknown said...

Dr. Pruss:

Sewing machines are all equally real. So why should an eternalist think that times are any more like places than like sewing machines?

Unknown said...
This comment has been removed by the author.
Unknown said...

Hey Michael:

Does 'the world' mean 'the whole of reality'? I.e., 'all the things that there are, considered as a whole'?

If so, then I think the eternalist can agree that the world is always changing. For any time t, there is some way F such that at t, the whole of reality is F; and at any time other than t, the whole of reality is not F.

That's compatible with eternalism, and it seems to be a decent translation of 'the whole of reality is always changing' into logic-ese.