tag:blogger.com,1999:blog-3891434218564545511.post8541244405891353951..comments2024-03-28T19:56:42.305-05:00Comments on Alexander Pruss's Blog: Distinguishing the A- and B-theoriesAlexander R Prusshttp://www.blogger.com/profile/05989277655934827117noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-3891434218564545511.post-6033928171279615512007-10-30T18:35:00.000-05:002007-10-30T18:35:00.000-05:00It seems to me insufficient to say, even given tha...It seems to me insufficient to say, even given that each objectively exists, that successive moments in the past, present, and future each comprise simply _different_ worlds, so that there need be no necessary connexion between each world--so that they merely lie over or under each other like the pages of a binder, subject, in principle, to re-arrangement.<BR/><BR/>If X is true now, and X is not true ten minutes from now, it will not be enough for those in the world ten minutes from now to say "X is true"; they should say, "X is true and X _was_ not true". That future world will include our present world, and its own present world, in distinct ways at least corresponding to spoken distinctions in tense--it will include its own present as our present includes itself, and it will include our present in the way that our present includes our past.<BR/><BR/>But it seems to me that this inclusion cannot be nested or recurive. There cannot ontologically be something like a pluperfect. The past of the past is not distinct from the past of the present. Consider, for example, light writing (or drawing), where some luminous object is used to outline a shape that becomes meaningful only when viewed on a prolonged exposure of film. _How_ that shape exists is a separate question; but its meaningfulness implies that we cannot nest pasts inside pasts: all pasts are one past within which things can exist without existing at any particular moment of the past.Paul M. Rodriguezhttps://www.blogger.com/profile/00925737399903171837noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-5671350971017462612007-10-30T15:44:00.000-05:002007-10-30T15:44:00.000-05:00I guess the B-theorist can say that we help to act...I guess the B-theorist can say that we help to actualize our world. Suppose in fact I will raise my left hand. Then, w2 is actual. But why is w2 actual? In part because of my own choice. So, I have helped to bring it about that w2 is actual. But this does not imply that different worlds are actual at different times. It was always true that w2 is actual, even before I made my choice, but it was true in part because of that choice. When I make my choice, I'll be able to prevent w2 from being actual, but in fact I won't use that ability.Alexander R Prusshttps://www.blogger.com/profile/05989277655934827117noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-54259067692781889552007-10-30T15:02:00.000-05:002007-10-30T15:02:00.000-05:00Alex,I guess the simpler way to put my worry is th...Alex,<BR/><BR/>I guess the simpler way to put my worry is that if there is no point in time at which I can actualize another world, fatalism quickly follows.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-58828707470925946012007-10-30T14:51:00.000-05:002007-10-30T14:51:00.000-05:00A B-theorist will say that I either will raise the...<I>A B-theorist will say that I either will raise the left hand, in which case w2 already is actual and w2=w1, or I will raise the right hand, in which case w3 already is actual and w3=w1. After all, if w1 is neither w2 and w3, what is it?</I><BR/><BR/>Yes, this is nice. But how is it that at t' I do not actualize possible world w2? You will agree that I could have actualized w3 at t', right? Had I done so, it would have been the case at t that w3 is the actual future of w1. It sounds like you're treating w2 as inevitable, but I might be reading this wrong.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-91759169404879407112007-10-30T14:21:00.000-05:002007-10-30T14:21:00.000-05:00Suppose I am in w1. Simplify to suppose that the ...Suppose I am in w1. Simplify to suppose that the hand-raising is the only indeterministic event in the future. If I raise my left hand at t', I actualize w2, and if I raise my right hand instead, I actualize w3. A B-theorist will say that I either will raise the left hand, in which case w2 already is actual and w2=w1, or I will raise the right hand, in which case w3 already is actual and w3=w1. After all, if w1 is neither w2 and w3, what is it? (A world with a hole in the future? But B-theorists don't accept such.)<BR/><BR/>What your point nicely shows is that open-future A-theorists have two different reasons to assert that a different world is actualized at different times. First, in virtue of the mere passage of time. Second, in virtue of the fact that more things become determinate as possibilities get closed.Alexander R Prusshttps://www.blogger.com/profile/05989277655934827117noreply@blogger.comtag:blogger.com,1999:blog-3891434218564545511.post-87461465170282385792007-10-30T10:21:00.000-05:002007-10-30T10:21:00.000-05:00So, let me propose a different characterization: T...<I>So, let me propose a different characterization: The A-theorist holds that at different times we inhabit different possible worlds, while the B-theorist denies this.</I><BR/><BR/>Alex, I'm guessing you mean to qualify this in some important ways. Certainly the B-theorist also holds that at different times we are in different worlds (or, as I would rather put it, at different times different worlds are actual, since I may well be worldbound).<BR/>Take world w and time t in w, any event that takes place after t (say, at t') is sufficient to actualize another world w' at t'. So, if I raise my left hand at t' I actualize one possible world at t', if I raise my right hand, I actualize another world at t'. B-theorists surely don't deny that. So I'm thinking you want to say something like, the <I>mere</I> passage of time from t to t' is not sufficient to actualize another world for B-theorists, since there is no genuine passage of time. Something like that?Anonymousnoreply@blogger.com