Posted by Estella on May 8, 2006, at 1:05:13
In reply to Re: part-whole relations » Estella, posted by zeugma on May 7, 2006, at 23:08:19
> ok. There are two objects that I am as I speak.
well... that is tricky. hard to know whether there can be two objects that share the same space time worm as a matter of fact, or whether you only get two objects in virtue of fission occuring at a later point in time. i think the notion is that only when fission happens are we justified in saying there were two objects all along. i guess i have trouble with backwards causation, but apparantly that doesn't entail that and there is no problem with backwards causation there though i can't remember / see why not...
> And one can be put in one body, another in a second. (if I understand this at all) I am composed of parts.
IF fission is in your future, yup. If not... Then I don't think so. But that is in the fission case. Fission case aside you are still composed of parts. Time slices. In fact in the fission case you share common time slices in the past it is just the future time slices (from point of fission) that are no longer identical.
> But...this is too strong a realism for me. Because there really is no relation (I would claim) between myself and a future time slice, because the future may be indeterminate for all we know, and so my relation to time slice C may not be one that exists (speaking crudely, up too late).
Do you believe that we can evaluate claims about the future now? If I say... 'On October the 6th 2006 and six it will rain in New York'... Then this statement is either true or false right now (though we won't be in a position to evaluate it until then). Also need a clause about the ambiguity of rain... But do you think there are facts about the past that exist eternally (ie we don't have to wait for the truth maker... our statements about the future are either true or false now we don't have to wait)? Because if you do think that... Well then I guess statements about your future time slices (including statements about their relational properties) will be either true or false now...
What is the relation between time slices?
there things start to get a bit dodgey... I think Lewis went with a Lockean memory criteria.
Think Lewis re possible worlds and counterparts for a moment. There the notion is that your counterpart is the individual on that world who shares the most properties with you. Then back to the relation between time slices. There the notion is that the time slice that shares the most properties with that time slice in the next instant in time gets to be the next time slice of you. But of course one might want to tighten that (and maybe lewis does - not sure) with something to do with one time slice being causally related to the previous. but then there are problems for Lewis' account. consider some time slices within an individual
A -> B -> C -> D -> E
so A might be a time slice of you when you were 4
and B might be a time slice of you when you were 8
or whatever. point is time is moving left to right. now the problem is that it seems possible in principle for C and E to share more psychological properties than D and E. i think that creates problems for Lewis' notion of continuity.(though i'm not so sure... consider MPD / DID)
> perhaps that will become the dominant mode of reproduction i the future. certainly less messy than sex (joking)
yes. aka cloning. that seems to me to be a case of fission...
> that is really the crucial point for me. and maybe i am a 'spatialist', prejudiced in favor of objects spatially defined rather than four dimensionally.okay. though there is meant to be conflict between:
an object is wholly present at one point in time
and
objects change over time
the thought is you can't have both something has to give you have to choose...
so four dimensionalists say righto then an object is not wholly present at one point in time... rather a time slice is present.> ok, but it doesnt seem to be causally related. it seems to be a similarity that relates them. and that is a property. (ok i can't do better this time of night...)
yeah. actually to be fair i'm not sure that lewis talks about causal relationship. he talks about sharing of properties and similarity relation. i think i'm the one to bring causation into it and maybe i shouldn't have. sorry about that. i think it comes of the notion that i want decisions i make today (and beliefs i form today and desires i form today) to CAUSE my future time slices to be a certain way. but so long as they share the properties i guess it doesn't really matter...
> But S appears to naturally come apart into a spatial extent (Long Island) and a temporal one (may 7 etc.).
but... space-time is supposed to be a single dimension...
> Because the spatial element is localized, but the temporal, not.
you only have a thing insofar as it persists through time
you only have time insofar as you have things changing
they are two aspects / sides of the same... thing? dimension? whatever... but i agree that this sounds counter-intuitive.
the notion is just like there are spatial parts to things (and things can be divided by cutting them up into spatial parts)
there are temporal parts to things (and things can be divided by cutting them up into temporal parts)
and what you end up is things that exist unchanging for a discrete moment (time slice).consider
A -> B -> C -> D -> E -> F
Here we have an object (let us call it G)
G is the whole four dimenstional space time worm consisting ofA -> B -> C -> D -> E -> F
G doesn't change. though it might pop into existence before A and pop out after F.
A, B, C etc are time slices of G. I don't think they are objects in their own right... But there are time slices of G. I guess I was thinking of causal but lets forget the -> as causation at the moment and consider that A -> B just means that A and B overlap in their properties more than A and C. The notion is that A, B, C, etc have different properties. hence... things change. time slices have different (though similar) properties.
But G doesn't change. It is the whole worm.
Problems include...
How long is a time slice anyways.
(heh heh).On Fission we have...
A -> B -> C -> D -> E -> F -> K -> L
A -> B -> C -> D -> E -> F -> M -> NWhere the fission occurs after F
Clones work like this too...
It is only because of the fission that Lewis thinks we are warranted in saying there were two distinct objects all along.But I could be misunderstanding completely...
I don't really know what to make of it...
poster:Estella
thread:618106
URL: http://www.dr-bob.org/babble/write/20060331/msgs/641196.html