Wednesday, April 14, 2010

all of the possible people who, for all i know, i am.

to break up a week of studying in the desert for my metaphysics comp, i'm going to try to do a quick entry each of the next four days going roughly through some little idea or other that i've been meaning to get down and never managed to. these will be timed, and therefore badly edited, and likely confusing at times-- but i hope not utterly incomprehensible.

day 1:

this is a little idea i've been meaning to write down forever-- as good a place as any to begin. you've all heard me talk (too much, too much) about possible worlds, and i hope you can forgive me if i start there again, as a kind of warm up. it will start out seeming very dry and technical, but i hope that by the end you'll see that it's really about the something so hard and true and human and familiar.

kripke famously objects to david lewis' analysis of the modal claims we make about ourselves and others-- claims about what we could have done-- on the grounds that this analysis, in some profound way, fails to capture what we mean when we say that we could have done something. lewis's analysis goes something like this: when terry malloy says, with the deepest conviction and longing, 'i could have been a contender', we should analyze this as being a claim about what terry malloy counterparts actually did in nearby possible worlds. to say that malloy could have been a contender is to say that in very many of possible worlds very like our own world, people in those worlds very closely resembling malloy (except, perhaps for very slight variations in his composition or circumstance) were contenders.

according to kripke, though, this analysis is fundamentally in error, no matter what other advantages it may have: when malloy says 'i could have been a contender', he means himself. it is irrelevant to him what some other person in some other possible world did, but very important to him indeed that he himself could have done. there's a good technical response to this objection, which i'm not going to talk about here, because even though i think it does technically answer kripke's objection, i think there's another response that gets more to the beating heart of the problem kripke raises, which i think is not quite shaken off by the technical fix. (and because i'm strictly timing this little writing exercise, and i'm already running short.)

to understand the response i want to give, you have to understand something about how david lewis conceives of learning. imagine that, as david lewis thinks, the world we live in is "located" in a vast logical space, containing every possible world-- every single way things might have been-- with worlds most like our own being the closest and those farthest away being the most different. (of course worlds must be like or unlike one another in some particular respect, so where our world is located in logical space is not static, but determined by some particularly modal inquiry.) learning, then, is a matter of locating ourselves in logical space. if you know nothing about the world you inhabit (if that's even possible), then, for all you know, any possible world you can conceive of might very well be the world you're in. but every single thing you learn about the world you're in narrows down the list of worlds which, for all you know, are your own. so long as we're ignorant of anything, there will be many possible worlds which, for all we know might be our own. we're forever adding and eliminating possible worlds from the list-- that's what learning is. the region of logical space containing all of the possible worlds which, for all you know, might be the world you live in, is the space of epistemic possibility.

so here's the thing: there's so much we don't know about ourselves. there are infinite possible people, who, for all i know, might be me. we imagine possible futures, and we hope for and fear them terribly sometimes. there are many possible people who, for all you know, might be you, and some you come to hope or fear you are-- and some you even come, out of hope or fear, to believe that you are, though the evidence is, in fact, still inconclusive. it stands to reason, then, that because we are (a) epistemically limited in ways that keep us from knowing just exactly who we are or what's coming next, and (b) prone, as a contingent fact of human psychology, to care about who we are and what happens to us, and to prefer certain outcomes to others, that we will come to have feelings for possible people that it turns out we aren't, which are as profound as any feelings we might have for the person who it turns out we are. it's a funny thing about us that we sometimes care more for those possible people it turns out we're not. we sometimes spend our whole lives mentally tracking a person that it turns out we aren't along a path we believed we might follow. there is a possible person, a contender, who terry malloy believed so fiercely was himself, and that, i think, is more than enough to explain all of the conviction and longing implicit in his famous proclamation.

it's this sort of obvious aspect of human psychology, and not that he overlooked a certain technical detail of lewis' analysis, that makes kripke's "me myself" objection seem so obtuse to me.

time's up.


Drew said...

First, what was your time limit?

Second, is that really how David Lewis conceives of learning, or is that how you conceive of David Lewis conceiving about learning? I still am not sure what you're talking about when you're talking about logical space. And I've felt that way for years now (not just you, but other people too).

Third, with my exams coming up, and thus procrastination kicking in to overdrive, expect more comments from me on your blog. Always ignore the third one.

Sara said...

it's amazing to me how similar these thoughts are to the sorts of things I have to think about in economic research to be sure what I'm getting are causal and unbiased estimates.

laura.g said...

1. 45 minutes, including breaks to get coffee, but not including breaks to pee.

2. well, you know, i haven't actually read over the lewis a long time, and i'm certain that what i'm saying is imprecise enough that some objections could be raised, but this was my own rough impression of lewis' view when i read it for the first time. it was the key, for me, to understanding lewis-- that we don't start with the actual world and build a conception of possible worlds from them, but that we start with the entire space of possibility, which exists a priori if it exists at all, and locate ourselves within it. (SIDE NOTE: i've been reading a book called the philosophical baby, which is fucking awesome, and explains how babies learn to think in terms of possible worlds as they learn to think causally, and the tight/weird/necessary relation between those things when it comes to learning. when i get a second to think it through, i suspect i will have something to say about what i take the significance of all this new data to be for the lewisian view of learning.)

as for understanding what we're talking about when we talk about the space of logical possibility, yr probably asking the wrong person. that was my big question throughout that lewis sem we took-- what the crap am i suppose to be picturing? i mean, i have an idea, but i'm not sure that it's any clearer than the one you've already got.

sara: yes! see my side note-- i've been thinking like it's my full-time job lately about the relationship between learning/understanding about causes and learning/understanding counterfactually (about possible worlds).