Saturday, March 15, 2008

Can Possibilities be Representational?

In metaphysics these days, nearly everyone accepts that there really are these things: possibilities. Nobody is quite sure what a possibility is. But possibilities appear to be absolutely indispensable to philosophical theorizing. Thus, almost all of us accept that there are possibilities.

There is an interesting disagreement, though, among those who think that there are possibilities. The disagreement is this: are possibilities representations or are possibilities the things represented by representations?

For instance, many of my friends think that possibilities are something like sets of sentences, perhaps in some idealized language. This would be a view on which possibilities are representations. That set of sentences represents a way the world could be down to the finest detail.

Lewis thought that possibilities were cosmos-like. For Lewis, possibilities were no more representational than stars or stones are representational. Lewis' view falls in the second category, where possibilities are the things that are represented.

I think the majority of people who believe that possibilities exist think that possibilities are representational somehow. I know that I used to think that possibilities are representational, in part because I was timid about positing strange things like non-representational possibilities. But now, I can't make sense of the idea that possibilities are representions. Here are my thoughts.

Start from the view that possibilities are representations. You can think of possibilities as long conjunction of sentences, or sets of sentences, or some such. Now consider the following questions: what do possibilities represent? It would seem that the representation relation is existence entailing. That is, if X represents Y, then X and Y must both exist. Moreover, if possibilities are representational, then they must represent something. What could it be? What could possibilities represent? Honestly, I don't know. I don't think there are any good answers to this question. Here are bad answers.

1. "Possibilities represent ways the world could be." But, then, what are possibilities? I thought possibilities were ways the world could be. More exigently, what are ways the world could be? Surely they aren't representational also. For what could they be representing? If possibilities represent non-representational ways the world could be, we might as well jettison possibilities for the non-representational ways the world could be that they represent.

2. "Possibilities represent possibilities." Think about how strange this is. We have sets of sentences that represent other sets of sentences, where those other sets of sentences represent still further sets of sentences. That would be totally weird. Worse, it would have catastrophic consequences. It would be a resultant mystery why we care about possibilities, or why they're useful in other philosophical definitions.

3. "Possibilities represent themselves." This is totally strange too. Think of other representations. Think of an arrow on a map, and imagine someone telling you that the arrow on the map represents that very arrow on that very map. My reaction would be: what do you mean, you've confused me. And, again, on this view, it is a mystery why we would care about things are possible.

3. "Nothing. Representational possibilities don't in fact represent anything." This is also really weird. First, it makes us wonder whether the possibilities are really representational. It might seem that in such a case possibilities are failed attempts to represent. But worse, why admit that there are possibilities, if later you are going to retreat to the view that possibilities are representational and then later retreat to the view that possibilities don't represent anything. What theoretically virtuous role could possibilities play if possibilities are representations of nothing? Also, if possibilities are representational, but don't represent anything, what makes them different possibilities? Do the possibilities have different representational properties? It would seem that they don't, since none of the possibilities represent anything.

I think that possibilities must be the things represented by other things. Possibilities can't be representational devices.


Richard said...

"if X represents Y, then X and Y must both exist."

Eh? A painting can represent a unicorn though no such thing exists. (Can't it?) I would say the same sort of thing about possible worlds.

Mind you, I'd be tempted to distinguish 'possibilities' from 'possible worlds', by saying that the latter represent the former. For example, we might say that a possible world is a set of sentences, and what it represents is a way the world could be (a possibility). What is this? The question is ill-formed, if you take it to presuppose that it is an existent thing at all. Better question: what does the mega-sentence represent? That is easier to answer - just read it!

P.S. If you read Lewis' remarks about Humphrey, it sure sounds like he thinks possible worlds are representational. He thinks that Humphrey's counterpart represents Humphrey.

jack said...

Maybe you're right. I'm still confused.

1. Does the painting represent something? If no, then it would seem like the painting isn't representational after all because it doesn't represent anything. If yes, tell me what it represents. That is, what thing or object or state of affairs it represents. If the painting doesn't represent a thing, or object, or state of affairs, even in the looser sense of those words, then how can we rightly say that it represent anything at all? Maybe the painting represents an abstract object. I could understand that. But consider how confused your audience would be if you told them this: this painting represents something, wait, no it doesn't, there nothing at all that it represents, but it still represents, it's just that are there no things or thing or object that it represent. Even in non-philosophical moments, I would ask, "What do you mean it represents? What does it represent?"

In my view, the painting represents a possible state of affairs with a unicorn as a constituent. But then it seems to me that possible state of affairs had better exist, for how else is it going to stand in representation relations to actual concrete things?

Are we venturing into the land of non-existents?

2. So there are ways the world could be, and they're not sets of sentences. Hmm. Are they things? Do they exist?

I don't understand how "What is this?" could be an ill formed question, especially in this context. When I say 'this' do I succeed in referring?

You make it seem that ways the world could be, namely what mega-sentences represent, are what mega-sentences mean (when read by English speaking folk, or something). Maybe. I am open to the thought that ways the world could be are proposition-like. But notice that if ways the world could be are what mega-sentences mean, then on pain of circularity we can't define meaning in terms of possible worlds or ways the world could be. This is why I am surprised you took this horn.

3. I know Lewis says that. And frankly, I find that so totally puzzling. Consider: you, Richard, represent some non-actual person who is a lot like you? I think that the flat-footed response is this. "No, no. You're mistaken. Richard just is a lot like the non-actual person. He is similar to the non-actual person. He doesn't represent being similar to the non-actual person. That would be weird. That would be like saying to your mother, mom from now on you will represent my mom, or represent being my mom." It seems gratuitous to have things represent exactly what they are.

Richard said...

1. Sure, the painting represents: a unicorn. And note that it does so even if Kripke is right that unicorns are essentially fictional (and hence do not possibly exist). We can represent impossible things -- Escher was good at this! (And it's even easier to do so with words rather than pictures.) That shouldn't entail that there are impossible things, in any deep metaphysical sense ('being').

2. I'm not sure what to make of the circularity worry. It's true that possible worlds can't ground all representation. They may still be helpful in explicating certain kinds of representation, though. We just need to take others as primitive.

3. "He doesn't represent being similar to the non-actual person." Of course, who said otherwise? The claim is that he represents the other person. I don't see why it's any weirder to have a person who's very similar to Humphrey represent Humphrey than it is to have an object (e.g. a word) that's very dissimilar to Humphrey represent Humphrey.

neild said...

Can we distinguish between possibility and possibilities? HOW we know the difference, (the difference which is more than the singular/plural thing), is what I mean here, what I wish to point to.

Beneath the beautiful play of logic, we know (something, somehow) about "possibility" being different than "a" possibility. The difference in meaning can be sensed, felt. Why would we want our thinking ABOUT "possibilities" to leave out this difference which we already have with(know from, feel about, MEAN BY)"possibility"? Why start with less than we already have?

bloggin the Question said...

I think I'm with Richard on this. You can make the same argument about beliefs and desires. Unsatisfied desires and false beliefs are bad things, but there is no conceptual difficult, unless you are autistic or below four years old. What realism about possibilities entails is that two people could disagree about what is possible, and one of them be right and the other wrong. eg.
Person 1. It is possible to fly faster than the speed of light.
Person 2. Oh no its not.
Person 1. It is possible to get more than 180 degrees in the internal angles of a triangle
Person 2. Oh no its not.
Realism just involves person 1 or 2 being right, at least some of the time, or relative to some assumptions. Does this permit possibilities being representations? It is a kind of general representation that could actually work, in other words could actually represent something at some point. I no this is getting a bit circular, but I'm just feeling around.
What I want to know is whether it is possible to know that something is both unknown and true.