Tuesday, January 13, 2009

Reifying Possibilia

Sally could have had a child, but didn't. Does that mean that there is some possible child, of Sally's, who doesn't actually exist? Can we give him or her a name - 'Kim', say - and lament for Kim's own sake that s/he wasn't brought into existence?

I think such talk is metaphysically confused. But it can sometimes be useful to talk of mere possibilia (e.g. possible people), so long as we take care to understand what is really being said. Suppose that, if Sally had had a child, it would have had a wonderful, flourishing life. This modal fact might give us a reason to prefer that Sally had the child. We might express this in shorthand by saying, "Kim's welfare gives us reason to want Kim to exist". But we are not really talking about Sally's child Kim - there is no such person to talk about. Rather, we are talking about the world and how it could have turned out. It could have turned out that Sally had a child with a flourishing life, and this fact about the world gives us a reason to wish things had turned out that way.

Compare our talk of fictional characters: it is convenient to reify them, and talk "about" Frodo and Sauron and the rest. We can even say true things using such talk: e.g. Frodo destroyed Sauron's ring of power. This is a truth, not about what actually happened, but about the fiction. There is not really an entity, 'Frodo', and another, 'Sauron', such that the former destroyed the latter's ring of power. You can't reify intentional objects so. There aren't really any such people or things. But it is sometimes convenient to talk as if there were, since that can help us talk about particular features of the fiction.

In the same way, we can talk "about" possible people in this loose, 'de dicto' sense. But it's just words. It would be a mistake to reify them, or to think that there are some particular possible people (de re) of which we speak. Talk of possible people should instead be understood as shorthand for talking about particular features of a way the world could be -- i.e. such that more people exist than currently do.

This theoretical point has at least two important applications: (i) in understanding what's wrong with the ontological argument, and (ii) in seeing that possible people cannot really be the ultimate source of the (even non-instrumental) reasons to bring them into existence.* More on this in a future post...

* = [Of course, there isn't really any 'them' to refer to. So that should read: "reasons to bring it about that the world contains additional people."]


  1. This view puts you in a *very* bad position to explain why our universe is such that there are observers, unless you take a very constrained view about what sorts of worlds are possible, which you don't, as far as I can tell.

  2. Anthropic fine-tuning.


    If you think that things could have been such that no observers would exist, and that most worlds, weighted for simplicity by Occam's Razor, include no observers, then your theory predicts no actual observers.

  3. Oh, you're thinking of concrete possibilia. That's a separate issue. I'm merely arguing against abstract possibilia here, or the thought that there are possible people that don't exist (in any concrete universe).

    [P.S. if Kim exists elsewhere, there's nothing to lament.]

  4. It's also relevant to showing a way in which possible worlds analysis of modality distorts what it is supposed to model; because if possible worlds analysis were wholly accurate it would be in-principle possible to identify 'Kim'. (The difficulty would simply be one of picking out the 'Kim'-world(s) in particular from all the infinite possible worlds in order to talk accurately about 'Kim' in particular.)

  5. By the by, Gollum destroyed Sauron's ring, not Frodo.

  6. Frodo should have done it:


  7. Heh, true, silly me.

    Brandon - I'm not sure I follow you. For all I've said here we may be able to pick out the 'Kim'-worlds. But that's not the same as picking out Kim (de re), because "intentional objects" aren't thereby objects.

  8. Richard,

    What is the argument that fictional characters and mere possibilia do not exist? Is there something more repugnant about the existence of fictional characters than the existence of other abstract objects, like works of fiction?

  9. Hi, Richard,

    I'm not sure what would be involved in picking out (say) Richard-worlds if you couldn't in principle pick out possible Richards as pertaining to those worlds; Richard-worlds are just possible worlds where Richard can in principle be picked out as belonging to the possible world. (And to be real Richard-worlds they'd have to be; they couldn't, for instance, just be worlds that could be described as having a Richard in them, because descriptions can be false and therefore they might not be Richard-worlds at all, and ditto with related ways of trying not to use possible Richards as the criteria for picking out possible Richard-worlds. If we can't pick out Richard, we can't ever be sure we have the right worlds to have actually picked out the Richard-worlds, except by stipulation.) And so with 'Kim'-worlds, although in such a case we are dealing with a more complex practical task because of the difficulty of getting precise enough to distinguish 'Kim' from other possible children; but given the stipulation that we've overcome that practical problem, we have all we need to talk about 'Kim' as a real possible (she's the element that makes a 'Kim'-world a 'Kim'-world rather than not a 'Kim'-world) -- if possible worlds analysis is taken at face value. The plausible alternative is to say that in possible worlds analysis we don't really ever pick out 'Kim'-worlds; we stipulate them as a feature of a model of real-world modalities. Then we can have 'Kim'-worlds without any 'Kim' to pick out. But if this is so, then possible worlds analysis is distorting to the extent that it (as a matter of the model rather than of reality) treats possibilia as distinct from modal features of the actual world.

  10. Richard,

    Why can we not have obligations to individuals who do not exist?

    For example, suppose that John and Bert are soldiers. They are friends; one day, Bert is shot and begins to die. While Bert is dying, John promises Bert, as Bert requests, to deliver his watch to his wife when he (John) returns home. Subsequently, Bert dies. Now, when John returns home after the war, he decides to pawn off the watch -- breaking his promise to Bert. Intuitively, it seems as though John wrongs Bert. It doesn't make a difference that Bert is dead.

  11. Timmo - Bert exists well enough -- it's just that his temporal location is in the past. Note that if there were no such entity as Bert, then it would be metaphysically incoherent to claim "John wrongs Bert." ("Wrongs who?") There clearly is someone we're talking about here -- an actual person. Whether he's around now is of no more metaphysical significance than whether he's around here.

    Brandon - I think possible worlds are purely qualitative, so description captures all there is to capture.

    Jack - mere possibilia definitely seem worse to me than other abstracta. It's harder to pin down why. Perhaps part of it is that mere possibilia misrepresent their own natures in a way that other abstracta don't. Frodo is essentially warm-blooded, say. But then Frodo can't be an abstract object, because abstract objects don't have blood at all.


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