Friday, July 24, 2009

Distributing vagueness: shifting the burden from singular to general terms

Orthodoxy has it that vagueness is first and foremost a property of sentences:

(1) That [pointing at my car] is red

or

(2) Bruce is bald. [where Bruce is Bruce Willis]

The vagueness of these sentences is usually analyzed by giving an account of the general terms red and bald, not the singular terms that and Bruce. So any account of vague objects will have to shift the intuitive source of the vagueness of paradigmatically vague sentences from the predicate to the subject. (Williamson suggests the canonical view's tendency to localize vagueness in predicates as a reflection of the `truthmakers are objects' principle, which is really, he says, an unjustifiable dogma.)

It is worth asking why we think that the vagueness of (1) and (2) should be explained by focusing on properties. I suspect the answer is not any insight into, or conviction regarding, the manifest precision of objects (whatever that would be) but rather our strongly-held beliefs about the modal plasticity of Bruce and my car:

(1') My car might have been red.

(2') Bruce might have had abundant hair all his life.

...while Bruce and my car are borderline cases, it is not essential to them that they are. But is the truth of (1') and (2')---which I take for granted---really material to the question of whether there are vague objects? The significance of (1') and (2') should be left an open question pending an account of the relationship between vagueness and modality.

Note also that while we have robust intuitions about the modal plasticity of persons and everyday objects, we generally lack intuitions about the modal profile of properties. While there is talk of vague predicates' being essentially vague, it is not clear what this means; to the extent that it is clear, it is a statement about the predicates' meaning, not their extension. By contrast the intuitions in (1') and (2') are definitely intuitions about the denotation (or extension) of `That' and `Bruce.' This is all the more easily shown given that the current going theory of proper names and demonstratives is that they do not have meanings (`meanings' understood here as Fregean senses.)

Two questions:
(#1) Are all these intuitions about general and singular terms really consistent? If we think of e.g. the predicate blue as the set of blue things, then if you change the color of my blue shirt, you will change the predicate blue...because you change the set of which the shirt is a member, and the identity conditions of sets are given by their members.

So the (1') intuition about the modal plasticity of my car [my car itself, not just the mode of presentation ``Melissa's car"] is equally an intuition about the modal plasticity of blue [blue itself--if such a distinction between the sense and the reference of a general term is even possible!*]

The identity conditions of properties are usually given by modal extensions (c.f. solving the renate-cordate problem.) But, again, that means that one fewer blue object in logical space will change blue into an entirely different property (because it would denote a different set.) Given our limited knowledge of what goes on in the outer reaches of logical space, this is not a very helpful definition of `blue', nor is it one which informs our intuitions about the term. But the fact remains that we are not sure what blue could be like, if it weren't like it is. (Is 2-dimensionalism helpful here?)

(#2) Can I make the same move I made with Sorensen? Here is my cri du coeur:

I just don't think this approach--starting first and foremost with vague sentences and then looking for a suspect to fix the vagueness on--is very profitable. After all, it does not seem to me that sentences are the primary locus of vagueness. The phenomenology of vagueness is something that strikes us when we look at continua: color continua, height spectra, etc. So it is, for example, a feature of color, and only derivatively a feature of sentences with color predicates. At the level of sentential form, we don't have enough information to determine whether ``Tim is pink" is vague. What we need is to see Tim, and to see his color.

This seems right to me even still. I do not think what is really at issue is an enormous debate over what it would mean for a general term to be a rigid designator, etc.

****

*Is it made possible by distinguishing between analytic truths, as McGee does, and truths constituted by use + world?

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