The following paragraph is from Vann McGee’s “There’s a Rule for Everything” (in Absolute Generality, which I mentioned in my post on the next Carnival):
......“Vagueness is omnipresent in human language. Our most rigorous efforts at
......scientific exactitude reduce, but do not eliminate imprecision. Unrestricted
......quantification offers us something quite extraordinary: a sharp boundary.
......Vagueness appears when there are actual or potential borderline cases, and
......something that’s alleged to be on the border between being and nonbeing is
......still something, and hence not on the border. A painting that’s sketched by
......Valázquez and completed by his pupil may occupy an intermediate position
......between ‘Valázquez’ and ‘counterfeit Valázquez’, but whoever its author is,
......the painting unmistakably exists. The idea of a thing occupying a position
......intermediate between being and nonbeing is nonsensical.” (McGee 2006: pp 183-4)
I’ve already assumed that such a “sharp boundary” is prima facie unlikely, in my recent glance at Russell’s paradox, but McGee’s paper is so well written (unlike most philosophical writing; and furthermore I agree with so much of it) that I’m now wondering if I should’ve. Essentially my thought was that the stuff around us is just that, stuff—real stuff as opposed to fictional stuff, or false theoretical stuff, but still—not necessarily things.
......Consider a photograph of a fluffy white cloud floating all alone in an otherwise perfectly blue sky. Generally there is a continuum of cloudiness, from indistinct patchiness to such clouds, and while an intermediate position will be occupied by something (some possibly fuzzy stuff) it would not necessarily be occupied by a cloud, whence we would seem to have problems quantifying over all clouds. We might say that no cloud is really a thing, but what then becomes of the fact that someone once saw that white cloud (and even took its photograph)? The problem is that the everyday objects around us are not so dissimilar to that cloud—tables and chairs, cats and dogs, for example, all shade indeterminately into other stuff (in their totalities, of all actual or possible ones, and also individually, both spatially and temporally) and so, is it nonsense to think of that other stuff not being things?
......Physics tells us that the real world actually consists of clearly delineated things such as electrons, but not only might that just be a good model of reality, do we really want to say, for example, that the chair that we are sitting on (or the word you are looking at now) is not one thing? That we do not really quantify over such things? But then the connection between quantification and communication (with which McGee began his excellent essay) would become quite mysterious. And what if physical particles are not actually so perfectly defined as the practice of physics (like the practice of logic) requires us to assume that they are? Would we then really be quantifying over nothing? It seems more likely that, whatever sort of stuff the world is actually made of, we individuate it as precisely as we need to, in order to communicate truths about the world, and that we quantify over those things. But then the idea of something occupying a position intermediate between such things and the bare stuff of the world is hardly nonsense (more like the idea of a linguistic possibility, perhaps).
......Now, two people might agree that there was that white cloud, but perhaps they would (were all the data available) disagree over what counts as being that cloud (as it formed and vanished). Surely there was just the one cloud there, and yet there might have been two distinct individuations of the actual stuff of the world. We could count the distinct individuations as giving us different things, but then what of the one cloud that we began with? The problem appears to be that were we to quantify over all things, we would inevitably be drawn into considering intermediate positions, where there might well be no objective fact of the matter about what are two things, and what are two views of the same thing.
......Consider McGee’s example, of the painting: By how much could it be restored before it was a different painting? And by how much could its author (whoever that was) have painted it differently (a brushstroke? a molecule of paint?) before it would have been a different painting? In order to quantify over every thing, we might need there to be objective answers to many such questions, about all kinds of things; and the plausibility of that is surely not obvious.