http://www.sorites.org/Issue_15/chibeni.htm
Recent analyses of ontic vagueness have focused almost exclusively on macroscopic objects, such as clouds, mountains and cats. Furthermore, when the constitution of these objects is discussed (as formed by atoms, for instance), the analysis is implicitly guided almost exclusively by theories of classical physics. Since these theories leave no place for vagueness -- in the sense that, according to them, all the properties of the elementary constituents of matter are in principle specifiable with complete precision -- this has the effect of biasing the whole discussion against ontic vagueness from the very beginning.
Thus, claims of vagueness in the material objects have been easily dismissed as merely «superficial» vagueness. On the usual (but debatable: see Chibeni 2004) assumption that the properties of the macroscopic objects supervene on the properties of their microscopic constituents, any vagueness in the former could in principle be eliminated by their theoretical reduction to the latter.
Attention to this important distinction between superficial and non-superficial, or fundamental, vagueness has been drawn by Keefe and Smith (1997a, 56-57) and Burgess (1990). Whereas the former authors do not take any position on the dispute, Burgess appears to regard superficial vagueness as genuine ontic vagueness, irrespective of what happens at the basic level. Although disagreeing with Burgess on this point, we strongly support his view that the issue of whether «the world is microscopically divisible into sharp objects ... is best treated as an empirical claim» (p. 285).
Now, we obviously get different answers to this question, depending on which theory we choose. We believe that our guide here should be the best currently available physical theory. The fact that this theory will, like any other, be fallible does not imply that the choice is immaterial. Even if our interest is restricted to the question of whether there can be vague objects -- as opposed to whether there actually are such objects in the world --, the theoretical choice is important. It is just silly to rely -- for whatever purpose -- upon a theory which is known to have met with refuting evidence. Curiously, this point has been largely ignored by the students of ontic vagueness. The first noticeable exception was, to our knowledge, provided by Lowe 1994.
In this article Lowe argued that a certain quantum mechanical system involving a pair of electrons constitutes a genuine instance of ontic vague identity...