Eodnhoj7 wrote: ↑Wed Feb 01, 2023 11:15 pmIwannaplato wrote: ↑Sat Jan 14, 2023 7:57 am
What things are distinct? I think we can agree that things like forests, humans, planets are not distinct. They interact with what is around them and also inside them and have fuzzy boundaries. But at the quantum level, pretty much every thing has these issues.
Thingness is distinction.
First of all, as for the concept of
distinctness: Two things can be distinct in the sense of being
numerically different/non-identical; and they can be distinct in the sense of
not overlapping mereologically, i.e. of not sharing any
parts—or, if the things in question are
sets, in the sense of being
disjoint set-theoretically, i.e. of not sharing any
members.
Mereological distinctness and set-theoretical distinctness entail numerical difference, but numerical difference doesn't entail mereological distinctness or set-theoretical distinctness.
For example, my head and my body are two numerically different things; but they are not mereologically distinct, because they overlap by having a part in common, viz. my head. (It is a mereological axiom that
everything is part of itself; so my head is part both of itself and of my body, which means that my head and my body overlap.)
As for the ontological possibility of vague things (objects), I think there is no such thing as
ontological vagueness, because vagueness is just a matter of
semantics, of semantic imprecision or "semantic indecision":
"The only intelligible account of vagueness locates it in our thought and language. The reason it's vague where the outback begins is not that there's this thing, the outback, with imprecise borders; rather there are many things, with different borders, and nobody has been fool enough to try to enforce a choice of one of them as the official referent of the word 'outback'. Vagueness is semantic indecision."
(Lewis, David. On the Plurality of Worlds. Oxford: Blackwell, 1986. p. 212)
"I doubt that I have any correct conception of a vague object. How, for instance, shall I think of an object that is vague in its spatial extent? The closest I can come is to superimpose three pictures. There is the multiplicity picture, in which the vague object gives way to its many precisifications, and the vagueness of the object gives way to differences between precisifications. There is the ignorance picture, in which the object has some definite but secret extent. And there is the fadeaway picture, in which the presence of the object admits of degree, in much the way that the presence of a spot of illumination admits of degree, and the degree diminishes as a function of the distance from the region where the object is most intensely present. None of the three pictures is right. Each one in its own way replaces the alleged vagueness of the object by precision. But if I cannot think of a vague object except by juggling these mistaken pictures, I have no correct conception."
(Lewis, David. "Many, but Almost One." 1993. Reprinted in: David Lewis, Papers in Metaphysics and Epistemology, 164-182. Cambridge: Cambridge University Press, 1999. p. 170)