 Many people recoil at the thought that the world itself could be vague or indeterminate, perhaps because they believe that indeterminacy must be a result of mismatch between what is represented (the world), and what does the representing (thought or language). Even those who don’t mind a bit of worldly vagueness may have reason to reject worldly vagueness in persistence, because this amounts to worldly vagueness in identity: it’s vague whether the original bicycle your uncle gave you is identical with the bicycle you now ride to work. Worldly vagueness in identity is thought to be especially problematic, because all identity is self-identity, and it’s hard to see how there could be any vagueness in self-identity.