An Ontic Theory of Indeterminacy and Vagueness

Semanticism about vagueness states that vagueness exists not in the world itself but only in our semantic representations of the world, whereas onticism acknowledges the existence of at least some vagueness in the world itself. Chapter 4 , while acknowledging that the Boolean many-valued approach itself is neutral to the semanticism/onticism debate, argues for onticism and spells out an ontic theory of indeterminacy and vagueness consistent with the Boolean many-valued approach. The theory postulates Boolean degrees in propositions, properties, and relations, including the numerical identity relation and the set-membership relation. Evans’s argument against vague identity is refuted.