ABSTRACT
Supervenience is a relation between two sets of predicates. The set of predicates A supervenes on the set of predicates B if and only if there is no difference with respect to the predicates in A without there being a difference with respect to the predicates in B. Supervenience involves no modal operators; supervenience involves a modal operator that ranges over sentences only; and supervenience involves quantifying over possible objects as well as over possible worlds. This makes it possible to attribute to an object modal properties that apply to it independently of how it is described, and thus to let the modal operator range over open formulae as well. The thesis of the supervenience of A on B is intended to provide an intermediate position between the view that the predicates of both sets are mutually independent, and the view that the predicates of A are reducible to the predicates of B.
