 For our purposes, it will be convenient to think of a Tarskian truth theory as a variant on the sorts of theories of reference introduced in  §2.1.1.  Recall that theories of reference of this sort specified, for each proper name in the language, the object to which that name refers, and for every simple predicate in the language, the set of things which satisfy that predicate. If we then consider a sentence which combines a proper name with such a predicate, like