Abstract: Facing the challenge of liar paradox, the minimalist theory of truth tried to avoid the paradox through defining the acceptable instance of the equivalence schema with the grounded proposition as the discriminant standard based on the true predicate and the use theory of meaning. In order to make up the shortcomings caused by the non-grounded proposition, Paul Horwich further proposed the semantic epistemicism, which defines the acceptable instance of the equivalence schema from the semantic level together with the grounded proposition.