The theoretical apparatus of semantic realism: A new language for classical and quantum physics

The standard interpretation of quantum physics (QP) and some recent generalizations of this theory rest on the adoption of a verificationist theory of truth and meaning, while most proposals for modifying and interpreting QP in a ''realistic'' way attribute an ontological status to theoretical physical entities (ontological realism). Both terms of this dichotomy are criticizable, and many quantum paradoxes can be attributed to it. We discuss a new viewpoint in this paper (semantic realism, or briefly SR), which applies both to classical physics (CP) and to QP, and is characterized by the attempt of giving up verificationism without adopting ontological realism. As a first step, we construct a formalized observative language L endowed with a correspondence truth theory. Then, we state a set of axioms by means of L which hold both in CP and in QP, and construct a further language L(e) which can express both testable and theoretical properties of a given physical system. The concepts of meaning and testability do not collapse in L and L(e), hence we can distinguish between semantic and pragmatic compatibility of physical properties and define the concepts of testability and conjoint testability of statements of L and L(e). In this context a new metatheoretical principle (MGP) is stated,which limits the validity of empirical physical laws. By applying SR (in particular, MGP) to QP, one can interpret quantum logic as a theory of testability in QP, show that QP is semantically incomplete, and invalidate the widespread claim that contextuality is unavoidable in QP. Furthermore, SR introduces some changes in the conventional interpretation of ideal measurements and Heisenberg's uncertainty principle.