A semantical and methodological analysis of physical theories is performed in order to find out their relation to reality and to human experience. It is shown that every physical theory refers immediately to an idealized model of waht is supposed to be a piece of reality?the mediate referent of the theory. Two kinds of physical interpretation of physical symbols are distinguished : objective and operational, and the difference between reference and evidence is stressed. It is claimed that for a theory to be physically meaningful it is necessary that it includes rules of objective reference. In some cases a theory contains, in addition, evidential reference rules, i.e. correspondences between some of its concepts and empirical items. But the test. of any theory requires, rather than operational rules, further theories that can bridge the gap between what the theory refers to (e.g., the passage of a cosmic ray) and its remote symptom (e.g., the click of a counter). The conditions for the semantical consistency are sketched and it is argued that there does not exist a semantically consistency inter?pretation of any of the formalisms of quantum theory. From this analysis arguments in favor of critical realism are drawn.