Part I is concerned with the tenet of modern Emperical Realism that while the theoretical concepts employed in science obtain their meanings entirely from the connections their usage establishes with the data language, the referents of such terms may be “unobservables,” that is, entities which cannot be discussed within the data language alone. Such a view avoids both the restrictive excesses of logical positivism and the epistemic laxity of transcendentalism; however, it also necessitates a break with classical semantics, for it follows from the empirical realistic position that a theoretical term must in principle be capable of simultaneously designating not just one entity, but indefinitely many.

Drawing upon the Carnapian explication of “analytic truth,” Part II examines a possible axiomatic basis for the empiricist theory of scientific meaningfulness to demonstrate that even if theoretical terms are able to designate entities inaccessible to the observation language, as held by Empirical Realism, so long as the meanings of theoretical terms derive from their connections with the observation language, the meaning content of a theory is exhausted by its observational consequences.