Several commentators have distinguished between two general philosophies of science, “logical empiricism” and “perspectivism,” and implied that communication theorists who use quantitative social scientific methods are, as a consequence, logical empiricists. This dichotomy ignores a third position, “scientific realism,” which is dominant in current philosophy of science. This essay distinguishes these three major philosophic movements and advances the argument that communication theorizing is realist when it presumes the reality and causal efficacy of critical theoretical concepts. An acceptance of the scientific realist approach implies a set of three commitments for the communication theorist: to the reality of one's theoretical concepts, to scientific explanation as causal process, and to the “reliability of meaning.” Relevant communication theorizing is discussed in light of these commitments.