Timothy D. Lyons and Steve Clarke Introduction: Scientific Realism and Commonsense

Scientific realism involves two key claims. First, science aims primarily at truth. Second, we can justifiably believe that our successful scientific theories achieve, or at least approximate, this aim. The contemporary scientific realism debate turns on the acceptability of these claims. To acquire a more robust picture of scientific realism, let us identify some of the related theses on which these key claims rest. In opposition to, say, solipsists, the scientific realist insists that there exists an 'external' world with which we interact. Contra social constructivists, the scientific realist holds that this world includes events, processes, and/or entities that are not contingent on our beliefs. Scientific realists take truth to be objective and to express a correspondence relation between statements and the world. Such a conception of truth is often juxtaposed against those conceptions espoused by internal realists (e.g., Hilary Putnam, Brian Ellis).! Opposing idealists such as Berkeley, the scientific realist maintains further that we can be justified in believing that the objects we observe exist and that our basic claims about their observable properties are true. In contrast to classical instrumentalists, such as Ernst Mach, positivists (e.g., Moritz Schlick, Rudolph Carnap) , as well as fictionalists, operationaiists, and phenomenalists, the scientific realist construes scientific theories literally; most terms contained in scientific theories are intended to refer to real entities.2 Scientific realists hold that, in general, theory change in science has been rational and progressive. Moreover, scientific realists tend to espouse the view that progress in science is determined by the extent to which its primary aim is achieved (or approximated). These tenets of scientific realism collectively serve to provide a framework within which the contemporary debate on scientific realism takes place. Most prominent contemporary opponents of scientific realism