Realists assert the actual or possible existence of some disputed entity, which may be a subatomic particle, a social structure, or the world or universe itself. Realism as a general philosophical position is often opposed to skepticism, the doctrine that we can never know whether something (or even anything) exists, and to positions that see reference to entities as merely a useful fiction to make sense of observations. Realism tends to be associated with materialism as opposed to idealism, although it is opposed to nominalism about “universals” or the referents of general terms. In this latter sense, it is closer to idealism in asserting the real existence of, say, something called redness as distinct from its instantiation in particular red objects. In modern philosophy of science, realism mainly opposed positivism and the claim made in logical positivism or logical empiricism that metaphysical questions about the reality of objects, as distinct from our observations of them, are meaningless. More recently, with the eclipse of positivism (see POSTEMPIRICISM), realists, especially those identifying with CRITICAL REALISM, have turned their opposition more to social CONSTRUCTIONISM and POSTMODERNISM. Others, however, combine a realist conception of science with a social constructionist account of human societies.
Arguments for realism fall into two broad classes. First, there are inductive arguments from scientific convergence. Where scientists increasingly agree about explanations that have been refined over many years, it may be reasonable to think that we are getting closer to a true representation of reality. Second, there are arguments of principle based on what is required for science to be possible or meaningful—notably, that the world exists in an ordered and predictable way. In the social sciences, both sets of arguments are more problematic: There is less convergence on agreed paradigms and not even complete agreement on the very possibility of social science (see naturalism). Social scientists are more likely to precede their references to social structures and mechanisms by an implicit “It is as if … .”
Realism does not entail a commitment to any particular theory of the social world, nor to any particular set of research methods. As an antior postempiricist position, however, it plays down the importance of repeated observation and prediction as criteria of explanatory success. Entities that are observable only in their effects, such as magnetic fields and social structures, may interact with others in such a way as to neutralize one another, although theoretical analysis and experimentation may, nevertheless, demonstrate their existence. Here on the Earth’s surface, we are subject both to its gravitational attraction and to the centrifugal force of its rotation; the result is that we mostly stay where we are. Social forces, individual or structural, may interact in a similar way, but again, they are harder to demonstrate to general satisfaction. Antirealists are suspicious of an apparently uncontrolled proliferation of entities, endowed like humans with causal powers (see CAUSALITY), and accuse realists of ESSENTIALISM.