The Debates on Scientific Realism Today: Knowledge and Objectivity in Science

Debates on realism in science concern two main questions: whether theoretical knowledge is possible, and whether it is objective. Today, as in the past, the possibility of theoretical knowledge is often denied because of the empirical underdetermination of theories. Realists rely on explanatory power, theoretical virtues, and instrumental but theory-free observation to solve this problem. Besides, they use the “no miracles argument” for the truth of successful theories. Antirealists, however, deny that explanation is either necessary or possible, and that is a cue to truth. Moreover, they reject realism and the cogency of the no miracle argument by the pessimistic induction from the falsity of since past successful theories. Some realists reply that there is a radical discontinuity between past science (largely off-track) and current science (basically sound). But this reply is at best insufficient, and most realists prefer to restrict their commitment to selected parts or features of theories, both past and present. Forms of “selective realism” are entity realism, structural realism, deployment realism and semirealism, but also the verisimilitude research program and the restricted-domain approach. Realists need criteria to identify the true components of theories, and a noteworthy candidate is essential involvement in functionally novel and surprising predictions. The second main question is a special instance of the old debate between realists and relativists or idealists: according to antirealists science cannot be objective, because of its inherently “perspectival” nature, characterized by a priori and subjective factors. On the contrary, perspectival realists argue the specific “viewpoints” within which scientists must work do not prevent them to discover objective features of reality.