Scientific realism and antirealism

Traditionally, scientific realism asserts that the objects of scientific knowledge exist independently of the minds or acts of scientists and that scientific theories are true of that objective (mind-independent) world. The reference to knowledge points to the dual character of scientific realism. On the one hand it is a metaphysical (specifically, an ontological) doctrine, claiming the independent existence of certain entities. On the other hand it is an epistemological doctrine asserting that we can know what individuals exist and that we can find out the truth of the theories or laws that govern them.

Opposed to scientific realism (hereafter just ‘realism’) are a variety of antirealisms, including phenomenalism and empiricism. Recently two others, instrumentalism and constructivism, have posed special challenges to realism. Instrumentalism regards the objects of knowledge pragmatically, as tools for various human purposes, and so takes reliability (or empirical adequacy) rather than truth as scientifically central. A version of this, fictionalism, contests the existence of many of the objects favoured by the realist and regards them as merely expedient means to useful ends. Constructivism maintains that scientific knowledge is socially constituted, that ‘facts’ are made by us. Thus it challenges the objectivity of knowledge, as the realist understands objectivity, and the independent existence that realism is after. Conventionalism, holding that the truths of science ultimately rest on man-made conventions, is allied to constructivism.

Realism and antirealism propose competing interpretations of science as a whole. They even differ over what requires explanation, with realism demanding that more be explained and antirealism less.