What is Realists’ view of knowledge about science?

If you want to view other related topics. Click Here.

What is scientific realism? 
An important strand in the story of the philosophy of science in the past three decades has been a struggle between realists and anti-realists. The debate turns around the most adequate way of interpreting scientific theories that refer to unobservable entities, processes, and properties. Realists maintain that the entities postulated by scientific theories (electrons, genes, quasars) are real entities in the world, with approximately the properties attributed to them by the best available scientific theories. Instrumentalists, on the other hand, maintain that theories are no more than instruments of calculation, permitting the scientist to infer from one set of observable circumstances to another set of observable circumstances at some later point in time.

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.

Arguing for realism
Late nineteenth and early twentieth century debates over the reality of molecules and atoms polarized the scientific community on the realism question. Antirealists like MACH, DUHEM and POINCAR… ñ representing (roughly) phenomenalist, instrumentalist and conventionalist positions ñ at first carried the day with a sceptical attitude toward the truth of scientific theories and the reality of the 'theoretical entities' employed by those theories (see PHENOMENALISM; CONVENTIONALISM).

Led by the successes of statistical mechanics (see THERMODYNAMICS) and relativity (see RELATIVITY THEORY, PHILOSOPHICAL SIGNIFICANCE OF), however, PLANCK and EINSTEIN helped turn the tide toward realism. That movement was checked by two developments. In physics the quantum theory of 1925ñ6 quickly ran into difficulties over the possibility of a realist interpretation (see QUANTUM MECHANICS, INTERPRETATIONS OF) and the community settled on the instrumentalist programme promoted by BOHR and HEISENBERG. This was a formative lesson for logical empiricism whose respect for developments in physics and whose positivistic orientation led it to brand the realism question as metaphysical, a pseudo-question (see LOGICAL POSITIVISM). Thus for a while empiricist and instrumentalist trends in science and philosophy eclipsed scientific realism.