Common Sense and Physics

Abstract

In The Central Questions of Philosophy (1973), chapter 5, section E, pp. 108–11,* Professor Ayer inquires into the compatibility of ‘the scientific view of the nature of physical objects and that which can be attributed to common sense’. We are presented with three alternative answers. One is that physical theory constitutes, in Ramsey’s terminology, a secondary system, the primary system being the world as conceived by common sense, or, rather, as we learn later (pp. 142–5), an attenuated version of it, stripped of dispositional and causal properties. The primary system embodies ‘the sum total of… purely factual propositions’ (p. 33); the function of the secondary system is ‘purely explanatory’, and the entities to which it refers, in so far as they cannot be identified with those figuring in the primary system, are simply conceptual tools serving to arrange the primary facts (pp. 109–10). This, then, is simply a version of instrumentalism: the actual facts, the hard facts, those that we really believe to obtain, are those of the primary system; the statements of scientific theory represent fictions, in which we do not really believe (as Ramsey confessed that he did not really believe in astronomy), but which we devise as a vivid means of encapsulating patterns and regularities detectable amongst the primary facts.