ABSTRACT

Presently accepted physical theories postulate a curved space-time structure, fundamental particles and forces of various sorts. What we can know for sure on the basis of observation, at most, are only facts about the motions of macrosopic bodies, the tracks that appear in cloud chambers in certain circumstances and so on. Most of the content of the basic theories in physics goes “beyond” the “directly observational” – no matter how liberal a conception of the “directly observational” is adopted. What is the status of the genuinely theoretical, observation-transcendent content of our presently accepted theories? Most of us unreflectingly take it that the statements in this observation-transcendent part of the theory are attempted descriptions of a reality lying “behind” the observable phenomena: that those theories really do straightforwardly assert that spacetime is curved in the presence of matter, that electrons, neutrinos and the rest exist and do various funny things. Furthermore, most of us unreflectingly take it that the enormous empirical success of these theories legitimises the assumption that these descriptions of an underlying reality are accurate or at any rate “essentially” or “approximately” accurate. The main problem of scientific realism, as I understand it, is that of whether or not there are, after reflection, good reasons for holding this view that most of us unre-flectingly adopt.