Test-theory methodology in physics.

Test theories are mathematical constructions with a methodological purpose. They enable experimental or other observational evidence, definitively to select a physical theory from out of a class of alternatives-a formal deductive method of testing which is (as I will show) distinct from the traditional hypothetico-deductive one. I believe that the study here of test-theory methodology is important for philosophers of science if they are properly to understand (i) methods of theory appraisal in physics, (ii) certain key conceptual issues in the foundations of physics, and (iii) more generally, the growth and structure of physical theory (history). I believe that this study is important also for physicists who desire a clearer understanding of the power, limitations, and conceptual presuppositions of the test-theory method. (i) Methods. I show how test theories establish relations between physical theory and phenomena which are at once stronger and more systematic than relations established by the hypothetico-deductive method. I use this result to defend some positivist methodological doctrines which philosophers today generally reject. I also use the result to criticise certain post-positivist doctrines which are meant to replace the very positivist doctrines I aim to defend. I compare some philosophical accounts of empirical confirmation with test-theory methodology in order to illuminate some features of the test-theory method and criticise standard philosophical accounts of confirmation. In this discussion I explore limitations of the test-theory method and identify general conditions which both knowledge and the world must satisfy if the method is to work. (ii) Foundations. I address some key issues in the foundations of physics issues concerning the nature of space, time and causation. I discuss how test-theory methodology reveals the extent to which the very foundations of physics are empirically determinable. This extent is limited I argue: my discussion points to the furthest application but also to some notable limitations of the test-theory approach. (iii) History. I argue that Newton pioneered the use of test-theory constructions in theoretical physics, and I show how twentieth century physicists have brought the test-theory method to a high level of sophistication. I argue both that the test-theory idea makes possible a coherent view of the history of physics, and that the history of physics deepens our appreciation of the power of the test-theory idea. There is unity, I argue, at the level of test-theory methodology across the seemingly disparate historical phases of physical inquiry (classical versus modern). There is power, I maintain, in a method which can fruitfully be applied in seemingly diverse conceptual contexts (Newtonian versus Einsteinian)