Reading Questions for Duhem’s “Physical Theory and Experiment”

Due Date: 10/16

What is Duhem’s distinction between and experiment of application, and an experiment of testing?

1. Why, according to Duhem, can the physicist never test an isolated hypothesis? Why can she never leave the theory ‘outside the door of the laboratory’? Why does a failed prediction (failed experimental test) not tell the scientist where the error lies, what can it tell her? What has all this to do with the experimental apparatus used?

2. Why can there be no ‘crucial experiment’? I.e., why is the experimental refutation of one theory NOT a result guaranteeing the truth of the alternate theory? I.e., why is it not reduction to absurdity?

3. Duhem argues that (despite what Newton famously claimed) Newton’s principle of universal gravity is not derived by induction and generalization from Kepler’s laws. How does Duhem support this claim? How does he explain the failure of the ‘Newtonian Method’ (i.e., the supposed method of deriving via induction and generalization only what the observations admit)? In particular, what is the importance of the symbolic and approximate character of laws of theoretical physics.

4. In the example of ‘free fall’, Duhem agrees with Le Roy that we will prefer maintaining rather than rejecting the theoretical idealization of free fall (i.e., we will no longer consider the concrete example of a fall as truly an example of free fall). Does Duhem take this to show that some hypotheses are immune to being refuted by experiment? If not, how does he explain why and to what extent we protect the theoretical idealization?

How does Duhem reject Poincaré’s claim that certain principles cannot be refuted by experiment because the principles themselves do not have experimental/physical meaning?

5. What, according to Duhem, is ‘good sense’, and how is it supposed to function in theory choice? After our readings from the first two units how convincing is Duhem’s view that ‘good sense’ and being an ‘impartial and faithful judge’ will lead to objectivity and truth? How can one be impartial if one can never leave the theory outside the door of the laboratory?