Une conception néo-poppérienne de l'explication en sciences sociales et ses difficultés internes

The paper investigates and objects to the neo-Popperian conception of explanation in social sciences that Maurice Lagueux propounds in his book Rationality and Explanation in Economics (2010). Inspired by Popper's (1967) famous article on the rationality principle, Lagueux makes this principle central to all social science explanations, including those of neo-classical economics. By retracing one of Lagueux's examples, i.e., Giffen goods, we will show that the rationality principle is neither necessary nor sufficient for a social science explanation. We will also discard as being ineffective the recourse to "situational logic", another move that Lagueux makes after Popper. The positive thesis underlying these objections was already sketched by Mongin (2001): far from unifying the social sciences, the rationality principle highlights their differences. Economics bases its explanations on specific principles, such as constrained optimization, whereas the other social sciences usually content themselves with reasoning only from the rationality principle.