La théorie de la décision et la psychologie du sens commun


Social Science Information / Information sur les sciences sociales

September-December 2011, vol. 50, n°3-4, pp.351-374

Departments: Economics & Decision Sciences, GREGHEC (CNRS)

AbstractTaking the philosophical standpoint, this article compares the mathematical theory of individual decision-making with the folk psychology conception of action, desire and belief. It narrows down its topic by carrying the comparison for Savage's system and his technical concept of subjective probability, which, like Ramsey's, is referred to the basic model of betting. The argument is organized around three philosophical theses: (i) decision theory is nothing but folk psychology stated in formal language (Lewis), (ii) the former substantially improves on the latter, but is unable to overcome its typical limitations, especially its failure to separate desire and belief empirically (Davidson), (iii) the former substantially improves on the latter and, through these innovations, overcomes some of the limitations. The aim of the article is to establish (iii) not only against the all too simple thesis (i), but also against the subtle thesis (ii).Keywordsbelief, Davidson, decision theory, desire, folk psychology, Lewis, Ramsey, Savage, state-dependent utility, subjective probability