This article deals with Michel Foucault's 1977–79 lectures on political economy. In the first part, we highlight his views on the market, which is equated to a social device instrumental in governing individuals so that they are induced to allow the ruler to reach his goal, which is providing security to the population. In the second part, we consider together Foucault's and Weber's views on the economy, since Foucault's concept of technique of the self is similar to Weber's concept of (...) life conduct, which is central in his sociology of religion. This opens the way to a history of the modern economic behaviour considered as a form of ascetism. (shrink)