The shift in Foucault’s work from genealogy to ethics finds consensus among Foucault scholars. However, the motivations behind this transition remain either misunderstood or understudied in large part. Foucault’s recently published or soon-to-be translated 1977/—9 lectures (published as Security, Territory, Population and as The Birth of Biopolitics) offer new elements for understanding this dense and uncharted period along Foucault’s itinerary. In this article, the author argues that Foucault’s interpretation of the liberal tradition, which is at the core of the 1977—9 lectures, must be examined in combination with Foucault’s other major interests in the late 1970s, namely the Iranian Revolution and Kant. The discovery of spirituality (Iran), the valorization of an autonomous subject (Kant) and the call for a tolerant environment towards minority practices (liberalism) pave the way for the later Foucault’s ethics, which are grounded in spiritual exercises and means of liberating the subject.