This paper argues that Foucault's late, unpublished lectures present a model for evaluating those ethical authorities who claim to speak truthfully. In response to those who argue that claims to truth are but claims to power, I argue that Foucault finds in ancient practices of parrhesia (fearless speech) a resource by which to assess modern authorities' claims in the absence of certain truth. My preliminary analytic framework for this model draws exclusively on my research of his unpublished lectures given at the Collège de France between 1982–84. I argue that this model proceeds in three stages: the truth-teller is first established as independently authoritative, he is subsequently tested under conditions of risk, and the encounter concludes by generating trust and a relation of ‘care’ with the audience. Foucault's model results in an ‘aesthetics of existence’ organized around a set of ethical practices, and thus offers an alternative to other forms of ethical subjectivity. In so doing, this model also critiques the place for risk in liberal political institutions.