This article analyses the set of ethical questions underlying the emergence of the modern politics of security, as articulated, in particular, in the work of Thomas Hobbes. An ethic is here understood – in line with its ancient philosophical use and the interpretation advanced by authors such as Michel Foucault and Pierre Hadot – as a domain of reflections and practices related to the cultivation and conversion of the self. The article aims to demonstrate that, besides attending to the physical (...) safety of the state and its citizens, modern apparatuses of security are also crucially implicated in the formation of their subjects as ethical and autonomous individuals. To substantiate this thesis, the article first illustrates how, since the first appearance of the term in the vocabulary of Western thought – and in Seneca’s work in particular – theories of security have been intimately tied to the cultivation of the self. It thus interprets Hobbes’s reflections on the subject as the upshot of a substantive, if implicit, re-articulation of Seneca’s ethic of security, by focusing on the two authors’ respective understandings of autonomy, the world, ascesis, and politics. Overall, it is suggested that the differences between the two authors testify to a wider political-historical shift: in modern regimes of governmentality, the ethical dimension of security no longer defines the rightful exercise of political power, but rather appears as an object of social and economic governance. (shrink)