Locating the politics of ethical collective identities in postcolonial South India, this work explores the ways in which different cultural communities forge their self-understandings in terms of practical reason: with respect to ideas of what a good life truly is and how we should live ethically in practice. Drawing upon more than ten years of ethnographic fieldwork, the author discusses the ethical concepts, practices, and politics of the Adivasi community of Jēnu Kuŗumba, the state of Tamil Nadu, and the recently established religious discourse of the deity Sanesvara. Values and conceptions of a good life of communities are constructed and articulated in ritual and political performances in public spaces. These rhetorical performances constitute what Foucault has called 'techniques of the self', where people imagine, debate, and shape their identities in a field of competing ethical concepts and imaginations. Analysing the acts of self-creation, hegemony, and cultural resistance in the given context, this anthropology of ethics gives us a crucial perspective in studying contemporary identity politics: that identities are constituted through both practical reason and political contestation.