This paper explores the ways in which the Anthropocene, this new epoch in which noearthly place, form, entity, process, or system escapes the reach of human activity, puts underpressure some traditional categories and concepts of liberal democratic theory. We begin byexplaining the notion of the Anthropocene, and then show how it may affect traditional liberalnotions of agency, responsibility, governance, and legitimacy. We conclude by describing thechallenge of designing new institutions appropriate to the Anthropocene.