This chapter establishes Hannah Arendt as a biopolitical thinker particularly attuned to the powers and implications of modern technology. The chapter identifies and articulates the two key trajectories that Arendt associates with modernity. The first is a growing prioritisation of life processes within politics. The second is a politicisation of such life processes through the use of new calculative technologies. In discussing each of these trajectories, the chapter argues that biological life and technological reason are best viewed as two distinct but related aspects of modern politics. It also suggests that these are always in tension with one another as the cyclicality of life processes runs up against linear projections of human progress.