This article places Hannah Arendt's fundamental view of the instrumentality of violence in dialogue with Walter Benjamin's ‘Critique of Violence' in order to demonstrate the importance for each of a notion of ‘mere life' or ‘life itself' to an understanding of the agency of violence in modernity. Arendt's critique of vitalism is most fully developed in "The Human Condition", where she describes an entanglement of the instrumental activity of homo faber with life and labour in the work of Bergson, Nietzsche and Marx. I suggest that Bergson's treatment of life as creative evolution unexpectedly yields an accurate description of politics as spontaneous, unpredictable motion that Arendt takes as typical of modernity. Since Arendt also credits Bergson with a decisive influence on what she takes to be a growing commitment to the life-enhancing, creative potential of violence in the oppositional movements of the 1960s, which she explores in her late essay, On Violence, I trace out the continuity between Arendt's earlier account of homo faber and her later critique of postmodern oppositional violence.