Friedrich Nietzsche, Martin Heidegger, Michel Foucault, and Jacques Derrida all engage in a more profound and precise thinking of force, in explicit and implicit dialogue with a long tradition of reflections upon its nature and qualities and the difficulties that it seems to pose for thought. This chapter describes what force means in the work of these four thinkers, traces their elaborations of its workings, and examines its importance to their work on language, politics, literature, and ethics. It discusses intellectual affiliations, divergences, debts, and inheritances among the thinkers, and in relation to the other writers they discuss, while also remaining alert to forces which traverse or trouble their writing in other directions. The chapter illuminates several aspects of the thinking and the writing of and about force in these four philosophers. Responding to the particularities of 'force' in his historical moment, each of the thinkers inhabits the differently articulated contexts, epochs, and temporalities of reading and writing and thinking.