This paper aims to show how Heidegger and Arendt’s reappropriations of Aristotle’s thought are structured around a reinterpretation of the double definition of man as a practical being, that is, aszôon logon echonandzôon politikon. I argue that by interpreting the notions that compose and circumscribe this definition — those of life (zôê),logos, production (poiêsis), action (praxis) and contemplation (theôria), Heidegger and Arendt find the main characteristic of human beings by developing upon two distinct possibilities contained in the ambivalent Aristotelian concept (...) ofpraxis. However, they both blur the distinction between activity (energeia) and motion (kinêsis), which expose their critique oftheôriato two difficulties — one concerning the praxical character oftheôria, the other its temporality. (shrink)