This paper develops a new interpretation of Heidegger's concept of conscience in order to show to what extent his thought establishes the possibility of civil disobedience. The origin of conscience lies in the self's appropriation of language as inviting a reciprocal response of the other (person). By developing the social dimension of dialogue, it is showsn that conscience reveals the self in its capacity for dissent, free speech, and civil disobedience. By developing the social roots of conscience, a completely new light is cast on the political implications of Heidegger's thought.