How did Londoners articulate their position as citizens as well as subjects? What modes of collective activity constituted their status, and what, besides obedience to the monarch, formed the basis of this collectivity? Taking The Book of Sir Thomas More as its central text, this essay explores homologies between theatrical practices and political formations to adduce a collaborative model of citizen activity. As the period’s most complex example of co-authorship, and as a play about citizen protest and a subject’s disobedience, More models collaborative practices in both its form and content, inviting us to read the collective labor of playwrights in relation to the common cause of citizens. Yet the play does not idealize these practices, as a rational sphere of unanimous consent, say, or as a form of utopian longing, and in this, More offers a way to extend recent work on collaboration to include a more fully articulated account of collective individuation and the reciprocities of pluralism. Based on notions of political friendship, in which the collective depends on but is not reducible to differentiation, collaboration in More requires a recognition of the paradoxical centrality of the figure of “the stranger,” not only as the demonized “constitutive outside” of citizen identity, as it is usually understood, but as a figure for the constituent differences at the heart of civic polity.