The essay explores Erasmus' development of a fourth category of rhetoric, the familiar, in its work as a rhetoric of the absent audience in both personal and sociopolitical contexts, and as a rhetoric resonant with early modern theories of friendship and temperance. The discussion is set against a background of Caxton's printing of the translation of Cicero's De Amicitia, because Erasmus casts friendship as the context for appropriate communication between people from quite different education and training, along with the probable rhetoric that enables appropriate persuasion. The probable rhetorical stance of temperate friendship proposes a foundation for a common weal1 based on a co-extensive sense of selfhood. This focus suggests that the familiar rhetoric set out in Erasmus' De Conscribendis epistolis draws on Cicero's rhetoric of sermo2 at the heart of friendship.3 It explores the effects of the rhetorical stance of probable rhetoric, both for personal and social writing, and for political action, and looks at the impact of sermo rhetoric on ideas of identity and civic politics in an age of burgeoning circulation of books (both script and print). The essay concludes with three post-Erasmian case studies in English rhetoric [Elyot, Wilson, Lever] that use probable rhetoric to document approaches to individual and civic agency and which offer insights into the Western neoliberal state rhetorical structures of today.