This article examines the usefulness of letters as evidence for reconstructing issues of conscience faced by early modern women. It considers the degree to which women's letters reveal the internal anatomy of conscience -in the sense of an inner intellectual faculty that judged the moral quality of past action and guided future action -and the nature of the process of self-examination women went through as they wrestled with the dilemmas posed by sixteenthcentury religious changes in particular. How far and in what ways did the letter develop as a 'private' confessional form? While recent studies have usefully moved away from viewing early modern casuistry as a Machiavellian science of dissembling towards a 'rigorous intellectual method', much attention focuses on these inward mechanics of conscience, arguably less on public actions and observances, and the construction of public personas, especially those of outward conformity. 1 This article, therefore, also investigates the ways in which women negotiated conscience in epistolary exchanges with state officials in letters of equivocation or dissimulation. A central issue for both categories of letter is the extent to which the epistolary medium is in actual fact capable of reflecting inner conscience. Certainly contemporary authors assumed that letters provided unrivalled access to the personality, moral character and inner spiritual world of a writer. Indeed, Miles Coverdale in his 1564 edition of the letters of imprisoned martyrs claimed that one could learn from men's epistles 'what the verye thoughts of their hartes were'. 2 To modern eyes as well, letters appear to represent private outpourings. 3 Moreover, letterwriting has traditionally been viewed as a genre that facilitated introspection, an interior self-consciousness among letter-writers. To Michel Foucault the I am grateful to