This book presents one of the first studies of the Renaissance notion of conscience, through examining theological manuals, legal treatises, letters and other sources of the period. • Represents one of the few modern studies exploring developments in scholastic and Renaissance notions of conscience • Synthesizes literary, theological and historical approaches • Presents case studies from England and the Hispanic World that reveal shared traditions, strategies, and conclusions regarding moral uncertainty • Sheds new light on the crises of conscience of ordinary people, as well as prominent individuals such as Thomas More • Offers new research on the ways practical theologians in England, Spain, and France participated in political debate and interacted with secular counsellors and princes