This book is an intellectual biography of the Venetian historian and theologian Paolo Sarpi (1552-1623). It analyses Sarpi’s natural philosophy, religious ideas and political thought. Kainulainen argues that Sarpi was influenced by Neostoicism, Neoepicureanism and the sixteenth-century scientific revolution; that Sarpi was a fideist and Christian mortalist who, while critical of the contemporary Church of Rome, admired the purity of the early church. Focusing on Sarpi’s separation between church and state, his use of absolutism, divine right of kings and reason of state, the book offers a fresh perspective on medieval and reformation traditions. It will be of interest to those interested in early-modern intellectual history and the interplay between science, religion and politics in sixteenth- and seventeenth-century political discourse.