In many respects these books, like their authors, are very different. John Dunn has spent his career as a professional political theorist calling into question the dominant idioms of his discipline. In addition to historical research on political thought and revolutions, and studies of contemporary West African politics, this enterprise has included exposing the assumptions of liberal and Marxist ideologies. Since the 1970s, running alongside this tremendous range of concerns, Dunn has also repeatedly returned to explore the history and theory of democracy. His latest book should be seen in the context of this extended preoccupation. It has its origins in the Stimson Lectures, delivered at Yale University in 2011, resulting in what the author describes as a compact study devoted to “a very large subject.” Herein lies the first contrast with Jonathan Israel's new book. Israel has produced a large-scale intellectual history, building on a series of studies of the European Enlightenment, which began to appear at the start of the new millennium. Before that, Israel had written on colonial Mexico, European Jewry, and early modern Dutch history. It was his work on the Netherlands that led him to the thought of Spinoza, which then drew him to the ideas of the Enlightenment. As an Enlightenment scholar his approach has been characterized by a certain obduracy: a fixed commitment to a morally charged thesis. This approach can again be contrasted with Dunn’s: while Dunn's book is a sceptical assault on moral complacency, Israel's is a more didactic performance, unflinchingly committed to the righteousness of its cause. As a result, ideology collides with dispassionate inquiry, arguably simplifying both.