[An] ambitious and thought-provoking book. * Takashi Shogimen, Journal of Ecclesiastical History * George Garnett's book is enlightening and informative about what fourteenth-century thinkers were, in context, really discussing. It is also an often amusing retelling of an immensely complicated story ... Those readers who are already familiar with the historical and religious tensions of this period will find much to appreciate in Garnett's book. * J. Coleman, Times Literary Supplement * As an introduction to the Defensor pacis for a beginning student of medieval history or as an eloquently argued and amply documented alternative view for a veteran in the history of political ideas, this book could hardly be bettered. * Speculum * Garnett has performed a superb service to the understanding of the Defensor Pacis, in that he has managed to put Marsilius's historical imagination and practice under the microscope. * Jurgen Miethke, Francia-Recension * Garnett has made a highly important contribution to the ongoing debate about how to interpret Marsilius and how to assess his significance. * English Historical Review *