Carole Spencer, of George Fox University in Newberg, Oregon, has produced one of the most ambitious, wide-ranging and provocative reinterpretations of the history of Quakerism in a generation. It has much to recommend it. Although at times challenging, the writing is generally lucid. The research base is broad. Spencer keeps her thesis constantly before the reader. And when she disagrees with other scholars, as she often does, she is at pains to be fair in her treatment of their work. Spencer challenges historians and theologians who have seen the heart of Quaker distinctiveness in the doctrine of the Inner Light, or immediate revelation, or silent worship. Instead, she sees it in the Quaker commitment to holiness, which she defines as ‘a spiritual quality in which human life is ordered and lived out as to be consciously centered in God’ (p. 3). Spencer begins by taking issue with historians, most notably Hugh Barbour, who see Quakerism as an extreme manifestation of left-wing Puritanism. Instead, by putting holiness at the centre of Quakerism, Spencer echoes the older view of Rufus Jones, arguing that Quakerism is a form of mysticism. Spencer goes beyond Jones, however, in seeing kinship not only with continental mysticism, but with the Eastern Orthodox tradition. She uses this as a platform to argue for the continuity of contemporary pastoral, evangelical Quakerism with early Friends, a continuity that more theologically liberal Friends have disputed. Spencer's argument is bold, and is already bringing challenges. This reviewer questions her treatment of holiness among Friends between 1870 and 1900 especially, a period when it transformed American Quakerism and laid the foundations for the pastoral system that most Friends embrace today. Spencer focuses on the American expatriate Hannah Whitall Smith, an admittedly attractive figure. Yet she pays little attention to far more influential holiness Friends, such as Dougan Clark and David B. Updegraff. Still, this will be a starting point for a new generation of Quaker historians.