This book examines the nearly 400-year tradition of Quaker engagements with mystical ideas and sources. It provides a fresh assessment of the way tradition and social context can shape a religious community while interplaying with historical and theological antecedents within the tradition. Quaker concepts such as Meeting, the Light, and embodied spirituality, have led Friends to develop an interior spirituality that intersects with extra-Quaker sources, such as those found in Jakob Boehme, Abu Bakr ibn Tufayl, the Continental Quietists, Kabbalah, Buddhist thought, and Luyia indigenous religion. Through time and across cultures, these and other conversations have shaped Quaker self-understanding and, so, expanded previous models of how religious ideas take root within a tradition. The thinkers engaged in this globally-focused, interdisciplinary volume include George Fox, James Nayler, Robert Barclay, Elizabeth Ashbridge, John Woolman, Hannah Whitall Smith, Rufus Jones, Inazo Nitobe, Howard Thurman, and Gideon W. H. Mweresa, among others.