Book excerpt: The Companion to Jean Gerson provides a guide to new research on Jean Gerson (1363-1429), theologian, chancellor of the University of Paris, and church reformer. Ten articles outline his life and works, contribution to lay devotion, place as biblical theologian, role as humanist, mystical theology, involvement in the conciliar movement, dilemmas as university master and conflicts with the mendicants, views on women and especially on female visionaries, participation in the debate on the "Roman de la Rose", and the afterlife of his works until the French Revolution. Some of the contributors are veterans of gersonian studies, while others have recently completed their dissertations. All map the relevance of Gerson to understanding late medieval and early modern culture, religion and spirituality.