The heresy of the Free Spirit was an important continental European heresy of the 14th century, and this volume examines the Free Spirit movement as it appeared in its own age, concluding that it represented a spectrum of belief that emphasized voluntary poverty and quietistic mysticism.

The Heresy of the Free Spirit in the Later Middle Ages has been widely recognized as the standard work on the subject in any language. Robert E. Lerner examines this fourteenth-century European heresy as it appeared in its own age. He concludes that the Free-Spirit movement was not a tightly organized sect of anarchistic deviants, but rather a spectrum of belief that emphasized voluntary poverty and quietist mysticism.