Field’s study concerns Marguerite’s background and contestation of the initial judgement of her Mirror of Simple Souls after the death of her first inquisitor, the background of her new inquisitor William of Paris, confessor to the French king Philip IV and their political intentions, the surprising entrance of the mystic Guiard and the background of the ‘Free Spirit’ movement, as well as the political subtext of the Albigensian heresy and its unfortunate conflation with the Beguine movement. It is a complicated drama that Field unfolds subtly. The author focuses very little on Marguerite’s theology and a great deal on the characters’ biographies and archived legal documents. The historical context is the early 1300’s.

Marguerite’s association with the Beguine and Beghard movement of lay female and male mystics is questionable, but not unreasonable. She was probably wealthy and had connections to important church leaders. Her work was indeed in consonance with the love mysticism of the Beguines, and thus placed her in the suspicious category of being a Beguine. Briefly, her work dealt with the annihilation of the soul to God in pure love. Her first inquisitor, Guido of Collemezzo, bishop of Cambrai, notoriously burned her book. As a canon lawyer Guido’s intention was administrative and legalistic, intending to regulate the new lay movements of northern France and Flanders. Marguerite fell into Guido’s political machine just as she later fell to the hands of inquisitor William and king Philip IV.

After her initial condemnation by Guido, and especially after Guido’s death, she sought out other ecclesiastic authorities who would validate her theological speculations. She found a local friar, a monk and a theological master who prefaced her edited and rewritten Mirror, though they warned her that her work was too theologically advanced for the common reader or even a legalistic bishop. What her work suggested, as well as Guiard and other new lay movements, was that the mystic believer who has lost their soul to God in love may perhaps be absolved of normal moral behavior. This was clearly an affront to the legalistic ecclesiasts.

Marguerite’s wrote in a dialogue format, and so, ironically, did her new inquisitor William of Paris although his works were written in a formulaic pedagogical format. Her book came to William’s attention after her insistence on printing new copies and presenting them to assumed sympathetic ecclesiastics. Her book eventually landed in the hands of an accuser and she was brought to trial.

Like Guido, William was also a canonist with a precise legal mind. Field recounts his legal career that culminates in his unprecedented position as both inquisitor and confessor to Philip IV that leads to his role in a supposedly papally and royally instigated prosecution of the Albigensians in southern France. His prosecution of Marguerite as a Beguine heretic followed this event.

The figure of Guiard of Cressonessart enters her trial from seemingly nowhere as a witness to her defense but finds himself on trial as well. Guiard’s comes to Marguerite’s defense as an angel of the apocalyptic church of Philadelphia who supports any holy person who is unfairly persecuted. In this case it is the divine king and his confessor persecuting the mystic Marguerite. Guiard’s testimony ranges from his own comparison to Christ, then his later comparison with the OT prophet Elijah, with John the Baptist and Christ being a forbidden NT personages to compare himself with.

Marguerite’s Mirror is subsequently reviewed by twenty-one theologians and later five canonists. A minority of the theologians were ambivalent about the book, but William and his canonists were of a similar legal mind. Guiard repented and was spared the stake and instead served life imprisonment. Marguerite did not repent and was found to be a rebellious, contumacious heretic because of her insistence on continually distributing her Mirror after its previous censorship by Guido.

Field argues that Marguerite’s prosecution rested on her actions rather than the content of her work, that Guiard’s actions were genuine yet misdirected against the ecclesiastic authorities, and that William and Philip IV were in a power game against the pope. Marguerite was ultimately caught in the political games of Guido and later of William and Philip IV.

As a historical work there are extensive references on sources, most of which come from carton J428 in the Archives nationals de France in Paris. Several epilogues and appendices include translations of important letters and trial documents that can serve the student of medieval history and ecclesiastical history quite well.