Marguerite Porete, also referred to as Marguerite Poiret, Porret, or as Marguerite de Hainaut, is the author of what is now considered a major spiritual text of French literature. For a long time, however, she was no more than a name, and her book was unknown. Her importance was recognized in 1946 when Romana Guarnieri conclusively identified the book that caused all her misfortunes: Le Miroir des simples âmes anéanties et qui seulement demourent en vouloir et desir d'amour (The Mirror of Simple Annihilated Souls Who Only Live in Hope and Desire of Love, before 1306), an anonymous treatise of mysticism widely known in several English, Italian, and Latin versions, which had been discovered in 1867 by Francesco Töldi, who mistakenly attributed it to St. Marguerite of Hungary.

Marguerite Porete's own story is mingled with the fortune of her book. What is known about her is...