The Movement of the Free Spirit

The Movement of the Free Spirit: General Considerations and Firsthand Testimony Concerning Some Brief Flowerings of Life in the Middle Ages, the Renaissance and, Incidentally, Our Own Time (Le mouvement du Libre-Esprit) is a 1986 book by former Situationist International (SI) member Raoul Vaneigem published in English in 1998 by Zone Books.

Summary
Vaneigem documents a number of radical heretical religious movements that took place in Europe between the twelfth and sixteenth centuries.