BIBLIOGRAPHY
An extensive bibliography of medieval heresy from the
twelfth century is contained in G. Leff, Heresy in the Later
Middle Ages, Vol. 2 (Manchester, 1967). Other important
studies are: A. Borst, DieKatherer (Stuttgart, 1963); H.
Grundmann, Religiöse Bewegungen im Mittelalter (Hilde-
sheim, 1961); J. B. Russell, Dissent and Reform in the Early
Middle Ages (Berkeley, 1965); C. Thouzellier, Catharisme
et Valdéisme en Languedoc à la fin du XIIe siècle et au début
du XIIIe siècle (Paris, 1966).
GORDON LEFF
[See also Analogy in Patristic and Medieval Thought;
Christianity in History; Double Truth; Gnosticism; God;
Heresy, Renaissance; Impiety; Pietism;
Prophecy; Religious
Toleration; Sin and Salvation.]