Kelly's arguments concerning Five Sermons on the Errors of the Roman Catholic Church and The Albigenses
are similarly compelling, if also similarly abridged.
It inevitably concentrates on the Holy Land, Byzantium, and their adjacent territories but also takes account of the 'crusading' factor in the wars of the Spanish re-conquest, the German expansion eastwards and in the Baltic, and the suppression of the Cathars or Albigenses
Seventeen centuries were covered by the first volume, divided into a book about the first fifteen centuries (offering much information about Waldenses and Albigenses
and about Wyclif and Hus), another book about the Age of Reformation in several countries, and a third book about the seventeenth century, containing much material about England and Scotland but also about a "revival of Christian piety about Hall in Germany" (Francke's Pietism).
Weil's attraction to the Albigenses
, the heretical medieval sect that sought to live in liberation from bodily necessity, reveals her conviction that the flesh, though created by God, must be transcended.
Their topics include heresy, madness, and possession in the High Middle Ages; the secret history of Marsiglio of Padua's Defensor Pacis in the thought of Nicole Oresme; two 17th-century views of the causes and functions of heres;, and the Albigenses
in ecclesiastical history and literature, 1550-1850.
He sees the spirit of Protestant doctrine passing from Waldenses to Albigenses
, from Wycliffe to Hieronymus von Prag and Jan Hus, from Luther in Germany to Zwingli in Zurich, from Oecolampadius in Basel to Capito in Strasburg, ending at Calvin's reformed Church in Geneva.