Die Apologia ad Wilhelmum abbatem S. Theoderici by Bernhard von Clairvaux (1091- 1153) is the most important Cistercian contribution to the debate with traditional Benedictine monasticism. This book examines this polemical work, focusing on its style, rhetorical strategies, and the overall tone of the apology. It also interprets texts that directly react to the apology.