Letter nine : to the Nuns of the Paraclete -- Prefaces to the three books of the Paraclete hymnal -- Dedication letter to the commentary on the six days of creation -- Letter sixteen : prologue to the sermons -- Letter ten : to Bernard of Clairvaux -- Letter fifteen : to his comrades, against Abbot Bernard -- Apologia against Bernard of Clairvaux -- Letter eleven : to Abbot Adam and the Monks of St. Denis -- Letter twelve : to a regular canon -- Letter thirteen : to an ignoramus in the field of dialectic -- Letter fourteen : to Bishop G[ilbert] and the clergy of Paris