William of Conches is one of the most important and innovative thinkers of the first half of the twelfth century. This second volume in the projected series of editions of his works contains his widely influential commentary on Boethius' Consolatio Philosophiae (dated to about 1120). In this continuous, lemmatic commentary William gives a systematic and comprehensive interpretation of Boethius' masterpiece. He far surpassed previous commentators in depth, originality and comprehensiveness, thereby laying the foundations for future work on this text, most notably that of Nicholas Trevet (ca. 1300) and vernacular renditions. William's work, however, is not only of considerable importance for the medieval Boethian tradition, but also for the development of twelfth-century philosophical thought. It testifies to his keen interests in natural philosophy, discussing various themes such as elements, the movements of the planets, tides and winds, the enfolding of the cosmos, the generation of life, and human psychology. These passages were used and further developed in his famous work on natural philosophy, De philosophia, and in his Plato commentary. Other important themes which William addresses are the Neoplatonic theory of the soul, human knowledge, and free will and divine providence. He develops for the first time his famous hermeneutic instrument of the integumentum (the veil of fabumous or heterodox narratives, covering profound truths) and applies it to Boethius' employment of pagan myths and Neoplatonic doctrines. The Glosae super Boetium, written by one of the most representative intellectuals of his generation, then, is a highly instructive example of the intellectual preoccupations and achievements of the first half of the twelfth century. The edition is based on a thorough examination of all the available manuscript evidence. Languages: Latin.