over the trial, during which Gilbert and Bernard were asked to cite and explain specific biblical texts. Bernard, lacking Gilbert's experience of the technique of the schools, was not able to condemn him. It was nevertheless decided to require Gilbert to reformulate parts of his book. Gilbert died in 1154. He was buried at the Église Saint-Hilaire-le-Grand in Poitiers. Works Authentic works Commentaria in Boethii opuscula sacra, edited by Nikolaus M. Häring, Toronto: Pontifical Institute of Mediaeval Studies, 1966. The Psalms Commentary of Gilbert of Poitiers, edited by T. Gross-Diaz. Leiden: Brill, 1996. Spurious works Hermes Trismegistus, De sex rerum principiis, edited by P. Lucentini and M. Delp, Corpus Christianorum Continuatio Mediaevalis (CCCM 142), Turnhot: Brepols, 2006. Gilbert is almost the only logician of the 12th century who is quoted by the greater scholastics of the succeeding age. The Liber sex principiorum, attributed to him, but in fact the work of an anonymous author, was regarded with a reverence almost equal to that paid to Aristotle, and furnished matter for numerous commentators, amongst them Albertus Magnus. Owing to the fame of this work, he is mentioned by Dante as the Magister sex principiorum. The treatise itself is a discussion of the Aristotelian categories, specially of the six subordinate modes. The author distinguishes in the ten categories two classes, one essential, the other derivative. Essential or inhering (formae inhaerentes) in the objects themselves are only substance, quantity, quality and relation in the stricter sense of that term. The remaining six, when, where, action, passion, position and habit, are relative and subordinate (formae assistantes). This suggestion has some interest, but is of no great value, either in logic or in the theory of knowledge. More important in the history of scholasticism are the theological consequences to which Gilbert's realism led him. In the commentary on Boethius' treatise De Trinitate he proceeds from the metaphysical notion that pure or abstract being is prior in nature to that which is. This pure being is God, and must be distinguished from the triune God as known to us. God is incomprehensible, and the categories cannot be applied to determine his existence. In God there is no distinction or difference, whereas in all substances or things there is duality, arising from the element of matter. Between pure being and substances stand the ideas or forms, which subsist, though they are not substances. These forms, when materialized,