Biography, Apprenticeship, and General Characteristics of His Philosophy

Gilbert was born in Poitiers shortly after 1085 and began his studies there under Hilary of Poitiers. Later he moved to Chartres where he was one of the students of Bernard. At Poitiers and Chartres, he studied the liberal arts, in particular grammar, dialectic, and rhetoric - in which his knowledge was legendary - and Platonic philosophy. He studied Plato’s Timaeus with Calcidius’ commentary, and Boethius’ Opuscula sacra and Consolation of Philosophy. From Chartres he moved to Laon, where under Anselm and Ralph he was educated in the understanding of the Fathers and Scripture. He was a master at Chartres from 1124 at the latest (at least according to most scholars, but see Gross-Diaz 1996), and, starting sometime between 1137 and 1141, at the cathedral school of Paris, where he had John of Salisbury among his students. John remarked that his teaching appeared obscure and arcane to the beginners, but that the experts, used to his original terminology and complex style, found it to be of great profundity. His teaching at Paris was cut short in 1142 when he was named Bishop of Poitiers, where he died in 1154. The rational and philosophical style of doing theology earned Gilbert, among others, an accusation of heresy by Bernard of Clairvaux (who also persecuted Abelard), from which he had to defend himself in front of the Pope in 1147, and later, in 1148 (Maioli 1979:XVI-XXI; Nielsen 1982:30-38). He was accused, in particular, of holding that the divine nature was identical, not with God but with a form, just as in the case of humanity, which is not identical to man but with the form thanks to which a man is a man; and of holding that the properties (generatio, filiatio, processio) through which the three persons of the Trinity are distinguished are distinct from the persons themselves (Pater, Filius, Spiritus Sanctus). Although Gilbert emerged from the trial without being formally condemned, there remained an aura of suspicion about him and his work. Nonetheless, his thought and his special terminology were appropriated, and reworked to various degrees, by a certain number of thinkers working in the second half of the twelfth century, who are usually known collectively as the ‘‘Porretan School’’ (Marenbon 1988; Marenbon 2002; Catalani 2009). These masters in turn, and in particular Alain of Lille, exerted an influence on other teachers of the period, above all with regard to the semantics and the logic of theological language (Valente 2008a). Among the works of Gilbert, the fundamental one is his Commentary on the Opuscula sacra of Boethius (except for De fide catholica), edited by N. M. Haring. Other certainly authentic works, unedited except for some fragments, are a commentary on the Psalms (studied by Gross-Diaz 1996) and one on the epistles of St. Paul (some passages are edited and discussed in Nielsen 1982). Various other writings attributed to Gilbert by editors are found to be inauthentic (Nielsen 1982:40-46); in particular, the so-called Liber sex principiorum, already attributed to him by Albert the Great (Lewry 1987), is not Gilbert’s.