GUGLIELMO di CHAMPEAUX. – Philosopher, born around 1070, died as bishop of Châlons sur Marne in 1121. He had as teachers Manegoldo di Lautenbach in Paris, then Anselmo di Laon, and finally Roscellino at Compiègne. He first taught at the school of the cathedral of Paris and then at S. Vittore.
Through Roscellino, G. di C. was brought into contact with the question of universals. Roscellino was a nominalist; Giovanni di Salisbury writes of him in particular in the Polycraticus, VII, 12 (ed. C. I. Webb, II, p. 142): «Fuerunt et qui voces ipsas genera dicerent esse et species, sed eorum iam explosa sententia est et fere cum auctore suo evanuit». Nominalism had led Roscellino to conceive the Most Holy Trinity as three gods. G. di C. opposed to this his realism and likewise found himself obliged to reconcile his philosophical theory with the mystery of the Most Holy Trinity, as appears from a significant passage in the Sentenze: «Vides has duas voces unum scilicet et idem duobus accipi modis, secundum indifferentiam et secundum identitatem eiusdem prorsus essentiae: secundum indifferentiam, ut Petrum et Paulum idem dicimus esse in hoc quod sunt homines: quantum enim ad humanitatem pertinet sicut iste est rationalis et ille, et sicut iste mortalis et ille. Sed si veritatem confiteri volumus, non est eadem ustriusque humanitas sed similis quum sint duo homines. Sed hic modus unius ad naturam divinitatis non est referendus» (Guillelmi Campellensis Sententiae vel Quaestiones XLVII, in G. Lefèvre, Les variations de G. et de la question des universaux, Lilla 1898, pp. 14 e 25). Two moments in G. di C.’s thought, or rather in the expression of his thought, are hinted at in this text. The first moment, that of essential identity, was abandoned by G. di C. under pressure from his pupil Abelardo, who claimed to see in it a profession of pantheism as well: «Erat autem (G. di C.) in ea sententia de communitate universalium, ut eamdem essentialiter rem totam simul singulis suis inesse adarrueret individuis, quorum quidem nulla esset in essentia diversitas sed sola multitudine accidentium varietas» (Historia calamitatum, cap. 2: PL 178, 119). The final words of the passage cited make it clear that G. di C.’s realism originated in the Boethian words of the De Trinitate, «Sed numero differentiam accidentium varietas facit», and that, although it could merit the accusation of reducing individuation to accidents by positing in reality (both in the first and in the second manner) an essence extrinsically individuated, it nevertheless excluded any profession of pantheism. Precisely in order to remove this ambiguity concerning pantheism, G. di C., in speaking of the second manner, referred to essential indifference rather than essential identity, with the above-mentioned qualification concerning the one and triune God: where, by conceiving the divine essence almost as a universal of the three divine persons, one must take care not to think of it as multiplied among those persons. Here there is identity, not merely indifference. The second phase of G. di C.’s thought developed at S. Vittore. G. di C. may be called an initiator of this school and of its mystical character.
Principal works, in addition to the aforementioned Sententiae: De Sacramento altaris (frg. in PL 163, 1039-40); De origine animae (doubtful; frg., ibid. 1043-44); Dialogus seu altercatio cuiusdam christiani et iudaei de fide catholica (ibid. 1046-72); De essentia et substantia Dei et de tribus eius personis (frg. in V. Cousin, Fragments philosophiques, II, Parigi 1865, pp. 328-35).