GUGLIELMO d'ALVERNIA. – Medieval theologian and philosopher, born at Aurillac after 1180, died in Paris in 1249. He was professor of theology at the University of Paris and, from 1228, bishop of that city.
His principal work is the Magisterium divinale (1223–40), divided into seven parts: De Trinitate, De universo, De anima, Cur Deus homo, De fide et legibus, De Sacramentis, De virtutibus.
Together with Guglielmo d'Auxerre and Filippo il Cancelliere, he belongs to that group of theologians who, after the condemnations of 1210 and 1215, found themselves obliged to confront Aristotle in order to correct and combat him on theses incompatible with Christianity, while in the meantime studying him and effecting a first assimilation of Aristotelianism by Catholic theology (F. Steenberghen). Within this group, G. d'A. is the most notable philosophical personality. He felt strongly the influence of Avicenna, but did not allow himself to be dominated by him (Masnovo, I, p. 205). He demonstrates the existence of God as the good and being by essence, the reason for the existence of all goods and beings by participation (in which essence and being are distinguished), and he also makes use of the argument from motion (ibid., p. 262). Unlike Guglielmo d'Auxerre, Filippo il Cancelliere, and Alessandro
di Hales, according to whom the concept that best makes known the nature of God is that of summum bonum, G. sees in the concept of “being by essence” the one that best characterizes God. Against Avicenna, G. vigorously asserts that God freely created the world and that the world had a beginning. In his voluntarist conception of creation (opposed to Avicenna’s naturalism), he finds support in Avencebrol, whom he considers a Christian and highly esteems. He conceives the human soul as the form of the body, spiritual and immortal, but not as the sole form of the human being. He does not admit the distinction between the agent intellect and the possible intellect: there is neither an agent intellect separate from the soul, in the manner of Avicenna, nor an agent intellect as a faculty of the soul, because, according to G., there is no distinction between the soul and its faculties.
According to Gilson (Masnovo dissents), G. is a typical representative of Avicennizing Augustinianism. The Alvernian’s theory concerning knowledge of the first principles and of the causal nexus, which would require a habitus or mos infused by God, recalls, according to Masnovo, that of D. Hume.