Medieval Trinitarian Thought from Aquinas to Ockham, by Russell L. Friedman

Abstract

This book is based on a series of lectures given at the Ecole Pratique des Hautes Etudes in Paris, in March and April 2008. It consists of a survey of the main arguments which scholastic theologians produced concerning the trinity in the period c.1250–c.1350. The author promises us for the future a lengthy monographic treatment of the subject: the summary has, as it were, come out first. The great merit of Friedman's book is that it gives a clear exposition of the intricacies of scholastic arguments which, on this most difficult of theological topics, were abstruse indeed. He begins by focusing on the fundamental problem: how to explain identity and difference within the trinity. We are led through the relational account, based on the notion of the opposition of relations in the persons of the trinity—thus the existence of the one (for instance, the Father) implies the other (the Son); the Holy Spirit is ‘breathed’ passively as opposed to the active ‘breathing’ of the Spirit by the Father and the Son. The emanational account is explained: the persons of the Father, Son and Holy Spirit are the same divine essence in three different ways, described by the mode by which each one emanates or originates. In addition, there was the psychological model which derived from Augustine and which drew on the philosophy of mind—the Son is a concept produced by the Father's intellect, the Holy Spirit is love produced by the will shared by the Father and the Son. In this view, theories of cognition, of concept formation, relate to the trinity.