The employment by Nicholas of Cusa (1401–64) of the works of Thierry of Chartres is familiar to most students of his thought. However, there has not been, until now, a monograph in English on the topic. David Albertson provides more than just a study of Cusanus’s use of that Chartrian author’s theology. His book examines the development of mathematical theologies in antiquity and Thierry’s adaptation of ancient thought to his own theological speculations.
Behind the pursuit by Thierry and Nicholas of mathematical theologies lay a complex set of ideas tied to Pythagoreanism, less the actual ideas of Pythagoras and his followers than the complex heritage of the later Platonic Academy, Neoplatonism, and Neopythagoreanism, a Hellenistic revival of Pythagoreanism. All of these trends existed despite the critique by Aristotle of Pythagorean thought. The study of these ideas is complicated by the frequently fragmentary nature of the surviving sources. In addition, mathematics, often presented in theologies, competed with dialectics as the potential guide to ultimate reality. Christianity adopted Platonic and Neopythagorean ideas, but Augustine of Hippo, after flirting with them, eventually focused on other lines of thought. All Christian theologians also had to fit into this picture the Christ, identified with the Logos or Word, as well as authoritative teachings on the Trinity.
By the early Middle Ages, dialectic was the dominant force in Western thought. Neopythagorean ideas survived in the early works of Augustine and in the writings of Boethius. Boethius had tried to combine theology with the quadrivium, the mathematically driven study of arithmetic, geometry, music, and astronomy. However, the Boethian inheritance was divided by later Christian thinkers between his theological and philosophical writings, on the one side, and the works that were foundational to the quadrivium, on the other. As Albertson notes, one of Thierry’s contributions to Chartrian thought was his reunification of the Boethian corpus as a guide to mathematical theology, including in his ideas about the Trinity.
There are problems with the surviving writings attributed to Thierry of Chartres. It is difficult to deduce his ideas from the surviving corpus. Faced with differences between texts, some interpreters have given up the search for a coherent whole, trying to decide if some attributions of authorship are false. Albertson takes the more interesting approach of treating these as a series of different efforts to pursue mathematical theology. Thierry’s ideas on enfolding and unfolding were developed in this series of texts. One of the more interesting aspects of Thierry’s legacy is its representation through others’ works, including the Fundamentum Naturae quod Videtur Physicos Ignorasse, a text that represents the Chartrian’s ideas accurately before criticizing them. This text was a significant conduit of Thierry’s ideas to Cusanus, as Maarten Hoenen has shown.
Cusanus’s knowledge of Thierry was at first heavily dependent on the Fundamentum, although Thierry’s own works became an element in the development of Nicholas’s thought. Albertson wisely avoids the trap of trying to make the first Cusanus work on speculative topics, De Docta Ignorantia, normative for the entire corpus. The influence of Thierry is evident in the three books of that text, culminating in its unifying Christology. However, the mathematical theology found in the next treatise, De Coniecturis, largely ignores Christology for ideas of mediation between God and creation. Only later would Nicholas return to his Christology, while also pursuing his own ideas of arithmos, especially his writings on squaring the circle.
Some scholars have thought that mathematics parted company with theology in Cusanus’s Idiota de Mente. Albertson takes a different approach, seeing the De Mente as a step in the development of a geometrical theology. A significant part of this development was the composition of the De Ludo Globi. The ball game of the title was Christocentric and geometric, including the physics of impetus on the ball, spherical but with a rounded portion cut out of it. Cusanus continued wrestling with these mathematical ideas, including a move into spherics; but he never ceased wrestling with ideas drawn from Thierry, especially in the De Theologicis Complementis, as he pursued mathematical theologies. Albertson’s exposition of these developments can be slow reading, but his book provides important insights into the development of Cusanus’s ideas.
