God’s Own Language. Architectural Drawing in the Twelfth Century offers a detailed analysis of the visual elements from the treatise In visionem Ezechielis written by Richard of Saint-Victor around 1160. This book cannot be approached as an art-historical study of illumination or painting in Paris in the 12th century, but rather as an analysis combining theology, exegesis, and philology to determine the theoretical and rhetorical function of the drawings that punctuate this treatise. From this perspective, and as the subtitle indicates, the author intends to rethink the function and nature of architectural drawing in the Middle Ages, which is why he elaborates in his analysis on references to plans, blueprints, or diagrams drawn before and after Richard of Saint-Victor’s writing of In visionem Ezechielis.

The book is organized into two main sections. The first chapter focuses on the figure of Noah’s Ark in the work of Richard’s predecessor, Hugues of Saint-Victor. In the 12th century, this Old Testament figure was used as a powerful machine for visual exegesis, providing a diagrammatic means of classifying information and producing a spiritual vision from biblical data. This first chapter sets out the intellectual context in which Richard developed his thought and explains the role of visual elements in the development of exegetical knowledge. For this first chapter, the author draws on the important scholarship regarding Hugues of Saint-Victor, but he already manages to go beyond the question of the design of the arch to consider it within a long history of architectural drawing. The originality of this book lies in the fact that it does not limit itself to a particular text, the In visionem Ezechielis, but seeks to establish the historical and anthropological foundations of the use of drawing in the design of medieval buildings. The second chapter is devoted more specifically to the figure of Richard of Saint-Victor, his writings and his place at the heart of the Paris abbey; a brief but essential chapter for understanding the author’s intellectual background and relevance. These first two chapters form a brief, well-documented, and very useful first part for the context.

The third chapter opens the second part of the book, devoted to drawings in the work of Richard of Saint-Victor. This third chapter is a milestone in the book, as it studies the first diagrams in the treatise, which, due to their synthetic or “hybrid” nature, needed to be studied separately. This chapter is essential because it enables the author to address the question of scale in these drawings in a very intelligent way, and to set out from the outset the great “flexibility” of architectural drawing, using examples of plans predating Richard of Saint-Victor’s treatise, including the famous plan of Saint-Gall. Chapters 4, 5, and 6 are devoted to precise monographs on a particular drawing and its exegesis by Richard: the gatehouse in chapter 4, the temple precinct in chapter 6, for which the author details the different versions of the drawings in the manuscript tradition of the In visionem Ezechielis, although he concentrates on one manuscript in particular preserved at the Bibliothèque nationale de France (Paris, BNF, ms. lat 2165). He describes the conditions for translating the Old Testament text into a plan, thanks to the use of inscriptions on the drawing itself, the use of the “grid” to consider the modules of the various elements, and the use of elevation to move from the flatness of the page to the third dimension of architecture. In analyzing these two constructions, the author shows how geometry can be used to put the elements of Richard’s discourse into relation and to construct his thought as one would construct a real building.

The role of geometry is even more striking in Chapter 5, which is devoted to a very unusual drawing in the treatise: the geometric diagram used to show the slope of Ezekiel’s Mountain, constructed from semicircles and reminiscent of how architectural treatises since Antiquity have thought about modular construction. This is undoubtedly where the author develops the most captivating points of his reflection on architectural drawing, since it allows us to question the long-term history of the notions of plane, surface, height and inclination, and their translation into a certain conception of the world governed by the notion of figura. The chapter that closes this second part is devoted to the last drawing in the treatise, the map of the Promised Land, obviously very different in conception since it no longer considers buildings but a territory, which the author proposes to read throughout the relationship between Richard’s thought and contemporary Jewish exegesis. The book closes without a conclusion, but with an afterword that takes up the idea that the drawings in Richard of Saint-Victor’s treatise have more to do with the history of architectural drawing than with exegetical thought. The author will not be denied this, as his demonstration is so rich and convincing.

This book is an essential milestone in the history of visual thought in the central Middle Ages, insofar as it gives drawing a considerable rhetorical function that goes beyond the simple illustration or diagramming of knowledge. It is therefore part of a very active historiography on diagrams and, more generally, on intellectual ways of visualizing knowledge. It is essential reading. Perfectly illustrated, with numerous color plates and precise documentation regarding the manuscript tradition of Richard of Saint-Victor’s treatise, the book is a true example of a monographic study within a complex vision of medieval thought.