The collections of the Dumbarton Oaks’s museum focus on Byzantine and Pre-Columbian art—two seemingly disparate cultural spheres. Any connection between these collections and their corresponding fields of study therefore depends on how one conceives of history and art history.

This talk, based on a chapter from the book The Metaphysics of Materials (Oxford University Press, 2019), will focus on two similar objects in the collection: one is a Romanesque portable altar, and the other is an early colonial portable altar from the Purépecha area of Mexico. The former has a porphyry top, while the latter is covered in obsidian. Prof. Cummins will explore the connection between these two distinct materials, both of which are used to form the same type of liturgical object.

Porphyry and obsidian were each inscribed with ancient mystical values—one associated with pagan Rome, the other with pagan Tenochtitlán, capital of the Aztec empire. Both materials later became preferred for the performance of the mystical act of transubstantiation. Is there something intrinsic to their materiality? Do mystical values transcend conversion and extirpation? We know much about the symbolism of porphyry, but why obsidian—the attribute of the god Tezcatlipoca? These are the questions that will be explored in Prof. Cummins’s presentation.