The sense of sight in the prologues of Theophilus Presbyter's De diversis artibus

The twelfth-century Latin treatise De diversis artibus, by Theophilus Presbyter, presents detailed information about the crafts of painting, paint making, glassmaking, and metalwork. This article focuses mainly on two questions raised by Theophilus's prologues: the author's evaluation of each of the materials on the basis of its optical qualities in relation to its use in the sacred space; and his notion of the aspects of visual perception of items placed in the sacred space. The analysis here focuses on the Latin text's multilayered hierarchic structure. According to Theophilus, the human eye can discern categories of objects on the basis of their use in liturgical procedures and can organize materials into a hierarchy. The optical characteristics of a given material yield crucial criteria for this sorting and ranking. The optical effects are also the determining feature in defining the role of objects within the liturgy. On this spiritual path of artisanal creation, Theophilus appoints human sight as the ultimate judge, corrector, and guide.