Seeing Through the Veil: Optical Theory and Medieval Allegory (review)

Optical theory may strike many of those working on late medieval vernacular literature as a somewhat rarified topic. Obviously visual metaphors permeate medieval literature, just as they permeate medieval - or modern - thinking in general, but the claim that academic optical theory had a significant literary influence may come as a surprise. Yet as Suzanne Conklin Akbari demonstrates in this forceful study, there are striking parallels between the flowering of optical theory in the thirteenth and fourteenth centuries, which entailed greater scepticism about the possibility of direct and reliable knowledge of the natural world, and the complication or even abandonment of allegory.

Akbari begins with two provocative claims. One is that 'the mechanism of vision is the underlying structure on which subjectivity is constructed'; vision is not just a metaphor but a paradigm for human knowledge. The other is that the 'transparent mediation between subject and object, between reader and meaning, is the purpose of allegory' so that the perfect allegory acts 'as a perfect mirror which unites the earthly domain of sense perception with the divine realm of intelligible knowledge.' Akbari's crucial point is that medieval optical theory increasingly stressed that vision cannot mediate transparently but inevitably entails a degree of distortion. In particular, she traces the influential theories of intromission (in which the visible form is sent out to an essentially passive viewer) of the 'perspectivists,' such as Robert Grosseteste, Roger Bacon, and John Pecham, who all drew on the work of Alhazen (Ibn al-Haytham), and the critique of their position by William of Ockham.

Unlike many attempts to locate medieval literature in its philosophical milieu, which have tended to deal in generalities, as if all medieval nominalists were of one mind, Seeing through the Veil does justice to the complexities of academic debate on optical theory before turning to the literature, in this case the problematization of seeing and knowing in Jean de Meun and Chaucer and their synthesis in Dante. Some of Akbari's more sweeping claims remain at the very least unproved. Can Chaucer's shift from allegory to the verisimilitude of the Canterbury Tales be directly linked to Ockham's rejection of the multiplication of visible species in perspectivist accounts of perception? But many of her points are telling. After a review of earlier attempts to establish the philosophical sources of Jean de Meun's optical imagery, for example, Akbari shows that Nature's account of the powers of different kinds of mirrors matches almost word for word a passage in Bacon's Opus maius and precedes to explore the parallels between Bacon's theory of the multiplication of visible species (as each visible form reproduces itself) and the sexual multiplication of the human species under Nature's tutelage. Advancing the general case that de Meun drew directly on technical optical theory, Akbari further shows that his use of the term deduit (joyous desire) puns on William of Conches's term detuitio (refracted vision).

Inevitably in such a wide-ranging study some points get short shrift. I would like to have heard more about the influence of John Pecham, especially his surprising insistence, despite his commitment to intromission, that 'vision is not a passive act.' The single reference to John Dumbleton's account of insolubles is so brief as to be cryptic. But the full elucidation of the relation between optical theory and logic would require a book of its own. Much has been written on late medieval recognition of the deceptive mediation of language, far less on the deceptive mediation of sight. Seeing through the Veil is an important effort to redress the balance and marks a huge step forward in our understanding of cultural implications of medieval optical theory.