Medieval Theories of Sight

Concepts that informed how the blind were represented in texts derived from Medieval ideas about the sense of sight and its role in cognitive perception of the world. Mary Jane Kelley, for example, has investigated Medieval medical and philosophical theories about sight and optics in the thirteenth century as they relate to depictions of the blind. She finds that authors obviously were familiar with the theories that defined sight as a necessary first step toward understanding and cognitive processing. Visual information about an object was believed to be carried by particles called species; these species multiplied likenesses of themselves in the space that separated the viewer from the object. ‘The principal way in which all outside entities, whether truly existing or conceptual, entered the mind was as a species received through the senses.’ Vision was considered essential to understanding because in the Neoplatonic worldview what one sees is but an imperfect reflection of the perfect world as embodied by God. Kelley further explains this belief: ‘The sensory stimuli humans absorbed as visual images represented information about the subjective, physical world. Platonic philosophy, and the Neoplatonism of the Middle Ages, distinguished between this subjective perceivable domain and an objective, true realm of being beyond the direct reach of human perception.’ James Burke explains that sight in the Middle Ages was considered to exist as two types. One was the physical sight that transmitted images to the sensory organs of perception while a second type of sight was a function of the soul. ‘This second and very superior way of “seeing” depended in the first instance upon those traces that physical vision (and the other senses) presented to the mind. But in addition the eye of the soul was able to utilize information that had been originally inscribed upon the soul by the Creator.’ It was believed that by looking at the material world as a reflection of God's will on earth, one could come closer to a knowledge of God. This concept was essential to St. Augustine's theology who claimed that ‘physical capacity for vision contributed to memory, which the properly oriented will could access to achieve understanding and ultimately lead the individual Christian to God’.