About Mirrors, In A Collection Of Astronomical And Mathematical Works
Medium: Ink and pigments on vellum
By the 13th century, European astronomers had access to information on planetary movements and other observations of the heavens that had been compiled by Arab astronomers in 11th-century Spain. This knowledge, with its methods of observation and emphasis on the natural world, was part of an intellectual revolution taking place in the late middle ages. Christian theologians responded to the new knowledge by integrating it into the church's doctrine. Monasteries provided the intellectual environment where the latin translations of arabic books were copied and studied. This manuscript of astronomical treatises belonged to St Augustine's, Canterbury.
To medieval theologians, light was mysterious and considered the one thing which could be sensed that was most like God because of its immeasurable qualities. Theories about it depended upon works such as this one, called 'About Mirrors' and wrongly believed to be the writing of the ancient Greek mathematician, Euclid. It contained an influential description of a camera obscura. It begins with a picture of a monk looking at a lens or a mirror, and the geometric diagrams over the page illustrate the discussion of light reflections.