page_title: Roger Bacon
section_title: Optics
hierarchical_section_title: Roger Bacon / Works / Opus Majus / Optics
context_page_description: Roger Bacon OFM, also known by the scholastic accolade Doctor Mirabilis, was a medieval English philosopher and Franciscan friar who placed considerable emphasis on the study of nature through empiricism. In the early modern era, he was regarded as a wizard and particularly famed for the story of his mechanical or necromantic brazen head. He is sometimes credited as one of the earliest European advocates of the modern scientific method. Bacon applied the empirical method of Ibn al-Haytham to observations in texts attributed to Aristotle. Bacon discovered the importance of empirical testing when the results he obtained were different than those that would have been predicted by Aristotle.
  His linguistic work has been heralded for its early exposition of a universal grammar. However, more recent re-evaluations emphasise that Bacon was essentially a medieval thinker, with much of his "experimental" knowledge obtained from books in the scholastic tradition. He was, however, partially responsible for a revision of the medieval university curriculum, which saw the addition of optics to the traditional quadrivium.
context_section_description: In Part V of the Opus Majus, Bacon discusses physiology of eyesight and the anatomy of the eye and the brain, considering light, distance, position, and size, direct and reflected vision, refraction, mirrors, and lenses. His treatment was primarily oriented by the Latin translation of Alhazen's Book of Optics. He also draws heavily on Eugene of Palermo's Latin translation of the Arabic translation of Ptolemy's Optics; on Robert Grosseteste's work based on Al-Kindi's Optics;  and, through Alhazen (Ibn al-Haytham), on Ibn Sahl's work on dioptrics.
caption: Bacon's diagram of light being refracted by a spherical container of water
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