Roger Bacon

Circa 1214/1220 - Circa 1292
natural philosopher

Sources

Experimental Method. An early advocate of employing direct, accurate observation and related mathematical analysis to test the theories of earlier scientists, Roger Bacon also wrote important works on logic, semantics, and semiotics.

Education and Career. Little is known about Bacon’s life. Some scholars believe he was born around 1220 while others place his birth date at about 1214. He studied at Oxford University and then began a career as a professor of philosophy at the University of Paris in about 1237. For about a decade he lectured there on Aristotle and pseudo-Aristotelian texts, and on the “new” logic, which was more complex than the old Aristotelian logic. Thirteenth-century scholars employed the new logic to develop a logica modernorum (modern logic), which involved some new methods of semantics. In about 1248 Bacon left teaching and for the next nine years devoted his financial resources to the study of languages, experiments, and “books of secrets” (works on subjects such as alchemy, medicine, and statecraft). In 1280 Bacon produced his edition one of the best-known books of secrets, the pseudo-Aristotelian Secretum Secretorum (The Secret of Secrets), a work of political education for a prince, which also includes a medical and scientific section.

Scientific Works. After becoming a Franciscan friar in about 1257, Bacon continued his studies, and during the 1260s he published his Opus maius (Great Work) and related writings—including Communia naturalium (Common Account of Natural Things), his outline for an encyclopedia of the sciences. His Opus maius is in seven parts, which cover the academic situation of the time, philosophy and theology, language, applications of mathematics, optics, experimental science, and moral philosophy. The section on optics includes a full physiological description of the eye and the optic nerve and describes a “separate science of vision” through which and without which other sciences cannot be known. That is, he considered optics the key to a universal science because vision allows the scientist to test theory with experience. The section on experimental science again emphasizes the need to test theory with observation. Bacon also applied a practical approach to his ideas on medicine, and he sought to put education on a scientific and experimental basis, hoping the bring about the moral and religious reform of society and church.

Sources

A. C. Crombie and J. D. North, “Roger Bacon,” in Dictionary of Scientific Biography, edited by Charles Coulston Gillispie (New York: Scribner, 1970), I: 377–385;

Jeremiah Hackett, “Roger Bacon and Aristotelianism,” Vivarium, 35, no. 2 (1997): 129–135.

Hackett, ed., Roger Bacon and the Sciences: Commemorative Essays (Leiden & New York: E. J. Brill, 1997).