Roger Bacon
Scholastic · Europe · 1220 to 1292
English friar who urged that knowledge of nature needs experience and mathematics as well as authority.
What it is
Roger Bacon was a thirteenth-century Franciscan scholar who taught at Paris and later worked at Oxford. He is remembered for arguing that knowledge of nature needs experience as well as reasoning, and he gave years to languages, optics and mathematics.
The sources give his birth as about 1220, or somewhere between 1214 and 1220, and agree that he died about 1292. He began as a teacher of Aristotle and then, in the later 1240s, moved toward the study of languages and light.
The main ideas
- Experience as well as reasoning. He held that knowledge is gained through reasoning and experience, and trusted claims more when experience confirmed them.
- Languages and the sciences in the schools. He proposed a reform of learning that would bring the study of languages and of nature into the studies of his day.
- Languages. He gave himself to the study of languages and counted it part of serious learning.
- Light and optics. He studied optics and the nature of light.
- A plan for the pope. He sent his proposals for reforming studies to Pope Clement IV.
What it looks like in practice
Imagine someone who reads that a certain kind of mirror can start a fire, and who has only the book to go on. Bacon would not stop at the page. He would ask whether the claim has been tried, and what the trying shows. This is an illustration of his way of thinking, not a passage from his writing.
Books and moments
- Paris. He lectured on Aristotle's works in the arts faculty.
- A change of course. In the later 1240s he turned to languages and optics.
- The Franciscans. He joined the order in 1256 or 1257, depending on the source.
- The great works of 1266. At the request of Pope Clement IV he wrote the Opus maius, the Opus minus and the Opus tertium, setting out his plan for reform.
- Death. He died about 1292.
Questions and criticism
- How much did he experiment? He is known for urging experiment, and it is fair to ask how far he practised what he preached.
- A modern scientist? He lived long before modern science took shape, and it is fair to ask whether the label fits.
- Was he condemned? Accounts of his later years in his order differ, and it is fair to ask what really happened to him there.
Close neighbours
The pages on Aristotle, Francis Bacon and William of Ockham sit nearby. Aristotle is the author Roger Bacon first taught, and the other two are later thinkers whose ideas about knowledge can be read alongside his.
Written by epchē in our own words, and checked against independent sources on 29 October 2026. The sources are listed below.
Who they connect to
Runs parallel to
- Francis Bacon · Both urged knowledge of nature by experience, three centuries apart; there is no direct link. (scholars disagree about this link)
Other Scholastic thinkers
- Anselm of Canterbury · 1033 to 1109
- Peter Abelard · 1079 to 1142
- Bonaventure · 1221 to 1274
- Thomas Aquinas · 1225 to 1274
- Meister Eckhart · 1260 to 1328
- John Duns Scotus · 1266 to 1308
- William of Ockham · 1287 to 1347
- Francisco Suarez · 1548 to 1617
Sources we used
- Roger Bacon · Stanford Encyclopedia of Philosophy, read on 29 October 2026
- Roger Bacon · Encyclopaedia Britannica, read on 29 October 2026