Medieval Maverick: Roger Bacon’s Quest for Knowledge and Truth

A biography we should all see early. He was an independent thinker who won patrons in spite of all that.

Yet he also a reminder of the path. In his time he largely advanced knowledge.  Yet great swathes of time would pass for another to arise.

Many call themselves philosophers, or scientists or academics.  Few truly make it.  

Medieval Maverick: Roger Bacon's Quest for Knowledge and Truth

23 APRIL, 2023 


In the Middle Ages, knowledge was largely limited to what could be gleaned from ancient texts and the teachings of the church. However, there were those who refused to accept the limitations of their time and pushed the boundaries of knowledge in pursuit of truth and discovery. Among these pioneers was Roger Bacon, a 13th-century scholar whose contributions to science, philosophy, theology, and linguistics challenged traditional ways of thinking and paved the way for new ideas and advancements. In this article, we will delve into the life, work, and legacy of this fascinating and influential figure, and explore the lasting impact of his ideas on the world we know today.

Roger Bacon, The Life of the Rebel Philosopher

Bacon was born in Ilchester in Somerset, England in the early 13th Century. His precise date of birth is unknown, with some earlier historians claiming he was born as early as 1210 and many modern historians opting for around 1220.

Little is known about his early life. It is believed that his family was relatively wealthy and that this allowed him to study at Oxford as a young man. It is likely that his tenure at Oxford was heavily influenced by Robert Grosseteste, another prolific English philosopher of the age.

Bacon went on to become a Master at Oxford, mainly lecturing his students on Aristotle, but there is no evidence he was ever awarded a doctorate. After leaving Oxford, Bacon accepted an invitation to teach at the University of Paris. During his time there he lectured on Latin grammar, Aristotle, arithmetic, and geometry, as well as astronomy and even music.

He stayed on at the University of Paris for around ten years, leaving in roughly 1247. He then became a private scholar and it’s uncertain where he spent the next decade. It’s believed he probably traveled between London and Paris. We know he was in Paris in 1251 because this is where he met another influential English Scholar, Adam March.

During this ten-year period, Bacon spent most of his time studying ancient Greek and Arab works on optics. A passage in his Opus Tertium also indicates that he took a two-year break from his studies during this time.

Friar Roger Bacon in his study. ( Public Domain )

Coming out of this period Bacon dedicated more and more of his time to religious studies, becoming a friar in the Franciscan Order between 1256 and 1257. This soon became a problem for Bacon.

After 1260, a statute was brought in that forbade members of his order from publishing their findings without prior approval. This was a problem for Bacon because nearly everything he was interested in studying was borderline heresy. During this period Bacon was essentially deemed too smart for his own good. For years he was given an endless stream of menial tasks meant to keep him too busy to think. He grew to resent his treatment, deeming it an enforced absence from academia.

By the mid-1260s Bacon had tired of his treatment and was actively looking for patrons who would permit/fund his return to Oxford. In 1266 he finally got what he wanted when Pope Clement IV commissioned his studies. Clement was relatively open minded but feared angering Bacon’s order so instructed him to carry out his work in the utmost secrecy.

A representation of Bacon presenting one of his works to the chancellors of Paris University. ( CC BY 4.0 )

Bacon wasted no time in getting to work. His work over the next year has been described as "one of the most remarkable single efforts of literary productivity", with Bacon producing around a million words in less than a year, producing epic works such as his Opus Majus , Opus Minus , De Multiplicatione Specierum , and De Speculis Comburentibus .

Unfortunately for Bacon, after a year of amazing productivity, he hit a roadblock. Clement died in 1268, leaving Bacon without a sponsor or protector. This may have led to Bacon either being imprisoned or placed under house arrest at some point within the next two years.

Modern scholars are torn as to whether Bacon was imprisoned or not. The first reference to Bacon being imprisoned dates to around 80 years after his death, and is often seen as less than credible. Modern scholars who do believe he was imprisoned, commonly believe that his imprisonment had less to do with his scientific studies and more to do with his politics and “combative personality”.

In short, if Bacon was imprisoned it’s likely because he made a nuisance of himself. Whether he was imprisoned or not, Bacon returned to the Franciscan house at Oxford sometime after 1278. It’s believed he spent the remainder of his life there, studying.

It’s generally thought he died sometime between 1294-1295, around age 70. No reliable historical records describe the circumstances surrounding his death but it is likely he simply died of natural causes or old age.

How He Challenged the Status Quo His Opus Majus

Bacon’s Opus Majus is arguably his greatest work. It contains his musing on mathematics, optics, alchemy, and astronomy including innovative theories on the positions and sizes of celestial bodies.

Bacon never intended for the Opus Majus to be a complete work. Instead, it was meant to highlight the areas he believed contemporary scholarship was lacking and to act as a proposal to reform the medieval university curriculum. Bacon believed new subjects such as perspective (optics), astronomy, weights (mechanics), alchemy; agriculture, medicine, experimental science, and a “philosophy of science” were needed to guide the next generation of academics.

He also used his work to criticize academics he didn’t like. In particular, he singled out Alexander of Hales and Albertus Magnus due to what he perceived as their “second-hand” knowledge of Aristotle. Indeed, he was pretty damning of contemporary philosophers in general.

He divided them into two groups. There were the Sapientes, a small number of gifted philosophers and thinkers whom he respected, and the vulgus philosophanitum , the common philosophers whom he disliked. He was particularly fond of Islamic thinkers from 1210 to 1265 whom he referred to as "both philosophers and sacred writers". His fondness for these thinkers won him few fans within the church.

Roger Bacon (1214-1294 AD). Source: Archivist / Adobe Stock.

Work on Optics

Bacon was fascinated by the field of optics, the study of light, and its properties. Bacon believed that light consisted of small particles or “corpuscles” that travel in straight lines and interact with the objects in their paths. He observed that when light passes through mediums of different densities (like water or glass) it changes direction, or is “refracted” where the two media meet. He suggested that this occurs because the speed of light changes as it passes through different media, causing a change in direction. This thinking was way ahead of Bacon’s time.

He also studied the properties of lenses and mirrors, developing the theory of “spherical aberration” which explained how the curve of a lens affects the quality of the image it produces. He suggested that for a clear image a more complex lens, like a convex lens was needed.

Bacon’s work on optics paved the way for later discoveries in the field and the development of eyeglasses and other optical devices such as the microscope and telescope. His ideas also contributed to the development of the modern understanding of the nature of light and its interactions with matter, which is a fundamental principle of modern physics.

Roger Bacon's circular diagrams relating to the scientific study of optics. By Roger Bacon, late 13th century. ( Public domain )


Two of Bacon’s writings, the Opus Majus and Opus Tertium are believed to contain the first European descriptions of gunpowder . He likely learned about gunpowder from his contact with Chinese scholars, who had been using gunpowder for centuries for military and other purposes.

In particular, it’s believed he likely witnessed at least one demonstration of Chinese firecrackers, probably obtained by Franciscans who had visited the Mongol Empire . He then went on to give a rough formula for the gunpowder he had witnessed, a mixture of saltpeter, charcoal, and sulfur.

It has been mistakenly claimed that Bacon “invented” modern gunpowder. In reality, he did no such thing. But his writings on gunpowder were important. They helped spread the knowledge of the chemical and its formula throughout Europe. Much like his writings on optics, this led to future breakthroughs such as the invention of cannons and other firearms.

"Roger Bacon discovers gunpowder". An image from Bill Nye's Comic History of England. (Public Domain )
Rewriting Alchemy

One of Bacon’s favorite areas of research was alchemy, the study of the transmutation of metals and the search for a universal elixir that could cure diseases and extend life. Bacon did not manage either of these things (no alchemist has) but his work did contribute to the development of modern chemistry.

Bacon tended to reject the more mystical and secretive practices of traditional alchemy and focused on the experimental. He believed alchemical transformations could be achieved through systematic processes like experimentation, observation, and documentation, rather than through divine intervention.

Bacon also made important contributions to the understanding of chemical substances and their properties. He recognized the importance of careful measurement and record-keeping in chemical experiments, and he emphasized the need for precision in the handling and testing of substances. He also developed new methods of distillation and other chemical processes that are still used in modern laboratories.

Much like his work with gunpowder and optics, Bacon’s work in the field of alchemy isn't defined by a single breakthrough. Instead, his emphasis on empirical observation and experimentation laid the groundwork for what was to come. His work also challenged the mystical and superstitious beliefs that were prevalent in the field of alchemy during his time.
Linguistics as a Road to Truth

Roger Bacon's study of linguistics was an important aspect of his broader interest in knowledge and the pursuit of truth. Bacon believed that language was a crucial tool for the expression of ideas and for the transmission of knowledge, and he was interested in understanding the structure and function of language in order to improve communication and understanding.

One of Bacon's primary contributions to the study of linguistics was his emphasis on grammar. He believed that a thorough understanding of the rules of grammar was essential for effective communication and for the interpretation of texts. Bacon was particularly interested in the study of Latin, which was the language of scholarship and the church during his time. He wrote several works on Latin grammar, including a treatise on the rules of Latin syntax and a work on the distinctions between different parts of speech.

Bacon was also interested in the study of semantics, or the meaning of words and phrases. He recognized that words could have multiple meanings and that the meaning of a word could change depending on its context. Bacon was particularly interested in the problem of equivocation, or the use of ambiguous language, and he believed that clear and precise language was essential for effective communication and for the pursuit of truth.

Bacon's work in linguistics contributed to the development of modern theories of language and communication. His emphasis on the importance of grammar and the study of syntax laid the groundwork for the development of modern linguistic theory, and his insights into the nature of language and meaning continue to influence the study of linguistics today.

His work on linguistics also gained him a fair few enemies within the church. For centuries one of the ways the Church had maintained its power was through its use of and control over language and the fact that the majority of Christians were illiterate. In his works on linguistics, Bacon’s emphasis on equivocation and semantics highlighted the tools the Catholic church used to control/ mislead its followers...

The Westgate plaque at Oxford reads:
“The Great Philosopher
Known as the Wonderful Doctor
Who by the Experimental Method
Extended marvellously the realm of science
After a long life of untiring activity