A remarkable 13th-century scientific text, lost for centuries and challenging modern assumptions about medieval thought, has been rediscovered in an Oxford library. The work by Dominican friar Richard Fishacre proposes a radical idea: that planets could exist orbiting stars other than our Sun.
A Radical Idea Hidden in Plain Sight
The discovery was made by historian and author Seb Falk while examining manuscripts in Oxford's Merton College library. The text forms part of Fishacre's commentary on the Sentences of Peter Lombard, a standard theological textbook of the era. Written around 1245, the treatise explores the nature of the heavens from a scholarly perspective.
Within this commentary, Fishacre poses a profound question about the creation of the universe. He asks whether, when God made the stars on the fourth day, He also created planets to orbit them, just as Earth and other planets orbit the Sun. This speculation places the concept of exoplanets—worlds beyond our solar system—firmly within the intellectual discourse of medieval Oxford.
Challenging the 'Dark Ages' Stereotype
This find directly contradicts the popular notion of the Middle Ages as a period of scientific stagnation. Falk emphasises that Fishacre was not engaging in wild fantasy but was applying rigorous logical reasoning, rooted in the works of Aristotle and other ancient authorities available at the time.
"He's taking a theory that is being discussed about our solar system and extending it to the rest of the universe," Falk explains. The friar uses a compelling analogy, suggesting that if God created 'lesser lights' (planets) to accompany our 'greater light' (the Sun), it would be fitting for Him to do the same for other stars. This demonstrates a sophisticated, rational approach to cosmology.
Fishacre, who died in 1248, was a pioneering figure at the University of Oxford. He is credited with writing the first commentary on the Sentences by a Dominican in England, setting a precedent for scholarly debate. His work shows that medieval thinkers were capable of abstract, speculative thought about the cosmos that went far beyond biblical literalism.
The Modern Relevance of an Ancient Text
The timing of this rediscovery is particularly poignant for modern astronomers. The first confirmed exoplanet orbiting a sun-like star was only detected in 1995, over 750 years after Fishacre's musings. Today, thousands of such planets have been catalogued by missions like NASA's Kepler telescope, proving that our galaxy is teeming with other worlds.
This manuscript serves as a powerful reminder that the history of science is not a simple linear progression. Innovative ideas can emerge, be forgotten, and later be rediscovered independently. It places Oxford at the heart of a much longer and richer conversation about humanity's place in the universe than previously recognised.
The story of Richard Fishacre's lost thesis encourages us to look at the medieval period with fresh eyes, seeing it not as an age of darkness but as one of keen intellectual curiosity where the seeds of future discovery were sometimes sown.
