Medieval Science

In the fourteenth century, a Spanish Franciscan monk named John of Rupescissa complained of two things: first, there were too few natural philosophers and, second, those who claimed to be natural philosophers were instead magicians, sorcerers, or swindlers. To John of Rupescissa and the Franciscans, one must purify the mind to know science, and, indeed, John claimed his devout practices had provided him with divine enlightenment, which in turn gave him insight into the secrets of the natural realm – a sort of scientific revelation. To him, and to the medieval mind, the pursuance of secret knowledge of the natural realm was closely tied with religious and devotional practice.

Born around 1362, John of Rupescissa was not just a monk, but a scholar, a scientist, an alchemist, an astrologer and an interpreter of papal prophecy. For monks like John of Rupescissa, older writers and their manuscripts served as didacts for scientific information, like the page from a late twelfth-century cosmographic manuscript (Cosmography W.73) seen below. This manuscript, intended to be a textbook for monks, is explored in this Science and Astronomy section. According to the text note on the Walters Manuscripts website, this manuscript is a “compilation of medieval scientific excerpts from early medieval scientific works” such as those by Bede, Isidore of Seville, and Abbo of Fleury, and it covers medicine, astrology, and other scientific subjects.

The first page of the manuscript is a diagram of terra, Earth, in the center, and the twelve signs of the fixed zodiac drawn in a circle around it, with Aries (March) marking the beginning of spring and, continuing counter-clockwise, Taurus (April), Gemini (May), Cancer (June), Leo (July), Virgo (August), Libra (September), Scorpio (October), Sagittarius (November), Capricorn (December), Aquarius (January), and Pisces (February). This is cosmography as it was understood at the time – Earth, mankind’s present home, at the center of the universe, with the fixed stars set in the sky above. Between the heavens and the earth were the planets, which appear in a diagram further on in the manuscript, and which are discussed in the next section.

Folio 1r of W.73 at the Walters Art Museum.