Esdras Calderan/Wikimedia Commons
Everybody knows that the Scientific Revolution began in the 16th century, when Copernicus, Kepler and Galileo (plus some philosophical input from Francis Bacon) revived the long dormant Greek love for knowledge about nature. But in fact the seeds of that revolution had been planted three centuries earlier, when a handful of thinkers, most of them religious scholars, began contemplating rational explanations for worldly phenomena. My rankings of them are guaranteed to be at least as good as pretournament NCAA basketball polls.
10. Adam Marsh (?-1259, aka Doctor Illustris)
Very little is known about Marsh, a Franciscan friar who was a student of Robert Grosseteste at Oxford. But Marsh was apparently an accomplished mathematician and was highly regarded by Roger Bacon, who considered Marsh in the same intellectual category as Grosseteste. That was high praise from Bacon, who thought most of his scientific contemporaries were dolts.
9. Zakariya al-Qazwini (c. 1203-1283)
Al-Qazwini was born in Persia. He studied in Damascus and later became a judge in what is now Iraq. His own insights were not especially groundbreaking, but he had vast knowledge of science and wrote major works on geography and the nature of the universe. As with most scientists of the era, al-Qazwini’s ideas were mixed in with religion, but he did believe that appreciating the spiritual wonder in the world required scientific knowledge about nature. That’s enough to get him into the Top 10, as there aren’t all that many candidates.
8. Henrik Harpestræng (?-1244)
Reputed to be the physician for King Erik Plovpenning of Denmark, Harpestræng wrote treatises on the medical use of herbs and other drugs and was a major figure in bringing “modern” medicine to Scandinavian countries. Roskilde, the capital of Denmark in those days, became an important center for studying medicine thanks to Harpestræng’s influence.
7. Peter Nightingale (aka Peter Philomena of Dacia, Petrus Danus)
His birth and death dates are unknown, but Nightingale was active in the last decade of the 13th century as a mathematician and astronomer. Originally from Denmark, he taught in Bologna and spent time in Paris before returning to Denmark. He wrote an important commentary on arithmetic, proposed a new way of calculating cube roots, and authored many important astronomical tables, some especially valuable for calendrical purposes. He also constructed novel astronomical instruments for computing the positions of the planets.
6. Witelo of Silesia (d. after 1275)
A Polish natural philosopher, Witelo apparently wrote several treatises on various earth, space and biological sciences, but most of them have not survived. A major work on optics, though, is enough to establish him as one of the century’s top thinkers. He surveyed the geometry of light rays, the nature of color and explored the physiology of vision and the nature of perceptual illusions. Witelo seems to have been influenced by Grosseteste and Bacon; in turn Witelo’s work influenced many later scientists, including Descartes and Galileo.
5. Leonardo Fibonacci (c. 1170-after 1240, aka Leonardo of Pisa)
Western Europe’s first big-name mathematician, Leonardo learned math as an accountant for his father’s business. That job took him traveling to places like Syria and Egypt, in the course of which he found out about Arabic numerals, which he introduced to Europe to make every accountant’s life easier.
He is also famous for the series of numbers named for him in which each number is the sum of the preceding two. So if a test asks you what number comes next in the series 1, 2, 3, 5, 8, 13 … a good guess would be 21.
4. Peter Peregrinus (aka Pierre de Maricourt)
Dates for birth and death unknown, but his most famous work, a treatise on magnetism, was completed in 1269. He might have been an engineer who served in the army of the King of Sicily during a campaign against the city of Lucera in Italy. Peter’s work provided the first comprehensive account of all the scientific aspects of magnetism. He particularly emphasized the physics of magnetic polarity and suggested improvements in magnetic compasses. His treatise was instrumental in the modern science of magnetism initiated by William Gilbert more than three centuries later.
3. Saint Albertus Magnus (c. 1200-1280, aka Albert the Great, Doctor Universalis)
Very few scientists achieve sainthood or get nicknamed “the great,” but Albert was exceptional. Born in Bavaria, he studied in Italy where he learned all about Aristotle before becoming a Dominican preacher. He later taught in Germany before studying theology in Paris. Albert wrote on all aspects of science and played a major role in bringing Aristotelian science to western Europe through elaborate commentaries on Aristotle’s works. On matters that Aristotle hadn’t treated, Albert filled in the gap.
Albert was a master of the entire spectrum of scientific knowledge; he emphasized that the scientific understanding of reality was compatible with religion and theology. His most famous student was Saint Thomas Aquinas. Albert himself was awarded sainthood in 1931. In 1941 Pope Pius XII designated him the patron saint for scientific researchers. One notable contemporary was not so impressed with Albert, though. Roger Bacon wrote that Albert’s useful writings could have been summed up in a 20th of his works’ actual length.
2. Roger Bacon (c. 1214-1292, aka Doctor Mirabilis)
Some consider Bacon the first modern scientist. Some older sources say he was a student of Grosseteste’s at Oxford, but there may not be solid evidence for that. In any case, Bacon was certainly influenced by Grosseteste, whose work he admired. Later Bacon studied at Paris, perhaps under Peter Peregrinus.
Bacon was a shrill advocate for experiment; he was an independent thinker, disdainful of authority and did not suffer fools well, all excellent qualities for a good scientist. Bacon became a Franciscan friar, though, and the Franciscans kept him quiet. He nevertheless wrote on all areas of science and made remarkably prescient forecasts of future developments, even envisioning machines for traveling on land or water, submarines and air travel.
1. Robert Grosseteste (c. 1170-1253)
An intellectual giant, no matter that his last name translates as “fathead.” He both recognized the importance of Aristotle but also insisted that experiments, not Aristotle’s writings, settled questions about nature. Grosseteste was an expert on every area of knowledge, and he established the scientific spirit in the minds of many medieval scholars. His treatises and philosophy influenced and inspired all the great thinkers that followed him in the 13th century, including Bacon and Albertus Magnus. Grosseteste emphasized the importance of mathematics and applied it in detail to optics and other realms of natural science.
Most of all, he emphasized that reason was not incompatible with religious faith, and that finding the rational explanations for the entirety of natural phenomena was a noble undertaking. “Truly Grosseteste was one of the great encyclopedic thinkers of the world,” his biographer Francis Seymour Stevenson wrote in the 19th century. “In the domain of intellectual activity Grosseteste must … be regarded as the founder and inspirer of … the encyclopedic school of the thirteenth century, imparting to it a unity of purpose and a loftiness of conception to which those who followed him hardly ever attained.”
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