CHAPTER LV
ROBERT GROSSETESTE
Chief sources for Robert Grosseteste—Reasons for Roger Bacon’s eulogy—Grosseteste’s scholarly career—His writings: absence of magic—His scientific writings little affected by his ecclesiastical position—Reliance on experience—Theory of vision and science of perspective—Experimental discovery of lenses—Mentioned also in The Romance of the Rose—Theories formed by experimenters with lenses—Mathematical physics: the radiation of virtue—The Computus and calendar reform—Juggling with numbers—From mathematics to astronomy to astrology—Astrology in natural philosophy, agriculture, alchemy, medicine and music—Some astrological technical detail—Man and the stars—Grosseteste’s theory of comets—Alchemy—Other treatises—Summa philosophiae ascribed to Grosseteste—Its contents—Oriental origin of philosophy—Greek men of learning—Arabs and medieval Christians—Ancient and modern science compared—Criticism of Aristotle and the Arabic text—Use of the word “modern”—Theology, philosophy, and science; speculative and experimental—Astrology in the Summa—Occult virtue and alchemy—Brother Giles on the comet of 1264—Appendix I. The Perspective or Optics of Witelo.
Chief sources for Robert Grosseteste.
The fame of Robert Grosseteste,[1421] who lived from about 1175 to 1253 and was bishop of Lincoln during the last eighteen years of his life, rests largely upon the praises of his countrymen and contemporaries, Matthew Paris and Roger Bacon, and upon his own writings. The historian, Matthew Paris, depicts him especially as the man of affairs, the churchman and statesman who dared oppose either king or pope for England’s sake. But with his repeated resistance in parliament to royal financial exactions, his outspokenness against abuses at the papal court and his refusal to admit papal provisors to benefices in his diocese, his aggressive and reforming activity in his bishopric and consequent quarrels with the monastic orders and his own cathedral chapter—with all this side of his career we are little concerned. It is rather as a great scholar of his time that like Roger Bacon we shall look back upon him.
Reasons for Roger Bacon’s eulogy.
Bacon’s eulogies of Grosseteste may seem rather extravagant. Writing fourteen years after his death he thinks that no living scholar can compare with him, nay, he ranks him and Adam Marsh, another Englishman of whom we know little, as in their day what Solomon, Aristotle and Avicenna were in theirs.[1422] One reason for this high praise is presumably that Grosseteste had been Bacon’s favorite teacher, and certainly that he was interested in the same learned pursuits, Greek and Hebrew, mathematics, optics, experimental science, as the friar who followed him. Roger practically admits that he owes much in those fields to Robert and an examination of Grosseteste’s writings makes this fact still more evident.
Grosseteste’s scholarly career.
A letter by Giraldus Cambrensis written before the close of the twelfth century speaks of the then youthful Grosseteste as already proficient in law and medicine. He seems to have been born of humble and poor parents at Stradbrook in Suffolk.[1423] He was educated at Oxford where he became rector scholarum and Chancellor and in 1224 the first rector of the Franciscans at Oxford. He perhaps also studied at Paris. After holding various archdeaconries and other prebends he was elected bishop of Lincoln in 1235 but continued his interest in the welfare of the university at Oxford. Roger Bacon, in affirming that Grosseteste surpassed all others in knowledge of the sciences, gives as a reason his long life and experience as well as his enthusiasm for study;[1424] and in another passage declares that hitherto it has taken thirty or forty years for a man to become really proficient in mathematics, as the case of Robert Grosseteste among others shows.[1425] Bacon also states that it was not “until the latter portion of his life” that he undertook the work of making translations and summoned Greeks and had grammars brought from Greece and other lands. Since Grosseteste appears at first to have studied law and medicine rather than ancient languages and mathematical sciences, Bacon’s statements suggest that the works of Grosseteste which we are about to consider were written late in life. This inference is further borne out by a passage in the treatise De impressionibus aeris seu de prognosticatione which gives the positions of the seven planets in the signs of the zodiac and states the date as “the Arabic year 646 or the year of grace 1249.”[1426]
His writings: absence of magic.