(b; Suffolk, England, ca. 1168; d. Buckden, Buckinghamshire, England, 9 October 1253)
natural philosophy, optics, calendar reform.
Grosseteste was the central figure in England in the intellectual movement of the first half of the thirteenth century, yet the only evidence for his life before he became bishop of Lincoln in 1235 is to be found in fragmentary references by Matthew of Paris and other chroniclers, by Roger Bacon, and occasionally in charters, deeds and other records.1 His birth has been variously dated between 1168 and 1175, but since he is described as “Magister Robertus Grosteste” (the first appearance of his name) in a charter of Hugh, bishop of Lincoln, of probably 1186–1190, the earlier date is the more likely. Tradition places his birth in Suffolk, of humble parentage. He may have been educated first at Lincoln, then at Oxford, and was in the household of William de Vere, bishop of Hereford, by 1198, when a reference by Gerald of Wales suggests that he may have had some knowledge of both law and medicine. After that it seems likely that he taught at Oxford in the arts school until the dispersion of masters and scholars during 1209–1214. He must have taken his mastership in theology, probably at Paris, during this period, some time before his appointment as chancellor of the University of Oxford, although with the title magister scholarum, probably about 1214–1221, when he must have lectured on theology.
Grosseteste was given a number of ecclesiastical preferments and sinecures, including the archdeaconry of Leicester in 1229; but in 1232 he resigned them all except for a prebend at Lincoln, writing to his sister, a nun: “If I am poorer by my own choice, I am made richer in virtues.”2 From 1229 or 1230 until 1235 he was first lecturer in theology to the Franciscans, who had come to Oxford in 1224. His influence there was profound and continued after he left Oxford in 1235 for the see of Lincoln, within the jurisdiction of which Oxford and its schools came. He contributed largely to directing the interests of the English Franciscans toward the study of the Bible, languages, and mathematics and natural science. Indispensable sources for this later period of his life are his own letters and those of his Franciscan friend Adam Marsh.
Grosseteste’s career thus falls into two main parts, the first that of a university scholar and teacher and the second that of a bishop and ecclesiastical statesman. His writings fall roughly into the same periods: to the former belong his commentaries on Aristotle and on the Bible and the bulk of a number of independent treatises, and to the latter his translations from the Greek. Living at a time when the intellectual horizons of Latin Christendom were being greatly extended by the translations into that language of Greek and Arabic philosophical and scientific writings, he took a leading part in introducing this new learning into university teaching. His commentary on Aristotle’s Posterior Analytics was one of the first and most influential of the medieval commentaries on this fundamental work. Other important writings belonging to the first period are his commentary on Aristotle’s Physics, likewise one of the first; independent treatises on astronomy and cosmology, the calendar (with intelligent proposals for the reform of the inaccurate calendar then in use), sound, comets, heat, optics (including lenses and the rainbow), and other scientific subjects; and his scriptural commentaries, especially the Moralitates in evangelica, De cessatione legalium, Hexaëmeron and commentaries on the Pauline Epistles and the Psalms. Having begun to study Greek in 1230–1231, he used his learning fruitfully during the period of his episcopate by making Latin translations of Aristotle’s Nicomachean Ethics and De caelo (with Simplicius’ commentary), of the De fide orthodoxe of John of Damascus, of Pseudo-Dionysius and of other theological writings. For this work he brought to Lincoln assistants who knew Greek; he also arranged for a translation of the Psalms to be made from the Hebrew and seems to have learned something of this language.
Although in content a somewhat eclectic blend of Aristotelian and Neoplatonic ideas, Grosseteste’s philosophical thinking shows a strong intellect curious about natural things and searching for a consistently rational scheme of things both natural and divine. His search for rational explanations was conducted within the framework of the Aristotelian distinction between “the fact” (quia) and “the reason for the fact” (propter quid). Essential for the latter in natural philosophy was mathematics, to which Grosseteste gave a role based specifically on his theory, expounded in De luce self de inchoation formarum and De motu corporali et luce, that the fundamental corporeal substance was light (lux). He held that light was the first form to be created in prime matter, propagating itself from an original point into a sphere and thus giving rise to spatial dimensions and all else according to immanent laws. Hence his conception of optics as the basis of natural science. Lux was the instrument by which God produced the macrocosm of the universe and also the instrument mediating the interaction between soul and body and the bodily senses in the microcosm of man.3 Grosseteste’s rational scheme included revelation as well as reason, and he was one of the first medieval thinkers to attempt to deal with the conflict between the Scriptures and the new Aristotle. Especially interesting are his discussions of the problems of the eternity or creation of the world, of the relation of will to intellect, of angelology, of divine knowledge of particulars, and of the use of allegorical interpretations of Scripture.
Grosseteste’s public life as bishop of Lincoln was informed by both his outlook on the universe as a scholar and his conception of his duties as a prelate dedicated to the salvation of souls. Analogous to corporeal illumination was the divine illumination of the soul with truth. He extended the luminous analogy to illustrate the relationship between the persons of the Trinity, the operation of divine grace through free will like light shining through a colored glass,4 and the relation of pope to prelates and of bishops to clergy: as a mirror reflects light into dark places, he said in asserting his episcopal rights against the cathedral chapter of Lincoln, so a bishop reflects power to the clergy5
In practice Grosseteste was governed by three principles: a belief in the supreme importance of the cure of souls; a highly centralized and hierarchical conception of the church, in which the papacy, under God, was the center and source of spiritual life and energy; and a belief in the superiority of the church over the state because its function, the salvation of souls, was more vital. Such views were widely accepted, but Grosseteste was unique in the ruthlessness and thoroughness with which he applied them, for example, in opposing the widespread use of ecclesiastical benefices to endow officials in the service of the crown or the papacy. As a bishop he had attended the First Council of Lyons in 1245, and in a memorandum presented to the pope there in 1250 he expounded his views on the unsuitability of such appointments while accepting the papal right to dispose of all benefices. Likewise, his opposition to the obstruction of the disciplinary work of the church by any ecclesiastical corporation or secular authority brought him into conflict both with his own Lincoln chapter and with the crown over royal writs of prohibition when secular law clashed with church law and when churchmen were employed as judges or in other secular offices. Grosseteste was a close friend of Simon de Montfort and took charge of the education of his sons, but the degree to which he shared in or influenced Montfort’s political ideals has probably been exaggerated. Above all he was a bishop with an ideal, an outstanding example of the new type of ecclesiastic trained in the universities.
Scientific Thought . Some of Grosseteste’s scientific writings can be dated with reasonable certainty, and most of the others can be related to these in an order based on internal references and on the assumption that the more elaborated version of a common topic is the later.6 From the evidence for his method of making notes on his reading and thoughts to be worked up into finished essays and commentaries,7 and from these writings themselves, it may be assumed that many of them arose out of his teaching in the schools. Gerald of Wales’s description of Grosseteste at Hereford as a young clerk with a manifold learning “built upon the sure foundation of the liberal arts and an abundant knowledge of literature”8 is borne out by what is probably his earliest work, De artibus liberalibus. In this attractive introduction he described how the seven liberal arts at once acted as a purgatio erroris and gave direction to the gaze and inclination of the mind (mentisaspectus et affectus). Of particular interest is his treatment of music, of which his love became proverbial, and of astronomy. As for Boethius, music for him comprised the proportion and harmony not only of sounds produced by the human voice and by instruments but also of the movements and times of the celestial bodies and of the composition of bodies made of the four terrestrial elements—hence the power of music to mold human conduct and restore health by restoring the harmony between soul and body and between the bodily elements, and the related power of astronomy through its indication of the appropriate times for such operations and for the transmutation of metals. Related to this essay was his phonetical treatise De generatione sonorum, which he introduced with an account of sound as a vibratory motion propagated from the sounding body through the air to the ear, from the motion of which arose a sensation in the soul.
Grosseteste developed his mature natural philosophy through a logic of science based on Aristotle and through his fundamental theory of light. In their present form most of the works concerned were almost certainly written between about 1220 and 1235. De lute and De motu corporali et luce, with his cosmogony and cosmology of light, seem to date from early in this period. The structure of the universe generated by the original point of lux was determined, first, by the supposition that there was a constant proportion between the diffusion or “multiplication” of lux, corresponding to the infinite series of natural numbers, and the quantity of matter given cubic dimensions, corresponding to some finite part of that series. Second, the intensity of this activity of lux varied directly with distance from the primordial source. The result was a sphere denser and more opaque toward the center. Then from the outermost boundary of the sphere lumen emanated inward to produce another sphere inside it, then another, and so on, until all the celestial and elementary spheres of Aristotelian cosmology were complete. Another seemingly early work in this series, De generatione stellarum, shows Grosseteste dependent on Aristotle in many things but not in all, for he argued that the stars were composed of the four terrestrial elements. Later, in his commentary on the Physics, he contrasted the imprecise and arbitrary way man must measure spaces and times with God’s absolute measures through aggregates of infinites.
In all these writings Grosseteste made it clear that by lux and lumen he meant not simply the visible light which was one of its manifestations, but a fundamental power (virus, species) varying in its manifestation according to the source from which it was propagated or multiplied and in its effect according to its recipient. Thus he showed in De impressionibus elementorum how solar radiation effected the transformation of one of the four terrestrial elements into another and later, in De natura locorum, how it caused differences in climate. An explanation of the tides begun in De accessione et recessione maris or De fluxu et refluxu maris (if this work is by him)9 was completed in De natura locorum, in which he argued that the rays of the rising moon released vapors from the depth of the sea which pushed up the tide until the moon’s strength increased so much that it drew the vapors through the water, at which time the tide fell again. The second, smaller monthly tide was caused by the weaker lunar rays reflected back to the opposite side of the earth from the stellar sphere.
In De cometis et causis ipsarum Grosseteste gave a good example of his method of falsification in arguing that comets were “sublimated fire” separated from their terrestrial nature by celestial power descending from the stars or planets and drawing up the “fire” as a magnet drew iron. Later, in De calore solis (ca. 1230–1235), he produced perhaps his most elegant exercise in analysis by reduction to conclusions falsified either by observation or by disagreement with accepted theory, finally leaving a verified explanation. He concluded that all hot bodies generated heat by the scattering of their matter and that the sun generated heat on the earth in direct proportion to the amount of matter incorporated from the transparent medium (air) into its rays.
Grosseteste set out and exemplified the formal structure of his mature scientific method in his Commentarius in libros posteriorum Aristoielis his Commentarius in viii libros physicorum Aristotelis,10 and four related essays giving a geometrical analysis of the natural propagation of power and light. It seems likely that he began the commentary on the Posterior Analytics when he was still a master of arts, that is, before 1209, and completed it over a long period, finishing after 1220 and probably nearer the end of the decade. The commentary on the Physics was written later, likewise certainly over a period of years, probably around 1230. It has striking parallels with some of the scientific topics of the Hexaëmeron but shows less than even the limited knowledge of Greek found in this work, suggesting that it just precedes it.
For Grosseteste, as for Aristotle, a scientific inquiry began with an experienced fact (quia), usually a composite phenomenon. The aim of the inquiry was to discover the reason for the fact (propter quid), the proximate cause or natural agent from which the phenomenon could be demonstrated:
Every thing that is to be produced is already described and formed in some way in the agent, whence nature as an agent has the natural things that are to be produced in some way described and formed within itself, so that this description and form itself, in the very nature of things to be produced before they are produced, is called knowledge of nature 11
His method of discovering the causal agent was to make first a resolutio, or analysis of the complex phenomenon into its principles, and then a compositio, or reconstruction and deduction of the phenomenon from hypotheses derived from the discovered principles. He verified or falsified these hypotheses by observation or by theory already verified by observation.
Besides this double method, Grosseteste used in the analysis of the causal agent as the starting-point of demonstration another Aristotelian procedure, that of the subordination of some sciences to others, for example, of astronomy and optics to geometry and of music to arithmetic, in the sense that “the superior science provides the propter quid for that thing of which the inferior science provides the quia.12 But mathematics provided only the formal cause; the material and efficient causes were provided by the physical sciences. Thus “the cause of the equality of the two angles made on a mirror by the incident ray and the reflected ray is not a middle term taken from geometry, but is the nature of the radiation generating itself in a straight path....”13 The echo belonged formally to the same genus as the reflection of light, but the material and efficient causes of the propagation of sound had to be sought in its fundamental substance: “the substance of sound is lux incorporated in the most subtle air....”14 This introduced a fundamental addition to the very similar discussion of the propagation of sound in De artibus liberalibus and De generatione sonorum.
Grosseteste developed his geometrical analysis of the powers propagated from natural agents in the four related essays written most probably in the period 1231–1235. He said in the first, De lineis, angulis et figuris seu de fractionibus et reflexionibus radiorum: “All causes of natural effects have to be expressed by means of lines, angles and figures, for otherwise it would be impossible to have knowledge propter quid concerning them.”15 The same power produced a physical effect in an inanimate body and a sensation in an animate one. He established rules for the operation of powers: for example, the power was greater the shorter and straighter the line, the smaller the incident angle, the shorter the three-dimensional pyramid or cone; every agent multiplied its power spherically. Grosseteste discussed the laws of reflection and refraction (evidently taken from Ptolemy) and their causes, and went on in De natura locorum to use Ptolemy’s rules and construction with plane surfaces to explain refraction by a spherical burning glass. “Hence,” he resumed, “these rules and principles and fundamentals having been given by the power of geometry, the careful observer of natural things can give the causes of all natural effects by this method.” This was clear “first innatural action upon matter and later upon the senses…”16
An example of the analysis of a power’s producing sensation is provided by Grosseteste’s De colore. The resolutio identified the constituent principles: color was light incorporated by a transparent medium; transparent mediums varied in degree of purity from earthy matter; light varied in brightness and in the multitude of its rays. In the compositio he asserted that the sixteen colors ranging from white (bright light, multitudinous rays, in a pure medium) to black were produced by the “intension and remission” of these three variable principles. “That the essence of color and a multitude of the same behaves in the said way,” he concluded, “is manifest not only by reason but also by experiment, to those who know the principles of natural science and of optics deeply and inwardly.... They can show every kind of color they wish to visibly, by art [per artificium].”17
The last of these four essays, De iride seu de iride et speculo, is the most complete example of Grosseteste’s method and his most important contribution to optics. The resolutio proceeds through a summary of the principle of subordination and its relation to demonstration propter quid into a discussion of the division of optics into the science of direct visual rays, of reflected rays, and of refracted rays, in order to decide to which part the study of the rainbow belonged. It was subordinate to the third part, “untouched and unknown among us until the present time";18 and it is his treatment of refraction that has the greatest interest.
This part of optics [perspectiva], when well understood, shows us how we may make things a very long distance off appear to be placed very close, and large near things appear very small, and how we may make small things placed at a distance appear as large as we want so that it is possible for us to read the smallest letters at an incredible distance, or to count sand, or grain, or seeds, or any sort of minute objects19
The reason, as he had learned from Euclid and Ptolemy, was “that the size, position and arrangement” according to which a thing is seen depends on the size of the angle through which it is seen and the position and arrangement of the rays, and that a thing is made invisible not by great distance, except by accident, but by the smallness of the angle of vision.” Hence “it is perfectly clear from geometrical reasons how, by means of a transparent medium of known size and shape placed at a known distance from the eye, a thing of known distance and known size and position will appear according to place, size and position20
Grosseteste followed this account of magnification and diminution by refracting mediums with an apparently original law of refraction, according to which the refracted ray, on entering a denser medium, bisected the angle between the projection of the incident ray and the perpendicular to the interface. “That the size of the angle in the refraction of a ray may be determined in this way,” he concluded, “is shown us by experiments similar to those by which we discovered that the reflection of a ray upon a mirror takes place at an angle equal to the angle of incidence.” 21
It was also evident from the principle that nature always acts in the best and shortest way. Grosseteste went on to use a construction of Ptolemy’s to show how to locate the refracted image, claiming again that this “is made clear to us by the same experiment and similar reasonings”22 as those used in a similar construction for locating the reflected image. The first of these references to experimental verification, since it would have been so inaccurate, may throw doubt on all such references by Grosseteste. As was true for the majority of medieval natural philosophers, most of these references came from books or from everyday experience. Clearly his interest was directed primarily toward theory. Yet he advocated and was guided by the principle of experiment and developed its logic.
Besides these works related to optics, Grosseteste wrote important treatises on astronomical subjects. In De sphaera, of uncertain date between perhaps 1215 and 1230, and De motu supercaelestium, possibly after 1230, he expounded elements of both Aristotelian and Ptolemaic theoretical astronomy. In a later work, De impressionibus aëris seu de prognosticatione, dating apparently from 1249, he discussed astrological influences and, again, his mature explanation of the tides. More original were Grosseteste’s four separate treatises on the calendar: Canon in kalenaatlilm and Compotus; correcting these, Compotus correctorius, probably between 1215 and 1219; and Compotus minor, with further corrections, in 1244. He showed that with the system long in use, according to which nineteen solar years were considered equal to 235 lunar months, in every 304 years the moon would be one day, six minutes, and forty seconds older than the calendar indicated. He pointed out in the Compotus correctorius (cap. 10) that by his time the moon was never full when the calendar said it should be and that this was especially obvious during an eclipse. The error in the reckoning of Easter came from the inaccuracy both of the year of 365.25 days and of the nineteen-year lunar cycle.
Grosseteste’s plan for reforming the calendar was threefold. First, he said that an accurate measure must be made of the length of the solar year. He knew of three estimates of this: that of Hipparchus and Ptolemy, accepted by the Latin computists; that of al-Battāni; and that of Thābit ibn Qurra. He discussed in detail the systems of adjustments that would have to be made in each case to make the solstice and equinox occur in the calendar at the times they were observed. Al-Battānī’s estimate, he said in the Compotus correctorius (cap. 1), “agrees best with what we find by observation on the advance of the solstice in our time.” The next stage of the reform was to calculate the relationship between this and the mean lunar month. For the new-moon tables of the Kalendarium, Grosseteste had used a multiple nineteen-year cycle of seventy-six years. In the Compotus correctorius he calculated the error this involved and proposed the novel idea of using a much more accurate cycle of thirty Arab lunar years, each of twelve equal months, the whole occupying 10,631 days. This was the shortest time in which the cycle of whole lunations came back to the start. Grosseteste gave a method of combining this Arab cycle with the Christian solar calendar and of calculating true lunations. The third stage of the reform was to use these results for an accurate reckoning of Easter. In the Compotus correctorius (cap. 10), he said that even without an accurate measure of the length of the solar year, the spring equinox, on which the date of Easter depended, could be discovered “by observation with instruments or from verified astronomical tables.”23
As with Grosseteste’s optics, it was Roger Bacon who first took up his work on the calendar; and Albertus Magnus first made serious use of his commentary on the Posterior Analytics, as did John Duns Scotus of that on the Physics. These attentions marked the beginning of a European reputation that continued into the early printing of his writings at Venice, the collecting of his scientific manuscripts by John Dee, and interest in them by Thomas Hobbes.24
2.Epistolae. H. R. Luard, ed., p. 44.
3. E.g.. Hexaëmeron, British Museum MS Royal 6.E.V (14 cent.), fols. 147v-15Ov; L. Baut, “Das Licht in der Naturphilosophie des Robert Grosseteste,” in Abhandlungen aus dem Gebiete der Philosophie und ihrer Geschichte. Eine Festgabe zum 70. Geburtstag Georg Freiherrn von Herding (Freiburg im Breisgau, 1913), pp. 41–55.
4.De libero arbitrio, caps. 8 and 10. in L. Baur, Die philosophischen Werke des Robert Grosseteste, pp. 179, 202.
5.Epistolae, pp. 360, 364. 389.
6. For the basic work on this question, see Baur, Die philosophischen Werke; and S. H, Thomon, The Writings of Robert Grosseteste—with the revisions by Callus, “The Oxford Career of Robert Grossetest,” Robert Grosseteste; A. C. Crombie, Robert Grosseteste and the Origins of Experimental Science (1953, 1971); and R. C. Dales, “Robert Grosseteste’s Scientific Works,” Commentarius in viii libros.
7. From William of Alnwick, as first noticed by A. Pelzer. See Callus,”The Oxford Career of Robert Grosseteste,” pp. 45–47.
9. See R. C. Dales, “The Authorship of the Questio de fluxu et refluxu maris Attributed to Robert Grosseteste,” in Speculum37 (1962), 582–588.
10. See the ed. by Dales. Grosseteste wrote probably about 1230 a summary of Aristotle’s views in his Summa super octo libros physicorum Aristotelis.
11.Commenturius in viii libros physicorum Aristotelis. lib. I . Dales, ed., pp. 3–4.
12.Commentaria in libros posteriorum Aristotelis, I , 12 (1494), fols. 11r-12r.
13.Ibid., I, 8, fol. 8r.
14.Ibid., II, 4, fol. 29v.
15.De lineis, angulis et figuris, in Baur. Die philosophischen Werke, pp. 59–60.
16.De natura locorum, ibid., pp. 65–66.
17.De colore, ibid., pp. 78–79.
18.De iride, ibid., p. 73, See L. Baur. Die Philosophie des Robert Grosseteste, pp. 117–118; Crombie, Robert Grosseteste (1971), pp. 117–124.
19.De iride, in Baur, Die philosophischen Werke, p. 74.
20.Ibid., p. 75.
21.ibid., pp. 74–75.
22.Ibid., p. 75.
23.Compotus, R. Steele. ed., pp. .215, 259.
24. See Crombie, Robert Grosreteste (1971); A. Pacchi, “Ruggero Bacone e Roberto Grossetesta in un inedito hobbesiano del 1634,” in Rivista critica di storia della filosofia, 20 (1965), 499–502; and Convenzione eipotesi nella formazione della filosofia naturale di Thomas Hobbes.(Florence. 1965).
I. Original Works. The earliest-dated printed ed. of a work by Grosseteste is Commentaria in libros posteriorum Aristotelis (Venice, 1494; 8th ed., 1552). It was followed by his Summa super octo libros physicorum Aristotelis (Venice, 1498; 9th ed., 1637); Libellus de phisicis lineis angulis et figuris per quas omnes actiones naturals complentur(Nuremburg, 1503); De sphaera, pub. as Sphaerae compendium (Venice, 1508; 5th ed., 1531); and Compotus correctorius (Venice, 1518). His Opuscula (Venice, 1514; London, 1690) includes De artibus liberalibus, De generatione sonorum, De calore solis, De generatione stellarum, De colore, De impressionibus elementorum, De motu corporali, De finitate motus et temporis (appearing first as the concluding section of his commentary on the Physics), De lineis, angulis et figuris, De natura locorum, De luce, De motu supercaelestium, and De differentiis localibus. All these essays, with De sphaera and the hither to unprinted De cometis, De impressionibus aëris and De iride, were published by L. Baur in Die philosophischen Werke des Robert Grosseteste (see below). For further modern texts see Canon in Kalendarium, ed. by A. Lindhagen as “Die Neumondtafel des Robertus Lincolniensis,” in Archiv för matematik, astronomi och fysik (Uppsala), 11 , no.2 (1916); Compotus, factus ad correctionem communis kalendarii nostri, R. Steele, ed., in Roger Bacon, Opera hactenus inedita, VI (Oxford, 1926), 212 ff.; S.H. Thomson, “The Text of Grosseteste’s Questio de calore, de cometis and De operacionibussolis,” in Medievalia et humanistica, 11 (1957), 34–43; Commentarius in viii libros physicorum Aristotelis…, R.C Dales, ed. (Boulder, Colo., 1963); and R. C. Dales, “The Text of Robert Grosseteste’s Questio de fluxu et reflux maris with an English Translation,” in Isis, 57 (1966), 455–474. See also Roberti Grosseteste episcopi quondam Lincolniensis epistolae, H.R. Luard, ed. (London, 1861).
II. Secondary Literature. For the fundamental work of identifying and listing Grosseteste’s writings see L. Baur, Die philosophischen Werke des Robert Grosseteste, Bishop von Lincoln, vol. IX of Beiträge zur Geschichte der Philosophie des Mittelalters (Münster, 1912): and S.H. Thomson. The Writings of Robert Grosseteste Bishop of Lincoln 1235–1253 (Cambridge, 1940). For further discussions of his scientific writings with references to additional items, see D. A. Callus, “The Oxford Career of Robert Grosseteste,” in Oxoniensia, 10 (1945), 42–72; D. A. Callus, ed., Robert Grosseteste, Scholar and Bishop (Oxford, 1955); A. C. Crombie, Robert Grosseteste’s Scientific Works,” in Isis52 (1961), 381–402. The basic modern biography is still F.S. Stevenson, Robert Grosseteste, judiciously sums up more recent scholarship. The pioneering account of his scientific thought is L. Baur, Die Philosophie des Robert Grosseteste, Bischofsvon Lincoin, XVIII, nos. 4–6 of Beiträge zur Geschichte der Philosophie des Mittelaters (Münster, 1917
A. C. Crombie
English scholastic, translator, and bishop; b. Suffolk, c. 1168; d. Buckden, Huntingdonshire, Oct. 9, 1253. Although born of humble parentage, he studied at Oxford and most certainly at Paris, where he heard jacques de vitry, stephen langton, and robert of courÇon. He became a master in arts between 1186 and 1191. While lecturing in arts, he wrote an Introitus to the study of the liberal arts, the treatise De generatione sonorum, and a commentary on Aristotle's Sophistici elenchi and Posterior Analytics (Venice 1494), in which he laid the foundation for all his later philosophical and scientific works. By 1214 he had become a master in theology either at Oxford or at Paris. Shortly after 1214 he was magister scholarum at Oxford, but the bishop of Lincoln would not allow him the title of chancellor. However, by 1221 this title was recognized at the Roman Curia; hence Grosseteste seems to have been the first chancellor of the University of Oxford (see oxford, university of). Of his lectures as regent master in theology there survive his commentary In epistolam Pauli ad Galatas, his Moralitates super evangelia, glosses on Psalms 1–100, and especially his Hexaemeron, which embodies materials from his lecture notes. He obtained several prebends, but after a grave illness he resigned all except a canonry at Lincoln in 1231. After the Franciscans enlarged their house in Oxford, they prevailed upon Grosseteste to lecture to them. This he did from c. 1232 until Lent 1235. Under him "within a short time they made incalculable progress both in scholastic discussions and in the subtle moralities suitable for preaching" [Eccleston, De adventu fratrum minorum in Angliam, ed. A. G. Little (Manchester 1951) 48]. Having great love for the order and sympathy with the Franciscan spirit, he profoundly influenced the Oxford Greyfriars through his theology and scholarship. While continental Franciscans disputed over the advantages of learning, the Oxford Greyfriars were firmly established in the tradition of learning. He was a teacher and intimate friend of adam marsh, the first Franciscan regent master at Oxford, and he exerted considerable influence on later English Franciscans, notably on roger bacon. The majority of Grosseteste's scientific treatises were written after 1230. While he was still lecturing to the Franciscans, he began serious study of Greek, which bore fruit in later years in many translations into Latin from the Greek. He also began the study of Hebrew but never acquired the same proficiency.
Episcopal Career. He was elected bishop of Lincoln in Lent 1235, received royal assent on April 5, and was consecrated at Reading on June 3, 1235. Immediately he began a visitation of his diocese, the largest in England. Zealous and uncompromising in maintaining his ideal of the Church, he deposed many abbots and priors who were lax in their office. Their chief fault was neglecting to staff adequately the parish entrusted to them. In 1237 he witnessed the confirmation of magna carta. From 1239 to 1245 he was at odds with the dean and chapter of his cathedral church, who claimed the right of exemption from episcopal visitation. This dispute, in which the dean was suspended and deprived of office, was settled by innocent iv in a bull of Aug. 25, 1245, which gave the bishop full jurisdiction over the chapter. In 1245 he attended the Council of lyons. During a visit to the papal court at Lyons in 1250, he spoke de coruptelis ecclesiae, denouncing the custom of appointing Italians, ignorant of the language and country, to rich English benefices. Although deeply committed to the doctrine of the plenitude of papal power, he opposed papal taxation of the clergy on behalf of the king in 1251 and 1252, and the appointment of the pope's nephew to a canonry of Lincoln in 1253. As a bishop, zealous in the service of the Church, he denounced ignorance among the clergy and did everything in his power to improve the state of learning. He continued the study of Greek, employed the service of Greek scholars, and obtained numerous Greek manuscripts. He himself translated Aristotle's Nicomachean Ethics, De lineis indivisibilibus, a part of De caelo and De virtute; works of St. john damascene and pseudo-dionysius; and the scholia of St. maximus the confes sor, the letters of St. ignatius of antioch, and the Testamenta 12 patriarcharum. Although other translations have been ascribed to him, their authenticity has not been firmly established. While he was bishop, he also commented on the four major works of Pseudo-Dionysius. His Commentarius in octo libros Physicorum Aristotelis (ed. R. C. Dales, Boulder, Colo. 1963) seems to have been written after 1230, while he was teaching the Franciscans or serving as bishop.
Many of his sermons are extant, at least in draft form. About 80 were collected by a student c. 1230 (Durham, Cath. Libr. MS A. III. 12); others belong to his episcopal period. Grosseteste often reworked his notes into a theological discourse. His Dicta were collected and arranged by himself from sermons and lectures; this work was highly popular in the 14th and 15th centuries. Passages from his Biblical commentaries were extensively quoted by Thomas Gascoigne in Liber de veritatibus collectis (Oxford, Bodl. Libr. Lincoln College MS 117–118).
Teaching and Influence. Grosseteste is important not only as an outstanding churchman, indefatigable in his service to the Church, but also as an independent thinker and scholar who influenced many generations of Englishmen. As a philosopher he was a pioneer in introducing the new Aristotelian learning to Oxford. However, he interpreted aristotle through augustine and Arab Neoplatonists, taking over especially the Augustinian doctrine of light and illumination. For him, light is a very subtle corporeal substance and the first form to be created in primary matter: "Formam primam corporalem, quam quidam corporeitatem vocant, lucem esse arbitror" (De luce; ed. Baur, 51). This first form of light multiplies its own likeness (multiplicatio specierum ) in all directions, begetting corporeal dimensionality and specific powers (virtutes ) according to determinable laws of mathematical proportionality. Grosseteste did not identify the first form called lux with visible light, which is only one manifestation. Natural philosophy studies the propagation of species and powers, but not the essence of lux itself, the cause of propagation; this is reserved to metaphysics. Since the multiplication of species follows geometrical laws, the whole of natural philosophy is subalternated to mathematics. A clear example of this kind of subalternation is to be seen in optics, the science of visible light: experiments and experimental knowledge provide the facts (quia ), but mathematics is required to provide the reason for the fact (propter quid ). While mathematics as such abstracts from corporeal phenomena, natural philosophy, optics, and other mathematical-physical sciences must study corporeal phenomena with the aid of mathematics.
The human soul is a special manifestation of light, for it can study the nature of light itself. However, in all knowledge the soul needs to be illumined by God, the source of all light. Thus the existence of God is immediately knowable, even though His existence can also be demonstrated from motion. God, moreover, is the exemplary cause of all things, as well as the efficient and final cause. Grosseteste gave support to the Franciscan school in teaching the primacy of will over intellect and the primacy of divine omnipotence.
The basis for Grosseteste's metaphysics of light is found in Gn 1.1–3, where God is described as having first created primary matter (materia prima ), then light (lux ). Similarly, the doctrine of divine illumination is established in Jn 1.9: "It was the true light that enlightens every man who comes into the world." Thus the whole of philosophy is subalternated to revelation.
Several attempts to secure his canonization came to nothing. He has always been highly regarded in England. His body is buried in Lincoln Cathedral.
Bibliography: a. b. emden, A Biographical Register of the University of Oxford to A.D. 1500, 3 v. (Oxford 1957–59) 2:830–833. d. a. callus, ed., Robert Grosseteste: Scholar and Bishop (Oxford 1955); "The Oxford Career of Robert Grosseteste," Oxoniensia 10 (1945) 42–72. s. h. thomson, The Writings of Robert Grosseteste (New York 1940). l. baur, "Die philosophischen Werke des Robert Grosseteste, Bischofs von Lincoln," Beiträge zur Geschichte der Philosophie und Theologie des Mittelalters 9 (1912) 1–143. Roberti Grosseteste episcopi quondam Lincolniensis epistolae, ed. h. r. luard (Rerum Britannicarum medii aevi scriptores 25; 1861). a. tognolo, Enciclopedia filosofica 4:170–172. f. l. cross, The Oxford Dictionary of the Christian Church (London 1957) 592–593. É. h. gilson, History of Christian Philosophy in the Middle Ages (New York 1955). a. c. crombie, Robert Grosseteste and the Origins of Experimental Science (Oxford 1953).
[j. a. weisheipl]
The English churchman and statesman Robert Grosseteste (1175-1253) played an important role in the politics of his time. He was also a major English medieval writer and thinker.
Robert Grosseteste was born at Stradbrooke, Suffolk, of humble parents. Educated at Oxford, where he became magister, or master, in 1199, he then studied at Paris. He was back in England by 1215, where he is believed to have been at the meeting of King John and the barons at Runnymede, where the King accepted the Magna Carta.
Since he was the first English scholar who knew both Greek and Hebrew, Grosseteste soon rose within the Church. In 1224 he was made the first rector of the Franciscans at Oxford, and the next years saw him going through a series of Church positions:archdeacon of Wiltshire, then Northampton and Leicester, prebend of Lincoln, and chancellor of Oxford.
Grosseteste was one of the few medieval churchmen to be sympathetic to the Jews. Tradition has it that he first came in contact with the Jews of England through learning Hebrew from a rabbi in Oxford, and by 1231 he was writing such works as De cessatione legalium to try and gain converts. In 1232 he gave up many of his posts so that he could remain at Oxford, but in 1235 he was elevated to the bishopric of Lincoln, one of England's largest sees.
For the next years Grosseteste was active in the administration of his cathedral and from 1239 to 1245 carried out a dispute with the chapter over his rights of visitation, which he finally won after visiting the Pope in Lyons to gain his support.
Grosseteste was active in support of the papacy in England and supported the papal claims against the barons at the Council of Merton, but he was also to stand out against the papacy in matters of practical abuses, such as papal attempts to find presentations in England for Italians. In 1253 he refused to place the Pope's nephew in the canonry of Lincoln due to his lack of knowledge of English. In addition, he often stood against the King. In 1244 Grosseteste prevented the granting of a subsidy to the King, was appointed a clerical representative to discuss the financial needs of the Crown, and was one of the 12 appointed to regulate the conduct of the King and his ministers. In 1252 he opposed Henry III's demand for a tenth of the Church's revenues, nominally granted for a crusade, even though it had papal support.
A friend and adviser to Simon de Montfort, Grosseteste played an important part in the politics of his age, but his most long-lasting influence was in his writings and his fame as a scholar. Roger Bacon was one of his pupils, and Grosseteste appeared in his own time as a universal genius as his long list of publications indicates. He produced works on law, philosophy, French poems, physics, and agriculture, as well as theology, and he produced translations and commentaries on such works as Aristotle's Physics and Ethics and on the Testament of the Twelve Patriarchs and the Ignatian Epistles. His work on optics was the basis of some of his rebuilding of Lincoln Cathedral.
Taken ill during the summer of 1253 while at Buckden, Grosseteste died on October 9 and was buried in the south transept of Lincoln Cathedral. Miracles were soon reported at his tomb, but repeated attempts for his canonization failed as his public career had been spent in opposition to papal authority, and he was to be canonized informally by the people of northern England. He has been described as an example of the best influences in the public life of the 13th century.
There are many biographies of Grosseteste, including Samuel Pegge, The Life of Robert Grosseteste:The Celebrated Bishop of Lincoln (1793), and the classic study by Francis S. Stevenson, Robert Grosseteste, Bishop of Lincoln:A Contribution to the Religious, Political and Intellectual History of the Thirteenth Century (1899; repr. 1969). His role in English life is discussed in C. R. Cheney, English Bishops' Chanceries, 1100-1250 (1950). See also A. C. Crombie, Robert Grosseteste and the Origins of Experimental Science (1953), and D. A. Callus, ed., Robert Grosseteste, Scholar and Bishop:Essays in Commemoration of the Seventh Centenary of His Death (1955). S. Harrison Thomson, The Writings of Robert Grosseteste:Bishop of Lincoln, 1235-1253 (1940), is a scholarly bibliography. □
Circa 1168 – 1253
Chancellor of the university of oxford and bishop of lincoln
Linking Science and Theology. Robert Grosseteste greatly influenced English scientific thinking by directing the interests of Franciscans there toward natural philosophy and mathematics. Grosseteste (which means “of the large head”) wrote some of the first commentaries on Aristotle’s physical-science works and composed his own treatises on astronomy, cosmology, comets, motion, sound, heat, light, optics, and the rainbow. He is known for promoting the search for rational and consistent explanations that incorporate natural and divine evidence, and he was also was one of the first scholastic thinkers to try to reconcile the Bible and Church Fathers with the Aristotelian works that were then available in Latin.
Education and Career. By 1190, Grosseteste, who had studied at the University of Oxford, was a member of the household of Bishop William de Vere in Hereford, then a center for scientific and theological knowledge. Sometime after 1198 he began teaching at Oxford, and in 1209 he went to the University of Paris to study theology. Returning to Oxford in 1214, he became chancellor in about 1225. As chancellor, he made the study of languages and the sciences an important part of the curriculum, at a time when the University of Paris placed a heavy emphasis on theology and forbade the study of natural science—especially the “pagan” works of Aristotle and his Arab commentators. He left the university in 1229 but remained in Oxford, where he taught young Franciscan friars until 1235, when he was elected bishop of Lincoln, then the largest diocese in England. As bishop he organized a team of scholars to translate Greek and Hebrew works into Latin.
Studies of Light. For Grosseteste, the fundamental building block of the universe was light, through which God’s power was manifested in the world. Consequently, he tried to explain the propagation of light (and sound), colors, reflection and refraction, and even the generation of stars. Although he did not necessarily achieve his goal of advancing a theological understanding of these phenomena, he did develop the medieval science of optics and the related mathematics—the geometry for describing how rays travel and the ratio theory for expressing intensities. He also broadened the concept of light to include the general idea of a fundamental, divine “power,” which then led him to consider the motion of the tides, sound, and comets. Although his explanations seem farfetched to modern readers, they were groundbreaking in the Middle Ages because they introduced the idea that these things have natural explanations.
A. C. Crombie, “Robert Grosseteste,” in Dictionary of Scientific Biography, edited by Charles Coulston Gillispie (New York: Scribner, 1970–1980), V: 548–554.
Crombie, Robert Grosseteste and the Origins of Experimental Science, 1100–1700 (Oxford: Clarendon Press, 1953).
Jeremiah Hackett, “Robert Grosseteste,” in Dictionary of Literary Biography, volume 115: Medieval Philosophers, edited by Hackett (Detroit & London: Bruccoli Clark Layman / Gale Research, 1992), pp. 225–235.
English Physicist and Philosopher
Though he is perhaps best known as the teacher of Roger Bacon (1213-1292), Robert Grosseteste distinguished himself as a scientist in his own right. He wrote on astronomy, discussing comets and advancing a theory of tides. He also presented his own theories concerning light and sound. He described light as the basic substance of the universe and postulated, with considerable accuracy, that sound was a vibrating motion passing through the air.
Grosseteste was born the son of poor parents, and at an early age was forced to earn his own living, at times resorting to begging. The mayor of his hometown, Lincoln, England, eventually recognized his intellectual abilities, and arranged to have him enrolled in school. There he distinguished himself so much that he went on to an academic career that took him successively to the universities of Oxford, Cambridge, and Paris.
In about 1215, Grosseteste was appointed chancellor at Oxford, a position in which he served until 1221. He became the first rector of the Franciscan monks at that institution in 1229 or 1230, then in 1235 received consecration as Bishop of Lincoln. Throughout his remaining career, he distinguished himself for his opposition to abuses of power by both King Henry III and Pope Innocent IV, whom he openly described as "the Antichrist."
Bacon, who studied under Grosseteste in the 1230s, described his teacher as one of the most learned men of his day. Grosseteste excelled in his studies of Greek and Hebrew, and wrote several works on Aristotle (384-322 b.c.).
Starting in about 1215, Grosseteste engaged in a number of scientific studies. Within a decade, he had conducted experiments in optics, using mirrors and lenses, in an attempt to explain the qualities of light in general, and of the rainbow in particular. In 1230, he published De generatione sonorum, his treatise on sound. In it, he advanced his theory of vibrations, which would be corroborated by later studies in the modern era.
As with many men of science during the Middle Ages, Grosseteste's curiosity earned him disapprobation as a suspected magician—a reputation no doubt compounded by his outspoken opposition to church and secular leaders of the day. It was reputed that he had published a study entitled Magick, and that he built a head of brass that could be used for discerning answers to questions and foretelling the future. Not only the scholar Gerbert (a.k.a. Pope Sylvester II, 945-1003) but even Grosseteste's student Bacon, repeated this bizarre tale.
Grosseteste, Robert (ca. 1175-1253)
Grosseteste, Robert (ca. 1175-1253)
Bishop of Lincoln, England, from 1235, generally known as Robert of Lincoln. A notable statesman and philosopher, he was also rumored to be proficient in the art of magic. Born of poor parents, he was compelled early to earn his own living and even at times to beg for bread. He was at length "discovered" by the mayor of Lincoln, who was attracted by his appearance and the shrewdness of his remarks and had him sent to school, where his capacity for study was so great that he was able to complete his education at Oxford, Cambridge, and Paris.
The illustrious Roger Bacon described Grosseteste and his friend Friar Adam de Marisco as the most learned men of their time. Grosseteste was well skilled in the sciences of mathematics and astronomy and was a master of Greek and Hebrew. As a member of the clergy he distinguished himself chiefly by his vigorous denunciation of the abuses in the court of Rome, particularly those of the pope, Innocent IV. Grosseteste did not hesitate to point out the misdeeds of the ecclesiastical dignitaries. He openly declared Innocent to be the Antichrist. In addition to reputedly publishing a treatise entitled Magick (probably a false ascription), legend also has it that he constructed a brazen head that would answer questions and foretell the future. (This story was also told of both Pope Silvester II and Roger Bacon.)
J. A. Cannon