Proceedings 8        29 April 1988        Danson Room, Trinity College

MEN AND BOOKS, CLOUDS AND STARS, THE MERTONIANS: a paper by Mr Keith Snedegar of Magdalen College, a founder member of SHMTS.

After brief introductory remarks by Dr. Crombie, the speaker prefaced his remarks with a dedication of the paper to his recently dead father.


Scientia astrorum, the science of the stars, was a suitable term to describe the unified science incorporating what we would call astronomy and astrology. There is no equivalent modern term, but while the two were considered concomitant studies in the Middle Ages, a sharp distinction between them was recognized. The two disciplines were viewed as twin branches of the same scientific tree, but literate people fully recognized the difference between them. Although scientia astrorum was not a standard classificatory term, it was occasionally used 1n 14th century treatises. As early as the 7th century, Isidore of Seville had defined astronomia as the science dealing with the motions, risings and settings of the celestial bodies; astrologia, which could be either natural or superstitious, drew interpretations from the motions. In the 12th-century astronomy was classed as an intermediate science because it considered real physical bodies, the stars and the planets, in. a descriptive mathematical sense. In the 1250s Robert Kilwardby gave a full up-to-date definition of the scientia astrorum. He divided the science into two or three parts - 1) mathematical astronomy, 2) natural astrology, which considered the influence of celestial virtues on natural events, human health, climate and so forth, 3) a third branch which pretended to the casting of nativities and the prediction of human fate.

Like Kilwardpy, Roger Bacon understood astrology within the framework of Aristotelian sciences, the question was how did it relate to mathematical astronomy. Astrology patently not subordinate to geometry or mathematics ~any kind, since it was qualitative discipline ordered under natural science. Yet it was dependent on mathematics, for without mathematical astronomy, astrological knowledge was impossible. Indeed, medieval (and early modern) astronomy had astrological prediction as its first goal. With some astronomers the concern with mathematical procedures served as a distraction, or even became an obsession--some star tables contained tens of thousands of digits and some master calculators derived intellectual satisfaction from tinkering with their calculations. Yet this fascination with the operations of numbers can hardly have been a sufficient cause for the astronomers' study of the heavens---the single practical outlet for astronomical calculations was their use in astrology.

Neither Albertus Magnus nor any other classifier of the sciences attempted to subdivide mathematical astronomy rationally. Thomas Aquinas spoke vaguely of soientia de spera mota as apart from the rest of astronomy but failed to elucidate the distinction. However distinct branches did come to enjoy implicit recognition. Olaf Pederson has identified a fundamental corpus astronicum comprising 1) computistical studies for the reckoning of the calendar; 2) spherical astronomy, concerning the fixed stars; 3) planetary astronomy. The first of these, concerned as it was with the correct calculation of Church feast days, was the senior branch.

For centuries the basic work in the field was that by the Venerable Bede until it was supplanted by the Computus of John Sacrobosco. In spherical astronomy too Sacrobosco was the author of the standard work. Ptolemy's Almagest provided the basis for planetary astronomy, complemented later in the Middle Ages with the adoption of astronomical tables. But the mathematics of the Almagest was much too technical for teaching purposes and in the 13th century a number of abstracts appeared.

Scientia astrorum in the Oxford arts curriculum

The position is spelt out fairly clearly in the university statutes. Bachelors incepting for the masters degree were expected to have attended lectures on arithmetic, part of Euclid's elements, the computus, spherical and planetary astronomy, though the last named does not appear to have been accorded an official place in the curriculum until the middle decades of the 15th century. None of the branches received more than cursory study - for example fewer than half the books of Euclid were studied. Next to logic and natural philosophy, astronomy played only a subsidiary role in the formal arts course. A major treatise on astronomy was the De Stellis by the Dominic~~ Robert Holcot. His presentation was largely unmathematical and gave brief consideration to natural astrology.

There was no mention of astrology in 14th century records of the university and no systematic treatment of astrological topics. Yet it appears there were occasional cursory lectures based on astrological books--such lectures became a noticeable feature in the arts in the 15th century.

The subjects of the quadrivium were not the responsibility of the public schools of the university, but their teaching had been delegated to the halls and colleges. In such circumstances University standards in a given subject might be mediocre while a college or hall might develop a speciality. It would appear that Merton fellows acquired a reputation for their teaching of the quadrivium.

The Merton School

John Maudith who entered the college in 1309 was the first recognized Mertonian specialist astronomer; in 1316 he drafted a star catalogue. A close contemporary, Walter Odington a monk at Evesham wrote on arithmetic, geometry, alchemy and on aspects of astronomy while another distinguished non-Mertonian was Richard of Wallingford, the greatest mathematician of his time. He had a comprehensive understanding of mathematical astronomy, made a notable contribution to the astrological literature and designed astronomical instruments most notably his mechanical clock at St Albans, where he was abbott. The speaker referred his audience to the classic work of Dr John North. While neither of them were Merton fellows, both Maudith and Wallingford were Oxford men and seem to have been acquainted.

The real initiator of the Merton school as such was, perhaps Thomas Bradwardine. Best known today for his pioneering work on mathematical proportions and dogmatic theology, he was an energetic teacher of the quadrivium including possibly astronomy, from about 1323 to the early 1330s. In his tractatus proportionum, he implies an astronomical purpose when speaking of the 'equinoctial radius' of a sphere. He showed an enthusiasm for the compilation and use of astronomical tables.

A notable grouping of Merton fellows concerned with the science of the stars emerged after the main period of Bradwardine's Oxford career. The main figures included Simon Bredon, William Brede, Nicholas of Sandwich and John Ashenden; their interests ranged from astronomy to medicine and many had a penchant for meteorology. Among numerous important works Simon Bredon, mentioned first in the college records in 1330, wrote a commentary on the Almagesti which inspired English students of astronomy for over 200 years. Leaving Merton in the early 1340s, he embarked on a career in medicine which proved highly successful--his patients including the Queen of Scots.

Some time about the year 1340 William Rede adapted the Alphonsine tables to the latitude of Oxford, thereby effectively establishing the Alphonsine standard in England for the next two centuries. Rede also made many calculations for astrological purposes and was probably responsible for the 1341-46 almanacs in Digby MS 176.

An important non Mertonian, William Merle, rector of Driby, Lincolnshire, practised a system of meteorology based on observation, keeping a weather diary for the years 1337-44. He was particularly interested in the use of meteorology in farming. In his de prognosticatione aeris he recommended two sources for weather studies, by questioning 'expertos', sailors, shepherds, farmers etc., and by the reading of theoretical treatises. Merle had correspondents in Oxford and is known to have borrowed a book from Bredon.

Outside Oxford, St Augustine's Abbey, Canterbury was a centre of astronomical studies, among the monks John of London had a large collection of scientific books including virtually every major work on astronomy and astrology then known. He bequeathed the collection to the Abbey library. Books were a principal bond between scholars and it could be said that the Mertonians themselves were a fellowship) maintained by the;. sharing of books. Many of them belonged to the circle of Richard de Bury the bibliophile Bishop of Durham, notably Bradwardine and Maudith. However there was quite a difference between de Bury's bookishness and Merton scholarship. Where the bishop was concerned mainly with elegance of style the Mertonians dealt rather in the substance of learning. The single most revealing document of the Merton circle, Digby MS 176, a miscellaneous collection of astrological works brought together by William Rede. It provides a remarkable cross section of the scientia astrorum Mertoniensis compiled by William Rede it included sections by Merle, Ashenden, Lambourne and others.

The Digby MS reveals the lively intellectual tradition at Merton in the first half of the 14th century, but it has its limitations. Foremost of these was the lack of constructive dialogue between the astronomers and the natural philosophers at the college. An important limiting condition was the fact that astronomy was a pursuit. of the youthful and the years of productive study were short. At Oxford as elsewhere the curriculum was intended to lead to the higher faculties: Medicine, Law and Theology. Not only were these subjects higher in the order of learning, they also offered greater career prospects in the outside world. The Merton group dispersed by a process of natural attrition during the 1350s-60s but astronomical activity in Oxford continued well into the next century.

The President thanked Mr Snedegar for his illuminating paper and the meeting concluded with questions from the floor

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