by Charles Burnett
© Oxford University Press 2004 All rights reserved
Bath, Adelard of (b. in or before 1080?, d. in or after 1150), scientist and translator, was a pioneer in introducing Arabic mathematics into England.
Evidence for his career
Although absolute confidence cannot be placed in the autobiographical details included within the fictitious context of his literary works, Adelard's connection with Bath is assured by a self-reference in his Quaestiones naturales and the reference to Bath in three of his other works--the astronomical tables, the Liber prestigiorum, and the De opere astrolapsus--in technical examples, which could mean that they were composed in Bath (though not adapted for the meridian of Bath) or that Adelard used the example of Bath simply because it was his place of origin. Independent evidence is provided by the cartulary of Bath Priory, in which the name AÝelardus appears four times, though these may not all refer to the same person. One document of 1106 describes AÝelardus as filius Fastradi: Fastrad was one of the principal tenants of Giso, bishop of Wells (d. 1088). If this AÝelardus is the scholar Adelard of Bath, his birth must be placed in 1080 or before. Giso's successor, John of Tours (d. 1122), moved the seat of his bishopric from Wells to Bath, where the Roman spa was being redeveloped and would have attracted doctors and scholars. John may have encouraged Adelard to go to Tours, the bishop's native city. Adelard's De eodem et diverso suggests that he went to Tours in the company of his 'nephew', and applied himself to 'Gallic studies': he met a famous, but unnamed, wise man, who elucidated the science of astronomy for him, and he learnt music there, playing the harp in front of a queen. Adelard's style and interests are remarkably close to those of another alumnus of Tours, Hildebert de Lavardin, who returned to Tours as bishop in 1125. In his Quaestiones naturales Adelard takes his 'nephew' and other students to Laon where his 'nephew' promises to pursue 'Gallic studies'. Laon was the natural place to go to, since the sons and nephews of several of Henry I's key administrators were students there, including the two nephews of Roger, bishop of Salisbury (d. 1139), Henry's viceroy. Having dismissed his students outside Laon, Adelard departed for a seven-year period of travel devoted to the 'studies of the Arabs'. Where Adelard spent these seven years, which resulted in the Quaestiones naturales, is not stated, but there is dependable evidence for an Italian phase of Adelard's career, perhaps also inspired by John of Tours, in the dedication of the De eodem et diverso to William, bishop of Syracuse in Sicily, whose bishopric falls between 1105 and 1124. The questions to which Adelard provides answers in the Quaestiones naturales are associated with Salerno, from where, according to the De eodem et diverso, Adelard was travelling when he met a Greek philosopher in Magna Graecia (Puglia, southern Italy), who was an expert in medicine and the nature of things. Adelard should probably be believed when he says that he also visited the Norman kingdom of Antioch, and Mamistra (Misis) in Cilicia, where the earthquake that he experienced could have been the severe one that affected the area in 1114.
The dedication of the Quaestiones naturales mentions Adelard's recent return to England after a long absence during the reign of Henry I--that is, before 1135--after which it is likely, but not certain, that he resided in Bath. At first he may have supported King Stephen, who held the city of Bath. By 1150, however, he seems to have followed the tide and at least sought the patronage of the young Henry Plantagenet, son of the Empress Matilda, and the future Henry II. Adelard's De opere astrolapsus is dedicated to a Henry regis nepos, who, Adelard continues, had reached 'the age of discretion'. This is most likely to have been the young Henry, who was the grandson (nepos) of Henry I and was formally declared by his father to have come of age early in 1150. At the same time he was invested with the duchy of Normandy and his succession to the English throne looked probable. Hence the appropriateness of addressing him as 'grandson of the king'. Adelard may have changed his allegiance earlier, for the earliest apparent knowledge of his Quaestiones naturales is in the Dragmaticon (1144-9) of William de Conches, who was tutor to Henry and the other sons of Geoffrey Plantagenet after Geoffrey had become duke of Normandy in April 1144. If this is so, the Richard, bishop of Bayeux, to whom the Quaestiones naturales is dedicated in most manuscripts is Richard of Kent, bishop from 1135 to 1142, the son of Matilda's principal supporter Robert, earl of Gloucester, rather than Richard fitz Samson, bishop from 1107 to 1133. One family of manuscripts dedicates the work to presul G, who may be William (Guillelmus in Latin), bishop of Syracuse. Adelard's astronomical tables probably also date from around this time, since they give the date 26 January 1126 in an example, and appear already in a manuscript copy written before 1140 (Bodl. Oxf., MS Auct. F.1.9). Some modern scholars have ascribed to Adelard a set of horoscopes drawn up evidently by a partisan of King Stephen on several dates between 1150 and 1151. These horoscopes show the use of the tables of al-Khwarizmi, which Adelard had translated; it is equally possible, however, that they were drawn up by Robert of Chester (fl. 1144-1150), who revised Adelard's translation and was in London (Stephen's centre of operations) in 1147 and 1150.
Philosophical works
Adelard's writings fall into two internally coherent groups: his original more literary works, intended for a wide audience; and the translation of a curriculum of mathematical works written presumably for fellow scientists.
The De eodem et diverso is a work in the tradition of the protrepticon--or exhortation to the study of philosophy--of which Boethius's De consolatione philosophiae was Adelard's principal model. It takes the form of a dramatic dialogue between Philocosmia, who advocates worldly pleasures, and Philosophia, whose defence of scholarship leads into a summary of the contents of each of the seven liberal arts. While Adelard adopts a highly literate and entertaining style, his serious aim is to show how the epistemology of Plato and Aristotle can be reconciled in a theory of universals which is very similar to what was later called the indifference theory: that is, that the terms (voces) 'individual', 'species', and 'genus' can be applied to the one thing (res) and differ only according to the different levels at which that thing is considered. Adelard's intention is to rescue such voces, as reaching 'the causes and beginnings [initia] of the causes of things', in the face of an Epicurean attitude in which only the sensible things (res) are regarded as of any relevance.
The Quaestiones naturales refers to a future discussion of 'beginning or beginnings [initia]', and complements the De eodem et diverso by concentrating on things themselves and their rational causes, rather than on voces and the epistemological order of knowing things. In fact, the approach taken in the De eodem et diverso is characteristic of what Adelard calls 'Gallic studies', which he contrasts to the method of 'the studies of the Arabs' followed in the Quaestiones naturales. The extent to which it is Arabic has been much debated. The dialogue is built on a framework of apparently pre-existing 'natural questions', which have Arabic parallels, and which probably formed the basis of debate in the school of Salerno, with which Adelard was familiar. The subject matter is summed up in a motto which Adelard inserted between the list of questions and the beginning of the text: Sic faciunt causae rerum ('This is how the causes of things work') , and, if the heart of the De eodem et diverso can be considered to be logic, that of the Quaestiones naturales is natural science. While some of the questions may appear frivolous (such as 'Why is the nose above the mouth?', 'Why are the fingers unequal in length?'), the answers apply consistent physical principles--such as that similars derive from similars--in a way that presages the arrival of Aristotle's libri naturales in the West.
The Quaestiones naturales itself is complemented by Adelard's De opere astrolapsus, which deals with cosmology: the first half of the work describes the cosmos itself, whereas the second half describes the visible model of the cosmos--the astrolabe--and gives instructions in how to use the instrument, some of which refer back to the section on geometry in the De eodem et diverso. In this, it is similar to another instructional work--on the abacus--which Adelard probably wrote early in his life. Finally, a little work on hawking--De avibus--is introduced as a diversion from the serious matter of the Quaestiones naturales, and gives advice, in dialogue form, on how to rear hawks and cure the diseases to which they are prone.
All these works except the De opere astrolapsus include a 'nephew' as participant in a dialogue with Adelard (Quaestiones naturales and De avibus), or as the silent auditor (in the De eodem et diverso). They are written in the highest quality humanistic Latin, are full of wit and verbal artifice, with many-layered allusions to classical literature, and (in the De eodem et diverso) the inclusion of verse. Thus they were as much models of style and learned discourse as instructional manuals, comparable to and perhaps influenced by the work of Hildebert de Lavardin. Their aim was evidently to provide a good humanistic education to the young noblemen that Adelard had in his charge.
Translations from Arabic
This broadly didactic purpose contrasts with the second group of works which Adelard probably wrote for himself and his fellow scientists. Here, he seems to have been following a programme set out by 'Arabic masters': this could well have been in the west midlands where the astronomer Petrus Alfonsi was instructing Walcher, prior of Great Malvern, in Arabic astronomy. This programme began with the study of Euclid's Elements, of which there is one translation (known as Adelard I) clearly in Adelard's style, and continued through the study of spherical geometry (Adelard may have worked on Theodosius's Spherics) to that of astronomy. Adelard expresses his debt to his Arabic masters for information on the cosmos in his De opere astrolapsus, but his own contribution to the field is a translation of the canons (rules) and tables of al-Khwarizmi. With these tables, from which one could work out the positions of the planets, the sun, and the moon, at any time, an astronomer could then apply himself to the practical aspect of his art--astrology. Adelard translated a convenient handbook on the subject (Abu Ma'shar's Abbreviation of the Introduction to Astrology), a set of astrological aphorisms (Pseudo-Ptolemy's Centiloquium), and a text on how to make astrological talismans (Thabit ibn Qurra, Liber prestigiorum). None of these translations has a preface or a dedication. They were apparently translated with the help of Arabic speakers and for the purpose of making advances in the knowledge of mathematics (including astrology).
Reputation as teacher and scholar
The evidence for his teaching in these subjects is provided in notes referring to Adelard's opinions in glosses both to Boethius's De musica and to another version of Euclid's Elements, known as Adelard II. The latter might well have been written by a pupil of Adelard (Robert of Chester has been suggested), as was the introduction to Helcep Saracenicum ('Saracen calculation')--written calculations with numerals having place value--composed for 'his master Adelard' by a certain Ocreatus. Adelard's reputation in geometry in particular is attested by his name appearing in a list of three 'modern' geometers in an introduction to arithmetic in Cambridge, Trinity College, MS R.15.16. While the precise place (or places) of his teaching activity is uncertain, he was evidently the key figure at the beginning of a scientific movement that developed in England throughout the twelfth century and culminated in the work of Robert Grosseteste (d. 1253) in the early thirteenth century.
Adelard's reputation as a mathematician was assured by the translation of Euclid. His name was attached to several versions of Euclid's Elements, works of chiromancy and geomancy and other texts on divination and magic. Although he was probably not the author of the texts on the algorism (pen-reckoning; the Dixit algorismi), the whole quadrivium (Liber ysagogarum Alchorismi), and glosses to Boethius's De arithmetica which have been attributed to him, it is very likely that mathematical texts were written by his pupils and associates, or under his influence.
Adelard's models are the Latin classics and, beyond them, Greek science and philosophy. He wished to rely on reason rather than on revelation; his God was the God of Aristotle rather than of St Paul. His works too were evidently appreciated as classics. His Quaestiones naturales were frequently copied alongside the classical text on natural questions by Seneca, and the De eodem et diverso, in the one manuscript that contains it, accompanies an entertaining retelling of the case histories in Pseudo-Quintilian's Declamationes XIX, for which Adelard may have been responsible. As a scholar he occupies a place on the European stage, and his work must rank alongside that of scholars in Paris, Chartres, and Orléans (with whom he must have had contacts) who showed a renewed interest in the Latin and Greek classics, and a new confidence in human reason. But in addition to the sources recovered by other scholars Adelard turned to Arabic texts; and in this respect he was unique for his time.
CHARLES BURNETT
Sources
C. Burnett, ed., Adelard of Bath: an English scientist and Arabist of the early twelfth century (1987)
Adelard of Bath: conversations with his nephew, ed. and trans. C. Burnett and others (1998)
C. H. Haskins, Studies in the history of mediaeval science, 2nd edn (1927), 20-42
L. Cochrane, Adelard of Bath: the first English scientist (1994)
B. G. Dickey, 'Adelard of Bath: an examination based on heretofore unexamined manuscripts', PhD diss., University of Toronto, 1982
C. Burnett, 'Algorismi vel helcep decentior est diligentia: the arithmetic of Adelard of Bath and his circle', Mathematische Probleme im Mittelalter: der lateinische und arabische Sprachbereich, ed. M. Folkerts (1996), 221-331
C. Burnett, 'Adelard of Bath's doctrine on universals and the Consolatio philosophiae of Boethius', Didascalia, 1 (1995), 1-14
W. Hunt, ed., Two chartularies of the priory of St Peter at Bath, Somerset RS, 7 (1893), pt 1, nos. 34, 41, 53, 54
Pipe rolls, 31 Henry I
Reg. RAN, 3.282 (no. 764)
horoscopes, BL, Royal MS App. 85, fols. 1-2
Robert of Chester's (?) redaction of Euclid's 'Elements', the so-called Adelard II version, ed. H. L. L. Busard and M. Folkerts, 1 (1992), 1-31 [the versions of Euclid's Elements attributed to Adelard]
Archives
BL, Royal MS App. 85, fols. 1-2
Bodl. Oxf., MS Auct F. 1.9
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