Adelard of Bath Biography

1075-1160

English Scholar

The contributions made by Adelard of Bath to mathematical knowledge were primarily in the area of scholarship, translation, and historical writing rather than original theory. Nonetheless, his achievements were crucial to the growth of learning in Western Europe, and included the first translation of Euclid's (c. 325-c. 250 B.C.) Elements, which became the first important geometry textbook in the West, and al-Khwarizmi's (c. 780-c. 850) Tables, which introduced Arab astronomy to Western thinkers. In presenting ideas derived from the East, Adelard brought two other concepts of staggering importance to the attention of Western mathematicians: trigonometry and Hindu-Arabic numbers.

Though he is known as an Englishman, Adelard spent much of his career outside his home country. In France, he studied at Tours and from 1100 taught at Laon. He later spent seven years traveling, first visiting the medical school at Salerno in southern Italy, a highly significant institution that served as a precursor to the idea of a university. He also visited Sicily, which had long been held by Arabs (though by then it was under Norman control), and it is likely that he gained his knowledge of Arabic while there. Later years found Adelard in Cilicia, now part of Turkey, from whence he traveled through Syria and Palestine. By 1130 he was back in Bath.

Early in his career, Adelard wrote a study of arithmetic based on the work of Boethius (480-524), as well as a philosophical work in 1116 that shows a heavy influence from Plato (427-347 B.C.). With his exposure to the East he gained access to new ideas—some of which were not new at all; rather, these were concepts from ancient Greece which had been lost to Western Europe, but were recovered by Arab thinkers. Thus he became influenced by the philosophy of Aristotle (384-322 B.C.), who was much more highly regarded than Plato by Arab scientists, and undertook his translations of Euclid.

With regard to the latter, three versions of the Elements have been attributed to Adelard. The first appears to have been drawn from an Arabic translation attributed to al-Hajjaj (661-714). By contrast, the wording of the second is so different from that of the first that historians assume it was based on another, unknown, Arabic version of Euclid. The second version is considered less thorough than the first, and did not acquire the status of his predecessor; however, a third translation—which may or may not have been the work of Adelard—was later quoted extensively, by Roger Bacon (1213-1292) and others.

In his work on al-Khwarizmi, it became necessary for Adelard to use symbols hitherto unknown in the West: the numerical characters developed in India, adapted by the Arabs (hence the erroneous name "Arabic numerals"), and still in use throughout the world today. Thanks to Adelard, Western scientists were also introduced to the concept of astronomical tables, and other works by him exposed them to trigonometry, as well as the abacus and the astrolabe.