ADELARD (or AETHELARD) of Bath (12th century), English scholastic philosopher, and one of the greatest savants of medieval England. He studied in France at Laon and Tours, and travelled, it is said, through Spain, Italy, North Africa and Asia Minor, during a period of seven years. At a time when Western Europe was rich in men of wide knowledge and intellectual eminence, he gained so high a reputation that he was described by Vincent de Beauvais as Philosophus Anglorum. He lived for a time in the Norman kingdom of Sicily and returned to England in the reign of Henry I. From the Pipe Roll (31 Henry I. 1130) it appears that he was awarded an annual grant of money from the revenues of Wiltshire. The great interest of Adelard in the history of philosophy lies in the fact that he made a special study of Arabian philosophy during his travels, and, on his return to England, brought his knowledge to bear on the current scholasticism of the time. He has been credited with a knowledge of Greek, and it is said that his translation of Euclid's Elements was made from the original Greek. It is probable, however, from the nature of the text, that his authority was an Arabic version. This important work was published first at Venice in 1482 under the name of Campanus of Novara, but the work is always attributed to Adelard. Campanus may be responsible for some of the notes. It became at once the text-book of the chief mathematical schools of Europe, though its critical notes were of little value. His Arabic studies he collected under the title Perdifficiles Quaestiones Naturales, printed after 1472. It is in the form of a dialogue between himself and his favourite nephew, and was dedicated to Richard, bishop of Bayeux from 1113 to 1133. He wrote also treatises on the astrolabe (a copy of this is in the British Museum), on the abacus (three copies exist in the Vatican library, the library of Leiden University and the Bibliotheque Nationale in Paris), translations of the Kharismian tables and an Arabic Introduction to Astronomy. His great contribution to philosophy proper was the De Eodem et Diverso (On Identity and Difference), which is in the form of letters addressed to his nephew. In this work philosophy and the world are personified as Philosophia and Philocosmia in conflict for the soul of man. Philosophia is accompanied by the liberal arts, represented as Seven Wise Virgins; the world by Power, Pleasure, Dignity, Fame and Fortune. The work deals with the current difficulties between nominalism and realism, the relation between the individual and the genus or species. Adelard regarded the individual as the really existent, and yet, from different points of view, as being himself the genus and the species. He was either the founder or the formulator of the doctrine of indifference, according to which genus and species retain their identity in the individual apart altogether from particular idiosyncrasies. For the relative importance of this doctrine see article SCHOLASTICISM.
See Jourdain, Recherches sur Les traductions d'Aristote (2nd ed., 1843); Haureau, Philosophie Scholastique (2nd ed., 1872), and works appended to art. SCHOLASTICISM.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)