, from Arabic into Latin, of Euclid's Elements, which became a standard textbook of geometry for the next eight centuries.
Modern scholars first became interested in Abelard, not for his translations or scientific works, but for De eodem et diverso, contrasting the virtues of the seven liberal arts with worldly interests. The historian of Aristotelianism, Amable Jourdain, first drew attention to the work in 1819, and Barth´el´emy Haur´eau devoted a whole chapter to the text in Histoire de la philosophie m´edi´evale (1850). In 1903, De eodem et diverso was the first of Adelard’s works to receive a modern critical edition, by Hans Willner. Josef Reiners gave a prominent position to Adelard’s doctrine in his study of scholasticism (Der aristotelische Realismus in der Fr¨uhscholastik), and attention soon shifted to Adelard’s contributions to the history of science. Recently scholars have revisited Adelard’s position on logic and the question of universals.
Adelard’s translation of Euclid’s Elements from Arabic into Latin was the first introduction of this work to European scholars. Adelard appears to have made three separate translations of Elements. The first version was a translation of all fifteen books (the thirteen original books written by Euclid and the two additional books written by Hypsicles), which seems to have come from a translation of al-Hajjaj's from Greek into Arabic. The second version contains different wording for the statements of the propositions, and the proofs are often only outlines or indications of how proofs might be constructed. Experts have concluded that Adelard used an unknown Arabic source for this version, rather than al-Hajjaj's translations. The third version of Euclid's Elements was a commentary rather than a translation of the original text, and may not be Adelard’s work although it was written before 1200, and is widely attributed to him. Roger Bacon quoted this third version in his works. Johannes Campanus probably had access to Adelard's translation of Elements; it was Campanus' edition that was first published in Venice in 1482 after the invention of the printing press and this became the chief textbook of the mathematical schools of Europe.
Adelard wrote a short treatise on the use of the abacus (Regulae abaci). He also wrote arithmetic books, the earliest of which, based on the work of Boethius, was written before he studied Arabic arithmetic. His Latin version of a treatise on Arabic arithmetic by al-Khwarizmi, the great Saracen mathematician whose name is associated with an important influence in the later European adoption of the Arabic notation for numbers replacing the intractable Roman numerals.
Adelard was a pioneer of the scientific renaissance of the twelfth century, one of the first to call for observation, experimentation, and innovation rather than blind acceptance of authority on scientific questions. His writings include speculation that animals must have souls because they possess the power of judgment, and the first known written account of the distillation of alcohol. He followed Galen and the Arabian physicians in attempting to localize mental functions. Adelard's Perdifficiles Quaestiones Naturales (Natural Questions) (first mass-printed in 1472) consisted of 76 scientific discussions based on Arabic science which are presented in the form of a dialog between himself and a nephew, which lasted from 1113 to 1133. Adelard considered the shape of the Earth which he believed to be round, and the question of how Earth remains stationary in space. He asked the question of how far a rock would fall if it were dropped into a hole drilled through the earth. (See: center of gravity) He theorized that matter could not be destroyed, (see: Law of conservation of matter), and examined the question of why water experiences difficulty flowing out of a container that has been turned upside down. Many of these questions reflected the popular culture of the time.
In the field of astronomy, Adelard translated al-Khwarizmi's tables (Kharismian Tables), which became the first Latin as