Adelard of Bath

Main works

Among Adelard of Bath's original works is a trio of dialogues, written to mimic the Platonic style, or correspondences with his nephew. The earliest of these is De Eodem et Diverso (On the Same and the Different). It is written in the style of a protreptic, or an exhortation to the study of philosophy. The work is modelled on Boethius' Consolation of Philosophy, evident in Adelard's vocabulary and phraseology. It is believed to have been written near Tours after he had already travelled, though there is no indication that he had travelled past Southern Italy and Sicily at the time of writing. The work 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 seven liberal arts. Underlining the entire work is the contrast between Philocosmia's res (perceptible reality), and Philosophia's verba (mental concepts). Each section of the liberal arts is divided into two parts. Presented first is a description of the allegorical figure representing the art, in which the importance of that art is indicated, followed by a summary of the doctrines of that art, as told by the allegorical figure who is presented as the founder or main proponent of the particular art.

The second of this trio, and arguably Adelard's most significant contribution, was his Questiones Naturales or Questions on Natural Science. It can be dated between 1107 and 1133 as, in the text, Adelard himself mentions that seven years have passed since his lecturing in schools at Laon. He chooses to present this work as a forum for Arabic learning, referring often to his experiences in Antioch. He sets out seventy-six questions, in the form of a Platonic dialogue about meteorology and natural science. It was used heavily in schools into and beyond the 13th century but the teaching on natural things would ultimately be superseded by Aristotle's writing. The text is broken up into three parts: On Plants and Brute Animals, On Man and On Earth, Water, Air, and Fire. Two of the more specific features associated with this text are (1) a preference for reason over authority in matters of science and nature (in other words, seeking solutions via reason and logic rather than through faith) and (2) the use of the literary device of invoking Arab teachings when presenting very controversial topics (e.g. that brute animals may possess knowledge and souls) Adelard didn't think that the use of reason to seek knowledge was in any way contradictory with Christian faith in God. The soul is a large part of the dialogue in this text as On Man discusses a corporeal soul in man, while the final section elaborates on the incorporeal soul of elements and animals. Questiones Naturales appears to have been an immediate success as it was copied on both sides of the English Channel and was even presented in a "pocket-book" format, suggesting that it was meant to be carried around.

The final section in his trilogy is a treatise on hawking called De Avibus Tractatus (Treatise on Birds). It is a medical text that addresses disease from head-to-toe. While it has been argued that this treatise was not widely distributed, an investigation of later Latin and French treatises reveals a number of excerpts from Adelard's work.

The remainder of Adelard's original works did not involve the persona of his nephew. He wrote a treatise on the use of the abacus called Regulae Abaci, which was likely written very early in his career because it shows no trace of Arab influence. This treatise is believed to be proof that Adelard was connected to the Exchequer table that was used for monetary calculations in the medieval period. If you read the source quoted, its obvious Adelard of Bath probably knew who worked at the Exchequer and might have met them at Laon, but what is common among them is that their educations are in Laon! Further evidence for this can be found in the Pipe Roll of Henry I, which shows that he had received a discharge from the "murder fine" (a fine levied on all inhabitants of a certain area based on the murder of a Norman that occurred in a generally accessible field in the area) levied on the community of Wiltshire in 1130, though there is no other proof for this fact. There is debate about whether the Adelard who lived in Bath and who was levied with this charge really is the same Adelard of Bath, considering Adelard is a common name. The work that Adelard of Bath is known for in the Latin world is his translation of the astronomical tables of al-Khwarizmi, the first widely accessible Latin translation of the Islamic ideas about algebra. In the Middle Ages he was known for his rediscovery and teaching of geometry, earning his reputation when he made the first full translation of Euclid's "Elements" and began the process of interpreting the text for a Western audience.

Influence

Adelard's work impacted the course of natural philosophy, notably influencing Robert Grosseteste and Roger Bacon. His work in natural philosophy helped lay the foundations for much of the progress that was made in the later centuries after Aristotle. His work surrounding Euclid's Elements provided training in demonstrative and geometrical proofs. While his original writings demonstrate a sincere passion for the seven liberal arts (grammar, rhetoric, logic, mathematics, geometry, music, and astronomy), his work in Quaestiones naturales illustrated a more encompassing dedication to subjects such as physics, the natural sciences, and metaphysics.

His influence is evident in De philosophia mundi by William of Conches, in the work of Hugh of Saint Victor, in Isaac of Stella's Letters to Alcher on the Soul and in Peter Abelard's Hexaemeron.

He introduced algebra to the Latin world and his commentaries in Euclid's Elements were extremely influential in the 13th century. Adelard was also responsible for introducing Arabic numerals, including the symbol for zero, to Western Europe. Adelard displayed original thought of a scientific bent, questioning the shape of the Earth (he believed it was round) and asking how it remains stationary in space. He developed the classic physics question of how far a rock would fall if a hole were drilled through the Earth and a rock dropped through it (see center of gravity). He later supplemented his mathematical translations with "De opere astrolapsus," a text explaining the use of an astrolabe.

Campanus of Novara probably had access to Adelard's translation of Elements, and it is Campanus' edition that was first published in Venice in 1482 after the invention of the printing press. It became the chief textbook of the mathematical schools of Western Europe until the 16th century.