Adelard of Bath

Adelard of Bath (Latin: Adelardus Bathensis; Arabic: أديلار الباثي‎‎, Adilar Al-Bathi; Greek: Άντελαρντ του Μπαθ, Antelarnt tou Mpath; c. 1080 –c. 1152 AD) was a 12th-century English natural philosopher. He is known both for his original works and for translating many important Greek and Arab scientific works of astrology, astronomy, philosophy and mathematics into Latin from Arabic versions, which were then introduced to Western Europe. He is known as one of the first to introduce the Hindu–Arabic numeral system to Europe. He stands at the convergence of three intellectual schools: the traditional learning of French schools, the Greek culture of Southern Italy, and the Arabic science of the East.

Given the period when he was alive, Adelard’s biography is incomplete in places and leaves some aspects open to interpretation. As a result, much of what is ascribed to Adelard is a product of his own testimony. As his name suggests, he was born in the Roman English city of Bath but how he lived is not entirely known. Despite his expansive travels, by the end of his life he had returned to Bath, where he died. Scholars are hesitant to ascribe definitive parents to the philosopher but Fastred, a tenant of the Bishop of Wells, is mostly plausibly identified as this figure. His name (Adelard) is of Anglo-Saxon origin, which would have placed him in the subordinate class, status wise, in 11th-century England. It is believed that he left England toward the end of the 11th century for Tours, likely on the advice of Bishop John de Villula, who had moved the seat of his bishopric from Wells to Bath in 1090. During his studies in Tours, an anonymous "wise man of Tours" inspired Adelard with his interest in astronomy to study the science. Adelard later taught for a time at Laon, leaving Laon for travel no later than 1109. After leaving Laon, he travelled to Southern Italy and Sicily no later than 1116.

Adelard also travelled extensively throughout the "lands of the Crusades": Greece, West Asia, Sicily, Spain, Tarsus, Antioch and potentially Palestine. The time spent in these areas would help explain his fascination with mathematics and his access to Arabic scholars. By 1126, Adelard returned to the West with the intention of spreading the knowledge he had gained about Arab astronomy and geometry to the Latin world. One aspect of particular interest with respect to Adelard, his teachings, and the time period he grew up, was the relation to the Crusades. This time of remarkable transition marked an opportunity for someone to gain valuable influence over the evolution of human history. While the Crusades offered little in the way of a “victor,” Adelard’s non-discriminatory scholarly work inspired him to bring back to England many ancient texts and new questions that would later give rise to an English Renaissance. Again, given the 11th-century time period that Adelard was alive, it was understandably difficult for Adelard to have achieved his educational pursuits. In the absence of a printing press and given the weak public literacy rate, books were rare items in medieval Europe—generally held only by royal courts or Catholic monastic communities (Kraye, et al. 1987). Fittingly, Adelard studied with monks at the Benedictine Monastery at Bath's Cathedral.

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 (i.e. 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. 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 inhabitants of a certain area based on the murder of a Norman that occurred in a generally accessible field in that same area) levied on the community of Wiltshire in 1130, though there is no other proof for this fact. 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.

When Adelard's influence on the study of philosophy is considered, it is clear that his ideas most notably manifested in the later works of Robert Grosseteste and Roger Bacon. While his work in natural philosophy is probably overshadowed by Aristotle, it still helped lay the foundations for much of the progress that was made in the later centuries. His work surrounding Euclid’s Elements, for example, was of great help in providing training that would help future scholars understand the relationships between demonstrative and geometrical proofs. While his original writings demonstrate that he had 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 possibly even metaphysics. His influence is also evident in De philosophia mundi by William of Conches, Hugh of Saint Victor, and Isaac of Stella's Letters to Alcher on the Soul. He introduced algebra to the Latin world and his commentaries in Version III of Euclid's Elements were extremely influential in the 13th century. Adelard also displays original thought of a scientific bent, raising the question of the shape of the Earth (he believed it round) and the question of how it remains stationary in space, and also the interesting 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.

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.