Wikipedia
Etymologiae ( Latin for "The Etymologies"), also known as the Origines ("Origins") and usually abbreviated Orig., is an etymological encyclopedia compiled by Isidore of Seville (c. 560–636) towards the end of his life. Isidore was encouraged to write the book by his friend Braulio, Bishop of Saragossa. The Etymologies summarized and organized a wealth of knowledge from hundreds of classical sources; three of its books are derived largely from Pliny the Elder's Natural History. Isidore acknowledges Pliny, but not his other principal sources, namely Cassiodorus, Servius and Solinus. The work contains whatever Isidore, an influential Christian bishop, thought worth keeping. Its subject matter is extremely diverse, ranging from grammar and rhetoric to the earth and the cosmos, buildings, metals, war, ships, humans, animals, medicine, law, religions and the hierarchies of angels and saints.
Etymologiae covers an encyclopedic range of topics. Etymology, the origins of words, is prominent, but the work covers among other things grammar, rhetoric, mathematics, geometry, music, astronomy, medicine, law, the Roman Catholic Church and heretical sects, pagan philosophers, languages, cities, animals and birds, the physical world, geography, public buildings, roads, metals, rocks, agriculture, ships, clothes, food and tools.
Etymologiae was the most used textbook throughout the Middle Ages. It was so popular that it was read in place of many of the original classical texts that it summarized, so these ceased to be copied and were lost. It was cited by Dante Alighieri, who placed Isidore in his Paradiso, quoted by Geoffrey Chaucer, and mentioned by the poets Bocaccio, Petrarch and John Gower. Among the thousand-odd surviving manuscript copies is the 13th-century Codex Gigas; the earliest surviving manuscript, the Codex Sangallensis, preserves books XI to XX from the 9th century. Etymologiae was printed in at least ten editions between 1472 and 1530, after which its importance faded in the Renaissance. The first scholarly edition was printed in Madrid in 1599; the first modern critical edition was edited by Wallace Lindsay in 1911.
Etymologiae is less well known in modern times, though the Vatican considered naming its author Isidore the patron saint of the Internet. Scholars recognize its importance both for its preservation of classical texts and for the insight it offers into medieval thought.