Euclid's Elements Euclid's Elements The Elements ( "Stoicheia") is a mathematical treatise consisting of 13 books attributed to the ancient Greek mathematician Euclid in Alexandria, Ptolemaic Egypt c. 300 BC. It is a collection of definitions, postulates, propositions (theorems and constructions), and mathematical proofs of the propositions. The books cover plane and solid Euclidean geometry, elementary number theory, and incommensurable lines. "Elements" is the oldest extant large-scale deductive treatment of mathematics. It has proven instrumental in the development of logic and modern science, and its logical rigor was not surpassed until the 19th century. Euclid's "Elements" has been referred to as the
Library of Alexandria god Serapis. Despite the widespread modern belief that the Library was "burned" once and cataclysmically destroyed, the Library actually declined gradually over the course of several centuries, starting with the purging of intellectuals from Alexandria in 145 BC during the reign of Ptolemy VIII Physcon, which resulted in Aristarchus of Samothrace, the head librarian, resigning from his position and exiling himself to Cyprus. Many other scholars, including Dionysius Thrax and Apollodorus of Athens, fled to other cities, where they continued teaching and conducting scholarship. The Library, or part of its collection, was accidentally burned by Julius Caesar during his civil