Excerpts from Books and Wikipedia
"Taken together, the thirteen books of Elements offer a comprehensive logical system and an introduction to deductive reasoning, essential to the development of the scientific method and rational philosophical inquiry. . . . For medieval Europe, the discovery of the complete Euclid was a sensation. The three earliest Latin versions, based on the translation of al-Hajjaj three centuries earlier, have historically been attributed to Adelard.' [Lyons: House of Wisdom, p. 112-3]