have spent most of the remainder of his life. His last dateable writing—the —was completed in 1292. He seems to have died shortly afterwards and been buried at Oxford. Works Medieval European philosophy often relied on appeals to the authority of Church Fathers such as St Augustine, and on works by Plato and Aristotle only known at second hand or through Latin translations. By the 13th century, new works and better versions – in Arabic or in new Latin translations from the Arabic – began to trickle north from Muslim Spain. In Roger Bacon's writings, he upholds Aristotle's calls for the collection of facts before deducing scientific truths, against the practices of his contemporaries, arguing that "thence cometh quiet to the mind". Bacon also called for reform with regard to theology. He argued that, rather than training to debate minor philosophical distinctions, theologians should focus their attention primarily on the Bible itself, learning the languages of its original sources thoroughly. He was fluent in several of these languages and was able to note and bemoan several corruptions of scripture, and of the works of the Greek philosophers that had been mistranslated or misinterpreted by scholars working in Latin. He also argued for the education of theologians in science ("natural philosophy") and its addition to the medieval curriculum. Opus Majus Bacon's 1267 Greater Work, the , contains treatments of mathematics, optics, alchemy, and astronomy, including theories on the positions and sizes of the celestial bodies. It is divided into seven sections: "The Four General Causes of Human Ignorance" (), "The Affinity of Philosophy with Theology" (), "On the Usefulness of Grammar" (), "The Usefulness of Mathematics in Physics" (), "On the Science of Perspective" (), "On Experimental Knowledge" (), and "A Philosophy of Morality" (). It was not intended as a complete work but as a "persuasive preamble" (), an enormous proposal for a reform of the medieval university curriculum and the establishment of a kind of library or encyclopedia, bringing in experts to compose a collection of definitive texts on these subjects. The new subjects were to be "perspective" (i.e., optics), "astronomy" (inclusive of astronomy proper, astrology, and the geography necessary to use them), "weights" (likely some treatment of mechanics but this section of the has been lost), alchemy, agriculture (inclusive of botany and zoology), medicine, and "experimental science", a philosophy of science that would guide the others. The section