Giovanni Girolamo Saccheri robertnowlan（乔凡尼Girolamo Saccherirobertnowlan）.pdfVIP

Giovanni Girolamo Saccheri Italian Jesuit and logician Giovanni Girolamo Saccheri (September 5, 1667 – October 25, 1733) made an elaborate and valiant effort to prove the parallel postulate of Euclid. Unfortunately, he was so thoroughly convinced that Euclid ’s was the only valid geometry that he missed the chance to disco er non-Euclidean geometry. It may be that Saccheri concluded that at the time, it was more prudent not to question the infallibility of Euclidean geometry. He was born in San Remo, Genoa and died in Milan. He entered the Jesuit Order at Genoa in 1685 and was sent to Milan in 1690, where he studied philosophy and theology at the Jesuit College, earning a doctorate of theology. While there he was encouraged to take up the study of mathematics by his teacher Tommaso Ceva. Saccheri was ordained in 1694 at Como. In the following years Saccheri taught at various Jesuit Colleges including Turin (1694 – 1697). He held the chair of mathematics at Pavia from 1697 until his death. One could argue persuasively (and several ha e) that the outstanding problem of Western mathematics for two millennia before Saccheri’s time was that of “Euclid’s fifth postulate.” There were many flaws in Euclid’s Elements as he attempted to establish geometry as a deductive system. The most serious of these was that his postulates were insufficient to establish the geometry he was building. This in no way diminishes the genius of Euclid, as these assumptions were so subtle that no one th recognized them as such until after the de elopment of non-Euclidean geometries in the 19 century. But almost from the time the ink was dry on Euclid’s papyrus, mathematicians (possibly e en Euclid himself) began to raise questions about the status of the last of the five fundamental postulates on which his ge