Mathematical Treasures - Saccheri on Euclid's Parallel Postulate

Frank J. Swetz (The Pennsylvania State University)

Euclides ab omni naevo vindicatus (1733), or Euclid Vindicated of All Errors, was a logical study of the structure of Euclid’s geometry with an emphasis on the place of the Parallel Postulate. Its author Girolamo Saccheri (1667-1733) was a Jesuit logician. Using the technique of reductio ad absurdum, his findings opened the possibility of the existence of other geometries.

This is the Preface for Euclides, in which Saccheri explained his work.

This is the first page of text for Euclid Vindicated of All Errors.

These images from its George Arthur Plimpton Collection are presented through the courtesy of the Columbia University Libraries.

Index to Mathematical Treasures