An Essay on the Foundations of Geometry was first published in 1897 when Bertrand Russell was 25 years old. It marks his first major foray into analytic philosophy, a movement in which Russell is one of the founding members and figurehead. It provides a brilliant insight into Russell's early philosophical thought and an engaging and authoritative introduction to the philosophical and logical foundations of geometry - a version of which was fundamental to Einstein's theory of relativity. Russell explores and introduces the concepts of geometry and their philosophical implications, including a historical overview of geometrical theory, making it an invaluable resource not only for students of philosophy but anyone interested in the origins of the thought of one of the twentieth century's most important and widely-read philosophers. This Routledge Classics edition includes a new Foreword by Michael Potter.