The foundations of mathematics; a contribution to the philosophy of geometry (1908)
Carus, Paul, 1852-1919 · Chicago, The Open court publishing co.; [etc., etc · leaf 30
ve two parallel lines as boundaries between the intersecting andnon-intersecting lines. We need not further develop Lobatchevskysidea. Among other things, he proves that if inany rectilinear triangle the sum of the three anglesis equal to two right angles, so is this also the casefor every other… … 22 THE FOUNDATIONS OF MATHEMATICS. consists in the fact that the assumption of a geometry from which the parallel axiom is rejected, doesnot lead to self-contradictions but to the conceptionof a general geometry of which the Euclidean is onepossibility. This general geometry was later onmost…
Geometry -- Foundations
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Works. Popular edition.] 2 series (1886)](https://img.insideoutlibrary.com/img/200/bl-bl_003191336_9-384-1.webp)
