An Essay on the Foundations of Geometry #248811

My chief obligation is to Professor Klein. Throughout the first chapter, I have found his Lectures on non-euclidean Geometry an invaluable guide; I have accepted from him the division of Metageometry into three periods, and have found my historical work much lightened by his references to previous writers. In Logic, I have learnt most from Mr Bradley, and next to him, from Sigwart and Dr Bosanquet. On several important points, I have derived useful suggestions from Professor James's Principles of Psychology.