“To abandon the struggle for private happiness, to expel all eagerness of temporary desire, to burn with passion for eternal things – this is emancipation, and this is the free man's worship.” —Bertrand Russell Mysticism and Logic is one of Russell's most celebrated collection of essays. They not only set the tone for analytical philosophy in the English-speaking world but are Russell's first proper foray into the role of public philosopher, one he would occupy for years to come. Both scientific and romantic, Russell explores and unpacks, in his inimitable pellucid prose, some of the thorniest problems and puzzles in philosophy. These include different ways of knowing something, the foundations of mathematics, the ultimate nature of matter and whether, in Russell's view, we should seek a philosophical theory of causation. Taken together, they show the considerable changes that occurred in Russell's thinking during the years he was producing some of his best philosophy, leading up to World War One. Also included is Russell's renowned essay 'A Free Man's Worship', where he argues that we can construct a deeper form of faith based on the power of reason for those who wish to be free. This Routledge Classics edition includes a new Foreword by Bernard Linsky.