2014 Reprint of 1927 Edition. Full facsimile of the original edition. Not reproduced with Optical Recognition Software. This works received much attention as a work of first importance not only for philosophers and physicists but for the general reader too. The first of its three parts supplies a statement and interpretation of the doctrine of relativity and of the quantum theory, done with Russell's habitual uncanny lucidity and humor, as is indeed the entire book. The book is candid and stimulating for both its subject and its treatment and was reviewed by the "Times Literary Supplement" as "one of the best books that Mr. Russell has given us."