This is Volume XI of twenty-two in a collection on 20th Century Philosophy. Originally published in 1994, this volume of the Muirhead library of philosophy in the author’s words attempts not what is difficult but what is impossible. What it attempts is a critical account of Russell's philosophy-just that-without supposing that every reader is himself a philosopher at the beginning, though he may be at the end. It is written for those who know of Russell's philosophy and wish to know about it, for those who know about it, and wish to know it.