Putnam is one of the most influential philosophers of recent times and his authority stretches far beyond the confines of the discipline. However there is a considerable challenge in presenting his work both accurately and accessibly. This is due to the width and diversity of his published writings and to his frequent spells of radical re-thinking. But if we are to understand how and why philosophy is developing as it is we need to attend to Putnam's whole career. He has had a dramatic influence on theories of meaning semantic content and the nature of mental phenomena on interpretations of quantum mechanics theory-change logic and mathematics and on what shape we should desire for future philosophy. By presenting the whole of his career within its historical context de Gaynesford discovers a basic unity in his work achieved through repeated engagements with a small set of hard problems. By foregrounding this integrity the book offers an account of his philosophy that is both true to Putnam and helpful to readers of his work.