This volume contains the published contributions of one of the founders of modern logic and America’s greatest logical genius. It is not only of historical but of contemporary interest because of its many acute discussions of fundamental logical problems. To assist the general reader, the editors have prefixed to the text a selected list of important topics and have provided many footnotes and an exhaustive index.

The present, the longest volume of the series of Peirce’s Collected Papers, reveals most clearly his stature as a logician and a student of the foundations of mathematics. It includes not only some striking anticipations of recent work in logic and the foundations of mathematics but also a number of vital contributions to these subjects as now understood. In addition there is an entirely original treatment of logical diagrams which makes possible a detailed analysis of the process of reasoning and provides the link between modern logic and Peirce’s conception of pragmatism. It is the most advanced and important of the volumes on exact logic.