The thirteen essays in this volume (except for the one on Leibniz, which has not been published before) are selected works of Robert E. Butts, originally published over a period of many years. Most of the essays analyze aspects of the work of Galileo, Leibniz, Kant and Whewell; others deal with the question of the unity of the sciences and with the question of toleration in academe. The papers share a common philosophical commitment to principle of pragmatism, and seek to show that pragmatism emerges historically in unexpected places. Emphasis is placed upon issues in methodology and theory of knowledge. The book will appeal to those interested in history of modern philosophy, history and philosophy of science, and the philosophical fortunes of pragmatism.