The editors are deeply indebted to their teacher and colleague, Professor Ernest Nagel. His influence in this book will be apparent to anyone familiar with the field of philosophy of science. He has given freely of his time and knowledge in discussing these selections, and for this we are grateful, but the debt is also a spiritual one.
We are in no way oblivious to the subtle redirection in our thinking induced by conversation and argument with Professor John C. Cooley, and would like to acknowledge here our respect for his philosophical acuity. A number of philosophers have made suggestions and criticisms which affected the shape of this work: Professors Adolf Griinbaum, N. R. Hanson, Israel Scheffler, Noam Chomsky, and Harold Weisberg; Dr. Frederic Schick and Mr. Arnold Koslow. Professors Grünbaum and Hanson in addition provided us with specially revised versions of their articles. Some of the writings appear here for the first time in English. We are obliged to Dr. Frederic Schick of Columbia University and Professor Rudolph Weingartner of San Francisco State College for their lucid translations of Mach and Boltzmann; and to Mr. William Ryding and Mr. Arnold Miller, of the French Department at Columbia, for similarly clear and excellent translations of Poincaré. Finally, we wish to express our gratitude to Mr. Arthur A. Cohen, the publisher of Meridian Books, both for his enthusiasm for this project