Richard Hofstadter

History is made up of facts, but also of opinions; it is not only, asLeopold von Ranke put it, "what actually happened/' but also what peoplewho know what happened think about past events. Facts are often difficultto track down and verify, but once located they are immutable and per-manently...

Introduction Periodically in modern history scientists have set forth new theories whose consequences go far beyond the internal development of science as a system of knowledge and far beyond such practical applications as they may happen to have. Discoveries of this magnitude shatter old...