Our conclusion, in brief, is that science bears little resemblance to its conventional portrait. We believe that the logical structure discernible in scientific knowledge says nothing about the process by which the structure was built or the mentality of the builders. In the acquisition of knowledge, scientists are not guided by logic and objectivity alone, but also by such nonrational factors as rhetoric, propaganda, and personal prejudice. Scientists do not depend solely on rational thought, and have no monopoly on it.