How do we come to trust our knowledge of the world? What are the means by which we distinguish true from false accounts? Why do we credit one observational statement over another? In A Social History of Truth, a leading scholar addresses these universal questions through an elegant recreation of a crucial period in the history of early modern science: the social world of gentlemen-philosophers in seventeenth-century England. Steven Shapin paints a vivid picture of the relations between gentlemanly culture and scientific practice. He argues that problems of credibility in science were solved through the codes and conventions of genteel conduct: trust, civility, honor, and integrity. These codes formed, and arguably still form, an important basis for securing reliable knowledge about the natural world. Shapin explains how gentlemen-philosophers resolved varying testimony about such phemonema as comets, icebergs, and the pressure of water by bringing to bear practical social knowledge and standards of decorum. For instance, while "vulgar" divers reported they experienced no crushing pressure no matter how deep into the sea they dived, gentlemen-philosophers preferred the evidence of crushed pewter bottles. Shapin uses richly detailed historical narrative to make a powerful argument about the establishment of factual knowledge both in science and in everyday practice. Accounts of the mores and manners of gentlemen-philosophers illustrate Shapin's broad claim that trust is imperative for constituting every kind of knowledge. Knowledge-making is always a collective enterprise: people have to know whom to trust in order to know something about the natural world. A Social History of Truth is a bold theoretical and historical exploration of the social conditions that make knowledge possible in any period and in any endeavor.