In recent years, ancient Pythagoreanism has tended to be a field pursued by a narrow group of specialists and ignored by most scholars of ancient philosophy and ancient civilization. The field can look like a morass that is better not entered at all or bridged by time-worn platitudes about Pythagoras. Many discussions of Pythagoras and Pythagoreanism in general works about ancient civilization or Western culture are thus woefully uninformed. For there has been a great deal of important scholarship on Pythagoreanism in the last fifty years, so that the Pythagoras of current scholarship is not your mother's let alone your grandmother's Pythagoras. The crucial moment in modern scholarship on Pythagoreanism was the publication fifty years ago of Walter Burkert's epoch-making study, which appeared ten years later in a revised version translated into English by Edwin Minar with the title Lore and Science in Ancient Pythagoreanism (1972). References to Burkert's book in the footnotes of this volume are surely more frequent than those to any other piece of scholarship on Pythagoreanism. Burkert's Pythagoras was a religious leader and founder of a way of life and not the great mathematician to which many general accounts tenaciously cling. Yet even Burkert's view has not won universal acceptance; Pythagoras the mathematician survives among some scholars even in this book, and there has been significant scholarship that both builds on and reacts against Burkert.