What is the importance of the Talmud, that it merits a comprehensive history? In this chapter, the author paints a picture, in broad strokes, of the importance of the Talmud, to both Jews and their neighbors, through history. The Talmud is the document that ultimately defined the contours and obligations of Jewish practice and belief; how did it gain that centrality and authority? How did the Talmud help shape Jewish society? Why did the Talmud provoke such powerful rejection in Christian circles, and later among Jewish reformers? Offering a word about the difficulties of writing such a history, then defining basic terms and directions, the author in this chapter establishes the foundation of the history to follow.