Contents -- Notes on the Contributors -- Introduction -- Part One Ancient -- Prologue: How Do We Know When We Are On To Something? -- Religious Variety and the Temple in the Late Second Temple Period and Its Aftermath -- The 'Sectarian' Calendar of Qumran -- Defining Sectarian by 'Non-Sectarian' Narratives in Qumran -- The Nazoraeans as a 'Sect' in 'Sectarian' Judaism? A Reconsideration of the Current View via the Narrative of Acts and the Meaning of Hairesis -- Legal Realism and the Fashioning of Sectarians in Jewish Antiquity -- Part Two Medieval and Modern -- The Qaraites as Sect: The Tyranny of a Construct -- The Hasideans and the Ancient Jewish 'Sects': A Seventeenth-Century Controversy -- Jews for Jesus: Occupying Jewish Time and Space -- Part Three Theory and Practice -- Is a Historical Comparative Sociology of (Ancient Jewish) Sects Possible? -- Weber-Foucault-Nietzsche: Uncertain Legacies for the Sociology of Religion -- Index of Names -- Index of Topics.