HASIDISM is a movement of Jewish spiritual revival which began in southeastern Poland during the second half of the eighteenth century and came to be characterized by its charismatic leadership, mystical orientation, and distinctive pattern of communal life. It became controversial during the last quarter of that century, when the Lithuanian rabbinic establishment denounced it as a heretical sect and conducted a militant campaign to eradicate it. In the early decades of the nineteenth century it again encountered belligerent hostilities, this time in Galicia, where Jewish Enlightenment activists, in collaboration with the Austrian authorities, campaigned to coerce it into compliance with their programme of radical Jewish reforms. In spite of all this, hasidism spread rapidly throughout eastern Europe and became, by the second half of the nineteenth century, a mass movement aligned with other sectors within Orthodox Judaism in resisting secularization and modernity. It survived the long series of traumas that eastern European Jewry suffered from the 1880s until the end of the Second World War, to become established during the postwar years in all the major centres of Jewish population in Israel and the West, where it forms a vital and distinctive element of Orthodox Jewish life.

More than any other movement or school of Jewish spirituality, hasidism has attracted the attention of scholars who have offered widely divergent interpretations, often ideologically charged, of its doctrines and extraordinary popular appeal. Since the beginnings of modern Jewish historiography in the nineteenth century, the movement has been variously portrayed: as a reactionary barrier to Jewish progress and political emancipation in Europe; as a revolutionary expression of social, material, and spiritual discontents on the part of the alienated Jewish masses of eastern Europe; as a conservative force in Jewish life which prevented the disintegration of traditional values and institutions in the face of secularization and modernity; as a radical challenge from within the tradition to the established value-system and its decaying institutional framework; as a national-messianic revival which both anticipated and facilitated the political ideology of Zionism; as a movement of popular mysticism which sanctified the concrete and the mundane by denying their very reality; or as the arena for the most authentic encounter in Judaism between God and man precisely within the freshly affirmed reality of the concrete and the mundane.