Hasidim or Chassidim (both: häsē´dĬm, khä–) [Heb.,=the pious], term used by the rabbis to describe those Jews who maintained the highest standard of religious observance and moral action. The term has been applied to movements at three distinct times. The first Hasidim, also called the Assideans or Hasideans, were an ancient Jewish sect that developed between 300 BC and 175 BC They were the most rigid adherents of Judaism in contradistinction to those Jews who were beginning to be affected by Hellenistic influences. The Hasidim led the resistance to the hellenizing campaign of Antiochus IV of Syria, and they figured largely in the early phases of the revolt of the Maccabees. Their ritual strictness has caused some to see them as forerunners of the Pharisees. Throughout the Talmudic period numerous figures were referred to as Hasidim. During the 12th and 13th cent., however, there arose in Germany a specific group known as the Hasidei Ashkenaz. Influenced by Saadia ben Joseph and with messianic and mystical elements, it held as its central ideology the unity of God, the application of justice in all situations, social and economic equality, and martyrdom at the hands of the crusaders rather than compromise of any kind. The chief ethical work that derived from the group was the Sefer Hasidim (tr. Book of the Pious, 1973). The third movement to which the term Hasidim is applied is that founded in the 18th cent. by Baal-Shem-Tov and known as Hasidism.
See S. Lieberman, Hellenism in Jewish Palestine (1962); S. G. Kramer, God and Man in the Sefer Hasidim (1966); A. L. Lowenkopf, The Hasidim (1973). See also bibliography under Hasidism.