Rabbi and pioneer Zionist (b. Leszno, Prussia, 1795; d. Thorn, Prussia, 1874). A student of Rabbi Akiva Eger and a strong opponent of Reform Judaism, Kalischer also acquired a knowledge of philosophy and other secular subjects. He spent most of his life as a rabbi in Thorn (now Torun, Poland), serving without salary. In 1882 he declared that the redemption of Zion would have to begin with action on the part of the Jewish people; the messianic miracle would then follow. He frequently had to defend these views against rabbinic opponents in both Europe and Eretz Israel who insisted that the Jewish people would have to wait for the Messiah without taking any action to hasten its deliverance. His volume Derishat Tziyon veHevrat Erez Noshevet (1862) was in effect the first Hebrew book to appear in eastern Europe on the subject of modern Jewish agricultural settlement in Eretz Israel.
Kalischer traveled through Germany asking wealthy and influential Jews to aid Jewish settlement projects. His influence inspired the founding of several settlement societies, and in 1864 he was responsible for the establishment of the Central Committee for Settlement in EretzIsrael in Berlin. Kalischer first interested the Alliance Israelite Universelle in aiding agriculture in Erez Israel, an interest which led to the opening of the Mikve Yisrael Agricultural School in 1870. In reply to the argument from various quarters in EretzIsrael that conditions were not propitious for the establishment of agricultural settlements, he proposed that the settlers organize guard units whose members would combine farm work with defense against attack. Tirat Tzevi, a religious kibbutz in the Bet She'an Valley, is named for him.