Mordecai Menahem Kaplan was born
Mottel Kaplan in Sventiany in the
Russian Empire (present-day
Švenčionys in
Lithuania) on June 11, 1881, the son of Haya () and Rabbi Israel Kaplan. Mordecai was brought over to New York in 1889, at the age of nine. In 1902, he was ordained at JTSA. In speeches and articles in 1912 and 1916, he chided American Orthodox Judaism for not adequately embracing modernity. Yet he remained the rabbi of the center until around 1922, when he resigned due to ideological conflicts with some of the lay leadership. He, along with a sizeable group of congregants, then established the
Society for the Advancement of Judaism, which later became the core of the Reconstructionist movement. Judith
read from the Torah at this ceremony, a role that had traditionally been reserved for males. In 1925, the American Zionist Organization sent Kaplan to
Jerusalem as its official representative for the opening of
Hebrew University. In 1935, a biweekly periodical (
The Reconstructionist Journal) was started under Kaplan's editorship, which was "dedicated to the advancement of Judaism as a religious civilization, to the upbuilding of
Eretz Yisrael (the Land of Israel) as the spiritual center of the
Jewish People, and to the furtherance of universal freedom, justice, and peace." Kaplan further refined the goals of his ideology in subsequent books, including:
The Meaning of God in Modern Jewish Religion (1937),
Judaism Without Supernaturalism (1958), and
The Religion of Ethical Nationhood (1970). Kaplan saw his ideology as a "school of thought" rather than a separate denomination, and in fact resisted pressure to turn it into one, fearing that it might further fragment the American Jewish community and hoping that his ideas could be applied across denominations. Kaplan was dissatisfied with traditional rituals and prayer and sought ways to make them more meaningful to Jews who agreed with him. In 1941, he wrote the controversial
Reconstructionist Haggadah, for which he received criticism from colleagues at JTSA. However, this did not stop him from publishing the
Reconstructionist Sabbath Prayer Book in 1945, in which, among other unorthodoxies, he denied the literal accuracy of the biblical text. As a result, he was
excommunicated by the
Union of Orthodox Rabbis of the United States and Canada, who held a
herem ceremony at which his prayer book was burned. Although Kaplan preferred that Reconstructionism remain a non-denominational school of thought rather than a separate denomination, in the late 1940s to early 1950s, a number of laypeople in synagogues throughout the United States decided to organize an independent federation of Reconstructionist synagogues, and by 1954, the
Federation of Reconstructionist Congregations and Havurot was organized. As the years passed, the number of affiliates grew, but it was not until the late 1960s that the movement actually became a separate denomination, when the
Reconstructionist Rabbinical College opened its doors in 1968. By the beginning of the 21st century, it would include over 100 congregations and . Kaplan was a prolific writer. In addition to his published works, he kept a journal from 1913 until the late 1970s, comprising 27 volumes, each with 350–400 handwritten pages. The journal is certainly the largest by a Jew, and may even be one of the most extensive on record. After the death of his wife in 1958, he married Rivka Rieger, an Israeli artist, in 1959. He died in New York City in 1983 at the age of 102. He was survived by Rivka and his daughters
Judith Kaplan Eisenstein,
Hadassah Musher,
Naomi Wenner, and
Selma Jaffe-Goldman, as well as seven grandchildren and nine great-grandchildren. His funeral was held at the
Society for the Advancement of Judaism, which he founded. ==Relationship with Orthodox Judaism==