For a religious tradition that has been active over more than three millennia, Judaism has surprisingly few sects, and only four major divisions, which can be easily distinguished.
The Reform movement arose in Germany in the early 19th century as a response to the gradual dropping of legal and political barriers against European Jews, by seeking to integrate Jews into a mainstream society that was increasingly available to them politically and socially. It abbreviated the liturgy, introduced prayers and sermons in the vernacular and singing with organ accompaniment, and rendered dietary and Sabbath restrictions optional. Faced with the opportunity to be accepted into German society without having to convert to Christianity, many German Jews felt compelled to eliminate all tribal and ethnic aspects of their Jewish identity, including beliefs that might be construed as superstitious. They even moved their Sabbath from Saturday to Sunday for a time. In America, the Reform movement became known for its relaxation of ritual overall, preferring to stress the Torah’s teachings on ethics.
Orthodox Jews insist on retaining traditional Jewish laws and customs, not only as they relate to liturgy but also to diet and dress. They demand full submission to the authority of halakhah, the massive accretion of written and oral laws of Judaism, feeling that the revealed will of God, not the value system of a particular age, is the ultimate standard of conduct. Those laws include separation of the sexes during worship, and other roles for women that are at odds with social changes sought by the women’s movement. The Hasidic sects comprise a significant segment of Orthodox Judaism — all Hasidim are Orthodox, but not all Orthodox are by any means Hasidic.
Conservative Judaism, originally known as “Historical Judaism,” began in the mid-19th century as a response to the perceived excesses of the Reform movement. Conservative Jews hailed the Westernization of Judaism in the areas of education and culture (embracing modern dress, for instance), but kept the use of Hebrew in the liturgy, the observance of dietary laws and the Sabbath, and almost all Torah rituals. In the 1980s the Conservatives decided to admit women as rabbis. The center of the movement is the Jewish Theological Seminary of New York; more American Jews are affiliated with Conservative synagogues than with Reform or Orthodox.
Reconstructionist Judaism was founded in 1922 in the U.S. by Rabbi Mordecai M. Kaplan (1881-1983), in an effort to adapt classical Judaism to current ideas on science, art, and reason. Reconstructionists see Judaism as an evolving civilization rather than a religion, and reject the notion of a personal deity, miracles like the parting of the Red Sea, and the whole concept of the chosen people. With only about 60,000 members, it is a minor branch, headquartered in Philadelphia, but it has strongly influenced Reform Judaism. Rabbi Kaplan performed the first Bat Mitzvah, conferring on young women a religious rite of passage previously reserved only for Jewish males, but now commonplace among Reform congregations; he also began the havurah movement, in which Jews meet in small groups to study and observe Jewish rituals. Recently, Reconstructionism has restored references in its prayerbooks to supernatural events that it had earlier excised as being unbelievable but now accept on the level of “myth.”