What was the Hasidic revival of the 1700s, and why did other rabbis oppose it?

Hasidism was an 18th-century revival that put joyful prayer and a mystic leader of the masses at the centre of Jewish piety, and leading rabbis campaigned against it. It arose as a spiritual revival movement in Western Ukraine, then spread rapidly through Eastern Europe. Its founder is regarded as Israel ben Eliezer, the Baal Shem Tov, who lived from about 1698 to 1760. Little is known for certain about him, and most of what is told comes from Hasidic hagiographic accounts.

The ingredients were already in the air. Kabbalah, once an esoteric teaching practised in secret by few, had become almost household knowledge through cheap printed pamphlets. The Besht stressed that God is present in the material world, so even physical acts like eating influence the spiritual sphere, and that worship should be joyful rather than based on abstinence and self-mortification. After him, Dov Ber the Maggid turned a circle of followers into an actual movement. Its defining figure was the Tzaddiq, the Righteous One, a mystic who, unlike earlier kabbalists, practised openly as a leader of the masses. Wordless melodies, nigunim, were a way to reach devekut, communion with God, in prayer.

Opposition came quickly. In 1772 Elijah of Vilnius and the community wardens launched a campaign against the sect, putting an anathema on them. He was suspicious of the stress on mysticism rather than Torah study and of its resemblance to the Sabbatean movement. Yet by 1830 the movement had hundreds of thousands of followers, and by the second half of the 19th century both sides basically considered each other legitimate.