The tzaddik — the rebbe — is Hasidism's most distinctive and contested institution: a spiritual leader whose connection to God is held to lift the whole community, who is consulted on business, marriage, and medicine, and whose court is inherited dynastically. Critics inside Judaism have called it a compromise of the direct relationship between a Jew and God. Its practical effect is enormous cohesion, and the succession disputes it generates are the main way Hasidic groups multiply.