In Buddhism, splitting a monastery takes at least nine monks
A schism is a split within a group, and religions treat it very differently. Theravada monastic law defines one precisely: nine or more monks breaking away to hold their own ceremonies. Buddhist tradition ranks causing such a rupture among the five gravest deeds, and says the first was engineered by Devadatta during the Buddha's own lifetime.
The word describes any division among people who once belonged together, most famously the East-West split in Christianity and the Sunni-Shia divide in Islam, though it can apply to friends or siblings too. A schismatic is someone who causes a break or joins a breakaway group, and the term is usually meant as an insult; those it is aimed at typically reject it.
Schism and heresy are often confused. Heresy rejects a doctrine a church considers essential; schism rejects communion with its authorities, which need not involve belief at all. The Western Schism is one example, and in 2004 the Patriarch of Constantinople and the Archbishop of Athens broke communion without a doctrinal quarrel. In practice the two charges travel together, since each side of a split tends to accuse the other of error and claim to be the faithful remnant. Roman Catholic thinking holds that every heresy is a schism, but not every schism is a heresy.
Buddhism handles the matter as a legal question about monastic rules within one community, not about teaching. Different lineages follow different codes of discipline, such as the Dharmaguptaka in schools descended from Chinese Buddhism and the Mulasarvastivada in Tibet, and they vary slightly on how many monks it takes. Despite common assumptions, Mahayana and Theravada do not regard each other as schismatic; the English word is borrowed for want of a better one.
Catholic canon law makes a deliberate act of schism punishable by automatic excommunication, which the 1983 Code describes as medicinal, meant to restore unity. It separates people who knowingly commit schism from those raised outside communion with Rome who hold orthodox faith. The Eastern Orthodox churches are considered far more closely tied to Rome than Protestant communities, which rejected apostolic succession.
Source: Schism
