Ten disputed practices
The Vinaya's Chapter on the Second Council says that a hundred years after the Buddha's death, monks of Vesālī were following ten practices that others considered against the rules. The most serious was accepting gold and silver from lay supporters.
A visiting monk, Yasa Kākaṇḍakaputta, saw the monks set out a bowl of water and ask lay people to put coins in it, and objected publicly. The local monks tried to expel him, but he found support among senior monks elsewhere.
The judgement
Seven hundred monks met at Vesālī. To avoid endless argument, a committee of eight elders, four from each side, examined the ten practices one by one. Led by the respected elder Revata, they rejected all ten as contrary to the discipline.
The first split
The Sri Lankan chronicle Dīpavaṃsa says the defeated monks refused to accept the verdict and held a 'great council' of their own, becoming the Mahāsāṅghika, 'those of the great community'. Other traditions tell a different story, dating the first split to a later dispute over doctrine or over additions to the monastic rules.
Why it matters
Buddhism begins developing into multiple interpretive and institutional traditions.
History and tradition
What historians can say
A dispute over monastic discipline around Vesālī is recorded in the Vinayas of several schools, which makes it more likely to reflect a real event than the First Council. Its date and connection to the first schism are uncertain. Scholars such as Jan Nattier and Charles Prebish have argued that the split with the Mahāsāṅghikas arose from disagreement over expanding the Vinaya, not simply from lax monks.