Another type of way Sangha could have practiced slavery in non-violent attitude. Might have been misinterpreted here after in Nalanda University. But the idea was to give the person another chance if he did something really grave against the sangha. Probably to teach him a lesson? Is there anything like that somewhere?
The book How the Brahmins Won
Xuanzang himself volunteered to participate in a debate on one occasion. The event is described as follows:186
At that time a heretic of the Lokāyatika school came to seek a debate and wrote his argument in fourteen points, which he hung on the door of the monastery, while he announced, ‘If anybody is able to refute any one point of my argument, I shall cut off my head to apologize!’
After the passage of several days, nobody came out to accept the chal- lenge. The Master [= Xuanzang] then asked his personal servant to take down the poster, destroy it, and trample the broken pieces under his feet. Being greatly enraged, the Brahmin asked, ‘Who are you?’ The servant said in reply, ‘I am a servant of the Mahayana-deva.’ The Brahmin, who had already heard of the fame of the Master, was ashamed of himself and did not say anything more. The Master sent for him and brought him to the presence of the Venerable Śīlabhadra [Xuanzang’s teacher of Nālandā Monastery], with various virtuous monks as witnesses, to start a debate with him about the principles of his school and the theories founded by other heretical sects as well.
At this point Xuanzang starts to criticise various heretical schools, among them the two Brahmanical schools of philosophy called Sāṃkhya and Vaiśeṣika, but not, surprisingly, the Lokāyatika school. Only his criticism of the Sāṃkhya school is given in some detail. The text then continues:
In this manner the argument was carried on with repeated refutations; and the Brahmin remained silent and said nothing. Then he rose to his feet and said with apology, ‘I am defeated, and I am ready to keep my word.’ The Master said, ‘We Buddhists do not take any man’s life. I now make you my slave, and you should work according to my orders.’ The Brahmin was glad to obey the Master’s orders with reverence, and was brought to his living quarters. All those who heard about this event praised it with delight.