A monk. He had been subjected by the Saṅgha to the ukkhepanīyakamma for refusal to renounce a sinful doctrine, namely, that the states of mind declared by the Buddha to be stumbling-blocks are not such at all for him who indulges in them.
Ariṭṭha left the Order and would not come back until the ukkhepanīyakamma was revoked. Vin.ii.25–28
He was a vulture-trainer (gaddhabādhiputta).
His case is cited as that of a pācittiya offence because he refused to give up a wrong doctrine even after the monks had three times requested him to do so. Vin.iv.135
In spite of the ukkhepanīyakamma the Chabbaggiyā (group of six) monks kept company with Ariṭṭha, thereby committing a pācittiya-offence. Vin.iv.137 We find the Buddha rebuking the nun Thullanandā for associating with Ariṭṭha after the ukkhepanīyakamma. Vin.iv.218
It was Ariṭṭha’s heresy that led to the preaching of the Alagaddūpama Sutta. MN.i.130ff.
In the Saṃyutta Nikāya, SN.v.314–315 Ariṭṭha is mentioned as having said to the Buddha that he practised concentration in breathing and as having described how he did it. The Buddha, thereupon, instructs him as to how such concentration can be done perfectly and in every detail.
An upāsaka mentioned in the Aṅguttara Nikāya AN.iii.451 in a list of householders and upāsakas who had seen and realised immortality and were possessed of unwavering faith in the Buddha, the Dhamma and the Saṅgha. They practised Ariyan conduct and had won wisdom and liberty.
A messenger of Vessavaṇa, employed by him to take his proclamations and publish them. DN.iii.201