At present eleven aṅgas are available. The 12th aṅga Dṛṣṭivāda has been lost. The twelve aṅgas are the compilation of gaṇadharas hence their authenticity is beyond doubt. Aṅgas are self evident (valid cognition). All the texts of the sthaviras are not considered as independent, authentic sources. Any āgama text is considered authentic if and only if its author possesses the prescribed rank of pūrva knowledge. Nandī asserts that the śruta of the possessor of the knowledge of the complete ten pūrvas (abhinna dasapūrvī), is definitely the right one (Samyakśruta).[1]
Jayācārya also accepted the same fact on the basis of the Nandī Sūtra.[2] After the salvation of Lord Mahavira, later Acharyas composed texts. Then probably a discussion may have occurred about whether certain texts should be considered as āgama texts or not, which raised the question of the authenticity of these texts composed by Acharyas. Finally, the texts of the fourteen pūrva proficients, ten pūrva proficients and sthaviras were decided to be considered under the āgama texts provided there was no contradiction with dvādaśāṅgī texts. Only then were they considered in the list of āgamas. Since they were not self-expository, they had to be kept in a different category from that of aṅgapraviṣṭa. Hence, in the context of such a situation another category by the name 'aṅga bāhya'emerged.[3]
- Nandī, A. 66
icceyaṃ duvālasaṅgaṃ gaṇipiḍagaṃ coddasasapuvissa sammasuyaṃ, abhiṇṇadasapuvvissa sammasuyaṃ, teṇa paraṃ bhinṇesu bhayaṇā. - Bṛhatkalpa Bhāṣya, v. 132
coddasa dasa ya abinne niyamā sammaṃ tu sesaye bhayaṇā