overviews and introductions to the Abhidharma. The oldest one of these was the Abhidharma-hṛdaya-sastra (The Heart of Abhidharma), by the Tocharian Dharmasresthin, (c. 1st. century B.C.). This text became the model for most of the later treatises. The most influential of these treatises however, is certainly the Abhidharmakośabhāsya (Treasury of Higher Knowledge, 5th century), a series of verses and accompanying commentary by Vasubandhu. It often critiques Vaibhāṣika views from a Sautrantika perspective. The Sautrantikas were a dissent group within the Sarvāstivāda tradition that rejected many of the core Vaibhāṣika views. This text remains the main source for Abhidharma in Indo-Tibetan and East Asian Buddhism. The most mature and refined form of Vaibhāṣika philosophy can be seen in the work of master Saṃghabhadra (ca fifth century CE), "undoubtedly one of the most brilliant Abhidharma masters in India". His two main works, the *Nyāyānusāra (Shun zhengli lun 順正理論) and the *Abhidharmasamayapradīpikā (Apidamo xian zong lun 阿毘達磨顯宗論), are key sources of late Vaibhāṣika Abhidharma. Other Abhidharma traditions The Śāriputra Abhidharma Śāstra (舍利弗阿毘曇論 Shèlìfú Āpítán Lùn) (T. 1548) is a complete abhidharma text that is thought to come from the Dharmaguptaka sect. The only complete edition of this text is that in Chinese. Sanskrit fragments from this text have been found in Bamiyan, Afghanistan, and are now part of the Schøyen Collection (MS 2375/08). The manuscripts at this find are thought to have been part of a monastery library of the Mahāsāṃghika Lokottaravāda sect. Several Pudgalavada Abhidharma type texts also survive in Chinese, such as the Traidharmakasastra (Taisho no. 1506 pp. 15c-30a) and the Sammatiyanikayasastra. These texts contain traditional Abhidharma type lists and doctrines, but they also attempt to expound and defend the unique Pudgalavada doctrine of the "person" (pudgala). Many Abhidharma texts have been lost- likely more than have survived. This includes texts brought from India by Xuanzang belonging to a variety of Indian schools that were never translated into Chinese. Many Abhidharma sastras discovered among the Gandharan Buddhist texts have no parallel in existing Indic languages or Chinese or Tibetan translation, suggesting the former breadth of Abhidharma literature. According to some sources, abhidharma was not accepted as canonical by the Mahāsāṃghika school. The Theravādin Dīpavaṃsa, for example, records that the Mahāsāṃghikas had no abhidharma. However, other sources indicate that there were such collections of abhidharma. During the early 5th century, the Chinese pilgrim Faxian is said to have found a Mahāsāṃghika Abhidharma