Sūtra Piṭaka (Skt; Pāli, Sutta Piṭaka). The collection or ‘basket’ of the discourses delivered or purported to have been delivered by the Buddha. An overall division into two types of Sūtra Piṭaka may be distinguished: the various collections of discourse that formed closed canons for pre- Mahāyāna schools, and the looser open canon of later Mahāyāna sūtras. In the case of the pre-Buddhist schools, the Sūtra Piṭaka forms a part of the teachings of the Buddha, originally transmitted orally, known variously as Āgamas or Nikāyas. The number of individual sūtras contained therein are approximately 5,000, although the precise number of discourses included and the manner of grouping them varied. Most commonly four divisions were recognized: the Dīrgha (Pāli, Dīgha) or ‘long’ collection; the Madhyama (Pāli, Majjhima) or ‘medium’ collection; the Saṃyukta (Pāli, Saṃyutta) or ‘linked’ collection; and the Ekottara (Pāli, Aṇguttara) or ‘incremental’ collection. To these four, the Theravādin school adds a fifth, namely the Khuddaka or ‘minor’ collection. The most complete recension readily available is that transmitted in Pāli by the Theravādin tradition, although Chinese versions affiliated with other schools such as the Sarvāstivāda, Dharmaguptaka, and others have survived, as well as a number of fragments extant in Sanskrit belonging to the Sarvāstivāda school. Scholars believe that many of the discourses contained in the Sūtra Piṭaka are compositions post-dating the death of the Buddha and that, despite its popularity, the Pāli recension may be no more an authoritative guide to the teachings of the Buddha than any of the other Hīnayāna recensions. The Mahāyāna sūtra collection may be viewed as an extension to the basic Āgama collection of sūtras; being an open canon, it was possible for Mahāyāna adherents to compose new texts or compile older fragments of teachings that had been available as a pool of oral tradition to propagate certain innovative ideas and practices.