mentions the "three turnings" is the Ārya-saṃdhi-nirmocana-sūtra or Noble sūtra of the Explanation of the Profound Secrets, the most foundational sutra of the Yogācāra school. The sūtra affirms that the earlier turnings while being authentic are also flawed or incomplete and require interpretation. The Saṃdhi-nirmocana further claims that its teachings are the ultimate and final truth. Major ideas include the basis-consciousness (ālaya-vijñāna), and the doctrine of cognition-only (vijñapti-mātra) and the "three natures" (trisvabhāva). Some Buddhist traditions also consider the Tathāgatagarbha (also known as Buddha nature) teachings as part of this turning. This was elaborated on in great detail by Maitreya via Asanga in the Five Treatises of Maitreya, which are also generally grouped under the third turning. The Yogachara school reoriented later refinements, in all their complexity, so as to accord with the doctrines of earliest Buddhism. In Tibetan Buddhism, Buddhist tantra and its associated scriptures are sometimes considered to also be part of the third turning. Other similar classifications Fourth Turning Vajrayana schools sometimes refer to Buddhist tantra as the "fourth turning." As explained by Lama Surya Das, some traditions consider Dzogchen as a fourth turning. Sanron school According to Japanese scholar Junjirō Takakusu, the Sanron (Sanlun) Madhyamaka school divided the teaching into three dharmacakras as well, but with different definitions for each: The root wheel of the Avatamsaka sutra. The branch wheel of Hinayana and Mahayana texts. The wheel that contracts all branches so as to bring them back to the root, the Lotus sutra. Tiantai The Chinese Tiantai school organized the Buddhas teachings into five periods (五時): Flower Ornament period 華嚴時, The sudden teaching is delivered as the Avatamsaka sutra, containing the direct content of the Buddha’s enlightenment experience. Few can understand it. Deer Park period 鹿苑時 (represented by the Āgama sūtras 阿含經), represent a gradual and simpler teaching. the Vaipulya period 方等時 (represented by the Vimalakīrti Sūtra 淨名經 and so forth); this and the next period represent gradually deeper teachings. the Prajñā period 般若時 (represented by the Prajñāpāramitā sūtras 般若經). Lotus-Nirvāṇa period 法華涅槃時, Lotus sutra and Mahāparinirvāṇa-sūtra, a teaching that is neither sudden nor gradual. Huayen Likewise, the Huayen school had a five period system of dharma teachings: The Hinayana-teachings, especially the Sarvastivadins The Mahayana-teachings, including Yogacara, Madhyamaka The "Final Teachings", based on the Tathagatagarbha-teachings, especially the Awakening of Faith The Sudden Teaching, "which 'revealed' (hsien) rather than verbalised the teaching" The Complete, or Perfect, Teachings