Ratnākaraśānti
Ratnākaraśānti (also known as Śāntipa) (c. 10th-century CE) was one of the eighty-four Buddhist Mahāsiddhas and a monk at the monastic university of Vikramashila in what is now modern-day Bihar in India. At Vikramashila he was instructed by Nāropa, and taught both Atiśa and Maitrīpa. His texts include several influential commentaries to Buddhist tantras, as well as works of philosophy and logic. He was known "kalikālasarvajña" meaning “Omniscient One of the Degenerate Age”. Life. Little is known about his life; in the "Biography of the Eighty-Four Siddhas", Abhayadatta Sri records that "King Kapina" invited Ratnākaraśānti  to Śrī Laṇka during the reign of the Pāla king Devapāla (c. 810-850 CE). However, according to Keith Dowman, "As history of Śrī Laṇkā the legend is incomprehensible. There is no King Kapina in the lists of Siṇghala kings… [and] there is no evidence of a Śāntipa contemporary with the Pāla Emperor Devapāla." Tāranātha provides a more realistic date, placing him during the reign of King Canaka (955-83 CE). Ratnākaraśānti composed three commentaries to the Guhyasamāja Tantra, as well as commentaries to the Hevajra Tantra and the Mahāmāyā Tantra. His exoteric works, generally written from a Yogācāra perspective , include several commentaries to the Perfection of Wisdom literature, such as his "Sāratamā" and "Pith Instructions for the Perfection of Wisdom" ("Prajñāpāramitābhāvanopadeśa"). He is also the author of two commentaries to Śāntarakṣita's Madhyamākalaṃkāra, and a technical treatise on the formal logic of pramāṇa theory (the "Antarvyāptisamarthana"). Ratnākaraśānti was a Yogācāra philosopher who defended the Alikākāravāda view of Yogacara as well as the compatibility of Madhyamaka with this Yogacara view.