rNgog Io-tsa-ba Blo-ldan-shcs-rab (1059-1109) was more than anyone else responsible for the establishment of Tibetan Buddhist scholasticism.'"`UNIQ--ref-00002B64-QINU`"' He founded in Tibet not only the main enduring lineages of logic and epistemology (Tshad-ma: Pramāṇa) studies but also of two other major branches of Mahāyāna Buddhist philosophy and doctrine—those of the Five Dharmas of Maitreya (Byams chos sde Inga) and of the Svātantrika Yogācāra-Madhyamaka.'"`UNIQ--ref-00002B65-QINU`"' rNgog-lo furthermore trained virtually the entire next generation of important Tibetan scholastics, his "four chief spiritual sons" being: (1) Zhang Tshe-spong-ba, (2) Gro-lung-pa Blo-gros-'byung gnas, (3) Khyung Rin-chen-grags, and (4) 'Bre Shes-rab-'bar.'"`UNIQ--ref-00002B66-QINU`"' Yet in spite of rNgog's central position in the history of Tibetan philosophical and doctrinal studies, until recently only a very small number of his works were known to survive, and of these the two most extensive and important have remained for decades largely inaccessible outside of Tibet, existing only as isolated xylographs in private collections.'"`UNIQ--ref-00002B67-QINU`"' Now, however, with the reprinting of two of his major works by the Library of Tibetan Works and Archives, including his very important commentary on the Ratnagotravibhāga described here, some of the seminal contributions of rNgog-lo can at last be easily assessed in the original.'"`UNIQ--ref-00002B68-QINU`"'
Both of these major works of rNgog-lo were commentaries on fundamental works of the Maitreyanātha tradition within the Yogācāra branch of Mahāyana Buddhism,'"`UNIQ--ref-00002B69-QINU`"' namely on the Ratnagotravibhāga and Abhisamayālaṃkāra.'"`UNIQ--ref-00002B6A-QINU`"' The works thus reflected another aspect of his illustrious career, for in addition to—and indeed in tandem with—his importance as a great teacher, he was also of crucial significance as a composer of commentaries on the works he expounded. (Jackson, "rNgog lo-tsa-ba's Commentary of the Ratnagotravibhāga," 339–340)
Jackson, David. "rNgog lo-tsā-ba's Commentary on the Ratnagotravibhāga: An Early-20th-Century Lhasa Printed Edition." In Tibetan Studies: Proceedings of the 7th Seminar of the International Association for Tibetan Studies, Graz 1995, Vol. 1, edited by Helmut Krasser, Michael Tortsen Much, Ernst Steinkellner, and Helmut Tauscher, 439–56. Vienna: Verlag der Österreichischen Akademie der Wissenschaften, 1997.
Jackson, David. "rNgog lo-tsā-ba's Commentary on the Ratnagotravibhāga: An Early-20th-Century Lhasa Printed Edition." In Tibetan Studies: Proceedings of the 7th Seminar of the International Association for Tibetan Studies, Graz 1995, Vol. 1, edited by Helmut Krasser, Michael Tortsen Much, Ernst Steinkellner, and Helmut Tauscher, 439–56. Vienna: Verlag der Österreichischen Akademie der Wissenschaften, 1997.;RNgog lo-tsā-ba's Commentary on the Ratnagotravibhāga: An Early-20th-Century Lhasa Printed Edition;Ratnagotravibhāga Mahāyānottaratantraśāstra;David Jackson;