Wŏnch'ŭk (Chinese, Yuance; Tibetan, Wen tshegs, 613–696) was a Korean expatriate scholar monk who lived in seventh-century China. Wŏnch'ŭk traveled to Tang China at the age of fifteen and studied YogĀcĀra school texts based on ParamĀrtha's (499–569) translations under Fachang (567–645) and Sengbian (568–642). Later studying under Xuanzang (ca. 600–664), Wŏnch'ŭk joined the comprehensive project to translate Indian Buddhist texts into Chinese, marking the start of the so-called New Yogācāra. This movement was based specifically on these new translations and especially the compilation of the Cheng weishi lun (Demonstration of Consciousness-Only), in contrast to the so-called Old Yogācāra, which was based on Paramārtha's earlier translations. Wŏnch'ŭk's work appears to be an attempt to reconcile the doctrinal differences between those two distinctive trends of Chinese Yogācāra doctrine. His interpretation of Yogācāra diverges from the interpretations of Kuiji (631–682) and Xuanzang, while sometimes resonating with the work of Paramārtha. This led to severe criticism from the later disciples of Kuiji who started the Faxiang school, which took Kuiji as their first patriarch. Wŏnch'ŭk's extant works include the Haesimmilgyŏng so, a commentary on the SaṂdhinirmocanasŪtra (the tenth and last fascicle is missing, but is available in Tibetan translation); the Inwanggyŏng so, a commentary on the Renwangjing (Humane Kings SŪtra); and the Pulsŏl panya paramilta simgyŏng ch'an, a eulogy to the Heart SŪtra. Unfortunately, Wŏnch'ŭk's Sŏngyusingnon so, a commentary on the Cheng weishi lun, which was probably his most representative work, is no longer extant and is known only through quotations.
With his vast scholarship on Yogācāra Buddhist doctrine and other philosophical trends within the Indian tradition, Wŏnch'ŭk significantly contributed to the development of Chinese Buddhism, influencing the doctrines of the Chinese Huayan school and the especially the thought of Fazang (643–712). However, Wŏnch'ŭk's influence was not limited to China. Even though he never returned to Korea, Wŏnch'ŭk's theories were inherited by the Korean monks Tojŭng (ca. 640–710) and T'aehyŏn (fl. 753), despite their lack of any direct contact with him. Wŏnch'ŭk also played an important role in the formation of the Japanese branch of Yogācāra, the Hossō (Chinese, Faxiang) school, and his works were admired by Gyōsin (ca. 750), Genjū (723–797), and Gomyō (750–834). The controversies and debates surrounding the issues that Wŏnch'ŭk and other Faxiang scholars explored in China challenged Japanese Yogācāra exegetes at the very moment that the school was founded during the Nara period. This admiration for Wŏnch'ŭk's scholarship changed around the end of Heian and into the Kamakura periods. At that time, the Hossō school instead took as authoritative the three patriarchs of Chinese Faxiang—namely Kuiji, Huizhao (650–714), and Zhizhou (668–723)—and Hossō monks designated some views as "orthodox" and others as "heretical." In addition, Wŏnch'ŭk's commentary on the Saṃdhinirmocana-sūtra was translated into Tibetan during the ninth century and was cited extensively by Tsong kha pa (1357–1419) and his Dge lugs (Geluk) successors. Wŏnch'ŭk's views were therefore influential in the subsequent development of Tibetan Buddhism.
Cho, Eunsu. "Wŏnch'ŭk's Place in the East Asian Buddhist Tradition." In Currents and Countercurrents: Korean Influences on the East Asian Buddhist Traditions, ed. Robert E. Buswell, Jr. Honolulu: University of Hawaii Press, 2004.