Essence-Function (體用) is a key concept is Southeast Asian Buddhism and particularly that of Korean Buddhism. Awakening of Mahayana Faith, attributed to Aśvaghoṣa (?80-?150 CE), employs Essence-Function. Essence-Function forms a fundamental syncretic and ecumenical application in the philosophy of Wonhyo (617–686CE). Chinul (1158 – 1210CE) and Kihwa (1376 - 1433CE) also employ and develop this idea of Essence-Function in their writings in particular ways. Woncheuk (613–696) employed the conceptual and analytical tool, Essence-Function, as an exegetical, hermeneutical and syncretic device.
Nomenclature, orthography and etymology
體, this character is known as Radical 188 and romanized as "Tai" or "T'i" and is employed in both Cantonese and Mandarin written Chinese where it holds the semantic field:  [n] body  [n] shape; form  [n] entity; unit  [n] style; fashion; system  substance; essence  theory (as opposed to practice).
用, this character is known as Radical 101 and romanized as "Jung" or "Yung" and is employed in both Cantonese and Mandarin written Chinese where it holds the semantic field:  [v]use; employ; apply; operate  [v] exert  [n] use  effect  finance  [vn] need  [v] eat; drink  Kangxi radical 101.
Essence-Function (t'i-yung, 體用)
A tree, a pervasive living metaphor and mythical symbol throughout human cultures and icon of the branching, generation or lineage archetype, is employed as a teaching tool or hermeneutic device for explaining the relationship and operation of Essence-Function where 'Essence' the deep underlying ineffable cause are the "roots", and the 'Function' are the discernible effects, the "branches". Muller (2005: unpaginated) identifies the metaphor of the "roots" and "branches" as an analogue of Essence-Function within the Great Learning: "Things have their roots and branches, affairs have their end and beginning. When you know what comes first and what comes last, then you are near the Way."
Doctor (2004: p. 101) renders into English a quotation from Mipham (1846–1912) which has the metaphor of 'roots' and 'branches'. Mipham, familiar with Woncheuk's Saṃdhinirmocana-sūtra commentary (known in Tibet as the Great Chinese Commentary as it was referred to by Tsongkhapa) that employs essence-function, includes in his Commentary to the Madhyamālaṃkāra of Śāntarakṣita an open quotation from the 'Mother of the Victorious Ones' (Sanskrit: Prajñāpāramitā):
Yet although it is definitely necessary to embrace general learning and reflection, it is meaningful to condense one's practice to its core. The Mother of the Victorious Ones give examples of those who abandon the root to search for the branches, those who have come to a sublime feast but search for an inferior meal, those who have found the elephant but search for its foot prints, those who do not turn to the lord who offers many welcome benefits, but turn to the slave who gives little and of inferior quality, and so on. There are some who have, in a similar way, abandoned the root of Dharma, becoming haughty from experiencing the mere husks of works, and who also despise those who possess the key points.
Application of concept
Muller (1999: p. 4) discusses Essence-Function (t'i-yung) in relation to "words, thoughts and actions" which are known in South-east Asian Buddhism as the Three Gateways:
The most important application of t'i-yung thought, however, is to the human being, where the human mind is seen as "essence," and one's words, thoughts and actions are seen as "function."
'Interpenetration' or 'coalescence' (Wylie: zung 'jug; Sanskrit: yuganaddha; Chinese: 通達) and Essence-Function are mutually informing and fundamentally related doctrinally.
- ↑ 1.0 1.1 Muller, A. Charles (1995). "The Key Operative Concepts in Korean Buddhist Syncretic Philosophy: Interpenetration (通達) and Essence-Function (體用) in Wŏnhyo, Chinul and Kihwa" cited in Bulletin of Toyo Gakuen University No. 3, March 1995, pp 33-48.Source:  (accessed: September 18, 2008)
- ↑ Sheik, Adam (2008). 體 or Tai. CantoDict v1.3.16. Source:  (accessed: December 20, 2008)
- ↑ Sheik, Adam (2008). 用 or Jung. CantoDict v1.3.16. Source:  (accessed: December 20, 2008)
- ↑ Muller, A. Charles (2005). Plumbing Essence and Function: The Culmination of the Great Buddhist-Confucian Debate. Source:  (accessed: December 20, 2008)
- ↑ Doctor, Thomas H. (trans.) Mipham, Jamgon Ju.(author)(2004). Speech of Delight: Mipham's Commentary of Shantarakshita's Ornament of the Middle Way. Ithaca: Snow Lion Publications. ISBN 1559392177, p.101x
- ↑ Muller, A. Charles (1999). "Essence-Function and Interpenetration: Early Chinese Origins and Manifestations" cited in Bulletin of Toyo Gakuen University, vol. 7 (1999). Source:  (accessed: December 22, 2008) P.4
- Muller, A. Charles (1995). "The Key Operative Concepts in Korean Buddhist Syncretic Philosophy: Interpenetration (通達) and Essence-Function (體用) in Wŏnhyo, Chinul and Kihwa" cited in Bulletin of Toyo Gakuen University No. 3, March 1995, pp 33–48.Source:  (accessed: December 22, 2008)
- Muller, A. Charles (1999). "Essence-Function and Interpenetration: Early Chinese Origins and Manifestations" cited in Bulletin of Toyo Gakuen University, vol. 7 (1999). Source:  (accessed: December 22, 2008)