The meaning of the two truths--the worldly or mundane truth samvrtisatya , and the real or supreme truth (paramarthasatya)-- was a hotly debated topic among Chinese Buddhists in the 5th and 6th century a.d. From the time of Kumarajiva this issue was discussed in terms of yu and wu . Usually yu was iden- tified with samvrtisatya and wu with paramarthasatya, leading to the mistaken conclusion that the two truths represent two separate realities. The ambiguous meaning of these terms also contributed to the confusion. Yu and wu have both positive and negative conno- tations for Buddhist philosophy. Yu understood as substantial Being is denied by the Buddhist concept of emptiness sunyata , but yu as conventional, conditioned, co-arising dharmas is compatible with the Buddhist concept of prat(')ityasamutpada. Wu understood as a nihilistic nothingness is a misunderstanding of emptiness, but wu as a lack of substantial Being is synonymous with emptiness. The use of these ambiguous terms to interpret the meaning of the two truths prevented a satisfactory resolution of the problem until the issue was dealt with by Chi-tsang, of the Sanlun tradition, and Chih-i, founder of T'ien-t'ai philosophy.In this dissertation I outline the debate on the two truths in China from the time of Kumaraj(')iva and Seng-chao, the first appearance of three truth formulations in Chinese apocryphal Sutras, the debate on the two truths led by Prince Chao-ming, Hui-yuan's discussion in his Ta ch'eng i chang, the positive evaluation of conventional existence by the Ch'eng shih lun scholars, and the contributions of Chi-tsang. Finally I discuss Chih-i's T'ien-t'ai philosophy and his resolution of the problem by means of his threefold truth concept. Chih-i tran- scends the yu/wu duality by emphasizing the oneness of reality and discussing the issue in terms of emptiness sunyata , conventional existence prajnaptirupadaya , and the middle madhyama . An annotated translation of the pertinent section of the Fa hua hsuan i (T. 33, 691-705) is included in an Appendix.
