Prior to the Sui-T'ang period, the concept of Buddha-nature,
[1] the fundamental or universal nature of enlightenment in sentient beings, was already a topic of central importance to Chinese Buddhists. In 418, when Fa-hsien translated the
Nirvāṇa-sūtra in six fascicles (
Ta-pan niyüan ching), the debate centering on Buddha-nature, as is well known, concerned Tao-sheng's (?-434) view of the
icchantika, a spiritual outcast forever excluded from enlightenment. Tao-sheng's thesis that all sentient beings, including the
icchantika, possessed the potentiality for Buddhahood was substantiated when the so-called "Northern edition" of the
Nirvāṇa-sūtra was translated in 421 by Dharmakṣema (385-433).
[2] While the
icchantika issue would again surface during the T'ang with the popularity of the Fa-hsiang school and its
triyāna doctrine, by the Sui period (589-612) the
ekayāna theme was well established. In the intervening years of the Liang and Ch'en dynasties, Chinese Buddhists in the south had moved on to other aspects of the Buddha-nature theory and were primarily concerned with the composition of exegetical commentaries which speculated on the specific meanings of universal enlightenment. That a variety of commentaries and Buddha-nature theories existed during this period can be seen if one examines the Liang compilation of the
Collection of Nirvāṇa-sūtra Commentaries (
Tapan nieh-p'an ching chi-chüeh).
[3] The
Collection, however, represents the peak of
Nirvāṇa-sūtra study in the south, for following the end of the Liang and Ch'en periods, the study of this text was superseded by the rise of Prajñāpāramitā-based traditions like San-lun and T'ien-t'ai. Exegesis of the
Nirvāṇa-sūtra and debate on the meaning of Buddha-nature continued within these schools, and while an independent scholastic tradition centering on the sutra had long passed from the Buddhist horizon by Sui times, it was during this period that the discussion of universal enlightenment was taken to a new degree of explicitness.
In the case of the San-lun tradition, the most intriguing discussion on this subject occurred in the writings of its systematizer, Chi-tsang (549-623).
[4] In his Buddha-nature essay, contained in the
Ta-ch'eng hsüan-lun (
A Compendium of Mahāyāna Doctrine), Chi-tsang sought to integrate the Prajñāpāramitā doctrine of emptiness and the
Nirvāṇa-sūtra concept of Buddha-nature.
[5] Assimilating two radically different aspects of Buddhist thought, Chi-tsang was the first individual in the history of East Asian Buddhism to argue that the inanimate world of grasses and trees also had the possibility of achieving Buddhahood. The most obvious peculiarity of this theory was the fact that, prior to Chi-tsang's time it was not a commonly accepted view of universal enlightenment. Indeed, it was a view totally rejected by earlier commentators of the
Nirvāṇa-sūtra, who associated the potentiality for Buddhahood with anthropocentric concepts such as "mind," "luminous spirit," "
ālaya-vijñāna," and "inherently pure mind." The textual basis for these earlier views was, of course, already established by the
Nirvāṇa-sūtra, which extended the promise of Buddhahood to all sentient existence, that is, to those who possessed the faculty of "mind." Although there was no doctrinal precedent for Chi-tsang's assertion, in his examination of Buddhist texts he found several passages to substantiate his theory of a comprehensive Buddha-nature. As we shall see, Chi-tsang took a highly qualified step in expanding the notion of salvation to include all of the natural, phenomenal world. As a San-lun scholar, however, Chi-tsang was neither interested, in a Taoist sort of way, in elevating nature to a religious dimension, nor simply concerned with the
Nirvāṇa-sūtra's anthropocentrically-limited promise of eventual enlightenment. Rather, Chi-tsang's most significant contribution to the discussion lay in his assertion that the Buddha-nature was a synonym for the middle path doctrine. The route by which he came to his expanded conception of Buddha-nature, then, was based on his primary view of
prajñā, and it is this that we wish to investigate in what follows. (Koseki, "Prajñāpāramitā and the Buddhahood of the Non-Sentient World," 16–17)