Articles/Outline of Western Scholarship on Buddha-Nature

Outline of Western Scholarship on Buddha-Nature

Alex Gardner

2019/07/16

Original content written for the Buddha-Nature Project.

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Gardner, Alex. "Outline of Western Scholarship on Buddha-Nature." Buddha-Nature: A Tsadra Foundation Initiative, July 16, 2019. https://buddhanature.tsadra.org/index.php/Articles/Outline_of_Western_Scholarship_on_Buddha-Nature.

Abstract

Scholars of Buddhism writing in European languages have celebrated, derided, and frequently misinterpreted the doctrine of tathāgatagarbha for well over a hundred years. While some have seen it as a crucial theoretical step to explain how deluded, impure sentient beings can become buddhas, others have dismissed the entire idea as non-Buddhist. Following Chinese and Tibetan scholiasts, Western scholars have labeled tathāgatagarbha as either Yogācāra or Madhyamaka, although most now understand that the doctrine arose independently of either of these main Mahāyāna schools. The philosophical question of whether ultimate reality can or should be described in positive terms, and the ethical matters of faith and practice all come to the fore in discussions of tathāgatagarbha, and scholars have for the most part spent the last century explicating the scripture and commentary that have sought to make sense of it all. To the degree that academics have assumed the role of interpreting Buddhist doctrine to Western audiences, tathāgatagarbha—“buddha-nature” to the popular reader—seems now to be the foremost shared interest of the academic and the practitioner. This essay attempts to be exhaustive, referencing all books, articles, and chapters that take buddha-nature as the primary focus. It discusses only scholarship published in European languages.

Part One: Buddha-nature Scholarship In The Twentieth Century

Western scholarship on buddha-nature seems to have begun in 1900 with the publication of D. T. Suzuki's Açvagosha's Discourse on the Awakening of Faith in the Mahāyāna. Suzuki had only recently attended the 1893 World's Parliament of Religions in Chicago, where he had met the German-American author Paul Carus. Then already famous for his Gospel of Buddha, Carus invited the young Japanese Buddhist scholar to live with him and encouraged him to make the translation, to which he contributed an introduction. The Awakening of Faith in the Mahāyāna (Dasheng qixin lun 大乗起信論) is a wildly popular Chinese treatise that attempted a resolution between the otherwise distinct doctrines of tathāgatagarbha and ālayavijñāna, or "storehouse consciousness," a central doctrine of Yogācāra Buddhism. The first teaches that all beings have the potential to attain buddhahood because enlightenment is inherent in their nature, while the second explains how defilement arose and continues. The treatise also introduced the concept of "original enlightenment" (本覺, Chinese: benjue; Japanese: hongaku), which became a primary modality of discussing buddha-nature in East Asia.

A decade later French Indologist Sylvain Lévi published a translation of the Mahāyānasūtrālaṃkāra, one of the central treatises of the Yogācāra school. This scripture, which in later Tibetan tradition came to be considered one of five texts given to the Yogācāra patriarch Asaṅga by the bodhisattva Maitreya, was one of the earliest to use the term tathāgatagarbha in a section that explains enlightenment. Lévi translated the term as "Matrice de Tathāgata." "Matrix," along with "embryo" and "womb," would become a common translation for garbha.

Lévi’s translation was appreciated by scholars, but it is difficult to evaluate how influential it was outside of the small circle of European scholars of Asia. French philosopher Paul Masson-Oursel noted both Suzuki and Lévi's translations of the term in his brief 1927 article "Tathāgatagarbha et Ālayavijñāna," which was one of the earliest critical explorations of the two concepts. According to Masson-Oursel, Swiss Indologist Paul Oltramare translated the word tathāgatagarbha as "embryon de Tathāgata" in his 1923 La Théosophie Bouddhique. Masson-Oursel himself proposed "la progéniture des Bouddhas," a not-entirely-unique take on the "embryo" sense of the term garbha; he cited Paul Demiéville as having proposed "fruit" to translate the word garbha.

Suzuki continued his studies and translations of Yogācāra scriptures in 1930 with Studies in the Lankavatara Sutra, followed by his translation of the Laṅkāvatāra Sūtra in 1932. Studies was one of the earliest introductions of Zen Buddhism to English readers and gave a decidedly Yogācāra presentation of the Mahāyāna and of tathāgatagarbha theory. Although Suzuki was not trained in a Western university, the book followed current Western protocols of academic study, comparing Chinese and Tibetan translations with the Sanskrit, tracing the reception of the sūtra in Chinese and Japanese history, and drawing out connections with other Mahāyāna scriptures such as the Prajñāpāramitā and the Lotus Sūtra. For its time it was a remarkable accomplishment.

The discussion of buddha-nature in the Laṅkāvatāra Sūtra comes in the sections on ālayavijñāna. This doctrine of a permanent pure consciousness—and the explanation of how that consciousness becomes and remains defiled—was controversial even in ancient India. As they did with tathāgatagarbha, critics condemned ālayavijñāna as an adoption of a heretical essentialism: the decidedly non-Buddhist assertion of a permanent self. Suzuki explained as well as he could that this was not the case. He addressed the controversy of the similarities between tathāgatagarbha and the ātman of Hindu doctrine, translating a famous passage from the sūtra in which the Buddha not only rebuffs the criticism but also offers the teaching of tathāgatagarbha as a means to soothe disciples afraid of the doctrine of emptiness. That is, the Buddha is presented as having taught that mind exists apart from the five skandhas, and he offered both this permanently present mind and buddha-nature to those who were troubled by the seeming nihilism of emptiness. In doing so, Suzuki, apologizing to the West for a doctrine that was almost universally embraced in Asia, made use of a strategy that Indian, Chinese, and Tibetan scholiasts had employed for centuries: buddha-nature was a provisional teaching for those afraid of emptiness and was not meant to be taken literally.

Tathāgatagarbha theory, while influenced by both, developed outside of Madhyamaka and Yogācāra circles, something Suzuki failed to note; he instead presented tathāgatagarbha as a fundamental part of Yogācāra doctrine. The Laṅkāvatāra was, in fact, one of the clearest attempts at synthesizing tathāgatagarbha theory with the Yogācāra doctrine of mind. In his introduction to his translation of the sūtra, published in 1932, Suzuki described the conflation of the two this way: "The Tathāgata-garbha, therefore, whose psychological name is Ālayavijñāna, is a reservoir of things good and bad, pure and defiled. Expressed differently, the Tathāgata-garbha is originally, in its self-nature, immaculate, but because of its external dirt (āgantukleṣa) it is soiled, and when soiled—which is the state generally found in all sentient beings—an intuitive penetration (pratyakasha) is impossible." Suzuki's work was immensely influential among both scholars and the general public, and his translation has been reprinted three times, in 1966, 1978, and 2003. Studies remains in print.

In 1931, one year after Suzuki's Studies and a year before the translation of the Laṅkāvatāra, Russian Buddhologist Eugène Obermiller published a translation from the Tibetan of the Ratnagotravibhāga under the title The Sublime Science of the Great Vehicle to Salvation, Being a Manual of Buddhist Monism. That same year he published the first part of his famous translation of Butön Rinchen Drup's History of Buddhism. Obermiller had trained under the great Russia scholar Theodor Stcherbatsky, who had established St. Petersburg as one of the centers of the European study of Buddhism. Stcherbatsky, who had met the Thirteenth Dalai Lama in Mongolia in 1905, had later sent Obermiller and his fellow disciple Andrey Vostrikov to Buryatia to collect books and learn from Tibetan Buddhists in the region. Obermiller's translation and study of the Uttaratantra was thus informed by contemporary lamas and by the great Tibetan historian Butön Rinchen Drup.

In his lengthy introduction to the translation, Obermiller characterized the work as "the exposition of the most developed monistic and pantheistic teachings of the later Buddhists and of the special theory of the Essence of Buddhahood (tathāgatagarbha), the fundamental element (dhatu) of the Absolute, as existing in all living beings." He described the seven topics of the text as "the Buddha (1), the Doctrine (2), and the Congregation (3)—the Three Jewels. The fundamental element of the Absolute, the Essence of the Buddha as it exists in every living being, obscured by the accidental defiling elements (4). The state of Supreme Enlightenment, that of the same element as delivered from all the Obscurations (5). The properties of the Buddha possessed by him after the attainment of this state of complete Illumination (6). The acts performed by the Buddha in pursuit of the welfare of all living beings (7)."

Obermiller translated the Ratnagotravibhāga in reliance on the great fifteenth-century Tibetan Gyaltsap Je Darma Rinchen's commentary of the work, and he identified the numerous scriptures to which the treatise makes reference. Following Tibetan convention, Obermiller classified the treatise as one of the Five Books of Maitreya, scriptures believed to have been revealed by the bodhisattva to Asaṅga. However, unwilling to ascribe divine provenance to the treatise, he supposed Asaṅga had composed them all, both treatises and commentaries. This presented him with the problem of the significant difference in philosophical views between the Ratnagotravibhāga and the other four books of Maitreya. Unlike the text at hand, those scriptures clearly advocate the classic Yogācāra doctrine of three classes of beings; the Ratnagotravibhāga, on the other hand, teaches universal buddha-nature. Obermiller explained the difference in doctrinal context with the hypothesis that Asaṅga changed his views over time. Obermiller's work was reviewed soon after by Belgian scholar Louis de la Vallée Poussin and has remained a classic in the field.

Obermiller appears not to have been aware that at least two scholars working in French had previously noted that what the Tibetans knew as the Uttaratantra (Rgyud bla ma) also existed in China—where it was known as the Ratnagotra-śāstra (Baozinlun 寶性論) or, as we know it today, the Ratnagotravibhāga. These were the Jesuit missionary Noël Péri and Prabodh Chandra Bagchi, a Bengali pandit who had studied in Paris under Sylvain Lévi. Neither of these scholars discussed the content of the treatise, but Péri attempted to identify the author of the text as understood by the Chinese: an Indian named Sthiramati. He gave the Chinese for Sthiramati as Kien-yi (jian yi 堅意) and the Chinese phonetic as xi chi luo mo di (悉恥羅末底). Péri in turn seems not to have been aware of the Tibetan tradition of ascribing authorship of the treatise's root verses to the bodhisattva Maitreya and the prose section to Asaṅga. The authorship of the treatise would be a source of consternation for Western academics for several decades.

In 1935 two well-known British Sanskritists named Harold Walter Bailey and Edward Hamilton Johnston published a fragment of the Ratnagotravibhāga written in the Saka script that Bailey had located in the Stein Collection (item no. 0047). The fragment confirmed, for the first time, the Sanskrit title as Ratnagotravibhāga, allowing the authors to undertake a comparison between the Tibetan and the Chinese translations and comment on the significant differences. They correctly faulted Obermiller for repeating the Tibetan attribution of the sūtra to the Vijñānavāda (i.e.,Yogācāra) school. Instead, they proposed that the author, Sthiramati, was a member of a fringe Madhyamaka group in India, not the same man as the Sthiramati who translated the Ratnagotravibhāga into Chinese; the second Sthiramati, they argued, was a student of Asaṅga and a follower of the Yogācāra, thereby explaining the text's embrace by Chinese Yogācārins. Belgian scholar Jan Willem de Jong later noted that Johnston and Bailey's theory of a second Sthiramati was savagely dismissed by Japanese scholar Hakuju Ui.

Western scholarship to this point had been limited by the absence of a complete Sanskrit original. In 1935, just as Bailey and Johnston’s article was going to press, an Indian scholar named Rāhula Sāṅkṛtāyana announced that he had photographed two Sanskrit manuscripts of the Ratnagotravibhāga at Ngor and Zhalu monasteries. Worth noting is the identity of his Tibetan assistant, the great twentieth-century Tibetan scholar Gendun Chöpel Johnston thereafter sent a mission to Zhalu to obtain better images, and on the basis of these an edited Sanskrit version was published in 1950 with the assistance of Professor T. Chowdhury of Patna College. Johnston had died in 1942, and the book had been delayed by the hardships of World War II and Partition; it had to be published without the benefit of his final revisions, resulting in errors that have been noted by several scholars since. Johnston did, however, leave behind an introduction in which he again rejected Asaṅga’s authorship and pointed to Sthiramati. Edward Conze made use of Johnston's Sanskrit to publish several translated passages in his 1954 Buddhist Texts Through the Ages, as did the Austrian Erich Frauwallner in 1956. Eminent Japanese scholar Hakuju Ui translated the Sanskrit into Japanese in 1959. In 1957 Bengali Sanskritist Manmatha Nath Dutt published an article in Indian Historical Quarterly making use of Johnston’s Sanskrit, in which he compared tathāgatagarbha to ālayavijñāna.

Japanese scholar Jikidō Takasaki, a student of Ui’s, compared Johnston's Sanskrit with the Tibetan and Chinese translations to produce a second English translation of the scripture in 1966. He identified the author as Kien-huei (jian hui 堅慧), which he reconstructed as Sāramati based on the Chinese transliteration (suo luo mo di 娑羅末底), and who was said by Fazang 法藏, the third patriarch of the Huayan school, to have been a "first-stage bodhisattva" and a member of the Kṣatriya clan, born in central India seven centuries after the Buddha's mahāpārinirvāṇa. Takasaki dated the text to the early fifth century. He appears to have been the first author working in a European language to avoid labeling the treatise as either Yogācāra or Madhyamaka, as previous scholars had attempted to do. Prior to the translation's publication, Takasaki had published ten articles on the Ratnagotravibhāga, and he continued to publish on it into the early twenty-first century.

Takasaki's 1966 translation was favorably reviewed by de Jong in 1968, who briefly surveyed previous scholarship and included ten pages of his own analysis of various passages from the Sanskrit and Tibetan. De Jong asserted that the Chinese tradition names Sāramati as the author but noted that several scholars have argued that the man's name is properly Sthiramati. The German Buddhologist Lambert Schmithausen reviewed Takasaki’s translation in 1971 in a lengthy article in which he sought to identify the earliest elements of the text.

Between 1968 and 1989 American-British scholar David Seyfort Ruegg, who trained in Paris and wrote mostly in French, published five studies of buddha-nature in Indian and Tibetan literature. The first, a survey of the Geluk treatment of tathāgatagarbha, was in a festschrift for the Dutch Indologist Franciscus Bernardus Jacobus Kuiper published in 1968. In 1969 he published his first book-length study, an analysis of the terms tathāgatagarbha and gotra in Buddhist philosophy. This was reviewed, in German, by Schmithausen. Ruegg followed in 1974 with a French-language analysis of buddha-nature in the writings of Butön Rinchen Drup and, in 1976, an English article on the concept of gotra and its usage in the Ratnagotravibhāga. The next year, in a festschrift for Edward Conze, Ruegg published a study of the doctrines of gotra and tathāgatagarbha in Prajñāpāramitā literature. His 1987 SOAS Jordon Lectures were published in 1989 as Buddha-nature, Mind and the Problem of Gradualism in a Comparative Perspective: On the Transmission and Reception of Buddhism in India and Tibet. Ruegg's work remains some of the finest and most detailed analysis of the topic, although as Klaus-Dieter Mathes fairly pointed out, Ruegg's work is entirely framed by the limited Geluk interpretation of buddha-nature and is not informed of the considerable controversy over the topic among Tibetan scholiasts.

Other than Suzuki’s work on the Laṅkāvatāra, until the mid-1970s attention to buddha-nature was focused almost entirely on the Ratnagotravibhāga, certainly a main source of tathāgatagarbha theory but by no means the only scripture to address the topic. Both Tibetan and Chinese historians had formulated a category of "tathāgatagarbha sūtra," with different authors listing different scriptures, but these had largely remained unexamined by Western scholars. The first study and translation of one of these other scriptures was Alex Wayman and Hideko Wayman's The Lion's Roar of Queen Śrīmālā, published in 1974. The Waymans dated the sūtra to the third century CE, hypothesized that it was composed by a Mahāsāṅghika community in northern India, pointed to its being quoted in the Ratnagotravibhāga and by Śāntideva in his Śikṣamuccaya, and showed that it influenced the Laṅkāvatāra and the Mahāyānasūtrālaṃkāra. The translation has not been well received but continues to be referenced.

The same year that the Waymans' book came out, Diana Paul submitted her dissertation at the University of Wisconsin, which was later published in 1980 as The Buddhist Feminine Ideal: Queen Śrīmālā and the Tathāgatagarbha. The book has many valuable contributions; it places the text in the early development of the Mahāyāna, and it includes surveys of earlier translations of key terms and an overview of tathāgatagarbha theory. Paul pointed out the key role that the bodhisattvas play for sentient beings as guides in the transition from ordinary being to buddha. The Śrīmālā, although it affirms that all beings share the same buddha-nature and emphatically embraces the idea of a single vehicle, nevertheless asserts that śrāvakas and pratyekabuddhas cannot comprehend the steps needed to shed adventitious stains and reveal the intrinsic purity of mind—only bodhisattvas can. Paul notes that while the Lotus Sūtra proclaimed the universal salvation via the single vehicle, and the Tathāgatagarbhasūtra proclaimed universal buddha-nature, it was the Śrīmālā that first combined those concepts.

In a 1981 article "Nonorigination and Nirvāṇa in the Early Tathāgatagarbha Literature," William Grosnick considered the place of early tathāgatagarbha literature in the development of the Mahāyāna, a historical event that beguiled Western scholars for many decades during the last century. Grosnick was interested in understanding the notion of "naturally pure or luminous mind" and its relationship to the doctrine of emptiness from the Prajñāpāramitā literature. He theorized that early Mahāyāna shifted the previous Buddhist goal of personal liberation—nirvāṇa—to buddhahood, which was seen as selfless and therefore intellectually defensible according to Buddhist no-self doctrine. Still, early Mahāyāna preserved a distinction between nirvāṇa and the state of buddhahood; the tathāgatagarbha literature, however, collapsed these two. For these texts, nirvāṇa was not an extinction but a state of natural purity, identical to the experience of a buddha. Tathāgatagarbha literature, Grosnick explained, advocated for a view of practice in which one accepts that saṃsāra is produced through ignorance, and thus for liberation one simply stops producing it. Nondiscriminatory wisdom, the sūtras suggest, does not produce a state of nirvāṇa; it simply ceases producing saṃsāra, enabling one to rest in a natural state of purity. This natural state can therefore be referred to as unproduced, eternal, and the like; these are positive descriptions that are not in conflict with the emptiness theory of the Prajñāpāramitā literature.

Beginning in 1980, scholars began taking a broader view of buddha-nature theory in Tibet, comparing views of different authors and tracing the historical changes in approach. Kennard Lipman, in his article "Nītārtha, Neyārtha, and Tathāgatagarbha in Tibet," offered his study of Nyingma and Kagyu exegesis as a response to Ruegg's exclusive reliance on the Geluk interpretation of buddha-nature. As the title suggests, the paper is an examination on how different scholiasts grappled with the question of whether buddha-nature is to be taken as a provisional or definitive teaching, briefly summarizing the writings of Pema Karpo, Jamgon Kongtrul, and Ju Mipam Gyatso. Lipman seems to have been the first to examine tathāgatagarbha in terms of the Tibetan doxographical struggle over the second and third turnings—that is, over the classifications of the myriad Mahāyāna teachings as either Madhyamaka or Yogācāra. He was also one of the first to note the connection between tathāgatagarbha theory and "other-emptiness" (gzhan stong).

Leonard van der Kuijp continued to widen the scope of inquiry in his 1983 Contributions to the Development of Tibetan Buddhist Epistemology: From the Eleventh to the Thirteenth Century. Although it does not address what he called "the tathāgata problematic" directly, the book took a comparative approach and outlined the history of tathāgatagarbha theory in Tibet. Van der Kuijp surveyed the epistemological writings of four major Tibetan authors—Ngok Lotsāwa Loden Sherab, Chapa Chökyi Senge, Sakya Paṇḍita, and Gorampa Sönam Senge—and drew into the discussion multiple others as well, such as Śākya Chokden, Tāranātha, and Jamgon Kongtrul—to provide one of the widest views of intellectual activity in Tibet since Tucci's Tibetan Painted Scrolls.

Van der Kuijp drew attention to the Tibetan categorization of Ratnagotravibhāga commentaries into two traditions: the "meditative tradition," stemming from Tsen Khawoche, and the "analytic tradition," stemming from Ngok Lotsāwa, both students of the Kashmiri paṇḍit Sajjana, who translated the sūtra into Tibetan with Ngok Lotsāwa's assistance. Although these tend to be presented as opposing positions, Śākya Chokden, for one, argued that the two are complementary rather than in conflict, the one focused on the intellectual approach to emptiness and the other on the recognition of the innate luminosity of mind, both of which, Śākya Chokden asserted, are necessary for the attainment of enlightenment. The fact that both stem from the same Indian teacher does support Śākya Chokden's argument. Van der Kuijp also quoted Śākya Chokden equating the natural luminosity of mind with tathāgatagarbha, a philosophical move made by those sympathetic to Yogācāra that gained widespread acceptance in Tibet.

The question of whether buddha-nature was better interpreted as Madhyamaka or Yogācāra was also an issue in early Chinese Buddhism. In the 1980s, Chinese-born scholar Liu Ming-Wood, who received his doctorate at UCLA, published four articles on buddha-nature, largely based on his research into the Mahāyāna Mahāparinirvāṇa Sūtra. In his first, published in 1982, Liu shows that the sūtra (not to be confused with the sūtra of the same name in the Pali canon) was a pivotal text in the development and popularity of buddha-nature in China, specifically in the merging of Yogācāra and tathāgatagarbha theory. For example, the Mahāparinirvāṇa Sūtra (at least in the later translation; see below) preserves the Yogācāra doctrine of three gotras (śrāvaka, pratyekabuddha, and bodhisattva) yet shifts it subtly; because of buddha-nature, all three have the same potential to attain the complete enlightenment of a buddha, but only those with the nature of a bodhisattva will be able to perceive that potential. The sūtra is adamant that buddha-nature is only a potential for enlightenment, possessed by virtue of the presence of consciousness; it is not an already-existing enlightenment. Even this was too much for early Chinese Madhyamaka philosophers such as Jizang (吉藏 549–623), who interpreted tathāgatagarbha as a provisional teaching meant to ease fear of nihilism. In any case, the Mahāyāna Mahāparinirvāṇa Sūtra became so popular that scholars such as Whalen Lai have posited the existence of a Nirvāṇa school in China centered around the text, albeit one that was short-lived and that was folded into later schools.

In 1989 Robert Buswell of the University of California, Los Angeles, published a study and translation of the *Vajrasamādhisūtra, one of the most influential apocryphal scriptures on buddha-nature: The Formation of Ch'an Ideology in China and Korea: The Vajrasamādhi-Sūtra, a Buddhist Apocryphon. The book contains an extensive study and a translation of the sūtra, and makes a convincing argument to rethink the "national lines of argument" that had previously dominated discussions of East Asian Buddhist traditions. Buswell showed how Chan developed in multiple communities; it was not a Chinese phenomenon that was then exported to Korea and Japan. He also shows how the scripture is firmly in the Chinese Yogācāra tradition of Paramārtha, containing an extensive discussion of "immaculate consciousness" (amalavijñāna), the ninth consciousness which unites saṃsāra and nirvāṇa in a "single taste." Buswell draws on Japanese scholarship, such as that by Mozuno Kōgen, who first concluded that the sūtra was an apocryphon. Although most Japanese assumed that since the text had been written in Chinese it must have been an ethnic Chinese author who composed it, Buswell tentatively proposed that the sūtra was composed in Korea between 680 and 685 by a monk named Pǒmnang, a Korean student of Daoxin, the reputed founder of the East Mountain School of Chan. The book is a meticulous analysis of the important role the scripture played in the formation of early Chan doctrines of original enlightenment and buddha-nature.

Liu's 1982 article on buddha-nature remains popular among dharma centers, for despite presenting the topic in a fairly limited context, the discussion is clearly laid out for the nonspecialist. Buddha-nature had become a topic of interest to the general public by the 1980s, largely due to D. T. Suzuki's enduring influence, and Tibetan teachers were beginning to respond to their students' requests for instruction. Under the guidance of Thrangu Rinpoche, Ken Holmes and Katia Holmes published a translation of the root verses of the Ratnagotravibhāga from the Tibetan in 1979. This was the second translation of the Ratnagotravibhāga into English. In 1985 Chökyi Nyima Rinpoche, a Nyingma lama based in Kathmandu with many Western students, requested Thrangu Rinpoche to teach the Ratnagotravibhāga. The resulting lectures were collected and published in 1988 as Buddha Nature: Ten Teachings on the Uttara Tantra Shastra. In his introduction Thrangu Rinpoche explains that the sūtra "examines something each of us possess—buddha nature. We each have the seed of enlightenment within ourselves, and because this potential can be actualized, it is said that we possess an enlightened essence." The definition offered here—a seed that is the potential for enlightenment—is very much in line with the explanation found in the Mahāparinirvāṇa Sūtra: not original, already-perfected enlightenment but a potential for perfection. The teaching, however, follows the "other-emptiness" interpretation of buddha-nature, and the "potential/essence" described here is the luminous nature of mind; buddha-nature is causal, because it shares the same essence—the dharmakāya—as the buddhas. That is, although complete enlightenment is not already present, the "end result of enlightenment" is.

One of the most influential scholars working in the West on the topic of buddha-nature (as well as the study of Yogācāra and other topics) was Professor Minoru Kiyota, an American who was trained at Kyoto University and who taught at the University of Wisconsin–Madison for close to thirty years. His students are among the best Buddhologists working today, and in 1990 many of them contributed essays to a volume in his honor: Buddha Nature: A Festschrift in Honor of Minoru Kiyota. The book includes articles on Indian scripture and both Chinese and Tibetan Buddhism, although, perhaps reflecting Minoru's influence, the content has a decidedly East Asian bent; in their introduction, Paul Griffiths and John Keenan stress that the English phrase "buddha-nature" is itself a Chinese concept with no single direct Indian parallel. They point out that the Chinese foxing (佛性) could be a translation for buddhatā, tathāgatagarbha, tathatā, buddhadhātu, prakṛtivyadadāna, and so forth. Other articles in the collection, however, are comfortable using buddha-nature and tathāgatagarbha interchangeably; it is, after all, the most common term for the theory, although the authors are right to remind us that multiple terms are used in scripture and they are not exact synonyms.

The collection begins with José Cabezón's fascinating The Canonization of Philosophy and the Rhetoric of Siddhānta in Tibetan Buddhism, in which he argues that Tibetan doxography (siddhānta, grub mtha’) has always been a hegemonic exercise, establishing what is orthodox and what is heretical. Tibetan scholarship organizes the entire span of Buddhist teachings into four schools: Vaibhāṣika, Sautrāntika, Yogācāra, and Madhyamaka. For most Tibetans these four are in hierarchical order—Madhyamaka is the highest teaching. Consequently, for those who considered certain positive-language Yogācāra doctrines and buddha-nature theory to be equal or superior to Madhyamaka's negative-language doctrine, Madhyamaka had to be defined in a way so as to accommodate both positive and negative language. The philosophical efforts in this regard of great scholars such as the Eighth Karmapa and Śākya Chokden, both mentioned by Cabezón, would be the subject of multiple books and articles several decades later.

Subsequent articles are equally compelling. In "Buddha Nature as Myth," William Grosnick argued that buddha-nature is a mythic element in Buddhism, different from the empirically verifiable truths on which the religion depends and from the intellectual processes of analyzing reality. Buddha-nature, he argues, was offered as a palliative; despite the wretchedness of existence, there is underlying good, so be comforted. In traditional Buddhist terms, of course, this would be framed as a provisional teaching, which is how many Buddhist philosophers have dealt with the theory. Roger Gregory-Tashi Corless deals directly with the provisional/definitive hermeneutic with his "Lying to Tell the Truth," an examination of the Lotus Sūtra's skillful means (upāya) teachings; buddha-nature, he suggests, is the "true truth" toward which all those skillful teachings are directed. Roger Jackson's article "Luminous Minds among the Logicians" is an examination of one attempt to put the "mythic" buddha-nature doctrine—specifically the notion of naturally luminous mind—into epistemological line with mainstream Madhyamaka, in this case the Pramāṇavārttika of Dharmakīrti and Dignāga. In "Painting Space with Colors," Paul Griffiths looks at the sole buddha-nature passage in the Mahāyānasūtrālaṅkāra, one of the earliest appearances of the concept. He argues that the gloss in the embedded commentary could be read two ways, leading to two very different philosophical positions: "all living beings possess the embryo of the tathāgatagarbha" or "all living beings are the embryo of the tathāgatagarbha." That is, either buddha-nature is a potential that must be developed or it is an already-existent presence that needs only be cleansed. This is, of course, one of the core debates in buddha-nature theory.

The remaining five essays are focused on Chinese Buddhism. Jamie Hubbard looked at buddha-nature and "universal buddhahood" (pufo 普仏) in the sanjiejiao (三階教) tradition in his chapter "Absolute Delusion, Perfect Buddhahood." Hubbard showed how the various sanjiejiao interpretations of buddha-nature led scholiasts to advocate austere religious practices and charity, a point he offers to counter Matsumoto Shirō and his "Critical Buddhism" position that buddha-nature is not Buddhist and leads to amorality. (Hubbard would lead the scholarly response to "Critical Buddhism"; see below.) In his "The Doctrine of Buddha Nature in Chinese Buddhism—Hui K'ai on Paramārtha," John Keenan examined how the translation of Buddhist scriptures into Chinese relied on preexisting Chinese concepts of human nature and showed how the translator Paramārtha frequently inserted the term buddha-nature into passages in order to broaden the text's appeal to Chinese readers. Sallie King, in her chapter "Buddha Nature Thought and Mysticism," surveyed three Chinese scriptures, arguing that three of them can be considered "mystical" in that they collapse the sacred and profane (that is, buddhas and sentient beings) and they promote experiences to realize that sameness. Heng-Ching Shih and Paul Swanson both focused on the Tientai founder Zhiyi, the former examining the Tientai doctrine of "inherent evil" and the latter examining Zhiyi's theory of buddha-nature as threefold, encompassing reality, wisdom (that is, accurate perception of reality), and the practice needed in order to attain that wisdom.

By the end of the twentieth century, lamas teaching to Western audiences were increasingly asked to teach buddha-nature theory. Books that came out as a result of these teachings include three commentaries on the Ratnagotravibhāga by Dzongsar Jamyang Khyentse Rinpoche, Thrangu Rinpoche, and Zasep Tulku Rinpoche. Comparative studies, such as Nicholas Groves's article in Buddhist-Christian Studies titled "Image-Likeness and Tathāgatagarbha: A Reading of William of St. Thierry's 'Golden Epistle' and the Ratnagotravibhāga" further indicate the spread of interest in buddha- nature outside of academic Buddhist Studies departments.

Meanwhile, the increase in scholarly interest in buddha-nature in the last decade of the twentieth century is evident in three full-length studies on the topic released in 1991: Sallie King's Buddha Nature, Brian Brown's The Buddha Nature, and S. K. Hookham's The Buddha Within. King’s book is a study of the Buddha Nature Treatise (Foxing lun 佛性論), a Chinese apocryphal work that was credited to Vasubandhu but was probably written by Paramārtha. The work is a key text in the Chinese Yogācāra-tathāgata synthesis to which Paramārtha was, as both translator and author, a major contributor. One of the many compelling points King makes is the suggestion that buddha-nature may have arisen in part from—or possibly as a cause of—Mahāyāna devotionalism and the East Asian Pure Land school, a suggestion that deserves more consideration; perhaps Tantra, too, might be traced to the development of buddha-nature theory in India. King also nicely frames the relationship between Madhyamaka, Yogācāra, and tathāgatagarbha, arguing that these three were not initially taken to be in opposition to one another but complementary, each dealing with emptiness and consciousness from a different perspective.

Brian Brown's book similarly deals with buddha-nature from an Indian and Chinese standpoint and is concerned with the Yogācāra-tathāgata synthesis. Brown makes reference to several key Indian and Chinese scriptures, but rather than being a piece of traditional scholarly exegesis, it is more a work of philosophy that "seeks to establish a coherent metaphysic of Absolute Suchness (Tathatā), synthesizing the variant traditions of the 'Tathāta-embryo' (Tathāgatagarbha) and the Storehouse Consciousness (Ālayavijñāna)," and is less valuable for understanding how Indians or Chinese Buddhists developed buddha-nature theory.

Hookham's book, the first translation of a Tibetan commentary on the Ratnagotravibhāga—that of Jamgon Kongtrul—is a study of what she terms the "Shentong Yogacara Madhyamaka interpretation of Tathagatagarbha." Prior studies of Tibetan buddha-nature theory relied almost exclusively on Geluk Prāsaṅgika Madhyamaka interpretation, in which buddha-nature is at best considered a provisional teaching; where other-emptiness had previously been mentioned, it was through the perspective of those who disputed it. The book is an introduction to historical and doctrinal issues, the first study from the perspective of a Tibetan who advocated a positive-language approach to ultimate reality.

Hookham positions the Ratnagotravibhāga as the link between the "Sutra-Madhyamaka" tradition and the "Tantra-Siddha traditions." She explains that although the "self-emptiness"/"other-emptiness" concepts are not explicit in Indian literature, Tibetan advocates of the doctrine argue that the teachings of other-emptiness are implicit in the scriptures of the third turning, which they consider to be definitive. Where Geluk and most Sakya masters reject buddha-nature and other-emptiness as either provisional or non-Buddhist, Jonang, Kagyu, and Nyingma teachers embrace both, seeing the two approaches as complementary and necessary stages of the path to enlightenment. In a testament to the growing desire of scholars to discuss buddha-nature, the book earned four reviews by respected scholars: Paul Griffiths, David Need, Robert Gimello, and Franz-Karl Ehrhard.

Tibetan lamas who dismissed buddha-nature have counterparts in Japan among the so-called Critical Buddhists, Japanese academics who, from the late 1980s through the 1990s, wrote a series of books and articles arguing that buddha-nature is not Buddhist. Hakamaya Noriaki and Matsumoto Shirō, both students of Jikidō Takasaki, were both professors at Komazawa University in Tokyo, which is affiliated with the Sōtō Zen tradition. Their argument was essentially in three parts: They proposed a normative definition of Buddhism which holds to no-self and dependent arising and is dedicated to the critical differentiation between phenomena and ultimate reality. Second, they classify as "dhātu-vāda"—a phrase Matsumoto coined—any theory that speaks positively about reality and posits an eternal, underlying basis from which all things arise. Because tathāgatagarbha and the closely related East Asian Buddhist concept of "original enlightenment" both do so, they are not Buddhist. Third, they argue that these "non-Buddhist" ideas have promoted and permitted social injustice in Japan, from racial and economic discrimination to Japanese imperialism.

Western academic responses to Matsumoto Shirō and Hakamaya Noriaki's writings began to appear in the early 1990s, some of which were eventually gathered together with new material in a book edited by Jamie Hubbard and Paul Swanson titled Pruning the Bodhi Tree. The book fairly presents the issues, bringing in scholars such as Dan Lusthaus and Sallie King to debate the points (not-Buddhist and "impeccably Buddhist," in the case of Lusthaus and King) and giving space to Matsumoto and Hakayama to respond to criticism. Hubbard, in his introduction, acknowledges that the issue of whether one can use positive language to describe ultimate reality or must only use "nonaffirming negation" is a Buddhist dialectic that dates back to the early days of the religion; he begins his essay with the ninth-century Japanese debate between the Tendai founder Saichō and the Hossō (Yogācāra) monk Tokuitsu over original enlightenment in the Lotus Sūtra, with the former advocating for the Lotus’s doctrine of One Vehicle (ekayāna) and original enlightenment and the later countering with the doctrine of the five gotras, including the iccantika. Saichō may have come out ahead, but the debate has never really ended.

The scholars who argued against Matsumoto and Hakamaya, such as Peter Gregory and Sallie King, offer a fairly standard apology: buddha-nature is a soteriological device, not an ontological principle, and was a response to excessive negative language in the emptiness teachings in the Prajñāpāramitā and Madhyamaka. Here, of course, soteriological is a Western way of saying provisional—its truth is relevant for the path rather than the goal. While there is ample textual support for these rather psychologically oriented interpretations, both Chinese and Tibetan scholiasts who advocated for buddha-nature did not themselves view the teaching as provisional—the people of the tradition did not, that is, qualify their descriptions of buddha-nature with the assurance that they were only soothing anxious would-be Madhyamikas. Buddhists who teach that the mind is naturally pure, or naturally empty and luminous, are making statements about ultimate reality that they understand to be definitive. A defense of buddha-nature theory that relegates it to provisional status is not a defense; it is taking sides in an age-old debate.

Part Two: Buddha-nature Scholarship In The Twenty-first Century

Western scholarship on buddha-nature was initiated at the dawn of the twentieth century by a Japanese man seeking to promote Yogācāra and tathāgatagarbha to a Western audience that for the most part was not able to differentiate Buddhism from Hindu notions of the ultimate unity of existence ("monism"). The century ironically closed out with Western scholars defending buddha-nature against Japanese who deemed it “non-Buddhist” for its apparent embrace of essentialism. Buddha-nature was by then firmly entrenched in the Western Buddhist imagination, and during the first two decades of the twenty-first century, scholarship on buddha-nature, primarily in a Tibetan context, has increased exponentially. Several remarkable book-length historical studies of the Ratnagotravibhāga have been published, as well as scores of articles examining literature and points of doctrine relating to buddha-nature, chief among these being other-emptiness in the Tibetan context, and the buddha-nature of grass and trees in an East Asian context. Scholars have also given us book-length studies of buddha-nature scriptures such as the Tathāgatagarbhasūtra, the Mahāparinirvāṇasūtra, and the Anūnatvāpūrṇatvanirdeśaparivartasūtra, the last of which was never translated into Tibetan.

In 2000 Rosemarie Fuchs published a translation of the Ratnagotravibhāga together with Jamgon Kongtrul's commentary Unassailable Lion’s Roar (the introduction to which was translated in Hookham 1991). Fuchs's translation, the third into English, was done at the request and guidance of Khenpo Tsultrim Gyamtso Rinpoche, who had first taught both texts to his Western students in the mid 1970s, and the book contains his extensive annotations on Kongtrul's commentary.

Eight years later, University of Vienna professor Klaus-Dieter Mathes, in his A Direct Path to the Buddha Within, translated yet another important Kagyu commentary, this by Gö Lotsāwa Zhönu Pal. Mathes had previously published several times on Gö Lotsāwa's commentary, including a critical edition in 2003, as well as others of Gö's works on related topics. Like Kongtrul's commentary translated by Fuchs, Gö Lotsāwa's is firmly in the "meditative tradition" said to have originated with Sajjana's student Tsen Khawoche, which contrasts with the "analytic tradition" of Ngok Lotsāwa.

Preceding the translation are three introductory chapters on the intellectual context of Gö's work, and following it are three chapters that individually address three questions: what are "subtle" buddha qualities, how is buddha-nature related to prajñāpāramitā, and how does Gö Lotsāwa read Mahāmudrā into the Ratnagotravibhāga and Yogācāra works? The book assumes a high level of understanding of the issues and is meticulous in its detail and documentation; the footnotes have footnotes. Mathes argues that Gö's intention with his commentary was to provide a sūtra basis for Mahāmudrā, the otherwise tantric teaching of the Kagyu tradition. Gö was hard-pressed to justify the central teaching of their tradition against criticism by Prajñāpāramitā-based Madhyamaka adherents in the Sakya and Kadam/Geluk traditions. Sakya, Kadam, and Geluk writers argued either that the Ratnagotravibhāga was provisional—seeing it as a Yogācāra teaching in need of interpretation—or that its teaching on buddha-nature was in line with a Madhyamaka presentation of emptiness, denying the language-positive elements of the scripture.

Gö Lotsāwa rejected both of these positions, arguing that the Ratnagotravibhāga is consistent with other third-turning teachings and that such teachings are definitive. This was a necessary move in order to conflate cataphatic Yogācāra doctrine with Mahāmudrā: buddha-nature for Gö is not a synonym for emptiness but rather for "the unfabricated nature of mind" and "luminosity," core Mahāmudrā doctrine. But Gö differentiated his approach from that of other advocates of a Yogācāra interpretation. He argued against the notion that buddha-nature is fully formed in every sentient being (the "buddha qualities" discussion), advocating instead that buddha-nature is a potential that needs to be developed. We are not like golden statues hidden in mud, according to Gö. Rather, we are like acorns that need water and sunlight to grow into oak trees.

One of Mathes's valuable contributions is a survey of the extensive Tibetan commentarial tradition on the Ratnagotravibhāga, starting with Ngok Lotsāwa and continuing through the Third Karmapa, Dolpopa, Longchenpa, and others. Karl Brunnhölzl, in his 2014 book When the Clouds Part, similarly lays out a historical context to situate a new translation (the fourth into English) of the Ratnagotravibhāga. Like Mathes, Brunnhölzl, an accomplished translator and scholar who trained at Hamburg and Kathmandu, is primarily interested in the treatise and its meditative exegetical tradition as "a bridge between Sūtra and Tantra" (the phrase is Brunnhölzl's subtitle), and he translated eight additional short works relating to the Ratnagotravibhāga that emphasize the tantric or other-emptiness approach, including compositions by the Eighth Karmapa and Jamgon Kongtrul.

Where Mathes focuses almost entirely on the Tibetan precursors to Gö Lotsāwa's commentary, Brunnhölzl casts a wider net, surveying all Indian literature mentioned in the Ratnagotravibhāga and its main commentary, as well as situating it in its traditional Tibetan context of being one of the Five Books of Maitreya and its relationship with Yogācāra. All told, Brunnhölzl's explanatory essays run some 325 pages, preceding 500 pages of translation; this is followed by about 150 pages of appendices in which he delves into issues such as the commentarial tradition on specific verses, after which comes 350 pages of notes, glossaries, bibliography, and index. The book is, needless to say a massive piece of scholarship.

Matching Brunnhölzl's breadth of research is Kazuo Kano's spellbinding Buddha-Nature and Emptiness, published in 2016. It centers on Ngok Lotsāwa's commentary on the Ratnagotravibhāga but covers many Indian and Tibetan works. Kano studied under Katsumi Mimaki in Kyoto and David Jackson in Hamburg, both specialists in Indian and Tibetan Buddhism, and while the book is a revision of his dissertation, it is also the culmination of close to three dozen publications on related topics in Japanese and English. The book is by far the most thorough study of the literary history of the Ratnagotravibhāga in Indian and early Tibetan Buddhism. Kano introduces every related text and person, and he writes with exceptional detail and clarity. His section summaries are particularly welcome, given the complexity and extent of the material he covers. The book also serves as an encyclopedia of sorts, with lists of extant versions of the Ratnagotravibhāga and tables charting positions and commentaries.

Kano repeats the generally held opinion that the initial intention of buddha-nature theory was to ease fears of nihilism and encourage practice. It was not an ontological argument and not meant to be compared or merged with emptiness. This changed with the Ratnagotravibhāga and its defense of buddha-nature as definitive; its statements about the ultimate are not to be taken as rhetorical devices or soteriological encouragement. Kano further argues that the Indians working on the Ratnagotravibhāga were interested in tathāgatagarbha theory itself and not in making tathāgatagarbha conform to Madhyamaka or Yogācāra. It was Tibetans and Chinese who felt compelled to do this, something that has never been done satisfactorily.

Ngok Lotsāwa's commentary is perhaps the most widely read in Tibet, the central text in the so-called analytic tradition of Ratnagotravibhāga exegesis. Rather than downgrade the treatise to provisional status, as Candrakīrti and Sakya Paṇḍita did, Ngok interpreted it in a way that made it conform to Madhyamaka doctrine. Living at a time when Yogācāra had not yet been sidelined by Tsongkhapa and his disciples, Ngok was free to consider buddha-nature to be definitive. He equated buddha-nature with emptiness and yet also with the ālayavijñāna, although only so far as the nature of mind is empty and that emptiness is a nonaffirming negation; buddha-nature, he maintained, is beyond conceptual thought.

A fifth book on the Ratnagotravibhāga in Tibet is Tsering Wangchuk's The Uttaratantra in the Land of Snows, a clear and concise introduction to the history of the Ratnagotravibhāga and buddha-nature theory in premodern Tibet. It is an ideal introduction for anyone not yet familiar with the buddha-nature debate in Tibet. Wangchuk summarizes the writings and views of several of the most important Tibetan philosophers who weighed in on buddha-nature between the eleventh and fifteenth centuries, from Ngok Lotsāwa through Sakya Paṇḍita to Dolpopa and Gyaltsap Je. The advantage of Wangchuk's historical frame is that all assertions are nicely placed in the context of an opponent's or a supporter's writing, reminding the reader that buddha-nature theory in Tibet is an ongoing conversation, a debate between the two fundamental doctrinal poles of positive and negative descriptions of the ultimate. Wangchuk has also published several articles continuing this comparative approach to buddha-nature theory.

In addition to the continual focus on the Ratnagotravibhāga, scholars have increasingly explored buddha-nature theory in Tibet in the context of other-emptiness. Klaus-Dieter Mathes recently edited a special volume of the Journal of Buddhist Philosophy dedicated to other-emptiness, with contributions by many scholars who have been investigating buddha-nature theory in Tibet. Much of the inquiry has focused on the Jonang tradition: Mathes wrote on Tāranātha in 2004; Jeffrey Hopkins translated Dolpopa's Mountain Dharma in 2006, which is a central treatise on other-emptiness; and Cyrus Stearns revised and reissued his study of Dolpopa in 2010, The Buddha from Dolpo. A useful addition to these is Dorji Wangchuk's article on Nyingma interpretations of tathāgatagarbha and the other-emptiness/self-emptiness debate. The article has the added value of briefly surveying buddha-nature discussions in early Tibet, a topic that has been overlooked save by David Seyfort Ruegg in his 1973 book.

Douglas Duckworth, a professor at Temple University, has published extensively on the philosophy of other-emptiness. Some articles are comparative, such as "Onto-theology and Emptiness: The Nature of Buddha-Nature” and "Grounds of Buddha-Nature in Tibet,"—one of the best short surveys of the doctrine. Most of his publications, however, have been either on Jonang other-emptiness or on the writings of Ju Mipam Gyatso, the great nineteenth-century Nyingma philosopher.

Both Mathes and Brunnhölzl have also published on the buddha-nature writings of the Eighth and Third Karmapas, respectively. Brunnhölzl's 2008 book is a collection of not only buddha-nature compositions of the Third Karmapa but also of later authors such as Jamgon Kongtrul, who commented on the hierarch's works. With current and former students, Mathes is currently undertaking a multiyear research project on the Eighth Karmapa and recently completed another project titled "'Emptiness of Other' (Gzhan stong) in the Tibetan 'Great Seal' (Mahāmudrā) Traditions of the 15th and 16th Centuries." Among the results of the first project is a remarkable comparative study by David Higgins and Martina Draszczyk on the works of Karma Trinle Chokle Namgyal, the Eighth Karmapa, the Fourth Drukchen Pema Karpo, and Śākya Chokden entitled Mahāmudrā and the Middle Way. Their book on the Eighth Karmapa came out in 2019.

The last of these classical authors, Śākya Chokden, stands out for his ecumenical and unique interpretation of other-emptiness and buddha-nature. Yaroslav Komarovski, a professor at the University of Nebraska-Lincoln, has published extensively on this iconoclastic Sakya master. His 2011 book Visions of Unity offers fascinating insights into the Tibetan attempts to reconcile Yogācāra and Madhyamaka. Śākya Chokden was a passionate critic of Tsongkhapa who stridently accused the Geluk patriarch of spreading nihilism to his own beloved Sakya tradition. Śākya Chokden was himself a follower of Madhyamaka, but he embraced many elements of Yogācāra; his attempt at a synthesis was to reclassify the different strands of Yogācāra and Madhyamaka so as to combine those that he embraced and dispense with those he did not. Although his writings were recognized for their brilliance, his criticisms of Tsongkhapa and Sakya Paṇḍita and his qualified acceptance of other-emptiness meant that he was almost entirely rejected by his Sakya peers. Komarovski has also published translations of Śākya Chokden's works, with another in process. His articles on Śākya Chokden have touched on his interpretation of the Ratnagotravibhāga and on other-emptiness.

The Ratnagotravibhāga, while certainly the most important Indian tathāgatagarbha scripture, is not the sole classical source on the doctrine. In the last two decades important translations and examinations of the buddha-nature theory of some of these other scriptures have been published. In his study of the Tathāgatagarbhasūtra, Michael Zimmermann, a professor at the University of Hamburg, agrees with earlier scholarship that the sūtra was intended as an ethical treatise—an encouragement to pursue enlightenment—rather than a philosophical argument on the nature of the ultimate. The first hundred pages of his book are Zimmermann's commentary on the sūtra and its place in Indian, Chinese, and Tibetan Buddhism. He suggests that there were two recensions of the scripture in India, of which the earlier went to China and the later was translated twice into Tibetan. Key to his argument is that the Chinese translations do not contain the first simile of a pure white lotus growing in a muddy swamp; he argues that this, the sole passage to use the term tathāgatagarbha, was thus added later, after the term had gained popularity in India. Zimmermann surveys the doctrinal issues raised by the scripture, including the relationship between buddha-nature theory and Yogācāra in China, and other-emptiness in the Tibetan context. The remainder of the book is an analysis of each recension and translation, an English translation incorporating all recensions and translations and a critical edition of the Tibetan and Chinese; there is no surviving Sanskrit version. Zimmermann continues to excavate the early history of buddha-nature theory in India, most recently with an article titled "The Process of Awakening in Early Texts on Buddha-Nature in India."

Michael Radich, a professor at the University of New Zealand, published a study of the Mahāparinirvāṇasūtra in 2015 in which he claims, counter to previous belief, that the Mahāparinirvāṇasūtra contains the earliest appearance of the term tathāgatagarbha. Similar to the way Yogācāra built on emptiness theory with positive descriptions of the ultimate, the Mahāparinirvāṇasūtra, Radich argues, offered a positive (albeit somewhat familiarly misogynistic) solution to the origin of buddhahood: because buddhas could not be conceived of as having been generated out of a human womb, they were given metaphorical wombs—garbha—that are somehow present in all sentient beings. Radich presents his argument alongside meticulous and extensive textual analysis to support his dating of the Mahāparinirvāṇasūtra to earlier than the Tathāgatagarbhasūtra. Other translations of the Mahāparinirvāṇasūtra include those by Mark Blum and Kosho Yamamoto. Stephen Hodge has published many valuable lectures and articles on the sūtra on his website.

Jonathan Silk's Buddhist Cosmic Unity: An Edition, Translation and Study of the Anūnatvāpūrṇatvanirdeśaparivarta is the first study of a tathāgatagarbha sūtra that exists only in Chinese translation, although it was (eventually) known to Tibetans through extensive quotations in the Ratnagotravibhāga. In addition to an informative introduction in which Silk takes on the meaning of tathāgatagarbha and its relationship to dharmakāya and dharmadhātu, he provides appendices on philological puzzles and textual citations of the sūtra. Christopher Jones, who recently completed a dissertation on tathāgatagarbha theory, has also published on the Anūnatvāpūrṇatvanirdeśaparivarta, in a comparison with the Mahābherīsūtra, as well as on the Aṅgulimālīyasūtra. The articles are valuable for, among other things, the discussion of the use of the term ātman; Jones argues that the scriptures’ use of the term was not a capitulation to non-Buddhist theories of self, but precisely in order to differentiate Buddhist tathāgatagarbha theory from those non-Buddhist doctrines.

Not all early twenty-first-century scholarship on buddha-nature is in an Indian and Tibetan context. Continuing his scholarship on East Asian apocrypha and Buddhism in Korea, in 2016 Robert Buswell published a study and translation of Wǒnhyo's commentary on the *Vajrasamādhisūtra. Wǒnhyo believed that the *Vajrasamādhisūtra was the scriptural basis for the Awakening of Faith, on which he had previously written a commentary, although scholars have since shown that it is a Korean composition, dating to possibly only a few years before Wǒnhyo's death in 686. Where the earlier commentary was dedicated to the abstract doctrines of "one mind and two aspects"—that is, original enlightenment and actualized enlightenment—in the *Vajrasamādhi commentary, Buswell explains, Wǒnhyo endeavored to provide a system for putting original enlightenment into practice. Wǒnhyo describes six techniques that culminate in "immaculate consciousness" (amalavijñāna), in which saṃsāra and nirvāṇa are united in a "single taste." One of Wǒnhyo's innovations is the notion that buddha-nature is both an active and passive principle, concealed under the obscurations yet actively encouraging sentient beings toward enlightenment.

Much of the recent writing on East Asian buddha-nature theory has been on the delightful topic of the buddha-nature of insentient objects. Needless to say, this is a topic that has left most Western scholars a bit puzzled. Berkeley professor Robert Sharf suggested in a 2014 essay that the question of whether grass and trees have buddha-nature, as it is most commonly formulated, is a thought experiment, a hypothetical that tests the implications and extent of difficult pieces of doctrine. Sharf is critical of buddha-nature theory, considering, much like Matsumoto Shirō and Hakamaya Noriaki, that Buddhism lost its way when it incorporated positive-language doctrine, and he would prefer that, if we have to consider such ideas, we take them as games rather than truth claims—as science fiction rather than factual. That the buddha-nature of grass and trees is a logical, if (to many) absurd, result of buddha-nature theory is for Sharf a reason to set aside buddha-nature altogether.

In his essay, a chapter in a book on the Indic origins of Chinese Buddhist thought, Sharf acknowledges a debt to Lambert Schmithausen's 2009 Plants in Early Buddhism and the Far Eastern Idea of the Buddha-Nature of Grasses and Trees. Schmithausen's book is similarly comparative, mining the Indian classics for references to the sentience of plants and for the roots of East Asian notions of vegetative buddha-nature. In the first half of the book, Schmithausen surveys Indian Buddhist literature and concludes that, for the most part, plants were seen as growing in a space between sentient beings and inanimate matter. In the second half of the book, Schmithausen dispenses with early Chinese writing on the topic, deeming it to be of native stock, and focuses instead on the writings of Jizang (549–623), Chan master Nanyang Huizhong (南陽慧忠, 675–775), and Jingxi Zhanran (荊溪湛然 711–82), three Buddhist exegetes who sought justification for his theory of the buddha-nature of grass and trees in Indian sources.

Chinese Buddhism, as with Buddhisms in all cultural regions, was translated using indigenous terms, many of which had centuries of signification. Scholars of buddha-nature are no strangers to this reality; a recent example is Adrian Chih-mien Tseng's 2014 doctoral dissertation at McMaster University, which is a recent study of the Daoist roots of the notion of the buddha-nature of inanimate objects, a particularly East Asian extension of the universality of buddha-nature. As Sharf and other scholars have noted, it was probably Daosheng (道生360–434) who was the first theorist to insist on universal buddha-nature, including both animate and inanimate objects. Indian tathāgatagarbha scriptures were ambivalent at best on the topic, and the Ratnagotravibhāga had yet to be composed. The Yogācāra doctrine of three natures held that certain classes of beings were not able to attain buddhahood. Drawing from other scriptures such as the Avatamsaka, Chinese scholiasts understood the phenomenal world to be pervaded by the dharmakāya; if all things are the body of the buddha, then the logical conclusion is that all objects have buddha-nature. Moreover, Yogācāra doctrine that all phenomena are mind, when paired with tathāgatagarbha theory that all mind is buddha-nature, resulted in the conclusion that all phenomena, sentient or otherwise, have buddha-nature. Theorists also turned to the doctrine of nonduality and the two truths; distinguishing sentience and insentience is dualistic thinking, and from an ultimate perspective the difference does not exist. From a relative perspective, since insentient things such as grass and trees and even roof tiles have no mind, they have never fallen into ignorance and are therefore enlightened already. Buddha-nature theory combined with universal dharmakāya leads logically to a world in which insentience is equivalent to enlightenment. Hence the famous Chinese aphorism that roof tiles and chrysanthemums preach the Dharma.

Later Chinese writers attempted to solve this absurdity by distinguishing between buddha-nature that knows (restricted to living beings, this is the capacity to become enlightened) and buddha-nature that is known (the dharmatā, which is universal across all phenomena and does not have the capacity for enlightenment). Precisely because they do not have mind, and therefore do not have delusion, insentient objects cannot become enlightened; if one is not dreaming, one cannot wake up from a dream. They may have buddha-nature, but it is not the right kind to bring one to buddhahood. As Sharf explained in his 2007 essay "How to Think with Chan Gongans," the above doctrinal conundrum over the buddha-nature of grass and trees was the historical and theoretical context for the famous Zhaozhou's dog koan. (A monk asked Zhaozhou: "Does a dog have buddha-nature?" Zhaozhou replied: "No.")