My thinking on the Heart Sutra was probably due for an overhaul, and I have been fortunate recently to correspond with an academic who has taken an interest in the Heart Sutra. This has led me to rethink some aspects of the "Chinese origins" thesis.
In particular, I have been thinking about what has been proven or (better) established about the history of the Heart Sutra. By "established" here, I think more of the legal criteria of proving something beyond reasonable doubt. I don't mean perfect and eternal certainty, since nothing in ancient history is ever that certain. I mean "established" in the sense that if a fair-minded person with the appropriate background knowledge and skill, would examine the evidence we have presented, they would agree that our methods are both practicable and applicable, and would come to the same, or very similar, conclusions. With the caveat that all conclusions are subject to revision if new information comes along.
So what have Watanabe Shōgo, Jan Nattier, Matthew Orsborn (aka Huifeng), and I actually proven, in this sense? I think three propositions can be regarded as well-established historical facts.
- Two passages in the Chinese Heart Sutra were copied from the Chinese Large Sutra translation by Kumārajīva (T 223).
- The Sanskrit Heart Sutra was translated from a Chinese source.
- The Heart Sutra enters the historical record in a Chinese document dated to 25 Dec 656 CE.
While I have made larger claims in the past, my recent correspondence has prompted me to clarify what seems certain and what is speculative.
1. The Chinese Heart Sutra copied two passages in Chinese
from the Large Text translation by Kumārajīva.
It was common knowledge amongst the early Tang commentators—by Kuījī 窺基 (T 1710), Woncheuk 圓測 (T 1711), Jìngmài 靖邁 (X 522), Fǎzàng 法藏 (T 1712), Huìjìng 慧浄 (X 521) and Zhishen 智詵 (Dunhuang ms.*)—that (at least some of) the text of the Heart Sutra was extracted from another Prajñāpāramitā text, with some of them specifically naming the Large Sutra. So this part of the thesis should be uncontroversial (and as far as I know, it is).
* The text of Zhishen's commentary has appeared in a Japanese publication by Yanagida and was used in a Japanese language study by Cheng (2007). On which see Notes on Zhishen's Heart Sutra Commentary (23 August 2024).
The two passages that we have identified are what Nattier called the "core section" and the "epithets section". Below I put the versions of the core section alongside each other, further broken down into three sections. As Nattier noted, you don't actually need to understand Chinese or Sanskrit at this point, you can follow this argument on pattern recognition alone.
Chinese
When we compare the two versions of the passage in the Chinese Heart Sutra and Kumārajīva's Mohe jīng, they are nearly identical on a character-by-character basis. The two texts have been punctuated differently in CBETA, so I have standardised this to make the comparison easier. I have highlighted the differences.
| T 251 | T 223 |
|
舍利子，色不異空，空不異色， 舍利子，是諸法空相，不生不滅，不垢不淨，不增不減。
|
舍利弗，非色異空，非空異色， 舍利弗，是諸法空相，不生不滅、不垢不淨、不增不減。 [是空法非過去、非未來、非現在]*， * bracketed parts are omitted from T 251 |
There are two main types of difference here: omissions and amendations.
Omissions
There are two large omissions: (1) A whole line in the middle is omitted. (2) The final section is cut short, so that, after mentioning zhì 智 "knowledge" and dé 得 "attainment", T 223 carries on to give examples of each. This section is complicated by Kumārajīva appearing to mistranslate na prāptir nābhisamayaḥ “no attainment, no realisation”. The significance of the phrase is still visible in T 223, however, which carries on to say:
亦無須陀洹無須陀洹果，無斯陀含無斯陀含果，無阿那含無阿那含果，無阿羅漢無阿羅漢果，無辟支佛無辟支佛道，無佛亦無佛道。
"There is no stream-enterer, no fruit of stream-entry; no once-returner, no fruit of once-returning; no non-returner, no fruit of non-returning; no arhat, no fruit of arhatship; no pratyekabuddha, no path of pratyekabuddha; no buddha, and no path of buddhahood."
This fits well with the Sanskrit text of the Gilgit manuscript (see below). The "stream-enterer" (須陀洹), "once-returner" etc are examples of prāpti "attainment", while the fruit (guǒ 果) of Stream Entry, etc are examples of abhisamaya "realisation".
We are more used to seeing the terms "path" (marga) and "fruit" (phala) here or, in Chinese, the sìxiàng sìguǒ 四向四果 "four accesses and four realisations". The sìxiàng 四向 are: 須陀洹 "stream-enterer", 斯陀含 "'once-returner", 阿那含 "non-returner", and 阿羅漢 "arhat", and sìguǒ 四果 are the guǒ 果 (fruit) of these. To this list, T 223 adds the pìzhī fó 辟支佛 "pratyeka buddha" and the fó 佛 "buddha". The list in Pañc also has an entry for the bodhisatva and the fruit of bodhisatva-hood.
Amendations
Where the text of T 251 is amended, words and phrases are changed from Kumārajīva's translation idiom to Xuanzang's translation idiom, i.e. Shèlìfú 舍利弗 becomes Shèlìzi 舍利子; and fēi sè yì kōng, fēi kōng yì sè 非色異空，非空異色 becomes sè bù yì kōng, kōng bù yì sè 色不異空，空不異色. The first expression negates the idea that 色 and 空 are different, while the second states that 色 and 空 are not different. It's just two ways of saying the same thing.
Note that my view on the latter change has shifted from what I wrote in Attwood (2021: 25-26). It has become clear from new notes added by CBETA to T 1858 that 非色異空，非空異色 is the version of the phrase in T 223. Thus, this difference appears to be better explained as another case of the text being amended to fit Xuanzang's idiom. See also the discussion on CBETA.
In any case, even without knowing Chinese, we can see that the two Chinese texts are substantially the same and, where they are different, we have a simple explanation of why they are different. As we will see, the relationship between the two Sanskrit texts is very different indeed.
Sanskrit
Below is the core passage in Sanskrit, using the revised edition I published earlier this year and the text of Pañc transcribed by Zacchetti (2005:393) from the Gilgit manuscript (actually one of three, but only one has been published and then only in a facsimile edition). Again, even without knowing any Sanskrit, one can see that the two texts have some very different choices of words and idioms.
| Hṛd | Pañc (Gilgit) |
|
[iha] śāriputra rūpameva śūnyatā śūnyataiva rūpaṃ rūpān na pṛthak śūnyatā śūnyatāyā na pṛthag rūpaṃ | evam eva vedanā-saṃjñā-saṃskāra-vijñānaṃ || |
na hi śāradvatīputrānyad rūpam anyā śunyatā nānyā śunyatānyad rūpam rūpam eva śunyatā śunyataiva rūpam evaṃ nānyā vedanānyā śunyatā | nānyā saṃjñā nānyā śunyatā | nānye saṃskārā anyā śunyatā | nānyad vijñānam anyā śunyatā | nānyā śunyatānyad vijñānaṃ | vijñānam eva śunyatā śunyataiva vijñānaṃ | |
|
[iha] śāriputra sarvadharmāḥ śūnyatālakṣaṇā anutpannā aniruddhā amalā avimalā anūnā aparipūrṇāḥ || |
yā śāradvatīputra śunyatā na sā utpadyate na nirudhyate | na saṃkliśyate na vyavadāyate | na hīyate na vardhate | [nātītā nānāgatā na pratyutpannā |]* |
|
[tasmāc chāriputra śūnyatāyāṃ]* na rūpaṃ na vedanā na saṃjñā na saṃskārāḥ na vijñāna, |
na tatra rūpaṃ na vedanā na saṃjñā na saṃskārā na vijñānaṃ |
na caksuḥśrotraghrāṇajihvākāyamanāṃsi; na rūpaśabdagandharasaspraṣṭavyadharmāḥ |
na cakṣur na śrotraṃ na ghrāṇaṃ na jihvā kāyo na manaḥ na rūpaṃ na śabdo na gandho na raso na sparśo na dharmāḥ |
[na tatra skandhā na dhātavo nāyatanāni]* | |
na cakṣurdhātur yāvan na manovijñānadhātuḥ |
na tatra cakṣurdhātur na rūpadhātur na cakṣurvijñānadhātur na śrotradhātur na śabdadhātur na śrotravijñānadhātuḥ na ghrāṇadhātur na gandhadhātur na ghrāṇavijñānadhātur na jihvādhātur na rasadhātur na jihvāvijñānadhātuḥ na kāyadhātur na spraṣṭavyadhātur na kāyavijñānadhātur na manodhātur na dharmadhātur na manovijñānadhātur |
nāvidyā nāvidyākṣayo yāvan na jarāmaraṇaṃ na jarāmaraṇakṣayo |
na tatrāvidyā nāvidyānirodhaḥ na saṃskārā nna saṃskāranirodhaḥ na vijñānaṃ na vijñānanirodhaḥ na nāmarūpaṃ na nāmarūpanirodhaḥ na ṣaḍāyatanaṃ na ṣaḍāyatananirodhaḥ na sparśo na sparśanirodhaḥ na vedanā na vedanānirodhaḥ na tṛṣṇā na tṛṣṇānirodhaḥ nopādānaṃ nopādānanirodhaḥ na bhavo na bhavanirodhaḥ na jātir na jātinirodhaḥ na jarāmaraṇaṃ na jarāmaraṇanirodhaḥ |
na duḥkhasamudayanirodhamārgā |
na duḥkhaṃ na samudayo na nirodho na mārgaḥ |
| na jñānam na prāptiḥ || * not present in Pañc |
na prāptir nābhisamayaḥ [na srotaāpanno na srotaāpattiphalaṃ na sakṛdāgāmī na sakṛdāgāmiphalaṃ nānāgāmī nānāgāmiphalaṃ nārhan nārhatvam na pratyekabodhir na pratyekabuddhaḥ na tatra mārgākārajñatā na bodhisatvaḥ na tatra bodhir na buddhaḥ]* *bracketed sections omitted from Hṛd |
One of the main developments within the Prajñāpāramitā literature was the expansion of abbreviated passages. So for example, an abbreviated list of dhātu found in Hṛd: na cakṣurdhātur yāvan na manovijñānadhātuḥ (where yāvan means something like et cetera or "and so on, up to"). In Pañc we get the unabbreviated list:
na tatra cakṣurdhātur na rūpadhātur na cakṣurvijñānadhātur
na śrotradhātur na śabdadhātur na śrotravijñānadhātuḥ
na ghrāṇadhātur na gandhadhātur na ghrāṇavijñānadhātur
na jihvādhātur na rasadhātur na jihvāvijñānadhātuḥ na
kāyadhātur na spraṣṭavyadhātur na kāyavijñānadhātur
na manodhātur na dharmadhātur na manovijñānadhātur.
This kind of difference is not problematic, since we know our witnesses of Pañc are ~250 years later than the version that Kumārajīva had. And this kind of change is exactly what we expect. Moreover, the general gist of the Gilgit passage is identical in the later Nepalese manuscripts edited in the Kimura edition of Pañc, with only minor differences.
The point I wish to make is that, even allowing for expansion over time, the core passage found in Hṛd cannot have been copied from Pañc or any text like Pañc. I will look at the details of some of the differences below, but here we are simply looking at whether Hṛd could have conceivably been copied from a version of Pañc (likely one with more abbreviations). If you are comparing them, focus on the first two parts above. See how the words and phrasing are considerably different,
There's only one plausible conclusion here since only one chain of events can explain this pattern of differences. The copying cannot have happened in Sanskrit because the Hṛdaya is clearly not a copy of any known text of Pañc; nor could it be a copy of some unknown text affected by known processes such as the expansion of abbreviated passages. The copying happened in Chinese.
An argument can be made that "any known text" is too narrow. Some people appear to believe that a version of the Large Sutra text must have existed in which the copied passage is the same as the Heart Sutra. It is true that these texts changed over time. However, it's they did not change at random. Rather the Large Sutra changed in relatively predictable ways, by far the most common was the expansion of abbreviated passages. Importantly, however, no matter what changes we find between versions, the whole text of Pañc was always in idiomatic Buddhist Sanskrit.
The changes we find between Sanskrit Heart Sutra and Sanskrit Large Text don't fit such known patterns of change. The Sanskrit Heart Sutra frequently diverges from well-known Sanskrit idioms. If it had to draw from a Sanskrit original, then we have to posit a whole lineage with nonstandard locutions which spawned their own lineage of Prajñāpāramitā but died out before anyone noticed them, but not before the Heart Sutra was composed and left no trace of its existence in India. Even if we didn't already have a much simpler answer, this scenario is far too convoluted to be plausible.
Arguments from absence are weak, but especially weak when the absent thing has been invented in the absence of evidence in the first place. Occam's Razor counsels us against inventing new entities to explain our evidence.
Everyone accepts that the copying took place. We know that Chinese Buddhists had already been copying passages from Buddhist texts for centuries. They copied passages to make inscriptions, for example, and to make handy summaries of long texts, or to carry around with them for the putative magical benefits. We also know that extracts of texts—either in the form of digest texts (chāo jīng 抄經) or parts of texts that circulated independently (bié shēng 別生) such as the Guānyīn jīng «觀音經» (a chapter of the Miàofǎ Liánhuá jīng «妙法蓮華經» or Lotus Sutra)—were common. Copying passages is an everyday routine operation in Chinese Buddhism. There is absolutely nothing strange about Chinese Buddhists copying passages.
The simplest solution is the best solution: the copied passages were copied in Chinese. This is straightforward, historically plausible, and explains all the facts that we have.
Of course, it is tempting to expand on this, and in the past, I have done so without much hesitation. But such expansions are conjectural. It is logical to assume that if one part of the text was composed in Chinese then the rest of it must have been also. But this is not proven, this is an open conjecture.
The likelihood is that the whole text was composed in Chinese. The fact is that the copied passages were copied in Chinese. Since these copied passages amount to about half the text, we have also proved that this half of the text was composed in Chinese.
2. The Sanskrit Heart Sutra was translated from a Chinese source.
We now shift focus to certain details of the Sanskrit texts, comparing the idioms in Hṛd with its parallels in Pañc with the aim of showing that the Sanskrit text in Hṛd is more plausible as a translation of a Chinese source.
Nattier (1992: 170) noted some diagnostic criteria for back-translations. These include “unmatched but synonymous equivalents” for some Sanskrit terms and “incorrect word order, grammatical errors that can be traced to the structure of the intermediary language, and incorrect readings (due to visual confusion of certain letters or characters in the intermediary language)”.
2.1. The first passage to look at is part of the famous phrase usually translated as "form is not different from emptiness".
| Hṛd | Pañc (Gilgit) |
|
rūpān na pṛthak śūnyatā śūnyatāyā na pṛthag rūpaṃ |
nānyā śunyatānyad rūpam rūpam eva śunyatā śunyataiva rūpam |
Again, even without a detailed knowledge of Sanskrit, one can see that, apart from certain jargon terms, both the words and the phrasing of Hṛd are quite different from Pañc. And this is definitely not an example of the kind of change that we expect to see over time. The manuscripts show that this type of idiom is stable over time and Prajñāpāramitā has a very strong preference for one over the other.
Hṛd has the syntax Y na pṛthak X, where Y is a noun in the ablative case (indicating "from Y") and na pṛthak means "not different". Hence, Y na pṛthak X means "X is not different from Y" (though English translations often get the word order wrong). This expression is not used in Pañc or Aṣṭa, though contra my previous assertions, pṛthak does occur as a standalone term in Pañc. Rather such comparisons are made using the formula: na anya X anya Y. Here anya "other" is a pronoun. A literal translation is not that helpful, but the idiom means "X is not other than Y". Sometimes I translate this as "It's not that X is one thing and Y another".
The two texts use different idioms to say the same thing. More than this, however, the idiom found in Pañc is widely used in Prajñāpāramitā literature, and other idiom is found only in Hṛd (To the best of my knowledge). As noted, this means that the copying happened in Chinese. The synonymous expression with unidiomatic wording is Nattier's "leading indicator" of a back-translation.
The Chinese expression fēi sè yì kōng 非色異空 is a conceivable translation of either rūpān na pṛthak śūnyatā or nānyā śunyatānyad rūpam.
2.2. The second example shows a much greater set of differences, not all of which are simply a choice of idiom.
|
iha śāriputra sarvadharmāḥ śūnyatālakṣaṇā anutpannā aniruddhā amalā avimalā anūnā aparipūrṇāḥ || |
yā śāradvatīputra śunyatā na sā utpadyate na nirudhyate | na saṃkliśyate na vyavadāyate | na hīyate na vardhate |
We need not dwell on the two different forms of the name—Śāriputra and Śāradvatīputra—since these are known to vary in Mahāyāna texts, meaning that this is not a diagnostic criterion.
The subjects of the two phrases are different. The sentence in Hṛd is about "all phenomena" (sarvadharmāḥ), while the sentence in Pañc is about "absence" (śūnyatā). Hṛd is generally read as saying that "all phenomena" are qualified by a series of three pairs of adjectives, necessarily in the plural. In Pañc, by contrast, "absence" is qualified by a series of three pairs of verbs in the singular present indicative. However, it is also possible to read Hṛd as saying that all dharmas are qualified by (-lakṣana) an absence (śūnyatā) and that absence is unarisen, unceased, etc.
And in the light of Pañc, I think this latter reading is preferable, but it doesn't change the point here.
The set of six adjectival qualifiers in Hṛd is found nowhere else in Prajñāpāramitā literature. One pair, anutpannā aniruddhā does occur elsewhere, but the other two adjectives are not found paired anywhere in the literature. By contrast, the set of six verbs does occur elsewhere in Prajñāpāramitā, and all of the pairs often occur independently as well.
Again, we have two distinct idioms. The idiom of Hṛd is confined to Hṛd alone, and the idiom in Pañc is simply a standard Buddhist Sanskrit idiom. As Nattier (1992: 170) pointed out, this pattern of differences in Hṛd bears all the hallmarks of a “back-translation”.
2.3 Huifeng (2014) noted, amongst other pertinent observations that yǐwúsuǒdégù 以無所得故 was Kumārajīva's translation of anupalambhayogena, whereas Hṛd has aprāptivāt.
While aprāptitvāt looks plausible based on the idea that dé 得 "attain" was used to translate Sanskrit words from pra√āp "attain", in fact, closer analysis shows that the verb here is a binomial, suǒdé 所得, which both Kumārajīva and Xuanzang use to translate words from √labh "obtain", particularly upa√labh "apprehend". In Sanskrit to apprehend an idea is to grasp it, obtain it, and understand it mentally. The cognitive metaphor here is IDEAS ARE OBJECTS (we have this same cognitive metaphor in English also). Once we make this equivalence we can metaphorically apply to ideas any action that applies to objects.
This word anupalambhayogena also provides an important key to understanding Prajñāpāramitā and forms the basis of my exegesis of the text (Attwood 2022)
2.4 I've made two contributions to this part of the project. Attwood (2017) shows, following a note in Nattier's article, that the original vidyā becomes mantra, with the Chinese míngzhòu 明呪 or zhòu 呪 providing the intermediary. And Attwood (2018) showed that the Sanskrit phrase tryadhvavyavasthitāḥ sarvabuddhāḥ "all buddhas of the three times" is a calque of the Chinese Sānshì zhū fó 三世諸佛, where we expect: atītānāgatapratyutpanna "past, future, and present" (Attwood 2018).
2.5 Compare also Hṛd nāvidyā nāvidyākṣayo and Pañc: na tatrāvidyā nāvidyānirodhaḥ. For me, this is the most iconic difference. We know that avidyā "ignorance" is the root condition for the whole nidāna sequence in the forward (anuloma) direction that leads to birth and death. In in the reverse direction, avidyā-nirodha the cessation of ignorance is the final step in liberating oneself from birth and death. And Indian Buddhist texts universally (across Pāli, Sanskrit, and Gāndhārī), with only one exception, speak of avidyā-nirodha. The exception is the Sanskrit Heart Sutra, which has avidyā-kṣaya.
Note that although Harada Waso (2002) claims to have found a discussion of avidyā-kṣayatva in the Aṣṭasāhasrikā, in fact, the whole passage he cites concerns the opposite of kṣaya, namely akṣaya "indestructible". (Cf Conze's translation 1973: 271 where he translates akṣaya as "inexhaustible").
Conclusion
There is a pervasive pattern of differences between Hṛd and Pañc. Not only is Hṛd not a copy from Pañc, Hṛd is largely an unidiomatic paraphrase of Pañc, where only well-known (and stable) Buddhist technical terms are unchanged. This is consistent with Hṛd being a back-translation from a Chinese Heart Sutra. It is not consistent with any scenario in which the Hṛd was composed in India or in Sanskrit. Moreover, in each case, the Chinese text is a plausible intermediary between the two different Sanskrit phrases and explains why the Sanskrit in the Heart Sutra is so peculiar.
However, there are a number of passages that make the source text uncertain. For example, in the first sentence, there is no Sanskrit counterpart of the Chinese expression dù yīqiè kǔ è 度一切苦厄. The omission is problematic, but in such a way as to complicate the picture, not as a refutation.
It is, therefore, a well-established historical fact that the core section and the epithets sections of Hṛd were translated into Sanskrit from Chinese. We have reason to be confident that the rest of the Sanskrit text is translated from Chinese as well since neither anupalambhayogena nor tryadhvavyavasthitāḥ sarvabuddhāḥ occurs in the core or the epithets section.
3. The Heart Sutra enters the historical record in a Chinese document dated to 25 Dec 656 CE.
Establishing this proposition as a fact is more difficult because we have conflicting historical records and scholarly opinions. The majority of scholars put the composition of the Heart Sutra in the third or fourth century CE, but we regularly see other dates from the first to the seventh century CE.
However, unbeknownst to the English-speaking world, the year before Nattier published her paper, the Japanese scholar Watanabe Shōgo (1991) had already made a huge contribution. Using entries in Chinese catalogues of Buddhist texts in translation, Watanabe was able to show that we can discount all the stories of older or lost translations. The oldest text we know of is T 251.
This is confirmed by two surveys of the oldest Heart Sutra inscriptions in China: Wang (2010) and He & Xu (2019). Of the two dozen or so Tang Dynasty Heart Sutra inscriptions, all have the text of T 251, though many have minor character substitutions that don't change the meaning or the pronunciation. This is followed by a rapid expansion in the number of inscriptions, commentaries, catalogue entries, and other kinds of evidence in China. These surveys confirm that the first physical evidence of the Heart Sutra is the stele from Fangshan dated 13 March 661 CE.
There is a mention of the title in Xuanzang's biography by Huili and Yancong (T 2053), in a letter from Xuánzàng 玄奘 (602–664) to Emperor Gāozōng 高宗 (15 July 649 – 27 December 683), dated 25 December 656 CE. Since Jeffrey Kotyk (2019) has shown that this letter is independently preserved elsewhere, we can credit this as the earliest mention of the title of the Heart Sutra, though note that this tells us nothing about the content of the text mentioned.
There is no physical evidence of the Heart Sutra from India, not a single scrap of manuscript has ever been identified (and given how idiosyncratic Hṛd is, a scrap with, say, avidyākṣaya on it would be sufficient). No other kind of evidence has turned up either: the title Prajñāpāramitāhṛdaya is never mentioned in any canonical or post-canonical Indian text, including several anthologies made using extracts of popular sutras. Absence of evidence is not evidence of absence, but if the Heart Sutra were an Indian text we would strongly expect to at least find some mention of it somewhere.
The Heart Sutra next turns up in the late eighth century in both Dunhuang and Tibet. This was at a time when Tibet ruled Dunhuang. While seven commentaries in Tibetan are credited to Indian Buddhists, some of these are clearly commenting on a Tibetan text (Horiuchi 2021). And the attributions have never been tested. Is the commentary attributed to, say, Kamalaśīla, consistent with other works known to have been composed by him? We don't know. And I suspect that when someone finally looks at this, they will find reasons to doubt all of these attributions. Part of the problem with these commentaries is that none of them includes a whole embedded text.
Thus in terms of the historical record, the first reliable evidence of the Heart Sutra's existence is the mention of the title by Xuanzang, on 25 December 656 CE. The first evidence of the content of the Heart Sutra is the Fangshan stele from 13 March 661 CE.
I have argued that the Heart Sutra cannot have existed before 654 CE when the Tuóluóní jí jīng «陀羅尼集經» (T 901). was translated by Atikūṭa. This is based on the idea that the Heart Sutra copied the dhāraṇī from this text, though my academic interlocutor has argued for an alternative conjecture that is not implausible. I therefore do not include this as an established fact, until we can get some clarity on this issue.
Conclusion
Based on these methods applied to this evidence, then, we can say that Watanabe, Nattier, Orsborn, and I have established three historical facts beyond reasonable doubt:
- Two passages in the Chinese Heart Sutra were copied from the Chinese Large Sutra translation by Kumārajīva (T 223).
- The Sanskrit Heart Sutra was translated from a Chinese source.
- The Heart Sutra enters the historical record in a Chinese document dated to 25 Dec 656 CE.
If anyone has a genuine way to dispute these facts I have yet to see it. I understand that many Buddhists find these facts unpalatable, but this is insufficient to falsify the facts. Polemics by Fukui, Harada, and Ishii make no dent in these facts.
To be clear, I think these facts are falsifiable. One simply has to find, for example, a manuscript or scrap of manuscript of the Sanskrit Heart Sutra from before the seventh century, or a much older Chinese witness. Or a previously unknown version of Pañc that is unidiomatic in the way that Hṛd is. Such evidence would be near miraculous, but if it turned up, we'd have to rethink things.
However, a historian composes a history based on the evidence at hand, not based on what might turn up in the future. "Black swan" events happen all the time, but the whole point of them is that we cannot predict them.
I believe that any open and fair-minded person would come to the same conclusion if they examined the evidence that we have published to date, using the (simple) methods that Nattier developed. Moreover, we now have quite a bit more evidence than Nattier had, and we have better access to the Sanskrit Pañc witnesses (Kimura's edition of the Nepalese and Karashīma et al's new facsimile edition of the Gilgit ms.)
These facts are consistent with comments made by the early Tang commentators, who were all associates of Xuanzang, but all took distinctly different approaches to the text. However, these facts are not consistent with the well-documented myth of the Heart Sutra. And so we are left with some mysteries: who created the Heart Sutra in the first place and for what purpose? Who translated the text into Sanskrit? Who added the extensions (and when and where)? We can fill some of these gaps with plausible conjectures, but in this essay, I wanted to focus on historical facts that can be considered established.
We could wish for more secondary literature on back-translations that was relevant. The problem is that back-translation has become a major tool for assessing the validity of translations, especially in sensitive areas such as translated medical advice pamphlets and for assessing machine translations. The literature on the application of back-translation is extensive, but I cannot find any other literature on back-translations in a situation such as we have with the Heart Sutra (I haven't given up, but wading through hundreds of irrelevant database hits is time-consuming and boring).
~~oOo~~
Bibliography
Dà Táng dà Cí’ēnsì sānzàng fǎshī chuán xù «大唐大慈恩寺三藏法師傳序» A biography of the Tripiṭaka Master of the Great Ci’en Monastery of the Great Tang Dynasty (T 2053). Translated into English by Li Rongxi (1995).
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Attwood, Jayarava. (2022) "The Cessation of Sensory Experience and Prajñāpāramitā Philosophy" International Journal of Buddhist Thought and Culture 32(1):111-148.
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Huifeng, Shi. [aka Orsborn, M.] (2014). "Apocryphal Treatment for Conze’s Heart Problems: “Non-attainment”, “Apprehension”, and “Mental Hanging” in the Prajñāpāramitā Hṛdaya." Journal of the Oxford Centre for Buddhist Studies 6: 72-105.
Nattier, Jan (1992). "The Heart Sūtra: a Chinese apocryphal text?" Journal of the International Association of Buddhist Studies. 15 (2) 153-223.
Watanabe, Shōgo 渡辺章悟 (1991). 経録からみた『摩訶般若波羅蜜神呪経』と『摩訶般若波羅蜜大明呪経』」印度学仏教学研究 39-1: 54–58. [“Móhē bānrě bōluómì shénzhòu jīng and Móhē bānrě bōluómì dàmíngzhòu jīng, As Seen in the Sutra Catalogues.” Indogaku Bukkyōgaku Kenkyū 39-1: 54–58.]
