Classical is Cooler

Many extravagant claims are made for quantum physics, and in comparison classical physics often seems to be dismissed, almost as though it is of little consequence.

Amongst other things, it has long bugged me that Buddhists hijack quantum mechanics and combine it with the worst of Buddhist philosophy—i.e. Madhyamaka—to create a monstrous form of bullshit. I've previously written three essays that try to address the perennial quantum bullshit that thrives amongst Buddhists.

• Erwin Schrödinger Didn't Have a Cat (29 October 2010).
• Buddhism and the Observer Effect in Quantum Mechanics (18 July 2014)
• Quantum Bullshit (05 October 2018)

Although, I don't seem to have had any appreciable effect on the levels of bullshit.

In this essay, I'm going to make an argument that classical physics is, in fact, much cooler than quantum physics, especially the bullshit quantum physics that doesn't use any mathematics

Life, the Universe, and Everything.

One way of describing the observable universe is to state the scales of mass, length, and energy it covers.

• The total mass of the observable universe is thought to be in order or 10⁵³ kg. From the smallest objects (electrons) to the whole universe is about 84 orders of magnitude (powers of ten).
• The observable universe is about 4 x 10²⁶ metres in diameter; and from the smallest possible length (the Planck length) to the whole is about 61 orders of magnitude.
• E=mc² gives the total energy of the universe as about 10⁷⁰ joules, and covers about 61 orders of magnitude.

Human beings can perceive roughly 18 orders of magnitude of mass, 12 of length, and 11 of energy, roughly in the middle of each scale. Much of the universe is imperceptible to our naked senses. Human beings evolved and thrived for hundreds of thousands of years without knowing anything beyond what we could see, hear, smell, taste, or touch with our naked senses.

It was the invention of the ground glass lens that alerted us to the existence of both larger scales (telescope) and smaller scales (microscope). And for this reason I count the lens the most significant invention in the history of science. I know people count Copernicus as the first European scientist, but to my mind he was merely a precursor. Galileo was the first to make systematic observations and thereby discover new things about the universe, e.g. acceleration due to gravity is a constant, the moon's surface is not smooth but cratered, and that Jupiter has satellites. Note that Galileo did not have evidence or a good case for a "heliocentric universe" (and his ideas about this were wrong in several ways, but that's another story).

400 years later, we have a number of hugely successful theories of how the universe works. We've identified four fundamental forces and two kinds of particle: fermions and bosons. However, no single approach to physics can cover all the many orders of magnitude. All of our explanations are limited in their scope. Newtonian mechanics fails with large masses or high relative velocities. Relativity fails on the nanoscale and especially at the time of the big bang. Quantum physics fails on the macro-scale.

Physicists still hope to find a way of reconciling relativity and quantum physics, which they predict will produce a single mathematical formalism that can describe our universe at any scale. After more than a century of trying, we don't seem to be any closer to this. To be fair a lot of time, effort, and resources went into pursuing so-called "string theory" which has proven to be a dead end, at least as far as reconciling nano and macro physics. 

What I want to do in the rest of this essay is contrast classical physics and quantum physics.

Classical Physics

Classical physics is a primarily a description of the world that we perceive. As such, classical physics will always be salient and applicable to our lives. When we need a lever to move something, we use classical physics. When we want to describe the universe on the largest scale, we use classical physics. This means that classical physics is largely intuitive (even if the maths is not). 

Classical physics is testable and has been extensively tested. While it was never my favourite subject, I studied physics as a distinct subject for four years up to undergraduate level and in that time I did many experiments. I was able, for example, to observe the applicability of ideas like Newton's laws of motion. 

I have personally observed that m₁v₁ = m₂v₂ (i.e. momentum is conserved). And you can too, if you put your mind to it. Classical physics is highly democratic in the sense that anyone can test its predictions relatively easily.

Classical physics shows that the universe (on this scale) follows relatively simple patterns of evolution over time that can be written down as mathematical statements. In the 19th century, such expressions were called "laws". By the mid 20th century we called them "theories". Simple examples include:

• the relationship between pressure (P), volume (V), and temperature (T) of any gas is PV/T = constant.
• the relationship between voltage (V), current (I), and resistance (R) in a circuit is V=IR.
• the relationship between force and acceleration of an object with mass is F=ma.

The mathematics of relativity is considerably more complex than these examples, but one gains several degrees of accuracy (≈ numbers after the decimal point) as compensation.

An interesting feature of our experience of the world is that time goes in one direction. This is a consequence of entropy. We can always tell when a film is playing backwards, for example, because the causality is all wrong. Broken cups never spontaneously reform and leap up from the floor to appear unbroken in our hands. Whole cups common fall down to the floor and smash. Once again, classical physics is intuitive.

Classical physics has never been made into an analogy by New Age gurus. No one ever compared the Heart Sutra to classical physics. No one ever says classical physics is "weird" or counter-intuitive. The fixed speed of light is a little counter-intuitive but it doesn't lend itself to the kind of Romantic flights of fancy that make religion seem interesting. If anything, religieux are apt to dismiss the whole topic of classical physics as irrelevant to "spirituality". Classical physics seems to resist being co-opted by woo-mungers.

And then there is quantum physics...

Quantum

Mathematically, quantum physics is profoundly accurate and precise method of predicting probabilities. However, unlike classical physics no one knows why it works. Literally, no one knows how the mathematics relates to reality. There are lots of ideas, each more counter-intuitive than the next and each relies on a series of assumptions that are beyond the scope of the mathematical formalism. But each set of assumptions leads to radically different metaphysics! And there is no agreement on which assumptions are valid. And at present there is no way to test these theories. I've seen Sean Carroll argue that Many Worlds does make testable predictions, but as far as I know, they have not been tested.

Einstein was of the opinion that quantum physics was incomplete. Sadly his proposed solution to this seems to have been ruled out. But still, I think the only viable stance is to consider quantum theory as incomplete until such time as we know how it relates to reality.

Which brings us to the first false claim that is commonly asserted by scientists: "the universe is deterministic." This assumes that quantum theory explains how matter behaves. But it doesn't. We don't know how mathematics relates to reality. So we don't know if the universe is deterministic or not. The claim that the the universe is deterministic goes far beyond our present state of knowledge. Most interpretations of quantum physics treat it as probabilistic rather than deterministic. And this undermines all claims that the universe is deterministic.

Another common falsehood is "quantum mechanics is a description of reality". But it should already be apparent that this is simply not true. Physicists do not know how the mathematics of quantum physics relates to reality. All they know is that the mathematics accurately assesses the probabilities of the various states that the system can be in over time. It doesn't tell us what will happen, at best it tells us what can happen.

At the popular level, quantum physics is plagued by vagueness and misleading statements. Scientists talk about "the wavefunction" as an independent thing (hypostatisation) and even as a physical thing (reification), when is it in fact an abstract mathematical function. They talk about "wave-like" behaviour without ever distinguishing this from actual wave behaviour. "Observation", so crucial to some approaches, is vague and more or less impossible to define.

We see statements like "energy is quantised" as though all energy is quantised. But this is not true. If you measure radiation from the sun, for example, it smoothly spans the entire electromagnetic spectrum (the sun glows because its hot, and that glow is blackbody radiation which is smooth rather than discreet). Energy is only quantised in atoms. And the solar spectrum is itself proof of this because the atoms in the sun absorb energy at precise wavelengths, causing the spectrum of sunlight to have darker bands when viewed at a fine enough grain.

The quantisation in atoms is explained in terms of an electron in an atom being conceived of as a standing wave - which means it can only vibrate at frequencies that allow for a whole number of wavelengths. For example, the harmonic series on a guitar string is also "quantised": the diagram shows different modes of vibration. The top shows wavelength = string length. but the string can also vibrate at twice the fundamental frequency so that 2 wavelengths = string length, then 3, 4, 5, 6, and 7 wavelengths = string length (out to infinity).

The energy levels for electrons in atoms show a similar pattern. But remember that an electron is 3 dimensional. Spherical harmonics look more like this

Which is similar to how we think electron orbitals look in Hydrogen.

Some of these results are confirmed by the shapes of molecules, which can be determined independently, for example by X-ray crystallography.

People talk about "measuring where the electron is in the atom". But this is almost pure bullshit. No one has ever measured the position of an electron in an atom. It's not possible. Within an atom, an electron is distorted into a spherical standing wave. "Position" is meaningless in this context. As are most other particle-related ideas. And remember, we cannot solve the equations when there are two or more electrons, we can only estimate (though current estimates are still very accurate).

We also see statements like "a system can exist in multiple states simultaneously", usually referred to as superposition (the "position" part is entirely misleading). This phrase is often used in popular explanations of quantum mechanics, but it’s misleading. The wavefunction describes a superposition of probability amplitudes, it does not describe a coexistence of multiple physical states. In fact, the term "state"—as it is usually used—is not applicable here at all, precisely because in normal usage it implies existence. In this context "state" confusingly means every single possible state, each with its own probability.

For example, if an electron has the wavefunction is ψ = ψ₁ + ψ₂ it doesn’t mean the electron is "in both states ψ₁ and ψ₂ at once." This is because neither ψ₁ nor ψ₂ is a physical state. Each is a probability distribution. So what superposition means is that, at some time, the electron's state has a probability distribution that reflects the combined amplitudes of ψ₁ and ψ₂. There is and can be no superposition of physical states, nor is their any theoretical possibility of observing such a thing.

All of those "interpretations" that treat the wavefunction as real simply assert its existence as axiomatic and introduce further a priori assumptions into order to try to make sense of this mess. If we make no assumptions then there is nothing about the mathematical formalism of quantum mechanics that forces us to think of the wavefunction as a real thing rather than an abstraction. It's a probability distribution. Which is an abstraction.

Which means that the idea that the wave-function can "collapse" is nonsensical. All probability distributions without exception "collapse" at the point of measurement.

If I roll a die, I get one number facing up. It can be any one of the six numbers. And each number is equally likely to be face up after a roll. Before I roll the die, the "wavefunction" of the die describes 6 possible "states" each of which is equally likely. When I roll the die I get one answer. Has anything mysterious happened? I think not. Let's say I roll a 2. I don't have to explain what happened to 1,3,4,5 and 6. Nothing happened to them, because they are not things. They are just unrealised possibilities. I get one result because only one result is physically possible. But before I know which result I have, all the possibilities have a finite probability. There's nothing "weird" or "mysterious" about this unless one first reifies the wavefunction.

Indeed, the whole idea of the "measurement problem" appears to be based on a serious misconception (as far as I can see). The measurement problem is based on the idea that the Schrödinger equation describes a system as existing in multiple physical states. But it doesn't. It describes probability distribution of possible physical states. A potentiality is not an existing state.

The only time measuring becomes problematic is when we assume that the wavefunction is a thing (reification) or that it reflects existent states rather then potential states. And these moves are simply mistakes.

Ironically, the one thing that Schrödinger's equation is not, as Nick Lucid explains, is a wave equation. The generalised wave equation contains a second-order partial differential with respect to time (a distorting force is countered by a restoring force, causing acceleration). This is a fascinating observation. I gather that using the constant i (√-1) in the Schrödinger equation allows for some "wave-like" behaviour, but no one really talks about this in lectures on quantum physics. Nor do they distinguish "wave" from "wave-like". And we still have to insist that the "wave-like" behaviour in question is a wave of probability, not a physical wave.

But then Nick Lucid, who typically is quite lucid (despite his "crazy" schtick), also introduces his video by saying "Schrödinger's equation governs the behavior of tiny quantum particles by treating them as wave functions." No equation anywhere "governs" anything. The equation describes the probability of a range of possible states. It's a descriptive law, not a prescriptive law. And as Lucid goes on to say, the equation in question is not a wave equation, it's a heat equation. The one thing that Schrödinger's equation doesn't do is "govern the behavior of tiny quantum particles".

This generalises: physics is a description, not a prescription. Abstract mathematical expressions cannot "govern" concrete entities. And in the case of quantum physics, it doesn't seem to relate to the "behaviour" either, since it only predicts the probability of any given state following from the present state. So it's not even a description of actual behaviour, just a description of potential behaviour at any point in time. With the most precise prediction as to probability, we still don't know what's going to happen next, and the actual outcome could always be the least likely outcome. That's why quantum tunneling is a thing, for example.

Unlike classical physics, which every undergraduate students proves to their own satisfaction, nano-scale physics is impossible to observe directly. It takes massive, complicated, and expensive equipment to get information from that scale. Information goes through many stages of amplification and transformation (from one kind of energy to another) before anything perceptible emerges. And that has to be processed by powerful computers before it makes any sense. And then interpreted by human beings.

That blip on the graph at 125 GeV that the LHC produced as evidence of the Higgs Boson is abstracted to the n^th degree from the thing itself.

At no time was a Higgs Boson ever observed, and at no time in the future will one ever be observed. What was observed was a particular kind of decay product, which the logic of the standard model says can only be produced if a Higgs Boson decays in the way that Peter Higgs predicted. Assuming that the standard model is right. Keep in mind that the model didn't predict the energy of the Higgs particle exactly. There was actually a lot of uncertainty. And the two different detectors actually measured slightly different numbers. Moreover, do you see how wide that peak was? That width is experiment error. Maybe the energy of the Higgs is 125 GeV, or maybe its a little more or a little less?

We cannot ever see the nano-scale. And because of this, we simply cannot imagine the nano-scale.

A 1 gram diamond, for example contains in the order of 5 x 10²² atoms. How big would that diamond be if each atom of carbon was 1mm³ or roughly the size of a grain of salt? It would be 5 x 10¹³ cubic metres. This is roughly the volume of Mount Everest. So an atom is to a grain of salt, as a grain of salt is to Mt Everest.

Imagination simply fails.

Conclusion

In short, at least at the popular level, quantum physics is a constant source of vague or misleading information. It is plagued by careless use of language and outright false claims by scientists themselves. The philosophy of quantum physics is difficult, but on the whole it fails to adequately distinguish epistemology and metaphysics. This is made worse by kooks and charlatans leveraging the confusion to pull the wool over our eyes. Sometimes, the kooks and the scientists are in a superposition: notably Eugene Wigner's theory about "consciousness" (another abstraction) collapsing the wavefunction. Wigner won a Nobel, but he was also a serious kook. And he has been responsible for a mountain of bullshit as a result.

Most of what is said about quantum physics outside of university lecture halls is bullshit, and quite a bit that is said in them is also bullshit or at least partially digested hay. Everything that is said about Buddhism and quantum physics is mendacious bullshit.

There is no doubt that insights gained from quantum physics are important and valuable, but the whole thing is over-hyped and plagued by nonsense. The actual work is largely about approximating solutions to the insoluble mathematical equations, which at best give us probabilities. It works remarkably well, but no one knows why.

The idea that quantum physics is any kind of "description of reality" is pure bullshit. It's a probability distribution, for a reality that no understands any better now than when physics genius Richard Feynman said: "No one understands quantum mechanics".

Classical physics on the other hand is seldom vague or misleading. It resists being leveraged by kooks by being precisely and accurately defined. It can readily be tested by more or less anyone. Classical physics is much less prone to bullshit. No one ever bothers to compare Buddhism to classical physics. Which is a good sign.

Classical physics is not only cooler than quantum physics. It is way cooler. 

Coda

If anyone is still unconvinced that quantum theory has no conceivable relationship with Buddhism, then I invite you to watch this video introduction to quantum mechanics from an Oxford University undergraduate physics course. This is a no bullshit course. 

I defy anyone to connect anything said in this video to any aspect of Buddhist doctrine. 

Minor Figures: Prajñā.

Bānrě 般若 or Prajñā, was a Buddhist monk from India who travelled to China and translated Buddhist texts. Prajñā was credited with the translation of Bānrě bōluómìduō xīn jīng «般若波羅蜜多心經» (T 253), though as we saw in the essay on Lìyán 利言, Chinese records show that Prajñā could not communicate in Chinese.

The following comments are my notes based on the biographical sketch of Bānrě 般若 or Prajñā found in the Zhēnyuán xīn dìng shìjiào mùlù «貞元新定釋教目錄» (T2157: 55.891a-), a catalogue of Buddhist texts in Chinese translation, compiled ca 800 CE by Yuánzhào 圓照. I draw additional material from Siu Sai-Yau's 蕭世友 PhD thesis (2019) and his recent book (2024). I'm processing this information for inclusion in my book.

My Thanks to Siu Sai-Yau for pointing me to this passage and for making his (2024) book open access. Bānrě 般若 is important to my work because he is credited with translating the Bānrě bōluómìduō xīn jīng «般若波羅蜜多心經» (T 253), along with Lìyán 利言 and others. 

Prajñā travelled to China by the southern sea route.

Upon learning that Mañjuśrī Bodhisattva was preaching in the Central Plains, Prajña resolved to visit China and propagate Buddhism. Carrying the original Sanskrit scriptures, he arrived in Guangzhou, during the early years of Emperor Dezong’s Jianzhong 建中 period (780–783) via the sea route. From there, he made his way to the capital. Upon the onset of the Zhenyuan 貞元 period, Prajña took up residence at the home of his relative, Luo Haoxin 羅好心, who held the position of a commander in the forbidden army, and patiently awaited an opportunity to commence his scripture translation endeavors. (Siu 2024: 61)

Introducing himself to the Emperor Táng Dézōng 唐德宗 (779 – 805 CE), Bānrě 般若 says:

I humbly state that I was born in Kapiśa. At fourteen, I left my homeland and travelled south to India, where I heard teachings I had not understood before. For over twenty years, I made pilgrimages to the sacred sites, including the Twin Trees and the Eight Stūpas. Having studied the Mahāyāna and Hīnayāna, I vowed to repay the four kindnesses. From afar, I have long admired China, often wishing to present offerings to the court but lacking the means. Recently, through my cousin Luó Hǎoxīn 羅好心, a tenth-rank officer of the Right Divine Strategy Army and Prince of Xīnpíng, who serves in the Imperial Guard, I was able to submit my petition and have it heard by Your Majesty. This is indeed my great fortune. (T 2157: 55.893a7-11)

The imperial response to Bānrě was positive:

On Zhēnyuán 貞元 6.7.25 [i.e. 25 August 790 CE], an imperial edict granted the honorary title Tripiṭaka and a purple kāṣāya robe. An edict was also issued for the Kingdom of Kapiśa to present a Sanskrit copy of the Liù Pāramì Jīng «六波羅蜜經» *Ṣaṭpāramitā Sūtra. The śramaṇa Bānrě 般若 should be granted the title “Tripiṭaka Bānrě” and also given a purple robe. (T 2157: 55.893c6-9)

The Liù Pāramì Jīng «六波羅蜜經» is no longer extant. Regarding the Heart Sutra, Siu (2019: 33) notes

般若、利言重譯廣本《心經》的原因，主要是因為時人認為玄奘舊譯內容有不足之處。般若來華所攜梵本中，有內容更為完備、前所未見的《心經》版本。

"As for the reason behind Bānruò and Lìyán's retranslation of the expanded Heart Sūtra, it was primarily due to the perception among contemporaries that Xuanzang’s earlier translation was lacking in some respects. Bānruò had brought with him a Sanskrit version containing a more complete and previously unseen rendition of the Heart Sūtra."

Traditionally, in China, a sutra is held to be composed of three “sections” (sānfēn kē jīng 三分科經): (1) an introduction (xùfēn 序分 “introductory section”; Skt. nidāna), (2) the main body of the text (zhèngzōng fēn 正宗分 “primary teaching section”) and, (3) a conclusion (liútōng fēn 流通分 literally “dissemination section”). 

The early commentaries by Kuījī 窺基 (T 1710), Woncheuk 圓測 (T 1711), Jìngmài 靖邁 (X 522), Fǎzàng 法藏 (T 1712), and Huìjìng 慧浄 (X 521) all mention the absence of the intro and conclusion in the Heart Sutra (the implications of this are discussed in my forthcoming book).

There follows a lengthy biographical narrative, interspersed with letters to and from the Emperor. As with other Buddhist hagiographers, Yuánzhào was eager to represent Buddhists as favoured by the Emperor of the day.

Siu (2019: 34) also notes:

譯本有傳入韓國地區，現時最早的般若、利言本漢文抄經便是見於《高麗大藏經》。 

"The translation also reached Korea, where the earliest surviving copy of the Chinese Bānrě and Lìyán version [i.e. T 253] appears in the Goryeo Tripitaka." 

The Goryeo Tripitaka is known in Chinese as Gāolí Dàzàngjīng 高麗大藏經; Korean: Goryeo Daejanggyeong 고려대장경. It literally means: Korean Great Treasury [of] Scripture. Although the character zàng 藏 here means "store", it also means "hide, conceal". Gāolí 高麗 is literally "lofty and beautiful"; so not a bad ethnonym. 

The Goryeo Tripitaka was printed from carved woodblocks. The first version was created in the 11th century but was later destroyed by the Mongols. A complete set of the carved woodblocks of the second version commissioned ca. 1236–1251 survives and is stored at Haeinsa Temple in South Korea (a UNESCO World Heritage Site).

Note that the Goryeo Tripitaka has also been referred to as the Tripitaka Koreana. In 2013, Robert Buswell noted: "The reality is that Goryeo Daejanggyeong is much bigger and broader in scale than the nomenclature used for the Tripitaka Koreana". In my book, I follow Buswell's suggestion and refer to the Korean Buddhist Canon.

As Siu notes, there is a gap of some centuries between the ostensible production of T253 (ca 788) and the earliest witness to the content of the text in the Korean Buddhist Canon (ca. 1236–1251). And we have no idea what happened to the text in the meantime. There are no commentaries on T253.

The biographical sketch in the Zhēnyuán lù «貞元錄» (T 2157) discusses Bānrě 般若 and the Heart Sutra attributed to him and records a memorial sent to the Emperor by a Buddhist monk called Zhìróu 智柔.

Zhìróu 智柔, the senior monk from Qiānfú Temple 千福寺, was known for his lectures and discourses. His observance of the precepts was rigorous, and he took delight in the Mahāyāna. He transmitted the Huāyán jīng «華嚴經» “Avataṃsaka Sūtra” and the Dàfódǐng «大佛頂» “Mahābuddhatopa Sūtra”. He also regularly chanted and contemplated the Bānrě xīnjīng 般若心經. This sūtra was translated by Luóshí 羅什 [Kumārajīva] and is titled Dàmíng zhòujīng «大明呪經».

When the Dharma Master Xuánzàng 玄奘 was about to depart westward, a divine being (shénrén 神人) bestowed [the Heart Sutra] upon him. While travelling through the treacherous sands and dangers, he sincerely chanted and upheld it, causing calamities and obstacles to recede. This is a great incantation (dàshén zhòu 大神呪), and these words are not in vain (bù xū 不虛).

Note that the Dàmíng zhòujīng «大明呪經» (T 250) enters the historical record in 730 CE in the Kaiyuan Catalog, i.e. Kāiyuán shìjiào lù «開元釋教錄» (T 2154). The attribution to Kumārajīva is clearly false (see Watanabe 1990).

Later, a Sanskrit text (fàn jiā 梵夾) was obtained. It was translated with no differences, except the absence of the introduction section (xùfēn 序分) and the later distribution (liútōng 流通) section.

Then, near the end of the Kāiyuán 開元 era (713 to 741 CE), the Tripiṭaka monk Fǎyuè 法月 retranslated this sūtra (T252). Both texts are extant. Now, we have obtained a copy from the Tripiṭaka monk Bānruò 般若, which includes these [missing] sections, making it the same original text as Fǎyuè's translation, but a different version.

With sincere intention, I earnestly request the reissue of the authentic text. Before I could consult in detail, the Tripiṭaka monk departed on a mission.

On the eleventh day of the eighth month, the work of verifying meanings, polishing the text, and transcribing was completed. A memorial was prepared and submitted, with the intent to circulate it widely.

Śramaṇa Zhìróu states:

"I humbly submit that the profound wisdom of the sages is vast and, through dissemination, spreads even further. The true source, supremely wondrous, is conveyed through words and symbols to be transmitted. This is the origin of the teachings of the many sages and the mother of all sūtras. Previously, the śramaṇa Xuánzàng translated it for circulation, and while the meaning was fully conveyed without omission, the text was missing the beginning. Yesterday, I encountered Bānrě, a monk from the Kingdom of Kapiśa, and personally saw the Sanskrit text. I earnestly requested him to transmit this understanding and again added praise and assistance. Only then did I realize that the Vulture Peak monastery truly revealed these noble words.

Those who recite it dispel doubts, and the true teachings spread even further. I humbly submit that Your Majesty personally upholds the Buddha's instructions, doing all that is good without exception. The Way reaches all beings, transforming everyone. Zhìróu 智柔, without considering his own limited abilities, rashly offers his sincere but humble dedication.

I hope to support the imperial virtues and contribute to the longevity of the sage. I humbly beg that Your Majesty, with heavenly insight, will review these noble words. If they are suitable, I respectfully request that they be promulgated within and beyond the court. In this way, all deluded beings, even through countless ages, may find great happiness. Unable to fully express my utmost sincerity, I respectfully submit this memorial for Your Majesty's attention." —(T 2157: 55.893c9-894a1)

Note that Yuánzhào 圓照 considers T 252 and T 253 to be the same text. In the sense that both texts incorporate T251 verbatim, they are the same. However, the introduction and conclusions of T 252 and T 253 could hardly be more different. Which suggests he didn't actually compare them. 

Note also that Yuánzhào conflates Bānrě xīnjīng 般若心經 (T 251) and Dàmíng zhòujīng «大明呪經» (T 250). Again, while these two texts are broadly similar, there are some significant differences. These four texts—T 250, 251, 252, and 253—are four of the five major versions of the text. The fifth is the Sanskrit translation, i.e. Prajñāpāramitāhṛdaya. T 252 is unique and was likely composed in Chinese. We know very little about the provenance of it. T 254 is a lightly edited version of T 253. T 255 was a Dunhuang text and has not yet been properly studied in its context. T 257 is a later translation from Sanskrit. 

Zhìróu 智柔 is relatively unknown. He is mentioned only once, in passing, in the Gāosēng Zhuàn «高僧傳» (T 2061: 50.721b27) and that in connection with Prajñā:

即貞元十一年也。至十二年六月，詔於崇福寺翻譯，罽賓沙門般若宣梵文，洛京天宮寺廣濟譯語，西明寺圓照筆受，智柔、智通綴文，成都府正覺寺道恒、鑒虛潤文，千福寺大通證義，澄觀、靈邃詳定，神策軍護軍中尉霍仙鳴、左街功德使竇文場寫進，十四年二月解座。(T 2061: 50.721b25-c2)

This was in the 11th year of the Zhēnyuán era. By the 6th month of the 12th year, an imperial edict was issued for the translation at Chóngfú Monastery 崇福寺. The śramaṇa Bānrě 般若 from Kapiśa recited the Sanskrit text, while the text was rendered into Chinese at Tiāngōng Monastery 天宮寺 in Luòyáng by Guǎngjì 廣濟. Yuánzhào 圓照 from Xīmíng Monastery 西明寺 recorded it in writing, with Zhìróu 智柔 and Zhìtōng 智通 editing the text. Dàohéng 道恒 and Jiànxū 鑒虛 from Zhèngjué Monastery 正覺寺 in Chéngdū polished the wording, while Dàtōng 大通 from Qiānfú Monastery 千福寺 verified the meaning. Chéngguān 澄觀 and Língsuì 靈邃 reviewed and finalized it. The Military Protector of the Divine Strategy Army, Lieutenant Huò Xiānmíng 霍仙鳴, and Dòu Wénchǎng 竇文場, Director of Merit on the Left Street, transcribed and submitted the work, completing the project by the 2nd month of the 14th year.

From this, we imply that Prajñā's only role in the translation was reciting the Sanskrit text. This seems to be quite typical. Indian or Central Asian monks who rocked up in Chang'an did not speak Chinese and most likely never gained the kind of mastery of the language required for discussion highly specialised Buddhist doctrines. If this was in Europe, we'd credit Guǎngjì 廣濟 with the translation. But Chinese traditions demands that it is credited to Prajñā. 

Of note, is the connection between Prajñā and the Japanese monk Kūkai, who was in Chang'an ca 802-804 and wrote the first esoteric interpretation of the Xīn jīng. This is mentioned several times in Hakeda (1972). According to Kūkai, in the Shōrai mokuroku, Prajñā expressed a desire to travel to Japan and regretted that circumstances did not allow it. He gifted Kūkai with copies of new translations of the Avataṃsaka Sūtra (T 293) and the Ṣatpāramitā Sūtra (T 261), and a number of Sanskrit manuscripts.

What Did Prajñā Translate?

Siu's account of Prajñā and the Heart Sutra overlooks the fact that T 253 cannot be a straightforward translation from Sanskrit. Significantly, T 253 incorporates all of T 251, verbatim. This means that at best Prajñā and co. only translated the introduction and the conclusion of the Heart Sutra, while retaining all of the translation attributed to Xuanzang. And this seems to be a pattern with works attributed to Prajñā.

In the Chinese Buddhist Canonical Attributions database, created by Michael Radich and Jamie Norrish (who died recently), Bānrě is credited with a number of translations:

• Dàchéng Běnshēng Xīndì Guān Jīng «大乘本生心地觀經» (T 159)
• Bānrě Bōluómìduō Xīnjīng «般若波羅蜜多心經» (T 253)
• Dàchéng lǐqù liù bōluómìduō jīng «大乘理趣六波羅蜜多經» (T 261)
• Dàfāngguǎng fó huáyán jīng «大方廣佛華嚴經» (T 293)
• Dà huáyán zhǎngzhě wèn fó nàluóyán lì jīng «大花嚴長者問佛那羅延力經» (T 547)
• Zhūfó jìngjiè shè zhēnshí jīng « 諸佛境界攝真實經» (T 868)
• Shǒuhù guójiè zhǔ tuóluóní jīng «守護國界主陀羅尼經» (T 997)
• Fó shuō zào tǎ yánmìng gōngdé jīng «佛說造塔延命功德經» (T 1026)

Several of the entries repeat a note attributed to Atsushi Iseki, in which he summarises a Japanese article from 1954:

According to Tsukinowa [1954], it is recorded that Trepiṭaka Prajña/Prajñā 般若三藏 translated nine titles in seventy-five juan scriptures [sic], and also composed a Banre sanzang gu jin fanyi tu ji 般若三藏古今翻譯圖紀 in two juan. However, Tsukinowa states, probably the Gu jin fanyi tu ji 古今翻譯圖紀 was written by somebody else, and Prajña’s true translation work most likely only comprises the version of the “Heart” Sūtra 般若心經 in one juan T253, co-translated with Liyan 利言 and others. Tsukinowa believes that almost all other titles ascribed to Prajñā were his own compositions, because 1) no original texts of his works have been found; 2) no alternate translation have been found in Chinese nor in Tibetan; 3) none of those works are cited in Indian texts; and 4) the contents and style of those works of his are too peculiar to be proper translation.

Tsukinowa (1954) is in Japanese so I cannot check it, though the bibliographic details are included below. There also individual notes on all of these texts.

• T 159 "Translation attributed to Prajña, ed. 般若: 6th year of Zhenyuan (貞元), Tang dynasty (唐), 1 but it was more likely done by someone else at a later date."
• T261 is more complex. "It would be a little far-fetched to classify the entire text of T261 as apocryphal, since there probably did exist an original underlying Indic text. However, Yoritomi asserts, substantial additions were made in China."
• T 293 "T293 feigns the impression of a new translation by adding material to the text, but is based more on T279 than on the original Sanskrit."
• T 547 "Tsukinowa does not seem to believe that this text is a proper translation, but he does not state it explicitly"
• T 868 "Tsukinowa concludes that T868 is based on the Vajraśekhara, and was produced to serve as an introduction to it. He agrees with Ōmura Seigai 大村西崖, who states in his Mikkyō hattatsu shi 密教發達志 that T868 is a conspectus of various scriptures, refining, epitomising and synthesising their contents 綜合折衷し打て洗錬したるもの."
• T 997 "Tsukinowa argues that none of the ten juan of T997 is a true translation" The text is a compilation of passages from other texts.
• T 1026 "Tsukinowa states that T1026 is another example of a pattern by which Prajña uses bits of different texts in producing a scripture, while adding something new of his own composition."

See also the comments under the entry for Prajñā.

The overall impression is that Bānrě was more interested in transmitting ideas and practices than in upholding orthodoxy or faithfully transmitting texts. He used texts in a very flexible way. One of his signature moves was precisely adding new material to an existing translation and presenting it as a new translation. Which is exactly what happened to T 253.

Tsukinowa's comments are problematic for the historically dominant narrative. Given that (a) Bānrě didn't know Chinese and was reliant on Chinese Monks (notably Liyan) to translate; and (b) the "translations" attributed to him all seem to have copied material from a range of existing Chinese translations, we have to wonder what Bānrě's involvement in T 253 really was.

Conclusion

Bānrě 般若 or Prajñā, is a minor figure in the history of the Heart Sutra. He is credited with translating T 253, but this version of the text was never important in China: i.e. it was not used in liturgies or as magical protection in the way that the Xīn jīng (T 251) was. The oldest extant version of T253 is in the Korean Buddhist Canon from the 13th century.

Siu (2024) confirms that Chinese translation was generally a collective affair. We have to put aside the modern, European idea of a lone scholar toiling away in isolation. Moreover, it seems likely that visiting monks who brought Sanskrit texts were generally dependent on translators. Prajñā certainly was. 

Tsukinowa (1954) has made the case that all of his "translations" were not really translations. Prajñā mostly seems to have curated passages copied from existing texts, sometimes adding them to other existing translations. But this editing seems to have happened in Chinese and evidence suggests that Prajñā could not speak Chinese. So this is a mystery. 

Tsukinowa was of the opinion that only T 253 was a genuine translation. But T 253 perfectly fits that pattern of other works attributed to Prajñā. For example, the main body of T 253 simply reproduces the text of T 251, but it adds the missing introduction and conclusion. 

Thus, if Prajñā had any input at all, it was only in the introduction and conclusion that were added to give the impression that the Heart Sutra was an authentic sutra.

The role of Liyan in the creation of T 252 and T 253 seems to deserve more attention, especially in the light of his role as Prajñā's day-to-day translator. Liyan seems to have been from Kucha and thus would have approached China via Dunhuang, which is home to numerous Heart Sutra manuscripts and some unique versions of the text that have yet to be formally studied. Tibetans invaded and controlled Dunhuang ca. 786-848. (On the Tibetan occupation of Dunhuang see The Chinese under Tibetan rule). 

It seems possible that Liyan was responsible for adding the missing introduction and conclusion to the Xīn jīng, creating both T 252 and T 253. In the case of T 253, he did this under the guidance of Prajñā who clearly had no qualms about such things. 

It's likely that Prajñā taught Kūkai Sanskrit (ca 802-804), which is a notable contribution. And relevant to my work since Kūkai later (ca 834) composed the first esoteric Buddhist commentary of the Heart Sutra, though curiously Kūkai commented on the Xīn jīng rather than Prajñā's version. 

~~oOo~~

Bibliography

Lopez, Donald S. (1996) Elaborations on Emptiness: Uses of the Heart Sutra. Princeton University Press.

Siu, Sai-yau 蕭世友 (2019). 唐代般若、利言《般若波羅蜜多心經》的漢譯研究 . 香港中文大學. [On the Chinese Translation of Prajñāpāramitāhṛdaya by Prajña and Satyacandra in the Tang Dynasty. PhD Dissertation. Chinese University of Hong Kong].

———. 2024. The Evolution of Team-Based Buddhist Scripture Translation in Tang China. Springer. [Open access online publication] https://link.springer.com/book/10.1007/978-981-97-2293-8 [accessed 7 Nov 2024]

Tsukinowa, Kenryū 月輪 賢隆. (1954). “般若三蔵の翻經に対する批議.” [Criticism of Prajna Tripitaka's Translation of Sutras]. Indogaku Bukkyōgaku Kenkyū 4(2): 434-443.

Watanabe, Shōgo. (1990). “Móhē bānrě bōluómì shénzhòu jīng and Móhē bānrě bōluómì dàmíngzhòu jīng, As Seen in the Sutra Catalogues.” Indogaku Bukkyōgaku Kenkyū 39-1: 54–58. [= 渡辺章悟. 1990. 「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.]. My English translation is online: https://tinyurl.com/33n3d8h4