The Tibetan Buddhist tradition classifies the discourses (sūtra, mdo) delivered by Śākyamuni Buddha in terms of the three turnings of the doctrinal wheel, promulgated at different places and times in the course of his life. Among them, the sūtras of the first turning expound the four truths, those of the second turning explain emptiness and the essenceless nature of all phenomena, while those of the third turning elaborate further distinctions between the three essenceless natures. The sūtras of the Perfection of Wisdom (prajñāpāramitā) are firmly placed by their own assertion within the second turning, promulgated at Vulture Peak near Rājagṛha.
It is in these sūtras that the role of the compassionate bodhisattva with a mind set upon enlightenment achieves pre-eminence over the śrāvakas and pratyekabuddhas of lesser attainment. The central message subtly integrates relative truth and ultimate truth, reiterating that great bodhisattva beings should strive to attain manifestly perfect buddhahood in order to eliminate the sufferings of all sentient beings rather than merely terminate cyclic existence for their own sake, even though, from an ultimate perspective, there are no phenomena, no sentient beings and no attainment of manifestly perfect buddhahood.
The relentless deconstruction of all conceptual elaborations with respect to phenomena, meditative experiences, and even the causal and fruitional attributes characteristic of the bodhisattva path, which is explicitly emphasized throughout these sūtras, may have been controversial, but it has given rise to both Madhyamaka dialectics and to the non-analytical meditative pursuits of the Chan (Zen) tradition. In Tibet, on the other hand, these sūtras are generally approached through study of The Ornament of Clear Realization (Abhisamayālaṃkāra, Toh 3786, a treatise said to have been dictated to Asaṅga by Maitreya) and its extensive commentaries, which constitute the Parchin (phar phyin) literature—one of the principal subjects of the monastic college curriculum. These treatises elaborate on the eightfold structural progression of the bodhisattvas’ goals, paths and fruit which are implied, though understated in all but the recast manuscript of the Sūtra in Twenty-five Thousand Lines.
Traditional Tibetan accounts hold that, following their promulgation by Śākyamuni, the sūtras were concealed in non-human abodes—the longest Sūtra in One Billion Lines among the gandharvas, the Sūtra in Ten Million Lines among the devas, and the Sūtra in One Hundred Thousand Lines among the nāgas—the last of these being retrieved and revealed by Nāgārjuna from the ocean depths and initially propagated in South India.
The extant texts forming this cycle of sūtras are replete with abbreviations, modulations and other mnemonic features, indicative of an early oral transmission—even today they are read aloud as an act of merit in monastic halls and public gatherings. At the same time, the medium length and longer sūtras explicitly extoll the merits of committing the sūtras to writing, in the form of books, as an offering for the benefit of posterity.
In Tibetan translation, the sūtras of the Perfection of Wisdom are contained in twenty-three volumes of the Degé and Narthang Kangyurs—comprising approximately one fifth of the entire collection. This division of the Kangyur precedes all the other sūtras in the Buddhāvataṃsaka (phal chen), Ratnakūṭa (dkon brtsegs) and General Sūtra (mdo sde) divisions of the Kangyur, reflecting the high prestige of the Perfection of Wisdom within Mahāyāna Buddhism as a whole.
They include twenty-three distinct texts, foremost among them being the “six mothers” (yum drug) and the “eleven children” (bu bcu gcig). The six mothers are the “longer” and “medium” length sūtras, which are said to be distinguished by their structural presentation of all eight aspects of the bodhisattvas’ path, as elucidated in The Ornament of Clear Realization. The shorter texts, being terser, do not fully elaborate this structure.
The six mothers are outlined as follows:
1. The Perfection of Wisdom in One Hundred Thousand Lines (Śatasāhasrikāprajñāpāramitā, Toh 8) comprises twelve volumes, three hundred and one fascicles and seventy-two chapters.
2. The Perfection of Wisdom in Twenty-five Thousand Lines (Pañcaviṃśatisāhasrikāprajñāpāramitā, Toh 9) comprises three volumes, seventy-eight fascicles, and seventy-six chapters.
3. The Perfection of Wisdom in Eighteen Thousand Lines (Aṣṭādaśasāhasrikāprajñāpāramitā, Toh 10) comprises two and a half volumes, sixty fascicles, and eighty-seven chapters.
4. The Perfection of Wisdom in Ten Thousand Lines (Daśasāhasrikāprajñāpāramitā, Toh 11) comprises one and a half volumes, thirty-four fascicles, and thirty-three chapters.
5. The Perfection of Wisdom in Eight Thousand Lines (Aṣṭasāhasrikāprajñāpāramitā, Toh 12) comprises one volume, twenty-four fascicles, and thirty-two chapters.
6. The Verse Summation of the Perfection of Wisdom (Prajñāpāramitāratnaguṇasañcayagāthā, Toh 13) comprises nineteen folios.
In most Kangyurs the long sūtras, 1-5 (Toh 8-12) each occupy their own primary section of the collection, but here they have all been placed under a single heading for the genre.
Of the shorter sūtras, all contained in a final “miscellaneous Prajñāpāramitā” (sher phyin sna tshogs) volume of the section, the best known are the Diamond Cutter (Vajracchedikā, Toh 16, in three hundred lines), commonly known as the Diamond Sūtra, and the Essence of the Perfection of Wisdom (Prajñāpāramitāhṛdaya, Toh 21), justifiably famous as the Heart Sūtra.
Others include increasingly condensed versions: a version in 2,500 lines known as The Questions of Suvikrāntavikrāmin (Toh 14), versions in 700 lines (Toh 24), 500 lines (Toh 15), 50 lines (Toh 18), In a Few Syllables (Toh 22), and even In One Syllable (Toh 23). The version in 150 lines (Toh 17) is strongly tantric in style and content, and indeed several of the sūtras are duplicated in the Tantra section of the Kangyur.
In addition to these Tibetan translations, there are extant Sanskrit manuscripts from Gilgit and Nepal, complete in some cases, partial in others, and Chinese translations representing all of the longer and medium length versions of the sūtra, with the exception of The Transcendent Perfection of Wisdom in Ten Thousand Lines.
A bibliographic appraisal of all texts within this division can be found in Conze, Edward, The Prajñāpāramitā Literature (2nd edition), 1978: Tokyo, The Reiyukai.