Sutra (IAST: sūtra सूत्र) is a Sanskrit word that means "string" or "thread". In Indian literary traditions, it also refers to an aphorism or a collection of aphorisms in the form of a manual or, more broadly, a condensed manual or text. Sutras are a genre of ancient and medieval Indian texts found in Hinduism, Buddhism and Jainism.
In Hinduism, sutra denotes a distinct type of literary composition, a compilation of short aphoristic statements. Each sutra is any short rule, like a theorem distilled into few words or syllables, around which "teachings of ritual, philosophy, grammar or any field of knowledge" can be woven. The oldest sutras of Hinduism are found in the Brahmana and Aranyaka layers of the Vedas. Every school of Hindu philosophy, Vedic guides for rites of passage, various fields of arts, law and social ethics developed respective sutras, which helped teach and transmit ideas from one generation to the next.
In Buddhism, sutra or sutta refers mostly to canonical scriptures, many of which are regarded as records of the oral teachings of Gautama Buddha. The Pali form of the word, sutta, is used exclusively to refer to the scriptures of the early Pali Canon, the only texts recognized by Theravada Buddhism as canonical.
In Jainism, sutra or suya refers to canonical sermons of Mahavira contained in the Jain Agamas and to some later (post-canonical) normative texts.
The word sūtra (Sanskrit: सूत्र, Pali: sūtta, Ardha Magadhi: sūya) means "string, thread". The root of the word is siv, that which sews and holds things together. The word is related to sūci (Sanskrit: सूचि) meaning "needle, list", and sūnā (Sanskrit: सूना) meaning "woven".
In the context of literature, sūtra means a distilled collection of syllables and words, any form or manual of "aphorism, rule, direction" hanging together like threads with which the "teachings of ritual, philosophy, grammar or any field of knowledge" can be woven.
A sūtra is any short rule, states Moriz Winternitz, in Indian literature; it is "a theorem condensed in few words". A collection of sūtras becomes a text, and this is also called sūtra (often capitalized in Western literature).
A sūtra is different from other components such as Shlokas, Anuvyakhayas and Vyakhyas found in ancient Indian literature. A sūtra is a condensed rule which succinctly states the message, while a Shloka is a verse that conveys the complete message and is designed to certain rules of musical meter, a Anuvyakhaya is an explanation of the reviewed text, while a Vyakhya is a comment by the reviewer.
Sutras first appear in the Brahmana and Aranyaka layer of Vedic literature. They grow in the Vedangas, such as the Shrauta Sutras and Kalpa Sutras. These were designed so that they can be easily communicated from a teacher to student, memorized by the recipient for discussion or self-study or as reference.
A sutra by itself is condensed shorthand, and the threads of syllable are difficult to decipher or understand, without associated scholarly Bhasya or deciphering commentary that fills in the "woof".
The oldest manuscripts that have survived into the modern era, that contain extensive sutras, are part of the Vedas dated to be from the late 2nd millennium BCE through mid 1st-millennium BCE. The Aitareya Aranyaka for example, states Winternitz, is primarily a collection of sutras. Their use and ancient roots are attested by sutras being mentioned in larger genre of ancient non-Vedic Hindu literature called Gatha, Narashansi, Itihasa and Akhyana (songs, legends, epics and stories).
In the history of Indian literature, large compilations of sutras, in diverse fields of knowledge, have been traced to the period from 600 BCE to 200 BCE (mostly after Buddha and Mahavira), and this has been called the "sutras period". This period followed the more ancient Chhandas period, Mantra period and Brahmana period.
Some of the earliest surviving specimen of sutras of Hinduism are found in Anupada Sutras and Nidana Sutras, the former distills the epistemic debate whether Sruti or Smriti or neither must be considered more reliable source of knowledge, while the latter distills the rules of musical meters for Samaveda chants and songs.
A larger collection of ancient sutra literature in Hinduism corresponds to the six Vedangas, or six limbs of the Vedas. These are six subjects that were called in the Vedas as necessary for complete mastery of the Vedas. The six subjects with their own sutras were "pronunciation (Shiksha), meter (Chandas), grammar (Vyakarana), explanation of words (Nirukta), time keeping through astronomy (Jyotisha) and ceremonial rituals (Kalpa). The first two, states Max Muller, were considered in the Vedic era to be necessary for reading the Veda, the second two for understanding it, and the last two for deploying the Vedic knowledge at yajnas (fire rituals). The sutras corresponding to these are embedded inside the Brahmana and Aranyaka layers of the Vedas. Taittiriya Aranyaka, for example in Book 7, embeds sutras for accurate pronunciation after the terse phrases "On Letters", "On Accents", "On Quantity", "On Delivery" and "On Euphonic Laws".
The fourth and often the last layer of philosophical, speculative text in the Vedas, the Upanishads, too have embedded sutras such as those found in the Taittiriya Upanishad.
The compendium of ancient Vedic sutra literature that has survived, in full or fragments, includes the Kalpa Sutras, Smarta Sutras, Srauta Sutras, Dharma Sutras, Grhya Sutras and Sulba Sutras. Other fields for which ancient sutras are known include etymology, phonetics and grammar.
Some examples of sutra texts in various schools of Hindu philosophy include:
Some scholars consider that the Buddhist use of sutra is a faulty Sanskritization of the Prakrit or Pali word sutta and that the latter actually represented Sanskrit sūkta, "well spoken, good news". The early Buddhist sutras do not present the aphoristic, nearly cryptic nature of the Hindu sutras even though they also have been designed for mnemonic purposes in an oral tradition. On the contrary, they are most often lengthy, with many repetitions which serve the mnemonic purpose of the audience. They share the character of sermons of "good news" with the Jaina sutras, whose original name of sūya in Ardha Magadhi can derive from Sanskrit sūkta, but hardly from sutra.
In Buddhism, sutra or sutta refers mostly to canonical scriptures.
In Chinese, these are known as 經 (pinyin: jīng). These teachings are assembled in part of the Tripiṭaka which is called the Sutta Pitaka. There are many important or influential Mahayana texts, such as the Platform Sutra and the Lotus Sutra, that are called sutras despite being attributed to much later authors.
In the Jain tradition, sutras are an important genre of "fixed text", which used to be memorized.
The Kalpa Sūtra is, for example, a Jain text with scripture of monastic rules, as well as the biographies of the Jain Tirthankaras. Many sutras discuss all aspects of ascetic and lay life in Jainism. Various ancient sutras particularly from the early 1st millennium CE, for example, states M. Whitney Kelting, recommend "bhakti as devotionalism is a central part of a Jain practice".
The surviving scriptures of Jaina tradition, such as the Acaranga Sutra (Agamas) exist in sutra format, as is the Tattvartha Sutra – a Sanskrit text accepted by all four Jainism sects as the most authoritative philosophical text that completely summarizes the foundations of Jainism.