A command needs a commander, or so it seems: an order is only as good as the person who gives it. The aphorisms that tradition ascribes to Jaimini deny this for the Veda. Their fifth sūtra, a terse statement meant to be memorised and explained by a teacher, holds that the bond between a word and its meaning is original, made by no one, so the Veda's instructions do not depend on any speaker whose honesty or knowledge could be doubted. A human witness can lie or be mistaken; a text that no one composed has no author whose mistakes it could carry.
The stakes were practical. The Veda prescribes sacrifices, and by the time these sūtras took shape, those sacrifices had serious critics: the śramaṇas, wandering ascetics among whom the Buddhist and Jain communities arose, rejected the authority of the Vedic scriptures altogether. The ritual texts posed a second problem from inside. They were vast, they mixed commands with hymns of praise and stories, and they did not say what to do when a prescribed substance was missing or who was entitled to sacrifice. Mīmāṃsā, the name of the school these sūtras founded, means investigation, and the investigation set out to settle both problems with one method.
Its first sūtras state the method. The inquiry is into dharma, right action, and dharma is whatever a Vedic injunction makes known. Perception cannot reach it, because perception grasps only what is already present, while a command says what is yet to be done. Only the text can, so the text must be read exactly: a passage that commands binds, a passage that praises only encourages, and rules decide which rite is primary and which serves it. This is the claim the school is remembered for, in ordinary words: duty can be known only from scripture, and scripture is trustworthy because no one composed it.
Of Jaimini himself, the record holds almost nothing. The sūtras quote his opinion by name beside those of other teachers, Bādari and Bādarāyaṇa among them, and the Brahmasūtra, the root text of the Vedānta school, quotes Jaimini in its turn. In the Mahābhārata and the Purāṇas, later compendia of sacred lore, tradition makes him a pupil of the sage Vyāsa, who taught him the Sāmaveda, one of the four Vedas; the Mārkaṇḍeya Purāṇa opens with Jaimini's questions. Most historians date the sūtras to between the fourth and the second century BCE; Bimal Krishna Matilal, a historian of Indian philosophy, placed their compilation later, in the first century BCE at the earliest.
For most of their history the sūtras were read through the commentary of Śabara, the oldest that survives, and through the two rival schools that Kumārila and Prabhākara built on it from the seventh century on. Those later thinkers carried the argument further than the sūtras do. They argued against Buddhist philosophers, held that a cognition is to be trusted until something shows it false, and saw no need for a God who made the world, just as the Veda needed no author. Some historians count the school among the forces behind the decline of Buddhism in India. Vedānta, which came to call itself the later Mīmāṃsā and Jaimini's school the earlier, eventually eclipsed it.
In 1990 Francis X. Clooney, an American Jesuit scholar of Hindu thought, published Thinking Ritually, an attempt to recover Jaimini's own system from beneath the commentaries. The rules the sūtras laid down for reading a text had long since become the working tools of Indian legal interpretation.