Wikipedia
Mimamsa is a Sanskrit word that means "reflection" or "critical investigation". It is also the name of one of six orthodox ( astika) schools of Hinduism. The school is known for its philosophical theories on the nature of dharma, based on hermeneutics of the Vedas. The school was influential and foundational to the vedāntic schools of Hinduism, with the difference that the Mīmāṃsā school (also known as Pūrva-Mīmāṃsā or Karma-Mīmāṃsā) developed and emphasized karma-kāṇḍa (study of ritual actions, early four Vedas), while the Vedānta schools (also known as Uttara-Mīmāṃsā) developed and emphasized jñana-kāṇḍa (study of knowledge and spirituality, later parts of Vedas, like the Upaniṣads).
Mīmāṃsā has several sub-schools, each defined by its epistemology. The Prābhākara sub-school (from Prabhākara Miśra) considered five epistemically reliable means to gaining knowledge - Pratyakṣha (perception), Anumāna (inference), Upamāna (comparison and analogy), Arthāpatti (postulation, derivation from circumstances), and Śabda (word, testimony of past or present reliable experts). The Bhāṭṭa sub-school (from Kumārila Bhaṭṭa) added a sixth to its canon of reliable epistemology - Anupalabdhi (non-perception, negative/cognitive proof).
The school of Mīmāṃsā consists of both atheistic and theistic doctrines and the school showed little interest in systematic examination of the existence of God. Rather, it held that the soul is an eternal, omnipresent, inherently active spiritual essence, then focussed on the epistemology and metaphysics of dharma. To them, dharma meant rituals and social duties, not devas (gods) because gods existed only in name. The Mīmāṃsakas held that Vedas are "eternal authorless infallible", that Vedic vidhi (injunctions) and mantras in rituals are prescriptive kārya (actions), and the rituals are of primary importance and merit. They considered the Upaniṣads (later portions of Vedas) and other self-knowledge, spirituality-related texts as subsidiary, a philosophical view that Vedānta school of Hinduism disagreed with.
Mīmāṃsā gave rise to the study of philology and the philosophy of language. While their deep analysis of language and linguistics influenced other schools of Hinduism, their views were not shared by others. Mīmāṃsakas considered the purpose and power of language was to clearly prescribe the proper, correct and right. In contrast, Vedāntins extended the scope and value of language as a tool to also describe, develop and derive. Mīmāṃsakas considered orderly, law driven, procedural life as central purpose and noblest necessity of dharma and society, and divine (theistic) sustenance means to that end.
The Mīmāṃsā school of Hinduism is a form of realism. A key text of the Mīmāṃsā school is the Mīmāṃsā Sūtra of Jaimini.