Each of the Vedas is considered to be composed of four parts: The Samhitas, the Brahmanas, the Aranyakas and the Upanishads. The first two parts are generally focused on the rituals and they form the Karma-kanda portion of the Vedas. The later two parts form the Jnana-kanda (concerned with knowledge) portion of the Vedas.

Purva-Mimamsa is based on the earlier (Purva = earlier) parts of the Vedas.

Uttar-Mimamsa is based on the later (Uttar = later) parts of the Vedas.

Purva-Mimamsa is also known as Karma Mimamsa since it deals with the Karmic actions of rituals and sacrifices. Uttar-Mimamsa is also known as Brahman Mimamsa since it is concerned with the knowledge of Reality. In popular terms, Purva-Mimamsa  is known simply as Mimamsa and Uttar-Mimamsa as Vedanta.

Jaimini is credited as the chief proponent of the Mimamsa system. His glorious work is Mimamsa-Sutra written around the end of the 2^nd century A.D. Mimamsa-Sutra is the largest of all the philosophical Sutras. Divided into 12 chapters, it is a collection of nearly 2500 aphorisms which are extremely difficult to comprehend.

Earlier scholars wrote commentaries on Mimamsa-Sutra. Unfortunately they are lost with the passage of time. The earliest available commentary is Sabarasvamin’s Sabara-bhasya, which is still the authoritative basis of all subsequent works on Mimamsa. Renowned scholars Kumarila Bhatta and Prabhakara independently wrote their commentaries on Sabara-bhasya. Prabhakara was a student of Kumarila Bhatta. However, they differed, to some degree, on the interpretation of  Sabara-bhasya  and  wrote separate commentaries. (Mandan Mishra, the erudite scholar, was a follower of Kumarila Bhatta. He also wrote a commentary, but at a later stage he changed his thinking and became a disciple of Shamkaracharya.)

This system out rightly accept the Vedas as the eternal source of ‘revealed truth.’ Thus though it differs from the earlier four philosophical systems (Vaisheshika, Nyaya, Samkhya, Yoga which neither accept nor reject the authority of the Vedas), a great chunk of Mimamsa philosophy  is derived from the Vaisheshika-Nyaya duo.

Mimamsa system attaches a lot of importance to the Verbal testimony which is essentially the Vedic testimony. Jaimini accepts the ‘Word” or the ‘Shabda’ as the only means of knowledge. The ‘word’ or the ‘Shabda’ is necessarily the Vedic word, according to Jaimini. This system strongly contends that the Vedas are not authored by an individual. Since they are ‘self-revealed’ or ‘apaurusheya’, they manifest their own validity.