Purva Mimamsa is earlier (purva) to Uttara (later) Mimamsa in a logical sense. The word Mimamsa means to analyze and understand thoroughly. By the Sutra period the Vedas were beginning to lose their glory in public opinion hence some scholars began to reanalyse the Vedas in order to defend them and justify Vedic ritualism. Mimamsa is to investigate Dharma (duty) as given in the Vedas. Purva Mimamsa examines the teachings of the Veda in the light of karma-kanda rituals. The karma-mimamsa system is called purva-mimamsa, which means the earlier study of the Veda, and Vedanta is called uttara-mimamsa, which means the later study of the Veda (Upanishads).

The foundational text for the Mimamsa school is the Purva Mimamsa Sutras of Jaimini. Mimamsa believes that all words and meanings exist eternally, and the human mind only perceives them temporarily. Jaimini accepts perception, inference and testimony but rejects intuition. He also believes that there is a connection between an act and its result. He mentions an unseen force, which brings these unseen results and names it as Apurva- a link between work and its unseen results.

Moksha (liberation) in Purva Mimamsa is in heaven. Mimamsa does not pay as much attention to Moksha or salvation as does Vedanta (also known as Uttara Mimamsa - investigation into the Uttara or "later" portions of the Vedas). The beliefs of the Mimamsa school include rejection of a creator God as well as scriptures on dharma outside of the Vedic tradition, and acceptance of the existence of svarga or heaven awaiting the person who has acted righteously in his or her life.

The Purva Mimamsa was an unsatisfactory system of philosophy, which could neither explain the working of the universe nor could clarify the existence of God but provided utmost importance to sacrifices and rituals.