The trigger for a discussion about the distinction of body and self in Mīmāṃsā is not or not primarily the polemic with the Buddhists, but rather the need to justify the validity of ritual prescriptions. In particular, a sentence, the yajñāyudhivākya `sentence about the one who bears the weapons of sacrifice’ identifies the entity being endowed with the weapons which consist in the sacrifice itself with the one which will reach heaven.
The problem is that the entity which carries these weapons is the body — and the body will clearly not reach heaven, since it will be burnt.
Interestingly, bodily resurrection seems not to have ever been taken into account as an option, so that the resulting dualism is much more radical than in a Christian milieu: Mīmāṃsā authors plainly agree that the body will not go to heaven and that the sentence should rather be read as addressing in fact the real agent of the sacrifice, which is not the body, but the self.
This, however, has an important consequence, namely that the self is identified with the real agent beyond the body’s acts. This makes Mīmāṃsā authors start far away from the Upaniṣadic, Sāṅkhya and Vedāntic ideas of an underlying self which is untouched by change and action.
Thus, Sacred Texts like the above sentence suggest that there is a self. Mīmāṃsā authors point also to further evidences, first and foremost our I-cognitions, that is, the cognition we have of an “I” whenever we refer to ourselves. Objectors can easily contend that “I” is used in sentences which in fact refer to the body, such as “I am tall”, thus concluding that this evidence is valueless. Mīmāṃsā authors answer that metaphorical usages of “I” as referring to the body do not rule out that it usually refers to the subject. Again, this claim bases on the idea that the Mīmāṃsā subject is not a changeless and super-individual entity, but that it is a changing and dynamic person, which can be rightly described in I-sentences such as “I am bright” or perhaps even “I am a scholar of Greek philosophy”.