Not all Purva Mimamsa followers believed in the existence of Brahman, but they all believed in the Jivatma.
They also believed the verses in the Upanishads that speak of Brahman actually refer to the soul.
Now, the word "Brahmana" means 'one who knows Brahman,' but since they believed Brahman refers to the Jivatma, does this mean they thought "Brahmana" means one who knows the Jivatma?
But they didn't consider self knowledge all that important, so how did this etymology affect their views?
Or perhaps there is another valid etymology of "Brahmana" ?