Jayarāśi Bhaṭṭa was an 8th or 9th century Indian philosopher (dated to ca. 770-830 by Franco 1994), author of the Tattvopaplavasimha (tattva-upa.plava-simha "The Lion that Devours All Categories"/"The Upsetting of All Principles"). The manuscript of this work was discovered in 1926 and published in 1940 (eds. Sanghavi and Parikh).
The text is often regarded as belonging to the Cārvāka school, which would make it the only extant authentic text from that school. Werner (1995) is sceptical of that attribution, while accepting that the text is an important secondary source for Cārvāka. Dr. Salunkhe holds that Jayarashi Bhatta did not belong to the Charvaka school of philosophy as he denies even Pratyakşa pramana and four Mahābhūtas that Charvaka had accepted. He notes Jayarshi as an agnostic and anti-philosophic rather than a materialistic Lokayat.[1]
The Tattvopaplavasimha examines epistemology, where he considers the pramana (sources of knowledge) accepted in establishing conclusions (perception, inference, and testimony), and proves that none of them are sufficient for establishing knowledge. Inference relies on inductive reasoning, which cannot be shown to be universal premises. Testimony requires the reliability of the witness, which must be established by another of the pramana. Even direct perception cannot establish truth, because it requires that the perception not be erroneous or illusory, which also cannot be established. Therefore, Jayarasi argues that none of the sources of knowledge are valid, and nothing can be known for certain.
Jayarasi challenged the astika establishment's belief in supernatural beings by attacking their epistemology. Since none of the sources of knowledge are valid, how can anything be said about these beings? Therefore, he argued for the reasonability of atheism, and that happiness in one's life is the most reasonable goal. Jayarasi represented extreme skepticism of the Cārvāka school, claiming no school of philosophy can claim its view of reality as knowledge, including the Cārvāka itself; however, because Cārvāka philosophy represents common sense, it could be used as a guide.