 Jayarāśi Bhaṭṭa, who most likely flourished between 800–840 probably in Southern India, was an Indian philosopher, a ‘qualified sceptic’, resorting to a kind of methodological scepticism, affiliated to the materialist Cārvāka / Lokāyata school of thought, the author of one of most extraordinary philosophical works in India, the Tattvôpaplava-siṁha (‘The Lion of the Dissolution of [all] Categories’ or ‘The Lion [Destroying] the Delusion of Categories’). His main claim is that it is not possible to arrive at true knowledge with standard means recognized by the traditionally adopted model of cognitive procedures (pramāṇa) in Indian epistemology, because one should first properly define basic criteria of validity for valid cognitive procedures, which is not possible without a prior true knowledge of reality against which we could test the procedures for validity etc. As it is traditionally argued, our knowledge of reality and of objects depends on valid cognitive procedures. However, as Jayarāśi points out, all valid cognitive procedures are either fundamentally flawed and ultimately unreliable or they require further valid cognitive procedures, and these stand in the same need etc. Therefore, within the traditional epistemological model, we can neither formulate proper definitions of valid cognitive procedures nor define what reality is and what basic categories are. This is at least the case, he claims, with all the cognitive tools and epistemological categories which are traditionally claimed to be now at our disposal. He has been differently classified as a sceptic, agnostic or materialist.