Khyātivāda (Sanskrit: ख्यातिवादाः) is the term used to refer to the Indian Theories of Perceptual Error – khyāti (ख्यातिः) besides referring to 'fame', 'renoun' etc., in Samkhya philosophy refers to the 'erroneous conception' (of the Atman) or 'false apprehension', and vāda means - 'proposition', 'discourse', 'argument'. These are all theories that deal with the nature of the object of illusory perception and not with the nature of the subject, whether the error consists in the object or in the subject’s cognition. There are five principal theories dealing with perceptual errors, which are:-