 In the oldest Sāṃkhya tradition, perception is the functioning of a sense organ. This is clearly inadequate, as the ancient skeptic Jayarāśi Bhaṭṭa (c. 8th century CE) is quick to point out. Perception in this sense cannot be a means of knowledge (pramāṇa) as it does not distinguish between proper and improper functioning of sense organs and, therefore, between valid and erroneous perceptions. A more sophisticated definition is later devised wherein perception is “an ascertainment [of buddhi or intellect] in regard to a sense faculty (Sāṃkhyakārikā 5 in Yuktīdipikā)”. This implies that perception is a modification of the intellect in the form of selective ascertainment of an object, brought about by the activity or functioning of a sense faculty. In some respects, this characterization of perception as an “ascertainment” of the intellect neatly captures the idea that perception, being an instrument of knowledge, is the primary means of knowledge. Ascertainment residing in the intellect is regarded as the instrument of perception, while residing in the self it is regarded as the result of the process of perception. Furthermore, the Sāṃkhyakārikā states that the function of the senses with regard to the objects is “a mere seeing” (Sāṃkhyakārikā, 28b), and the function of the intellect, referred to as ascertainment, can be thought of as “identification” of the object as in “this is a cow”, etc. (Sāṃkhyakārikā 5ab). This suggests a two-stage process: first the functioning of the sense faculty results in “mere seeing” of the object (non-conceptualized awareness) and, later this mere seeing is acted upon by the intellect or mind and results in a conceptual identification of the object. This two-stage process is very similar to the detailed account of conceptual (savikalpaka) perception offered by the Mīmāṃsakas and the Naiyāyikas.