The science of logic in Hinduism is known as Tarka Vidya. Nyaya is rendered as tarkavidya by the Mitakshara commentary on Yajnavalkya Smriti (I.3), which further states that fourteen vidyas are the means of knowing dharma. Tarka is an important aid to the attainment of valid knowledge and is known as one of the sixteen categories of Nyaya Philosophy.
The word tarka occurs in Katha Upanishad (II.9), where it is said that knowledge of Self cannot be obtained by only ratiocination. The earlier verse (II.8) of the text states, ‘soul being more subtle than anything is not to be obtained by arguing.’ (aniyanhyatarkyamanupramanat).
Gautama Dharmasutra (II.23) defines tarka as ‘the means for securing justice among contending parties.’ Tarka is accepted as an anga (limb) of Yoga in Maitrayani Upanishad (VI.20), which further quotes a passage stating that by control of speech, mind and prana (breath), one apprehends Brahman with the help of tarka. But the Mahabharata (VI 5.12) states – ‘one should not try to solve incomprehensible matters by ratiocination.’
It is laid down by Smriti writers themselves that blindly following the words of shastra would lead to loss of dharma and that, in case of conflict between two smritis, reasoning should be resorted to and popular opinions and practices should be considered. However, it should not be supposed that Shankaracharya and other India writers desired to throw reasoning overboard altogether. What they emphasized was that mere reasoning of one or more men should not as a rule be followed if the conclusions arrived at by reasoning are in direct conflict with Vedic and Smriti texts (Brahmasutra II.1.1, 11). Hence, tarka vidya has some direct impact on men in society and it is to be considered as ‘true knowledge’.