The key development in the history of logic in India is the formulation and application of the trirupahetu, or the three forms of a (logical) reason. The Tarkasastra (Ru Shi Lun T1633) adopts the trirupahetu to distinguish good arguments from bad arguments (T1633 31b11 ff.).
The Tarkasastra (Ru Shi Lun), as we have it, comprises three chapters. The first chapter is an extended debate pertaining to the claim that there are truths. The second chapter enumerates and critically discusses 16 fallacies (jati). The third lists and explains 22 situations in which a participant in a debate is deemed to have lost (nigrahasthana). The paper critically assesses the text's treatment of five fallacies: the first, the second and the fourth, where the text applies the trirupahetu; and the fifth and sixth, where the text discusses two arguments typically associated with Nagarjuna (3rd century ce).