The scope and audacity of Bhaṭṭoji Dīkṣita’s contributions to Sanskrit grammar has made him one of early-modern India’s most influential, if not controversial, intellectuals. Yet for as consequential as Bhaṭṭoji’s has been for histories of early-modern scholasticism, his extensive corpus of non-grammatical writings has attracted relatively little scholarly attention. This paper examines Bhaṭṭoji’s work on Vedānta, the Tattvakaustubha, in order to gage how issues of language became an increasingly important site of inter-religious critique among early-modern Vedāntins. In the Tattvakaustubha, Bhaṭṭoji (...) reproaches Madhvācārya, the founder of the eponymous Mādhva or Dvaita Vedānta system, for his use of ungrammatical words. In extending his accusations of grammatical negligence to include Madhva’s early commentator Jayatīrtha, Bhaṭṭoji sought to undermine Mādhva claims to authoritative scriptural exegesis. Bhaṭṭoji’s provocation impelled later Mādhva scholars like Rāghavendratīrtha to bring a sharper set of grammatical tools to core commentarial works. Where others have pointed to Vyāsatīrtha as a turning point for Mādhva scholastic discourse in the areas of Pūrva Mīmāṃsā and Navya Nyāya, this paper suggests that it was the post-Bhaṭṭoji scholar Rāghavendratīrtha who brought a hitherto unrivaled grammatical expertise to Mādhva writings. That both Mādhva and Advaita Vedāntins wielded grammatical legitimacy as a cudgel against the other raises important socio-historical questions about the relationship between text-criticism, conceptions of scholastic legitimacy, and inter-religious contestation in early-modern South Asia. (shrink)