The thesis focuses on the relationship between Sanskrit classical grammar, Ahludharma, and the debates between Madhyamaka and Yogacara. In particular, it shows how the karaka system, and the idea of laksana, influence philosophical argumentation in the context of medieval Indian Buddhist thought. The karaka system is the way in which classical Sanskrit grammarians discuss syntax, and in particular, actions and agency. Laksana means a defining trait, or a definition, at once a scholastic tool and a fundamental way to identify existent entities. There are five Chapters and two Appendices. Chapter One shows the close links between Sanskrit classical grammar and basic ideas in Buddhist thought, and isolates the karaka system as being most relevant in this regard. It also shows certain structural analogies between the karaka system and certain important features of Buddhist philosophy. Chapter Two is mostly based on Vasubandhu's Abhidharmakosabhasya and its sub-commentary; it highlights and reconstructs the discussions on laksana and agency found therein. Chapter Three shows how Madhyamaka understands similar issues, and what is the proper context and significance of its refutation of laksanas,. Chapter Four shifts the focus upon the Madhyamaka understanding of conventional truths, and the role of the laksana of Abhidharma, as well as of the karaka system, within satfivni) Chapter Five compares the Yogdcdra views on the very same topics. Appendix 1 is a translation of Prajnakaramati's commentary to Bodhicarydvatdra 9.1-34, a work where many of the philosophical debates discussed throughout the thesis are well represented. Appendix 2 is a photographic reproduction of a manuscript, containing an anonymous commentary to Nagarjuna's Lokatitastava.