This paper is a study of debate practices as seen in the Nyāyasūtra and a number of commentaries. It concentrates on the ‘Points of Defeat ’, i.e., those occasions that if met in debate would entail defeat. The conditions under which a debater would meet with defeat were discussed widely in India and have also attracted considerable attention from modern scholars. In order to better understand this subject, use is made of some of the intuitions about language and conversation that (...) we owe to the philosopher H. P. Grice as well as of some recent theoretical advances in argumentation theory and informal logic, particularly of those most influenced by Grice’s thought. The Points of Defeat are studied both individually and as a group and it is shown that they point towards the practice of debating as being a rational, cooperative and goal-directed activity. (shrink)