 The second characteristic of Abhidharma literature is its bent for discursive hermeneutics through catechetical exposition. The texts seem to be the products of discussions about the doctrine within the early Buddhist community. Again, such discussions are already found in the Āgama/Nikāya collections (e.g., M I 292–305, III 202–257): they often begin with a doctrinal point to be clarified and proceed to expound the topic at stake using a pedagogical method of question and answer. The texts also record more formal methods of argumentation and refutation of rival theories that shed light on the evolution of the Abhidharma as responding to the demands of an increasingly polemical environment. The process of institutionalization undergone by Buddhist thought at the time and the spread of the Buddhist community across the Indian subcontinent coincided with a transition from oral to written methods of textual transmission and with the rise of monastic debates concerning the doctrine among the various Buddhist schools. Intellectual assimilation and doctrinal disputes also existed between the Buddhist monastic community and the contemporaneous Sanskrit Grammarians, Jains, and Brahmanical schools with their evolving scholastic and analytical movements, which must also have contributed to the Abdhidharma discursive hermeneutics and argumentative style. The dialectic format and the display of awareness of differences in doctrinal interpretation are the hallmarks of the Kathāvatthu and the Vijñānakāya. Later on, post-canonical Abhidharma texts became complex philosophical treatises employing sophisticated methods of argumentation and independent investigations that resulted in doctrinal conclusions quite far removed from their canonical antecedents.