 During the Han period, commentaries emerged as the principal medium of philosophic discourse. Methodologically, Han commentaries emphasized detailed explanation of individual words and phrases of the classics. This necessitated heavy specialization, which heightened virtuosity but also opened the door for vain scholastic display and fragmentation of learning. One of the most important debates in Xuanxue confronts directly the question of interpretation, which brought hermeneutics to the forefront of Chinese philosophy. More will be said about this debate later.