 Huayan is one of the most philosophically interesting and historically influential Buddhist schools. The distinctive contributions of Huayan include the doctrines that “one is all, and all is one,” that ultimate reality is ontologically identical with the illusory world of common sense, and that realizing these facts leads to universal compassion. Huayan is known also for the incisive nature of its arguments, particularly in Fazang’s “Rafter Dialogue” and Zongmi’s On the Origin of Humanity.