Great Calming and Contemplation (Mohe zhiguan)

The major meditation treatise of Zhiyi, founder of the Tiantai school, delivered as lectures in 594 and recorded and edited by his disciple Guanding. It sets out a complete path of 'calming' (zhi, Sanskrit śamatha) and 'contemplation' (guan, vipaśyanā). The work was planned in ten chapters, but the lectures stopped partway through the seventh. The early chapters explain the aim of awakening and describe four kinds of samādhi: constant sitting, constant walking, part walking and part sitting, and neither walking nor sitting, which takes any activity as the object of practice. Later chapters set out preparatory disciplines and then the ten modes of contemplation, applied to objects such as the aggregates, the passions, illness, karma and demonic states. Here Zhiyi teaches the threefold contemplation of emptiness, the provisional and the middle within a single mind, and the well-known claim that three thousand realms are present in a single moment of thought.

It is the most systematic meditation manual in Chinese Buddhism and the key source for Tiantai philosophy, showing how abstract teaching on emptiness was turned into a detailed practice of the mind.