Chih-i (538-597) was the principal founder of the T'ien-t'ai (Tendai) school, one of the most influential and enduring traditions of East Asian Buddhism. In the Mo-ho chih-kuan (Great calming, contemplation), an extraordinarily comprehensive treatise on the theory and practice of meditation, the revered master sets forth the \"perfect and sudden\" approach to Buddhahood, a distinctively East Asian conception of the Buddhist path regarded by Chih-i and his contemporaries as the epitome of the Buddha's teaching. In many ways Chih-i's systematization of Chinese Buddhist meditation practice led the way to the development of Ch'an (Zen) and Pure Land. Such an illustrious history and catholicity of appeal secure it a place alongside Buddhagosa's Visuddhimagga and Tsong-kha-pa's Lam-rim chen-mo as one of the great classics of Buddhist spirituality.\nThe original text of the Mo-ho chih-kuan consists of ten main chapters distributed over ten fascicles - the equivalent of four or five volumes in English. The translation of the first chapter is offered here together with the influential preface composed by Chih-i's disciple Kuan-ting (561-632), the man responsible for recording and editing the work. Known as the Synopsis, this chapter rehearses in condensed form the basic structure and thematic content of the Mo-ho chih-kuan as a whole. Because of the self-contained character of this chapter, T'ien-t'ai exegetes have treated it almost as a work unto itself; it contains an important and influential exposition of the Four Forms of Samadhi (not contained in the body of the text). The annotation provided in this volume draws from the authoritative commentary by Chan-jan (711-782). Scholars of Buddhism, most especially the T'ien-t'ai tradition, will appreciate the availability in English of this important work.