Chih Tun (314-366 A.D) whose tzu was Tao-lin, hailed from Honan province. His surname as a layman was Kuan. He is a representative Buddhist thinker of the Eastern Chin Dynasty (317-420 A.D.) but was also famed for his accomplishments in metaphysics and ch'ing-t'an. Since he frequented the imperial palace, and the nobility as well as celebrities liked to make friends with him，Buddhism became widespread among the upper classes and could develop rapidly.
Chih Tun was an expert in philosophical Taoism and had a thorough understanding of `prajna-paramita.` "Following in the footsteps of `Asvaghosa` and `Nagarjuna`, his thought corresponded with the fundamentals of truth and were in accordance with the real mark,"as The Biographies of Eminent Monks(fasc. 4) put it. In his later years, he expounded sutras in the mountains, his reputation spreading everywhere. The contemporaries of this leading metaphysician and Buddhist scholar admired his genius and eloquence as well as his scholarship and lofty character.
The present paper first investigates the core of Chih Tun's thought and compares it with contemporary commentaries on Chuang-tzu. Then an attempt is made at presenting the characteristics of his thought, like his idea of transcending thinking or his theory of sudden and gradualness. The author's intention was to gain thereby some understanding of the relationship between metaphysics in the Wei and Chin Dynasties (220-420 A.D.) and Chinese Buddhist thought of the earliest period.
