Ven,Yin-shung's masterpiece "The Exploration of `sunna` "elucidates fluently the `sunna` of `agama`,Sectarian,Prajnna and even Nagarjuna. This work leads scholars to understand the meaning of `sunna` and inspires the author of this paper to read again the four `agamas` and the five nikayas. This paper is thus resulted. Ven,Yin-shung says, "The `sunna` of `agama` is the way of liberation which emphasizes on practice. "His enlightening view is mainly based on this opinion. He also touches on the `desana` and `vibhanga` of `sunna`. Regarding the classification of `sunna`,he describes, following the development of Indian Buddhism,in two chapters--the `Sunna` of Sectarian Buddhism and the `sunna` of Prajnna. Thanks to these clarifications, this paper intends to make a review and discussion on the `desana` and vibhanga of `sunna` as contained in the four `agamas` and the five nikayas.
Firstly,this paper refers to the Pali nikayas and the Chinese `agamas` to explain the meanings of `sunna`.
Secondly,in `agamas` and nikayas there are already "the separate establishment" or "classification" of "internal `sunna`,external `sunna`,internal-external `sunna`,worldly `sunna`,great `sunna`,ultimate truth `sunna` , absolute-unsurpassed-purified `sunna`,etc." The instructions and explanations of `sunna` are made in order to cultivate the mind,to understand the Reality,to purify one's wisdom and view,and,to realize nirvana. Therefore,the original meaning of the term "`sunna`" was extended or even new term was invented in later ages of Sectarian Buddhism and `Mahayana` Buddhism. These "extended meanings" and "invented meanings" can be clearly traced back to `agama` or nikaya.
Due to the limitation of space,this paper only deals with the above-mentioned problems by referring to the `sutras` and abhidharmas. In future,the author will write another paper to prove that while primitive Buddhism drew up the anguttara nikaya, "' `sunna` ' was used to replace 'non-self'". As to "the correct practice of the `sunna` samadhi and the `sunna` view" and "other teachings regarding `sunna` "will be treated at last.