In Buddhism, great importance has been attached from the very outset to the mind, which is called citta, manas, vijñāna, etc., in Sanskrit. The Buddha would probably have observed his mind in a very careful manner, taught what he had learnt from this experience to his disciples, and encouraged each of them to train their minds in order to attain eternal peace (nirvā?a). In this article, I set out to analyze and interpret some noteworthy Buddhistic interpretations of the mind with special reference to the idea of sanjie weixin in the history of East Asian Buddhism, including the Huayan and Chan schools, for the purpose of re-evaluating the mind, which seems to have become overwhelmed by material concerns in modern society. My main conclusions are as follows: (1) The thesis of cittamātram traidhātukam in the Da?abhūmika-sūtra is based on deep meditation and implies that each human being creates his or her own universe of cognition. (2) Generally speaking, the substantial existence of the three worlds (tridhātu) is wholely rejected in the context of Indian Buddhism. (3) In East Asian Buddhism, the reality of being is strongly upheld, while the sensitiveness or perceptiveness of the mind as an aspect of the original meaning of weixin tends to be disregarded, although it is almost always stressed. (4) We now need to realize the importance of the mind, which bears the field of subjectivity that not only covers but also changes the whole circumstances, by understanding the nature of the teaching of sanjie weixin.
