Madhyamaka(中觀學)teaching is essentially a continuation of Prajñāpāramitā(般若波羅蜜) teaching. Thus, all the major themes of the Prajñāpāramitā-sūtras(般若經) are also central to the Madhyamaka(中觀學), forming the general doctrinal background to the polemical arguments which abound in Madhyamaka(中觀學) writings. The Madhyamaka(中觀學) upholds "non-attachment" as the most basic Buddhist principle. So it takes the abandoning of and the total separation from all things as the primary features of the "great wisdom(摩訶般若)", and maintains that it is by not coursing in any dharma(法) and by not acquiring any dharma(法) that a bodhisattva(菩薩) acquires the perfection of wisdom. Furthermore, the Madhyamaka(中觀學) call for non-attachment is as comprehensive as that of the Prajñāpāramitā-sūtras(般若經), as can be seen from the advice to give up the thoughts of nirvāna(涅槃) and of the Buddha(佛). Seng-chao(僧肇) was a key figure in the first phase of the development of Chinese Madhyamaka(中觀學), and the Chao-lun(肇論), his collection of essays, demonstrated almost all the main features of Madhyamaka(中觀學) thought. These features included the emphasis on absolute non-attachment and non-discrimination, the upholding of the principle of non-duality, the teaching of the equality of all dharmas(諸法), the application of the idea of causality to the explanation of the idea of emptiness, and the employment of the logical method of refutation. Both as a philosophical and as a Buddhist work, the Chao-lun( )was clearly superior to the other 肇論Buddhist writings of its period, and its accuracy and consistency in the treatment of distinctive Buddhist themes were truly remarkable.