朱熹（1130－1200）〈觀書有感〉：「半畝方塘一鑑開，天光雲影共徘徊。問渠那得清如許，為有源頭活水來。」真學問，應窮源溯本，始能克竟其功。由於清代上承古代下啟當代，其特殊的《四庫》編纂時代背景，造就了清代具有總結《易》學端緒的特色，職是之故，析釐清楚《四庫提要》對於「《易》學兩派六宗」之說，便成了辨識《易》學根源與甄別諸論的重要線索與關鍵，從而幫助吾人重新看待《易》學的本質與淵源。本文旨在探討《四庫提要》的《易》學歸類方式之依據所在，析釐「兩派六宗」的內涵，囿於篇幅限制，不加以評論，容後撰專文再深入評議。

Zhu Xi (1130-1200) said in Guan Shu You Gan, -The half square pool as if spreading shining mirror. The blue doom and the colorful cloud lingering around the side of the pool, dancing and rippling. 'How can you always keep limpid as if stream?' It's all because the running water influxes and never stops.＂ The true knowledge should be traced back to the originality so as to refine the skill. Because Qing dynasty inherent from last era and light up the next generation and because of its unique background of writing Si Ku, it creates the characteristic that Qing dynasty has the ability to conclude Yi Xue; thus, clarifying the concept of Si Ku Ti Yao to Liang Pai Liu Zong in Yi Xue is the key to distinguish the root of Yi Xue and with this approach, we can further look over the nature and the origin of Yi Xue. The main idea of this context is to explore how to classify Yi Xue in Si Ku Ti Yao and clarify the connotation in Liang Pai Liu Zong. Because of the length of the article, I am not going to further explain and I would dig more hereafter.