六朝時期的三教交涉，一直是學術文化史上既重大而又複雜紛繁的課題，其中道、佛二教，在當時既各擅勝場，亦相激相盪。洎乎齊、梁，二教的矛盾對立加深，至終顯題化爲「夷夏論爭」，然而在這樣的氛圍中，卻有一位「門世恭佛」的名士張融(444-497)，嘗試爲二家作出調節，而有《門律•通源》之論。〈通源〉之論，顧名思義，在於融攝道、佛二家，張融因此而提出「道本佛迹」的主張，實則爲一種開放性的《老》學理解。其理論特色，在以道釋佛的前提下，又復援佛以入道，進一步推闡出其「得意有本」的「道／佛」融攝觀：就「理境」言，著重於「性靈」（心性）主體臻於「神靜」的體道之境；就「道體」來說，以《莊》學之環中合同《老》學之「虛無」，復基於此言「老藏即色」乃「盡無」亦「盡有」之化，以達到其張皇對「道」本闡釋的目的。張融的〈通源〉之論，雖爲融攝「道／佛」提供了一個解決可能，卻仍失之究竟。周顒的反駁，基於〈三宗論〉的佛教立場釐析辨異，言其道本因「藏」即色，故有闕未「盡」，僅爲「知有」、「知無」，有類當時「空假名宗」分談二諦，謂「俗諦」假有，「真諦」空無的說法。質言之，即滯於「本／迹」、「真／俗」在理境上的實有意義，故失之相即，是一種未完全脫化玄學本體論的理論型態，周顒以此作出辨異，並至終推闡出以佛本歸統三教的主張。〈通源〉之論，就學術思想史的意義來說，可視爲道教面對佛教的普及與佛理教義的強勢威脅，並在「夷夏論爭」的緊張關係中，嘗試於理論上提昇與轉型的自覺表現，就其與佛理思維應對的跡象來看，這當中亦蘊涵道教義理向「重玄學」發展過渡的因素。

Syncretism of the three main teachings in the Six Dynasties has always been a significant and complex subject in the studies of the history of literature and culture. Among them, Daoism and Buddhism are both influential religions with numerous adherents, thus leading to contradictions and arguments between them. Up until the Qi and Liang dynasties, the clash between the two religions deepened and exacerbated, and finally concretized the argument of "barbarian (foreign) vs Chinese (orthodox)." In this social atmosphere, however, one prominent scholar, Zhang Rong, tried to mediate between the two schools and developed his argument in "Tongyuan" in Menlü. The implication of "Tongyuan" is to adjust both Daoism and Buddhism; thus Zhang Rong proposed that Daoism be the foundation with Buddhism as the form. It is by nature a broad-minded interpretation of Lao Zi with the premise that by using Dao to explain Buddhism, the latter can be merged into the former. It is further developed into a harmonious mixture of Daoist/Buddhist philosophy. In terms of the "logic realm," it focuses on the subject's conscience (mind-nature) in order to achieve inner stillness. On the other hand, in terms of the context of teaching, it combines Zhuang Zi's "middle thought" and Lao Zi's "nothingness." Zhou Yong's rebuttal is based on Buddhism's "Theory of Three Schools" to clarify the distinction between the two teachings. He contends that Lao Zi's "nothingness" is still limited to the "logic realm" of "knowing" (the "being" or "non-being"), which is similar to the "false (or exoteric) religion." As a result, Zhou concludes that all three teachings should go back to Buddhism. In the end, the historical and cultural meaning of "Tongyuan" lies in its self-consciously upgraded and transformed theorization in the face of the threat of rising Buddhism and its doctrine, and the tension from the "foreign-orthodox" theory at the time. It also explains the transitional factors that lead Daoist teachings towards the development of the Chong Xuan School.