老子的道向來被認為是形而上的絕對真實，它周行不殆、獨立不改，居萬物之先並為萬物生成的根源。惟牟宗三卻獨標新義，他雖然同意老子的道具有存有論的性格，但它並非一「客觀的實有」而是繫屬於人的「主觀的境界」；質言之，道就是虛靜自然，亦即通過人為進作之消解、所證成之無為無執的開放心靈。牟宗三的「主觀境界說」義理別緻而論詮精當，其最大的貢獻是證明了老莊之間慧命相續的可能，也為人間道家的何所是，完成了理論的建構。然而「主觀境界說」是否完全符應了《道德經》的原義 ? 它沒有以莊解老的嫌疑 ? 凡此「客觀實有論」者都一直強烈批評，彼此之孰是執非，也成了學界間長期以來所爭或不下的難題。本文之做，是在全懿呈現「主觀境界說」的精義，並忠實記錄牟宗三這劃時代見解在觀念及表達上的發展過程。其目的之一困在表揚牟先生貞定人間道家之地位的精采，並同時指出，他的限制是忽略黃老道家的價值及其在思想史中的重要地位；另一方面則希望給由此文的清楚勾勒，有效提供「客觀實有論」者在反駁對方之前，能先獲得恰當的理解，以免流於無的放矢之機。

　　　　　 The Dao of Lao Zi has long been viewed as a phenomenological absolute reality, which is restless, everlasting movement, independent and changeless. Preceding all things, this Dao is held to be the source of the formation of all beings. Although concurring in the view that Lao Zi's Dao is characterized by ontological thinking , Mon Zong San presents the new interpretation that the Dao is not an "objective reality" but rather belongs to the "subjective realm" of man. Mou Zong San says, in essence, that the Dao is Nature, and embodied in a boundless mind without action and attachment through the dissolution of artifice. The "subjective realm interpretation" of Mou Zong San is a subtle idea and is supported by his refined and precise arguments. This interpretation's greatest contributions are that it demonstrates the possiblity of the intellectual succession between Lao Zi and Zhuang Zi, and that it erects a theoretical framework for humanistic Daoism. However, it must be asked whether or not the "subjective realm interpretation" fully reflects the original meaning of the Dao De Jing. Does it exhibit the suspicion to explain Lao Zi through Zhuang Zi? Supporters of the "objective reality theory" have constantly and strongly criticized the aforesaid interpretation, and the ideological duel between the two camps has become a long-standing subject of endless contention in