十八世紀無疑是人類歷史上驚心動魄的一個年代，先是美國獨立運動造就了世界上第一個新興民主國家，而後法國大革命所產生的巨大政治效應更是遍及歐洲，不僅撼動封建體制的大廈，同時揭示民主時代的到來；托克維爾身處歷史劇變之際，對於民主此一沛然莫之能禦的洪流有著深刻的體察與省思。自由的概念在托克維爾的理論體系中佔居極重要的位置，當民主浪潮衝破封建貴族的老舊體制卻同時導致人民趨於同化甚至庸俗化時，為避免再度面臨宰制與奴役的命運，托克維爾主張公民必須更積極地實踐自由，培養參與公共事務的習性與精神。因此，美國傳統中的「鄉鎮制度」(township)與陪審團機制，以及私人通過行會途徑組織次級公民團體等活動皆為托克維爾賦予甚高的民主意涵；由此看來，托克維爾對於自由所抱持的高度期盼與契約論傳統自由主義所主張的「個人享有免於被干涉的自由」之間實存在根本性的差異，而與共和主義推崇公民「行動性」(agency)之傳統理念相互契合；但是，這樣的自由內涵並非意味著毫無章法的衝撞，而是在穩健的政治制度之架構下，進行理性與節制的公民政治參與，如此則又與新羅馬共和傳統重視制度(institution)的精神相互呼應。結合前述兩個面向，我們稱之為「制度共和主義」式(institutional republicanism)的自由概念。本文即試圖體現托克維爾的理論內涵中所延續的共和主義價值，期望對其自由觀進行更寬廣的闡釋。

The eighteenth century is doubtlessly an astonishing chapter in human history. Following America's independence that brought the first new democratic country to the world, the French Revolution further aroused tremendous political effects all over Europe, shocked the foundation of feudalism, and announced the advent of democratic era. Confronted with all these historical impacts, Tocqueville has achieved profound understanding and retrospection on the inevitable prevalence of democracy. The concept of liberty plays a very important role in Tocqueville's theory. As the wave of democracy crashed outmoded institution of feudalism, it also caused people to grow. assimilated, or even philistine. In light of this, Tocqueville proposed that, in order to preclude domination and slavery, people should more actively grasp their liberty and develop the habitude and spirit of participating public affairs. Therefore, township and jury system in American tradition, as well as individual activities of organizing secondary civil groups through gilds, are highly regarded by Tocqueville with democratic connotation. From this viewpoint, Tocqueville's great expectation on liberty is essentially different from "human's liberty from interference" of contractarian liberalism but is in harmony with the conventional idea of people's "agency" in republicanism. This connotation of liberty, however, doesn't imply clashes without limit but suggests reasonable and restrained political participation within the schema of stable political institution. Thus, the concept echoes the conventional appreciation upon institution in roman republicanism. The researcher regards the integration of the aforementioned two aspects as "liberty of institutional republicanism". This research intends to embody the republicanism value in Tocqueville's theory with an expectation to broaden the definition of liberty.