本文分析康士坦的自由觀念、平等思想與憲政民主主張。康士坦區分自由為古代人的自由與現代人的自由，大體上褒揚後者而懷疑前者在商業社會的實踐可能。不過康士坦絕非柏林所說的「消極自由」代言人，他事實上也重視政治參與的價值。在平等思想方面，康士坦採取蘇格蘭政治經濟學派的立場，認為政治權利的平等與經濟權利的不平等並非水火不容—— 雖然在宗教情操的影響下，人類最終還是會達致普遍平等的境況。康士坦的憲政主義排除至高無上的主權概念，堅信基本人權不容侵犯，而權力分立與代議民主則是落實此項原則之保障。最後，本文也比較康士坦所代表的十九世紀自由主義與當前自由主義思想的異同，指出在「普遍主義」、「價值中立」、「愛國情操」等議題上，康士坦的思想如何可能提供我們關於自由主義的另類思考。

　　　　　In the article I examine Benjamin Constant's ideas of liberty, equality and constitutional democracy. Constant is celebrated for his contrast of “the liberty of the ancients” and “the liberty of the moderns,” with a seeming praise for the latter and doubt of the former. Close reading reveals, however, that Constant is as affirmative to “positive liberty” as to “negative liberty.” His concept of equality also displays an ambiguous spirit: the equality of political rights is compatible with the inequality of wealth and property, though in the long run human beings are destined to live in a condition of general equality. In the issue of constitutionalism, Constant criticizes Rousseau's idea of unlimited sovereignty and Hobbes' absolute power, arguing that the only way to safeguard civil rights is separation of powers and representative democracy. Last, I point out in what sense Constant's liberalism can throw light on the weakness of contemporary liberalism, at least in regard to the question of universality, neutrality and patriotism.