國族是什麼？國族主義又是什麼？ 面對許許多多歧異又紛雜的關於國族與國族主義的論述，本論文嘗試另闢蹊徑，從哲學層面來闡釋這一問題。本文區分國族之形成的主觀條件與客觀條件，認為國族不同於國家與民族，不能單純以客觀條件作為依據，而是必須以主觀條件作為依據。本文又進一步區分形式條件與實質條件，認為主觀條件中必須同時包括形式條件與實質條件，也就是說，一群人若要組成一個國族共同體，這些人必須是出於各自之自由意志，決定共同組成一個不同於其他之團體的共同體，而且要尋找並形成某種歸屬核心，當做共同體之根本質素，使之成為維繫共同體之長久存續的道德基礎。 本文以羅爾斯的政治自由主義與民族觀點作為論述根基，由此開展一種新的國族觀點，一種特殊的、只在自由主義式的民主政治體制中存在的政治共同體。並認為，人類理性必然要求人類朝這樣的政治共同體邁進，使每個人的自由都夠有最合理的、最和諧的發展，而不致釀成戰爭衝突。 / What is “nation”? And what is “nationalism”? There are many diverse and conflicting theories about nations and nationalism. We look into these theories and then abandon them because there are too many definitions. We believe that the nation is a special and unique political community and it accrues only in the liberal constitutional democracy of the modern period. There are two kinds of conditions for the construction of a nation: the subjective condition and the objective conditions. The former is an inner characteristic, while the later are external features. Unlike a state or a people, a nation must be founded the subjective condition as much as the objective conditions. In other words, the subjective condition, human beings’ free will, is the essential bedrock for the construction of a nation. In this perspective, we further distinguish the formal condition from the substantive condition. The formal condition has no content; its only function is pure decision-making. If a group of people is willing to associate together and form a community, it’s necessary for them not only to make a decision but also to decide what community they want to be. Furthermore, they have to search for and fashion their own defining core as the underlying element of the community as well as the moral foundation for the continuance of the community. Based on John Rawls’ political liberalism and his views about peoples, this paper evolves a new viewpoint of the nation as a unique political community that exists only in the liberal democracy. We also assume it is required by human reason that mankind should move forward to such a political community, enabling everyone to develop his or her liberty in the most reasonable and harmonious way without leading to wars and conflicts.