亞里斯多德向來被推崇為西方政治學的鼻祖，但是他究竟怎樣理解「政治」卻是一個鮮少為人注意的問題。本文試圖從亞里斯多德關於「政治動物」、「政治社群」、「政治統治」等概念之陳述，分析出他對「政治」本質的暸解。作者發現：在生物性的基礎上，亞里斯多德是以「群居共利」界定政治。在人文世界的脈絡裡，政治是指人類獨有的「理性言說」本能。這個本能落實到政治體制上，則以平等互利為統治原則的「共和制」最能符應政治生活的理趣。由於「理性言說」使人的政治性突出於其他動物的政治性之上，使合理的城邦生活成為可能，並且保證了自由公民之間可以採行平等的輪流統治，因此「理性言說」可以說是亞里斯多德「政治」概念的核心。 　以「理性言說」界定政治，其獨特處是與當前視政治為權謀詭計之流行觀念形成強烈對比。亞里斯多德並非蒙昧於權術在實際政治中的份量，但是他堅信政治的真義不在鬥爭，而在理性溝通與說服。其立場之堅定，理據之堅強，足以促使我們反省現代政治理念的偏失之處。本文末了對這些問題做了簡短的討論。

　　　　　Aristotle has long been regarded as the founder of western political science, yet what he understands by "the political" is a question that few scholars have paid attention to. The article tries to find out Aristotle's understanding of "the political" by examining his arguments about "political animal", "political rule", etc. My discovery is that, in biological terms, Aristotle defines "the political" as "living together and working towards a common end;" and in humanistic terms, as "having the capability of logos (rational speech)." When logos is realized in the political world, we finds its best configuration in polity, a system based on equal-rule. As logos makes man "more political" than other political animals, distinguishes the "correct" regimes from the "variant" ones, and makes possible equal-rule among free citizens, it is the essence of Aristotole's concept of "the political." The advantage of defining politics as something related to logos is to demonstrate the sharp contrast between Aristotle's politics and power politics. Aristotle is not ignorant of the role power plays in real politics, but he insists that the essence of politics be rational communication and persuasion, rather than power struggle. The argument of Aristotle's rational politics is so convincing that it deserves not only a careful exploration, but a reflection on our part upon the problematic of the modern view of politics.