本文的中心論旨，主要有二：其一，是陳述當前審議民主研究所呈現出來的、某種偏向於科學主義的論述趨勢；其二，更為重要的，是藉著引述柏林（Isaiah Berlin）的實踐理性觀點，轉從道德與政治哲學的視野，對科學主義進行初步檢討，並就理性與正當性等重大的公共議題，提出不同的理論參照。至於連接這兩部分討論的橋樑，則是柏林關於一元主義與多元主義之歷史轉移的觀念史研究。於柏林看來，科學主義實是啟蒙計畫的遺產、一元主義的變形，然而，實際刻畫現代民主社會的實踐處境，卻是他所闡揚的價值多元主義。就此而言，現代民主社會所面臨的一項嚴肅的理論課題，是如何擺脫一元主義與科學主義的糾纏，而在多元主義的歷史條件下，認真對待政治自由與政治判斷。

The purpose of this article is twofold: firstly, it aims to recapitulate the scientistic orientation inherent in contemporary deliberative democracy theory; secondly and more importantly, it offers an alternative theoretical retrospection to this scientistic inclination in understanding core issues such as reason and legitimacy in political realms. The reflections are inspired by Isaiah Berlin’s study of the history of ideas, through which Berlin expounds the historical transition from monism to pluralism and the significance of practical reasoning. From this Berlinian view, scientism is the fruit of the Enlightenment project and the metamorphosis of philosophical monism. Nevertheless, the practical predicament faced in modern democracies, according to Berlin, is unequivocally pluralist. To cope with this predicament, one needs to be wary of the persevering dominance of monism and scientism, and take political freedom and political judgment more seriously under the historical condition of value pluralism.