本文試圖探究人們在表達公共論述，該如何尋找一個合理的基點。特別是在「探究真理」與「閒談」等極端意見之外，能找到更合理的判準嗎?例如在大眾媒體發達的時代，無論當紅的政治人物或網路意見領袖都會對輿論造成影響，甚至左右政府決策，相關論述卻不見得合理。本文將分析漢娜.鄂蘭(Hannah Arendt)的「共同體感受」(sensus communis)與「擴展心靈」(the enlarged mentality)等概念，並將它們對比於哈伯 瑪斯的公共領域理論，以得出合理的政治論述框架。

This article attempts to explore how to build a reasonable basis for expressing public discourse. Can a more reasonable criterion be found, especially beyond extreme opinion spectrum such as "exploring the truth" and "gossip"? For example, in the era of mass media, popular political figures or online opinion leaders have a massive impact on public opinion and even have power to influence government decision-making, but the relevant arguments are not necessarily reasonable. This article will analyze Hannah Arendt’s theory of “sensus communis” and “the enlarged mentality” and contrast them with Habermas's theory of the public sphere to find a rational framework for political discourse .