本文藉由「血氣心知」與「身體理性」(body-reason; Leib-vernunft) 這兩個概念探討戴震與尼采(Nietzsche) 的修身哲學與文化批判的關係。戴震以「血氣心知」來界定人性，他主張「理存於欲」，貫徹了自明朝中葉以來的形上批判的工作，亦即將宋儒修身哲學的重心從「超越地返回存有根源的體證」轉向為「經驗地展開氣化整全的實現」。尼采則由「身體理性」的提出，反轉以意識主體為基礎的「再現的真理觀」，形式同一的先驗自我被拒斥為理性的虛構，而流動的經驗自我則在回返自然的要求中實現「體現的真理觀」。對於戴震和尼采來說，理性從來就不可能離開身體，倘若以為價值的創造可以透過割離身體與情感的途徑來完成，將是一種病態的文化。「血氣心知」和「身體理性」兩個概念的提出是為了貫通自然本能與人文理性，健康的、積極的文化並不歧視身體與自然，而是肯定其高貴之目的及意義。

This article explores the concepts of xieqi xinzhi 血氣心知 and body­reason proposed by Dai Zhen (戴震, 1724-1777) and Friedrich Nietzsche (1844-1900), respectively. It also discusses the re1ation between the two philosophers' cultural critiques and their philosophy of self-cultivation. Dai Zhen defined human nature by his term xieqi xinzhi and advocated that "reason exists in sense." In so doing, he summed up critiques on metaphysical thought from the middle part of the Ming dynasty to his day. That is to say, he transformed the Song Confucians' emphasis on "a transcendental retum to proof through xinxing 心性, which contains the origin of all things" into "an empirical understanding of the incarnation of reality as a whole." Similarly, the cultural critique of Nietzsche suggested a reversal from the "truth of representation" implied by the ground of conscious-subject to the "truth of embodiment" being ruled by the body itself. According to Nietzsche, a formal identity of transcendental self would therefore be refused, and "body-reason" is for him a floatingself which tries to provide us a fluid and creative norm, that could be established by retuming to nature. His thoughts offers a solution to overcome the division between sense and reason in Platonism and Kantian ethics.