本文從司馬光洛陽時期的園林生活切入，分析其「獨樂」的生活境界與「中和」之道相配合的修身理論，及其實踐情形。在士人群聚遊宴風氣盛行的洛陽，司馬光闢建「獨樂園」，標舉「獨樂」的生活理想。「獨樂」既非困於「自傷」，更是揚棄「自傷」，而與「中和」之道相輔為用的士人生活理想。司馬光將「中和」理論貫徹於園林生活，踐行一種切於實際的心、身修養之道。獨樂境界與「中和」之道的連結，不同於程朱「中和」之論，也可以力破釋老虛浮之弊。持中治心，是引「自然」入「人文」，共享「中和」之最高原理。這是北宋儒學修身哲學的成就之一，值得留意。

Based on Sima Guang's writings on his garden from the period when he lived in Luoyang, this article analyzes a theory of self-cultivation contained in the combination of his philosophy of daily life, ”Solitary Enjoyment” (du le), and his method, ”Harmony of the Mean” (zhong he), thereby considering the ways he put this theory into practice in his own life. Within the culture of Literati gatherings that flourished in Luoyang during this period, Sima's choice of ”Garden of Solitary Enjoyment” as the name for his own garden, highlights this key concept in his philosophy of daily life. For him, Solitary Enjoyment was an antidote to his personal grievances at self-imposed exile from court, while Harmony of the Mean was the means to support this philosophy of daily life. In his garden, Sima could realize his theory of Harmony of the Mean and more nearly approach an actualization of his cultivation of body and mind. Moreover, movement and meaning of the body was the most fitting expression of Centered Harmony. This combination of Solitary Enjoyment and Harmony of the Mean was thus a means to assuage his own feelings of personally wrongs. For a literatus who held to the mean and controlled his emotions, this enjoyment of Harmony of the Mean was the highest means of drawing Nature (zi ran) into Humanism (ren wen). At the same time, it was one of the high points of the Song Confucian tradition of self-cultivation.