律學是《周易時論合編》的其中一項核心內容。《周易時論合編》收錄的多篇文章，不只表現出對十二律呂計算的興趣，也對其中蘊含的哲學意義有所關切。該書的作者方以智 (1611-1671) 正是從律學的推算中獲得靈感，以此發展出一套獨特的《易》學詮釋。本文首先考察《周易時論合編》對律學和數學的看法，再討論漢代以降的象數學如何影響其表達模式。接著，透過對「聲數同原」觀的分析，我們得以描繪出方以智哲學系統的大致輪廓，以及他如何看待律學與哲學之間的關聯。最後，上述的考察成果可以幫助我們理解方以智和明末清初的思想家們，為何把律學、數學和其他自然科學知識的研究當成是下學而上達、上通《易》理玄奧的一條途徑。

Musical temperament is one of the major subjects discussed in the Zhouyi shilun hebian 周易時論合編. Several essays in the text show an interest in the metaphysical meaning and calculation of the twelve pitches. Inspired by the traditional Chinese chromatic scale, the work’s author, Fang Yizhi 方以智 (1611-1671), developed a unique philosophical interpretation of musical temperament. This article first investigates the Zhouyi shilun hebian’s discussion of musical temperament and mathematics; it then examines the way in which the image-number system from the Han dynasty influenced its expression in the text. It continues by analyzing the notion of the “shared origination of sound and number,” and describes the outline of Fang’s philosophical system and its relationship with musical temperament. Finally, it explains why Fang and several of his contemporaries felt that the study of sound, mathematics and other natural science disciplines represented a means of learning the metaphysical truth of the Zhouyi.