本文試圖解釋青年朱熹的哲學探索，以《延平答問》為文本，將焦點集中在「理一分殊」的討論，以期對了解朱熹哲學成熟時的思想有所助益。在李侗的指導下，對一些重要的哲學概念及其相互之間的關係（諸如「仁」、「義」、「理一分殊」），朱熹呈現自己的理解，並得到李侗的指正，這點在兩人對「理一分殊」的討論上尤其有意義。一方面可以顯示李侗哲思的特質，另一方面可以看出朱熹哲學的大體方向。

This paper attempts to explicate young Chu Xi's philosophical inquiry. In the light of the text, The Correspondence between Li-tung and Chu Xi, I focus on their discussion on ”li-yi-fen-shu” (this doctrine states that the principle is one but its manifestations are many. LYFS below). From this, we can understand Chu Xi's later mature philosophy more adequately. Under Li-tung's supervision, Chu Xi presented his cognition of importance philosophical concepts, such as ”benevolence (Jen),” ”rightousness (Yi),” and ”LYFS”, including their interrelations. His interpretation of these concepts was amended immediately by Li-tung in their correspondence. Moreover, it is significant that LYFS was discussed thoroughly and deeply between them. On the one hand, we can show the characteristics of Li-tung's philosophical thinking; on the other hand, the direction of Chu Xi's philosophical development would be envisioned.