法、理、情三者的關係、一直是法律學人爭論不休的議題。本文從司法的角度切入，利用《折獄龜鑑》與《名公書判清明集》中的案例，回答兩個問題：一是天理的具體內容為何；二是天理與法律的關係為何，亦即天理對審判有何作用。天理的內容具有一定程度的確定性與一致性，大多指天性、天倫、人倫綱常，故多適用於親屬相爭，而不適用於凡人相爭。天理與法律的關係、應分兩個面相來分析：一是對受害者權益的維護，二是對加害者行為的懲罰。在前者，天理與法律平行而彌補其不足，沒有導致司法的不客觀、不確定或不一致。在後者，為了縫補受害人和加害人彼此的天倫，天理有時凌駕法律，以道德訓誨代替刑罰，這其實跟傳統司法「先教後刑」的原則相差不大，也使天理論述顯得多餘，因為三綱五常被抬舉為不可違背的最高道理後，並未帶來合乎比例的賞與罰，反倒多用來減免刑罰，這跟不談天理的道德裁判者又有何分別呢？此外，跟法律一樣，天理對加害人有時也束手無策。也許因觸犯天理而加重刑罰的情況，在宋代以後比較多見，其原因值得進一步研究。

The relationship among fa (law), li (principle), and qing (compassion) has been debated endlessly by legal scholars. From the perspective of judiciary and through the cases in ”Zheyu guijian (折獄龜鑑, Mirror for Adjudication)” and ”Minggong shupan qingmingji (名公書判清明集, Enlightened Judgments by Famous Masters)”, this paper attempts to answer two questions: What are the substantial contents of tianli (the principle of heaven), and how is tianli related to fa, or how does tianli affect adjudication? To a large extent, the contents of tianli are quite certain and consistent in these cases, generally referring to inborn human nature, nature family bonds (like parenthood, brotherhood, etc.), and family ethics and duties. Therefore, tianli is mostly applied to family members in dispute, not to non-family members. The relationship between tianli and fa ought to be analyzed in two respects: protection of the victims ' rights, and punishment of the perpetrators for their offences. In the former, tianli is parallel and complementary to fa, causing no unobjectivity, uncertainty, or inconsistency in adjudication. In the latter, for the sake of restoring family bonds between the victim and the offender, tianli at times takes precedence over fa, replacing punishment with moral lectures. This in fact is not much different from the principle of ”teaching before penalizing” in traditional adjudication, thus apparently rendering the discourse of tianli unnecessary. In spite of having been elevated to be as high and inviolable as a heavenly principle, the Three Principles and Five Virtues in their judicial application do not bring about proportionate reward or punishment, but more often lead to reduction or even exoneration of punishment in their judicial application. How is this different from a traditional moralistic adjudication that makes no reference to the principle of heaven? Moreover, just like fa, tianli is at times ineffectual against the offender. Perhaps it is after the Song that the violation of tianli will more often incur penalty heavier than the code stipulated. The reasons for this warrant further research