尝闻之有所云天心者。仰而观之。浩浩焉。邈邈焉天之大不可测也。而何
从见其心。素问曰。南方赤色。入通于心。则疑以离为天之心矣。心果若是
之虚且明乎。子思作中庸。首揭天命之谓性。而子舆氏则曰。尽其心者。知
其性也。知其性则知天矣。则是又以天心即人心矣。可见心之为物。存者
其诚。而发者其明也。忠者其体。而怒者其用也。若易诚而妄。则心之病一。
易明而昧。则心之病二。易忠而欺。则心之病三。易恕而忍。则心之病四。试
思天之所以贵乎人。与人之所殊乎物者。非此心乎。存之为君子。去之则
异类。苟或不克操之。任其出入。而莫知其乡。将何以立于天坏间耶。盖天
理者。人之所以为心也。惟在摄之正之。公之平之。以之立身。以之垂后。无
不由于此中。人盖可忽乎哉。
喜怒者情之常。使必有喜而无怒。则矫矣。虽然。人情贵于坦适。尤贵于安
和。苟乘一时之忤。执一己之偏。则未有不悔于事后者。经曰。肝者将军之
官。其病善怒。毋论乖违谋虑。伤于拂郁。尤可言也。愤乱机务。败于经纬。不
可言也。故古来大怒必出于大忍。则有济。轻怒必出于不忍。则多暌。任情
一往。不审从违者。妇寺之见也。从容不迫。按节而动者。大度之举也。是以
器识宏远之流。见天下无可怒之事。见天下无可嫉之人。及其怒且嫉也。
如天之雷霆。然偶一发焉。而天下莫不慑服者。有以畏其不测也。然则人
之喜怒不常者。其亦可以自反矣。
I have heard it said that the "Heart of Heaven" (Tianxin), when looked up at, is vast and boundless, distant and profound; the greatness of Heaven is unfathomable, so how can one see its Heart? The *Suwen* states: "The red color of the South enters into communication with the Heart." Thus, one might suspect that the Li trigram (symbolizing Fire and the Heart) represents the Heart of Heaven. Is the Heart truly as empty and bright as this? Zisi, in writing the *Zhongyong* (Doctrine of the Mean), first elucidates that "What Heaven confers is called Nature." Mencius (Ziyu Shi) then said, "One who exhausts their Heart knows their Nature; knowing their Nature, they know Heaven." This equates the Heart of Heaven with the human Heart. It can be seen that for the Heart as an entity, preserving it relies on Sincerity (Cheng), while expressing it relies on Clarity (Ming). Loyalty (Zhong) is its substance, while Anger (Nu) is its function. If Sincerity is changed to falsehood, this is the first disease of the Heart; if Clarity is changed to obscurity, this is the second disease; if Loyalty is changed to deception, this is the third disease; if Forgiveness (Shu) is changed to cruelty, this is the fourth disease. Consider why Heaven values humans and what distinguishes humans from other beings—is it not this Heart? Preserving it makes one a Junzi (gentleman); losing it makes one akin to beasts. If one cannot cultivate and control it, allowing it to enter and exit without knowing its direction, by what means can one stand between Heaven and Earth? Essentially, Heavenly Principle (Tianli) is that which constitutes the human Heart. One must only rectify it, correct it, make it public, and make it fair. Using it to establish oneself and to leave a legacy for posterity, nothing does not originate from within this center. Can humans neglect it?
Joy and anger are normal manifestations of emotions. If there were necessarily joy but no anger, it would be artificial. Nevertheless, human emotion values openness and comfort, and especially values peace and harmony. If one acts upon a momentary grievance or clings to personal bias, one will inevitably regret it after the fact. The Classics state: "The Liver is the official of the General; its pathology involves frequent anger." Regardless of whether it contradicts strategy or causes injury through frustration and depression, this can still be discussed. However, if indignation disrupts affairs and ruins order, this is beyond discussion. Therefore, since ancient times, great anger often follows great forbearance, leading to success; light anger often stems from an inability to endure, leading to discord. Acting impulsively based on emotion without considering compliance or opposition is the view of women and eunuchs (metaphor for narrow-mindedness). Acting calmly and unhurriedly, moving according to rhythm, is the act of a person of broad mind. Thus, those with profound insight and vision see nothing in the world worth being angry about, and no one worth envying. When they do feel anger or envy, it is like thunder in the sky; occasionally released, yet all under heaven fear and submit, because people dread their unpredictability. Therefore, regarding the irregularity of human joy and anger, one should also engage in self-reflection.