The ancient Chinese honored and respected heaven's will. They believed that when one is attuned to heaven's will one can understand human affairs and act righteously. The ancients observed, studied, and hypothesized about the movement, changes, and rules that govern the universe and nature. The findings allowed them to understand the ever-evolving human society and the rules that govern humankind’s existence. Based on that, they deduced that the principles of moral conduct should harmonize with heaven and earth and prevent one from deviating from the righteous path.

In ancient times, the governments set up various official posts to observe phenomenon in the sky. These observations were used to predict and foretell auspicious or ominous events in the future. During the Western Han Dynasty (202 BC – 9 AD), there was a man named Sima Jizhu who discussed the heavenly principles and human affairs based on what he observed and predicted.

According to Shi Ji (Records of the Grand Historian), there lived a virtuous court official, Sima Jizhu, in the kingdom of Chu. He studied in Chang’an, an ancient capital of China during the Han, Sui, and Tang dynasties and now called Xi'an. He was well versed in The Book of Changes, and the teachings of the Yellow Emperor and Lao Zi. Besides that, he had broad knowledge and great foresight. One time, court officials Song Zhong and Jia Yi paid a visit to Sima Jizhu to ask his thoughts on human affairs. At the time, Sima Jizhu was having a discussion with three students regarding heaven and earth, sun and moon, yin and yang, and fortunes. When they noticed Song Zhong and Jia Yi, they invited them to sit and join the discussion. Song Zhong and Jia Yi responded that they only wished to listen. Sima Jizhu continued to talk about the movements of heaven and earth, the sun and the moon, and their relationship to benevolence and righteousness, as well as the good and the bad omens. Everything was explained in an organized and logical manner. Song Zhong and Jia Yi both listened attentively and with great respect.

Sima Jizhu said, "A gentleman is straightforward when offering good advice and does not expect to be repaid when giving praise. He kindly and honestly points out other's mistakes, keeping the nation and people's well-being in mind with utmost importance. A genuinely virtuous person will not accept a government position if he does not think he can perform it well, nor will he take a salary that exceeds his efforts. He is not ecstatic when offered a position, nor is he worried about losing his job; the key is that he does things conscientiously. On the other hand, a sly person who is hungry for power uses his authority to threaten others. He uses the law as a tool to force out the righteous person and exploits the common people. He will do anything for personal gain, and that is despicable. A wicked official does not enforce the law to prevent robberies, does not take care of and reform the neighboring barbaric tribes when they refuse to respect the government, and does not stop other wicked ones from uprising and obstructing the path of the sages. All kinds of disasters occur as a result of degenerated moral values."

Song Zhong and Jia Yi were impressed and humbled by Sima Jizhu's speech and commented, "It is true that good moral values lead to peace, whereas power and force lead to danger. One should learn and follow the laws of heaven in one's activities, and become a righteous instead of a sly person who caters to the powerful."

After the fall of the Qin Dynasty (221 – 206 BC), the Marquis of Dongling was relegated to the level of a common person. One day he visited Sima Jizhu to have his fortune told. Sima Jizhu asked, "What do you want to know about your future?" The Marquis of Dongling replied, "I've heard that when annoyance and depression reaches the extremes, ventilation will follow; when the temperature gets too hot, the wind will blow; and what is congested for a period of time will begin circulating. From winter to spring, what is curled up will become extended. Things rise and fall and they come and go. However, I still have doubts and would like to hear your advice."

Sima Jizhu said, "You seem to understand the principles, then why do you need me to talk about your future?" Marquis of Dongling replied, "I don't seem to thoroughly understand the profound meanings of what I have heard and hope you can guide me." Sima Jizhu responded, "Who does the heavenly law favor? It favors those who are virtuous. When a virtuous person conducts himself according to heavenly law and does things to benefit the common people, the gods will help him. From dusk till dawn, flowers wilt and bloom; winter departs and spring arrives; all things wane and will be reborn. There is always a calm and deep pool at the end of the rapid river water. There must be a deep canyon underneath the high mountain ridge. There is cause and effect, and all matters are predestined. When a person cultivates to become virtuous, good fortunes will follow."

Ancient Chinese have believed and followed the principle of "man and heaven are one." They knew that there was a direct relationship between cosmic changes and changes in human affairs, and that good deeds will be rewarded and bad deeds will receive retribution. Therefore, they placed great importance on elevating their moral standards.

敬天知命
循道而行

古人敬顺天意，提出“推天道以明人事”，是指通过探索推演宇宙、自然运动变化的规律，从而使人明白人类社会发展和个人生存变化的规律，明白做人的道理，达到“与天地合其德”，使自己的行为绝不偏离正道。古代设立了司星官、钦天监、卜官等，观象授时，很多事情通过预测和占卜来预知吉凶祸福。以下为西汉星占家、卜筮家司马季主谈论的一些关于遵天理、明人事的道理。

据《史记》记载：“司马季主者，楚贤大夫，游学长安，通《易经》，术黄帝、老子，博闻远见。”一次，中大夫宋忠和博士贾谊一同去拜谒司马季主，想听听他对一些人事上的看法。司马季主正在和三个学生一起探讨天地、日月、阴阳、祸福等，他们看到宋忠和贾谊来到，礼貌的请他们坐，宋忠和贾谊表示只想继续听他们的谈论。司马季主谈到天地、日月星辰的运行轨迹，并参入与仁义之间的关系，陈述吉凶的行兆，说了很多，无不条理顺畅。宋忠、贾谊在一旁正襟危坐，恭敬、严肃地听著。

司马季主又讲到：“大凡君子的行为，都以率直的言辞来做正直的劝谏，他称誉别人，并不希望别人回报；善意地指出别人的过失，心怀坦诚，一切只以国家和民众的利益为重。所以真正的贤人，给他一个官位，但非他所长，他是不当的；给他俸禄，如果不能和他的劳力相称，他是不拿的；得官的不喜，去官的不忧，关键的是在于无愧于心。而那些互相以权势相攀引的小人，只知道利用官位作为威势，利用法令作为工具，排斥正人君子，盘剥百姓，追求私利而不择手段，最令人深恶痛绝。盗贼发生而不能设法禁止，蛮夷不服不能感化摄收，奸邪兴起不能遏阻，妨碍真正圣者的进路，各种灾难的众多往往是因道德的堕落而造成的。”

宋忠和贾谊听了司马季主的这番话，为之折服，说：“真是道高益安，势高益危呀！为人处事，就是要学习、效法天道，做堂堂正正的正人君子，而不要去做趋炎附势的小人。”

东陵侯在秦亡后被废为平民，一次，他到司马季主那里去占卜，司马季主说：“您要占卜什么事呢？”东陵侯说：“我听说烦郁之极就要开畅，闷热太甚就会起风，堵塞之久就要流通。一冬一春之间，不会总是屈而不伸；事物有一起就有一伏，没有只去不来的。然而我对此私下里还有疑惑，愿听听您的指教。”司马季主说：“既然这样，那么您已经明白了，又何必要占卜呢？”东陵侯说：“我总觉得还没有透彻地了解其中深奥的道理，但愿您能好好开导我。”司马季主这才说：“天道对谁最亲近呢？最亲近有德之人。只有有德之人做循天时、顺民意的好事时，才能得到吉神相助。『自天佑之，吉无不利』，因而，一夜一日间，花谢花开；冬去春至，万物凋零而又复苏。需知湍激的河流下，必有静静的深潭；高高的山岭下，必有深深的峡谷。因果循环，世上的事情皆有定数。勤修德行，美好的礼仪自会来的。”

中国人自古以来，相信和遵守天人合一，相信天象改变和人事变更直接对应，相信善恶有报的真理，因此非常注重提升自己的道德水准。