Sima Qian, courtesy name Zichang, hailed from Xiayang (today's south Hancheng, Shaanxi Province). Initially employed as a court attendant, he later assumed his father's position of historian official in 108 BC, the third year of the Yuanfeng era. The new position required him to read all books collected by previous historians. In 104 BC, the first year of the Taichu era, he amended the Taichu Calendar along with several  fangshi  (people engaged in medicine, astronomy, divination, astrology, or similar professions in ancient China) such as Tang Du and Luoxia Hong. Later, Sima Qian offended the emperor by coming to the defense of the disgraced general Li Ling. He was incarcerated and castrated. After being released, he assumed the post of the head of the Secretariat and wrote the  Book of Lord Grand Historian  to "study the mechanism behind the rise and fall of a state," "examine the relationship between nature and mankind," and "gain an understanding of historical changes." The book was later renamed  Records of the Grand Historian  ( shiji ). It is the first general history book of China compiled in the  Jizhuanti  style, a format that reflects historical events through narration of people's activities.

The book faithfully records historical facts without exaggeration of the good or understatement of the evil. The author championed Taoism but also learned from other schools to develop his own Tao. Sima Qian held that Tao was the origin of all beings in the world, a "hazy, chaotic" primal energy, shapeless and nameless. He distrusted fate and attributed the failure of Xiang Yu, general and leader of the rebel forces that overthrew the Qin Dynasty (221–206 BC), to his own errors. Sima Qian also disbelieved in karma, and was skeptical about the saying that, "In the way of Heaven, there is no partiality of love; it is always on the side of a good man," and argued that it was common to see bad people leading an affluent life while good men suffering miserable deaths. In the "Biography of Boyi" chapter of the  Records of the Grand Historian , he wrote, "Were Boyi and Shuqi good men or not? Noble and virtuous as they were, they still ended up dying from hunger." Nevertheless, Sima Qian's skepticism did not completely deny the validity of fatalism.

His view on social history reveals his acknowledgement of constant historical changes. In the  Self-Preface of the Records of the Grand Historian , he wrote that one could predict the end of history through observing its beginning; and one could also foresee future decline from current prosperity. In the "Treatise on Equalization" chapter of the  Records of the Grand Historian , he mentioned inevitable historical changes after a dynastic fall and also asserted that the entire history resembled an incessant repetition of the rules of the Xia, Shang and Zhou dynasties. From above, we can see that Sima Qian was under the deep influence of the idea of the generational cycle of history. Further, Sima Qian stressed that man himself, rather than Heaven or any spiritual beings, determined the destiny of mankind. He attributed the "rise of a state" to the "employment of righteous gentlemen instead of base persons" and the "fall of a state" to the "surrender of sages to treacherous ministers." He contended that social development was the offspring of people's pursuits toward "gains" and that profit drove the world to thrive ("Biographies of Usurers,"  Records of the Grand Historian ). In Sima Qian's opinion, it is human nature to seek profit. In the chapter "Biographies of Usurers," he wrote that, since the period of Yu (legendary pre-Xia Dynasty) and Xia ( c . 2070–1600 BC), mankind had gone to extremes to satisfy their insatiable desire for pleasure and delicious food. He further defended those who pursued wealth and sought profits by saying that, "No man could bring a person wealth or deprive him of it. However, smart people tend to earn more than those who are not. Wealth does not confine itself to certain professions, and its ownership constantly changes. Competent merchants could soon accumulate wealth while incompetent ones may squander them all away." Meanwhile, Sima Qian also criticized those who gained wealth at the expense of others' financial health. He wrote that wealth acquired through farming was the most valuable, while gathering from business inferior, and that through cunning extortion the lowest. Inheriting the theory of Xunzi, philosopher and educationist of the late Warring States Period (475–221 BC), on the origin of moral standards, Sima Qian believed that "morality and rites" were certain rules promulgated by previous sovereigns to harness people's desire and thereby prevent altercations. He also elaborated on the view on morality of Guanzi, stateman and prime minister of the state of Qi of the Spring and Autumn Period (770–476 BC), stating that moral principles were typically observed when people were living a life of abundance and abandoned upon destitution. "Therefore, when a noble gentleman is wealthy, he tends to show his benevolence," he wrote. "Morality only comes with wealth." While acknowledging the Confucian moral principles, Sima Qian also spoke highly of some of the good qualities of wandering swordsmen, such as "absolute integrity," "resolute action," "promise keeping" and "requital of grievance with kindness."

His aesthetic philosophy was centered upon the theory of "desperate struggle." Sima Qian claimed that most masterpieces in history were "products of desperate struggles of sages." However, he objected to the emotional restraint imposed by Confucian doctrines, arguing that joy and anger were "natural emotions," and he showed an aesthetic ideal of inharmony and asymmetry. In addition, Sima Qian's aesthetic principle in literature was based on its function of "sarcasm and allegory."