Who is Sima Tan 司马谈?

Sima Tan 司马谈(?～110 BCE) was a historian and Taoist philosopher of the Western Han Dynasty, and the father of Sima Qian. He was a native of Xiayang County, Zuo Fengyi (present-day Hancheng, Shaanxi).  

In his early years, he studied under Tang Du, an astronomer specializing in astrology; Yang He, an expert in the *Book of Changes* (*Yi Jing*); and Huangzi, a scholar of Huang-Lao philosophy (a form of Taoism). He was widely learned and profoundly knowledgeable. In the early years of Emperor Wu of Han's reign, he served as Taishiling (Grand Historian), overseeing celestial phenomena and calendar systems, ritual ceremonies, and the collection and preservation of ancient documents: "Within a hundred years, all lost historical records and ancient events under heaven were gathered by the Grand Historian" (*Records of the Grand Historian: Autobiography of the Grand Historian*).  

Sima Tan highly revered the Huang-Lao philosophy prevalent in the early Han Dynasty and praised Taoist thought. He argued that Taoism absorbed the strengths of other pre-Qin philosophical schools while avoiding their weaknesses, enabling it to appropriately handle and respond to all things. He stated: "Taoism focuses the spirit, aligns actions with the formless, and nourishes all things. Its methodology follows the grand principles of Yin and Yang, adopts the virtues of Confucianism and Mohism, extracts the essentials of Logicians and Legalists, adapts to the times, responds to changes in things, and is suitable for establishing customs and handling affairs. Its guidelines are concise and easy to practice, achieving much with little effort" (ibid.).  

Based on the Taoist concept of natural non-action (*wuwei*), he proposed principles for engaging with the world:  
1. Advocacy of following nature, i.e., "taking emptiness as the foundation and adaptation as the application" (ibid.).  
2. Opposition to subjective prejudices and fixed patterns, emphasizing "no fixed tendency, no constant form, thus able to grasp the true nature of all things" (ibid.).  
3. Upholding Laozi’s view that "putting oneself last leads to precedence; regarding the body as external leads to preservation," he advocated achieving correctness through reversal: "Neither leading nor trailing things, one can become the master of all things" (ibid.).  
4. Advocacy of adapting to the times, adhering to laws and regulations without rigidly following them: "Having laws yet being lawless, engaging in affairs according to the times; having norms yet being normless, aligning with things as they are. Hence, it is said: The sage is imperishable, for they uphold the changes of time" (ibid.).  

He summarized all these principles into *emptiness* (*xu*) and *adaptation* (*yin*), asserting that "emptiness is the constant of the Dao; adaptation is the guiding principle for rulers" (ibid.). Regarding the relationship between form (body) and spirit (*shen*), he particularly emphasized the role of the spirit, regarding it as the foundation of life. He stated: "In humans, life is sustained by the spirit, and housed in the body. Excessive use of the spirit depletes it; excessive labor of the body wears it out; the separation of spirit and body leads to death. The dead cannot be revived, nor can the separated be reunited. Thus, sages value this relationship. From this perspective, the spirit is the root of life, and the body is its vessel" (ibid.). His deeds and *Essentials of the Six Schools* can be found in Volume 130 of the *Records of the Grand Historian*.