Sima Zhi () (170 - 230s), courtesy name Zihua, was a government official who served in the state of Cao Wei during the Three Kingdoms period of China. He previously served under the warlord Cao Cao during the late Eastern Han dynasty.
Early life Sima Zhi was from Wen County (), Henei Commandery (), which is present-day Wen County, Henan.(司馬芝字子華，河內溫人也。) Sanguozhi vol. 12. He was a distant cousin of Sima Lang and Sima Yi, whose descendants became the ruling family of the Jin dynasty. In his early life, when he was still a relative nobody compared to his cousins, Yang Jun (楊俊) recognised his potential and remarked, "Sima Zhi may not be as well known as Sima Lang, but he is actually more talented (than Sima Lang)."(又司馬朗早有聲名，其族兄芝，衆未之知，惟俊言曰：「芝雖風望不及朗，實理但有優耳。」) Sanguozhi vol. 23.
Originally a scholar, Sima Zhi had to leave home when chaos broke out throughout China in the final decades of the Eastern Han dynasty. While en route to Jing Province (covering present-day Hubei and Hunan) in southern China, he and his fellow travellers encountered bandits in the hills near Luyang County (魯陽縣; present-day Lushan County, Henan). As the bandits approached, the other travellers abandoned their elderly and frail companions and fled. Sima Zhi remained behind to protect his mother.(少為書生，避亂荊州，於魯陽山遇賊，同行者皆棄老弱走，芝獨坐守老母。) Sanguozhi vol. 12. When the bandits brandished their weapons at him, he kowtowed and begged them to spare his mother: "My mother is old. Please help me take care of her!" The bandits said, "He's a filial son. It would be unrighteous for us to kill him." They spared him and his mother. Sima Zhi later found a cart for his mother to ride as they continued their journey towards the south.(賊至，以刃臨芝，芝叩頭曰：「母老，唯在諸君！」賊曰：「此孝子也，殺之不義。」遂得免害，以鹿車推載母。) Sanguozhi vol. 12.
Sima Zhi lived in Jing Province for over ten years and spent his time farming. He also strictly adhered to moral principles.(居南方十餘年，躬耕守節。) Sanguozhi vol. 12.
Service under Cao Cao As a county chief In 208, Cao Cao, the warlord who controlled the Han central government, seized control of Jing Province after the provincial governor Liu Cong surrendered to him. Cao Cao recruited Sima Zhi into government service and appointed him as the Chief () of Jian County (菅縣; east of present-day Jiyang County, Shandong).(太祖平荊州，以芝為菅長。) Sanguozhi vol. 12.
Around the time, as the Han Empire was in a state of disorder, there were many people who openly disregarded the laws. In Qing Province's Jinan Commandery (), which Jian County was under, there was one Liu Jie () who served as a registrar () in the commandery office. Liu Jie came from an elite background and had over 1,000 retainers under him. Some of them were actually robbers and bandits, while others were corrupt bureaucrats.(時天下草創，多不奉法。郡主簿劉節，舊族豪俠，賔客千餘家，出為盜賊，入亂吏治。) Sanguozhi vol. 12.
When it was time for Wang Tong () and some other retainers under Liu Jie to serve in the army, Sima Zhi's personal assistants reminded their superior that Liu Jie had never allowed anyone from his household to perform mandatory military service.(頃之，芝差節客王同等為兵，掾史據白：「節家前後未甞給繇，若至時藏匿，必為留負。」) Sanguozhi vol. 12. Sima Zhi then wrote a letter to Liu Jie as follows: "Sir, you come from an influential family and occupy an important position in the commandery office, yet you allow your retainers to repeatedly avoid serving in the army. The people are very resentful and disappointed. Even the higher-level officials know about this. Wang Tong and the others are due to report for military service. Please send them over when it is time."(芝不聽，與節書曰：「君為大宗，加股肱郡，而賔客每不與役，旣衆庶怨望，或流聲上聞。今條同等為兵，幸時發遣。」) Sanguozhi vol. 12.
On the day the men were ordered to report for duty, Liu Jie not only refused to send Wang Tong and the others to the camp, but also secretly instructed (or bribed) a commandery-level inspector to go to Jian County and deliberately find fault with Sima Zhi's administration. Sima Zhi's subordinates felt intimidated by the inspector so they agreed to serve in the army in place of Liu Jie's retainers.(兵已集郡，而節藏同等，因令督郵以軍興詭責縣，縣掾史窮困，乞代同行。) Sanguozhi vol. 12. When Sima Zhi found out, he wrote to Hao Guang (), the Administrator of Jinan Commandery, to explain the situation and expose Liu Jie's wrongdoings.(芝乃馳檄濟南，具陳節罪。) Sanguozhi vol. 12. Hao Guang, who respected and trusted Sima Zhi, realised that Liu Jie was in the wrong so he ordered Liu Jie to serve in the army. Liu Jie had no choice but to follow orders. After this incident, there was a saying circulating around Qing Province: "(Sima Zhi) turned a commandery registrar into a soldier."(太守郝光素敬信芝，即以節代同行，青州號芝「以郡主簿為兵」。) Sanguozhi vol. 12.
Refusal to associate with Liu Xun Sima Zhi later became the Prefect () of Guangping County (廣平縣; north of present-day Quzhou County, Hebei). At the time, Liu Xun, one of Cao Cao's generals, behaved arrogantly because he believed that, given his past acquaintance with Cao Cao, no one would dare to do anything to him. When he was in charge of guarding Henei Commandery (), Sima Zhi's home commandery, he allowed his relatives, subordinates and retainers to behave lawlessly and do as they wished.(遷廣平令。征虜將軍劉勳，貴寵驕豪，又芝故郡將，賔客子弟在界數犯法。) Sanguozhi vol. 12.
Liu Xun once wrote a letter to Sima Zhi, without signing off, to ask him for favours. Sima Zhi ignored Liu Xun and continued to do everything by the book.(勳與芝書，不著姓名，而多所屬託，芝不報其書，一皆如法。) Sanguozhi vol. 12. Later, when Liu Xun was accused of plotting a rebellion, many people who had connections to him were implicated and arrested. Sima Zhi, who was unaffected by the incident, received praise for his wisdom in choosing to distance himself from Liu Xun.(後勳以不軌誅，交關者皆獲罪，而芝以見稱。) Sanguozhi vol. 12.
As a judicial officer and commandery administrator Sima Zhi later served as a dalizheng (大理正; senior judicial officer) in Cao Cao's vassal kingdom of Wei () after Emperor Xian enfeoffed the warlord as a vassal king in the year 216.(遷大理正。) Sanguozhi vol. 12.
During this time, Sima Zhi heard a case of theft in which a maid was accused of stealing silk from the official treasury and hiding it in the latrine. She had already been arrested and thrown into prison for interrogation.(有盜官練置都厠上者，吏疑女工，收以付獄。) Sanguozhi vol. 12.
After hearing the case, Sima Zhi wrote to Cao Cao: Cao Cao heeded Sima Zhi's advice.(太祖從其議。) Sanguozhi vol. 12.
Sima Zhi was later reassigned to be the Administrator () of Ganling (甘陵; around present-day Linqing, Shandong), Pei (沛; around present-day Xuzhou, Jiangsu) and Yangping (陽平; around present-day Handan, Hebei) commanderies. He performed well while serving in these offices.(歷甘陵、沛、陽平太守，所在有績。) Sanguozhi vol. 12.
Service under Cao Pi Sima Zhi continued serving in the state of Cao Wei, established by Cao Cao's son Cao Pi, after the end of the Eastern Han dynasty in late 220. In the middle of Cao Pi's reign, he was appointed as the Intendant of Henan (), i.e., the administrator of the capital commandery. During his tenure, he kept elite influence in check, helped the poor, and governed in an impartial manner without showing favour to anyone.(黃初中，入為河南尹，抑彊扶弱，私請不行。) Sanguozhi vol. 12. He also managed to convince Cao Pi to restore the wuzhu () coinage, which was previously used in the Han dynasty, as an official currency of the Cao Wei state.
On one occasion, a palace official wanted a favour from Sima Zhi but was afraid to ask him directly, so he requested Dong Zhao, an uncle of Sima Zhi's wife, to ask on his behalf. However, Dong Zhao also felt intimidated by Sima Zhi and did not ask him.(會內官欲以事託芝，不敢發言，因芝妻伯父董昭。昭猶憚芝，不為通。) Sanguozhi vol. 12.
Sima Zhi once lectured his subordinates:
His subordinates heeded his words and worked diligently and faithfully.(於是下吏莫不自勵。) Sanguozhi vol. 12.
In one incident, a sentry serving under one of Sima Zhi's subordinates was arrested on suspicions of stealing a hairstick. Although his statement contradicted the evidence, the authorities still deemed him guilty and threw him into prison.(門下循行甞疑門幹盜簪，幹辭不符，曹執為獄。) Sanguozhi vol. 12. When Sima Zhi heard about it, he remarked:
Service under Cao Rui In 226, after Cao Rui succeeded his father Cao Pi as the new emperor of Wei, he enfeoffed Sima Zhi as a Secondary Marquis () to honour him for his contributions.(明帝即位，賜爵關內侯。) Sanguozhi vol. 12.
Case of Princess Linfen's servant and Cao Hong's wet nurse Shortly after, a servant of Princess Linfen and the former wet nurse of the veteran general Cao Hong were arrested and imprisoned for heresy because they worshipped a certain "deity" of Mount Wujian () at the northeast of Luoyang.(頃之，特進曹洪乳母當，與臨汾公主侍者共事無澗神繫獄。) Sanguozhi vol. 12.(臣松之案：無澗，山名，在洛陽東北。) Pei Songzhi's annotation in Sanguozhi vol. 12.
Grand Empress Dowager Bian, Cao Rui's grandmother, sent a palace eunuch, Wu Da (), to order Sima Zhi to release Cao Hong's wet nurse and Princess Linfen's servant. Sima Zhi did not inform Cao Rui about the Grand Empress Dowager's interference in the case. Instead, he instructed the officials in charge of the case to continue performing their duties accordingly.(卞太后遣黃門詣府傳令，芝不通，輙勑洛陽獄考竟， ...) Sanguozhi vol. 12.
After the case was closed, Sima Zhi wrote a memorial to Cao Rui:
Cao Rui replied: "I have read your memorial and I understand your intentions. You did the right thing when you followed the imperial edict and authorised the officials to perform their duties. As you were acting in accordance with an imperial edict, you did nothing wrong so there is no need to apologise. You do not have to inform me the next time a palace eunuch comes to see you."(帝手報曰：「省表，明卿至心，欲奉詔書，以權行事，是也。此乃卿奉詔之意，何謝之有？後黃門復往，慎勿通也。」) Sanguozhi vol. 12.
As the Intendant of Henan Sima Zhi served as the Intendant of Henan () for 11 years. During his tenure, he dealt with numerous complex legal cases (e.g. cases in which the law could not be applied straightforwardly) and gained a reputation in the Wei imperial court for being impartial and fair.(芝居官十一年，數議科條所不便者。其在公卿間，直道而行。) Sanguozhi vol. 12.
In 231,(八月，詔曰：「古者諸侯朝聘，所以敦睦親親協和萬國也。先帝著令，不欲使諸王在京都者，謂幼主在位，母后攝政，防微以漸，關諸盛衰也。朕惟不見諸王十有二載，悠悠之懷，能不興思！其令諸王及宗室公侯各將適子一人朝。後有少主、母后在宮者，自如先帝令，申明著于令。」) Sanguozhi vol. 3. when the various princes came from their respective principalities to Luoyang to pay tribute to Cao Rui, some of them violated imperial protocol by privately visiting officials based in Luoyang without permission. (The princes were forbidden from contacting officials in the central government without permission from the emperor.) When these violations came to light, Sima Zhi was accused of negligence as he allowed them to happen under his watch. As a result, he was removed from office.(會諸王來朝，與京都人交通，坐免。) Sanguozhi vol. 12.
As Minister of Finance Sima Zhi was later restored to government service as Minister of Finance (). Before he assumed office, the officials in charge of agricultural production had, in fact, been encouraging their subordinates and the common people to focus more on commercial rather than agricultural activities because commerce was more profitable.(後為大司農。先是諸典農各部吏民，末作治生，以要利入。) Sanguozhi vol. 12.
Sima Zhi assessed the situation and wrote a memorial to Cao Rui:
Cao Rui heeded Sima Zhi's advice.(明帝從之。) Sanguozhi vol. 12.
Later life and death At the time, when some officials were summoned to meet their superiors, they often consulted their superiors' personal assistants to find out what their superiors wanted. The personal assistants then advised them accordingly and taught them how to provide satisfactory answers to their superiors.(每上官有所召問，常先見掾史，為斷其意故，教其所以荅塞之狀，皆如所度。) Sanguozhi vol. 12. Sima Zhi, in contrast, was known for being candid, outspoken and upright. When he had disagreements with his colleagues during discussions, he voiced his objections in front of them, criticised them directly and never spoke behind their backs.(芝性亮直，不矜廉隅。與賔客談論，有不可意，便靣折其短，退無異言。) Sanguozhi vol. 12.