General Secretary Xi Jinping pointed out that "since ancient times, China has formed a unique Chinese legal system in the history of the world's legal system, and has accumulated a profound legal culture." The law of reason and reason is one of the most important legal philosophy issues in China's excellent traditional legal culture. It originated from the judicial requirements of imprisonment, and is closely related to the legislative spirit, legal system, and people's lives. It is related to the construction of the traditional Chinese social legal order, provides multi-dimensional guarantees for contractual integrity, and also has enlightening significance for the construction of a trustworthy society in the new era. Human nature "emotion" refers to the common emotions that people have in their lives, and the behavioral reactions they make based on them are in line with the experience and cognition of most people. For traditional contractual integrity, human nature is reflected in internal moral constraints. Ethical requirements such as benevolence and righteousness are important components of human nature. Ren "is reflected in promoting oneself and others, as recorded in the" Analects of Confucius: Yongye ":" Those who are benevolent should establish others when they want to establish themselves, and reach others when they want to achieve their goals. "It emphasizes empathy and compassion, reflecting the inner moral requirements of self-cultivation and goodness. 'Righteousness' is often used to evaluate the legitimacy of behavior, as recorded in Xunzi's' Zhengming': 'What is done for the sake of profit is called a thing, and what is done for the sake of justice is called an action.' This means that what is done for the purpose of profit without losing its righteousness can only be called a thing; What is done in accordance with the standards of righteousness is called virtue. Regarding the relationship between "benevolence" and "righteousness" and contractual integrity, "Xunzi · BuGou" states: "A gentleman should cultivate his heart without being good at sincerity. Sincerity is nothing else. Only by observing benevolence can one act with righteousness." It can be seen that only by adhering to "benevolence" and "righteousness" can a gentleman achieve "sincerity," emphasizing to some extent that the moral consciousness of integrity precedes legal coercion. The concept of blessings and the emphasis on family ethics are also typical human nature. The Ming Dynasty philosopher Lv Kun mentioned in his poem "Zong Yue Ge: Advice on Buying and Selling": "In life, trust comes first. How can there be two things in one's heart and mouth? Buying and selling only seek peace and profit, while managing to earn money and deceive others. Strong is like grinding one's mouth with false prices, not like the truth with only one word. Foolish and weak people can hide it from heaven, and no one has ever hidden it from heaven since ancient times." The three stars of "Fu, Lu, and Shou" on the Chinese old scale are a reflection of the concept of "no one has ever hidden it from heaven since ancient times." Many stories of blessings have also been recorded in official books throughout history. At the same time, traditional contracts often occur in familiar societies, closely linked to family relationships, favors, face, etc. Contract integrity is an extension of the harmonious relationship of family ethics. With the guidance of family laws and regulations, as well as local rules and agreements, it can achieve the goal of treating each other with courtesy, maintaining harmony, and regulating faults. The common sense of things refers to the principles that people follow when viewing similar things and can obtain universally applicable principles. For traditional contractual integrity, the common sense of things is reflected in objective and rational criteria. Both parties fully respect and acknowledge the contract they have reached. Since the Eastern Han Dynasty, there have been a large number of clauses at the end of contracts, such as "the people have private needs and must act as two masters, each signing as a letter", "officials have political and legal affairs, and people follow private contracts", "signing contracts with both parties and drawing fingers as a letter", "fearing that people will not trust, so this contract is established as a reference", reflecting the respect for the effectiveness of private contracts and the emphasis on integrity; Even in order to prevent the occurrence of rulers pardoning both public and private debts, the contract includes clauses such as "if there is a popular amnesty granted by grace, it is not within the limits of reason" or "if the collection of public and private debts is suspended, it is not within the limits of suspension". The repeated appearance of amnesty clauses is related to the frequent issuance of national amnesty orders for civil debt relief, as well as the importance attached by the parties to the effectiveness of contracts. The contracting parties attach great importance to the credit guarantee system composed of dental, Chinese, and insurance parties. Ya Ren and Zhong Ren are intermediaries, mediators, and witnesses in contract transactions, responsible for "three sided negotiation" and "bargaining based on the agreement", playing a bridging role in facilitating transactions. At the same time, dental professionals need to review the legality of the rights to land, land, and houses in transactions to prevent fraud, and middlemen often act as mediators in handling contract disputes. The guarantor provides guarantee responsibilities, such as assuming ownership defect guarantee responsibility and performance guarantee in the sales contract, and assuming repayment responsibility and prudent guarantee responsibility in the loan contract. These three types of people play an important role in facilitating contract formation, ensuring contract performance, and intervening in contract dispute resolution, providing credit endorsements to individuals with specific identities in the social network for the behavior of both contracting parties. The law of a country is a deterministic rule that is enforced by the coercive power of the state and serves as the basis for judicial activities. For traditional contractual integrity, national laws provide a solid external guarantee mechanism. The law emphasizes the subjective state of "harmony and agreement" between the contracting parties. 'He' refers to the voluntary agreement between both parties, 'Tong' refers to the mutual agreement of their intentions, and 'He Tong' emphasizes the voluntary nature of the contract between both parties. The opposite of "harmony" is "strength", and the so-called "discord is called strength". As stipulated in the "Commentary on the Tang Code": "Those who do not agree with each other in buying and selling, but have a fixed price; and those who enter the market and regulate themselves, will be punished with a cane of eighty. Those who have already obtained heavy gains will be considered as thieves." The listed behaviors such as "relatively fixed", "more open and closed", and "participating in the market" are all acts that violate the integrity of the contract and are prohibited by law. The law focuses on the form of contracts, contractual obligations, and market management. Since the Eastern Jin Dynasty, the government has required special types of sales contracts to be stamped with official seals in order to collect deed taxes. Later generations have followed suit and improved upon this practice, promoting the standardization and standardization of contracts. As stated in the Tang Dynasty law, 'buying slaves, maidservants, cattle, and horses does not require the establishment of vouchers', it is required that both contracting parties establish market vouchers (red contracts, official contracts), and' no restrictions are allowed on private vouchers'. It is stipulated that 'after the voucher is established, those who have old illnesses must repent within three days, those who bully others without illnesses must abide by the law, and those who violate the law will be punished with forty lashes'. At the same time, it is necessary to clarify contractual responsibilities and prohibit behaviors such as "illegal accumulation of profits", "prohibited profit taking", "debt breach of contract and non payment", "theft and sale", "trade in", "impersonation", etc. In terms of market management, punishment will be imposed for behaviors that damage the integrity of contracts, such as "private filling of dental docks", "controlling the market", "unauthorized production of weighing scales", and "improper use of cloth and silk". Judicial trial activities strictly adhere to the legal system of contractual integrity. When dealing with contract dispute cases, on the one hand, judicial officials pay attention to whether the parties have forged the contract. In the Qing Dynasty, officials Fang Dashi summarized nine methods of defect detection based on the records of predecessors such as He Ning and Wang Huizu, combined with his own experience as an official, including anti excavation and repair, paper color inspection, handwriting inspection, seal inspection, year and month examination, boundary identification, value verification, name verification, and reasoning; On the other hand, judicial officials pay attention to behaviors prohibited by the law, such as "buying land and houses at will" and "supervising property at the loan office", to prevent officials from having "authority in their hands and surplus in securities and contracts", which violates contractual integrity and leads to substantial unfairness and irrationality. The inheritance and development of the traditional law of reason emphasizes the trinity of human common sense, common sense of things, and national laws, which has built a multidimensional credit guarantee system for traditional contractual integrity and has reference significance for the construction of a trustworthy society in the new era. Firstly, balance moral self-discipline and legal heteronomy. On the one hand, we should pay attention to the shaping of the spirit of integrity at the moral level, promote the socialist core values, emphasize the importance of cultivating the virtue of integrity from the perspectives of social, folk, and family culture construction, and guide people to aspire to and pursue a life of morality, respect for morality, and adherence to morality; On the other hand, fully leverage the institutional guarantee role of the law in the construction of a trustworthy society, establish and improve the integrity system from various separate laws to unified social credit legislation. Secondly, establish a system that combines rigidity and flexibility. Rigidity is mainly reflected in clarifying the legal responsibilities of relevant dishonest behaviors based on laws, administrative regulations, and local regulations, and establishing mechanisms for incentivizing and punishing dishonesty. Flexibility is mainly reflected in the handling of dishonest behavior, using flexible, educational, and restorative measures to guide dishonest entities to actively correct errors and restore credit. Finally, we must adhere to the integrated promotion of overall layout and key planning. On the one hand, accelerate the promulgation of the Social Credit Construction Law to achieve the legalization of social credit construction; On the other hand, guided by the integrity of government affairs, we will seize this key area to promote the construction of integrity in key areas such as business integrity, social integrity, and judicial integrity, in order to achieve the requirements put forward by the Third Plenary Session of the 20th Central Committee of the Communist Party of China - "to build a system for inheriting traditional Chinese virtues, to strengthen the system and mechanism for building social morality, professional ethics, family virtues, and personal ethics, to improve the long-term mechanism for integrity construction, and to educate and guide the whole society to consciously abide by the law and follow public order and good customs". (New Press) (This article is a phased achievement of the National Social Science Fund's general project "Research on the Evolution of Contractual Concepts during the Ming and Qing Dynasties' Social Transformation Period")