人們何以訂定契約？契約的權威從何而來？本文探究秦漢時代的契約如何產生證明力與強制力。當時的契約採取券的形式，以合券為驗證機制，然而合券自身的證明機能有限。先秦的盟誓以神靈為契約的見證者及裁罰者，而讓訂約者願意承認並遵守契約內容。秦漢契約的見證人已轉為生人，人際網絡取代神秘力量，成為契約約束力的主要來源。但人際網絡即使足以確認契約的真實性，賦予契約強制力的能力卻相對薄弱。訂約者只能期待公權力主持公道，而公權力也願意積極介入民間契約，以減少紛爭，維持社會安定。公權力介入最有效的辦法，是在一開始就參與契約的訂定，而得以為契約真實性提供不可動搖的保證。不過限於行政成本，似只有部分特受關注之契約可獲得此類保證。更多未經官方認證的契約，如因履約糾紛而提起訴訟，需要傳喚當初訂約時的見證人。此時偽證的刑責成為最佳利器，得以確保見證人在法庭上所言並無虛構，而可認定為事實。至於公權力強制履約的能力應無庸置疑，甚可能對人身自由加以限制並施加刑罰。漢代以後，契約的形式及官方與契約的關係均逐漸發生變化。

This article focuses on the source of the authority of contracts, that is, what forces compelled contracting parties to recognize and comply with the terms of their contracts. In the Qin-Han period, contracts took the form of “quan.” The same text was written twice on a single wooden tablet; the tablet was then divided, and one half given to each party. The legitimacy of a contract could be proven only when each party was willing to match the copies they possessed. In the earlier times, religion and interpersonal relationships could be recognized as powerful forces to back up contracts. Nevertheless, religion was losing its place during this period, and although interpersonal relationships could confirm the authenticity of contracts, they had limited power to enforce them. Signatories to contracts expected the political authority to enforce their terms. At the same time, the political authority also hoped to intervene in private contracts in order to maintain social order. The best way for the political authority to intervene in contracts was to participate in the making of contracts at the beginning. By making political administrators the witnesses to contracts, and keeping one copy in the official archive, the authority of contracts could not be doubted. However, this practice could not be applied to all contracts. For contracts without public notarization, witnesses recorded in the contracts might be required to testify regarding the authenticity of contracts in a lawsuit. Severe penalties for perjury during this period guaranteed the veracity of witness testimony. Thus there is no doubt that the political authority had coercive powers in enforcing its judgement. Personal restraint and punishment were also utilized to guarantee the performance of contracts. After the Han period, the form of contracts and the relationship between the political authority and private contracts changed.

契約;券;貰賣;訴訟;署名

contract; quan; credit sale; lawsuit; signature