英国1991年“威廉姆斯案”对约因理论的挑战

The Challenge Posed by the English Case of Williams against Consideration

约因英美契约法的独特要素,约因法理的成熟形态——“交易约因论”是古典契约法的基石。1809年的Stilkv.Myrick案确立了重要的约因法则——受诺人对已存义务的履行不能作为新的允诺的约因,这实质上在很大程度上否认了契约变更的效力。英国1991年“威廉姆斯案”是英美契约法史上的经典案例,因为该案案情与Stilk案非常相似,可法官得出的判决结果却截然不同。“威廉姆斯案”案判决改写了众多传统约因法则,动摇了约因理论的基础,而且,因为它与Stilk案判决的难以协调,还引发了“胁迫论”对“约因论”的挑战。

Consideration being the necessary element is the unique content of Anglo-American contract law. The mature status of consideration theory is ＂Bargain Theory of Consideration＂, which is the basis of classical contract laws. The case of Stilk v. Myrick in 1809 established an important doctrine of consideration： the performance of existing contractual duty cannot be consideration. Another case of Williams v. Roffey Bros ＆ Nicholls Ltd [1991] 1 Q.B. 1 is one of the famous cases in the history of Anglo-American contract law, for it had the similar facts with Stilk v. Myrick, but had much different judgment. The case of Williams has changed much traditional doctrines of consideration, and almost un- dermlned the basis of consideration. Also, because of the contradiction between the above two cases, the case of Williams has also brought about the challenge posed by ＂theory of duress＂ against consideration.