영미 계약법에 있어서 불법계약의 효력과 급부물의 반환청구

I wrote this article at George Washington College of American University in Washington D. C. during my sabbatical year, 2011-2012. At that time, I had concern for the maxim, ex turpi causa non oritur actio in common law. I intend to introduce the effect of illegal contracts and that maxim to ours. English writers commonly says that a contract may be illegal in four distinct ways. In the first place, a contract may be illegal in respect of the very act of making it. All contracts the making of which is thus prohibited by law are for this reason and in this sense illegal contract, and are commonly void accordingly. In the second place, a contract may be illegal in respect of the performance of it. That is to say, it may consist of or involve an undertaking to do an unlawful or immoral act, and for this reason the contract itself is commonly void. However, a contract is not illegal and void merely because its performance would amount to the breach by one of the parties of prior and inconsistent contract made by him with some third person. In the third place, a contract may be illegal and void because made for an unlawful or immoral consideration. When the consideration is executory, this case is identical with illegality in performance. Fourthly, a contract may be illegal and void in respect of the ulterior purpose or object of one or both of the parties in entering into that contract. In such case if the wrongful purpose of the one party is known to the other the contract is illegal and void. In common law, contracts are affected by illegality into a number of classes. One object of this classification is to make it possible to generalize about the effects of illegality, another object is purely expository. Various criteria have been used for the purpose of classifying the cases. The first criterion is the nature of the objectionable conduct. They classified the cases into those where the contract was contrary to positive law, those where it was contrary to morals or good manners, and those where it was contrary to public policy. The main difficulty with it is that the second category of contracts contrary to morals or good manners is hard to define and that is may overlap with the third. It can be argued that public policy is the ground for invalidating all contracts affected by illegality, so that the third category includes the other two. A second possible criterion for classification is the formal source of the invalidation rule, which may be derived from common law or from statue. But the distinction is not decisive where the illegality consists in the making or performance of the contract. The third, classification may proceed by the legal consequences of the contracts concerned. Thus a writer distinguished between ‘illegal contract’ and ‘nugatory contracts, and the same classification has been adopted by later writers who distinguished between ‘illegal contract’ and ‘void contracts’. The maxim ex turpi causa non oritur actio has no application to a nugatory contract, but applies exclusively to those which are illegal. A contract which is void for illegality, and therefore not binding on either of the parties, may nevertheless be in fact performed in whole or in part by one or both of them. In an illegal contract for the sale and purchase of goods the seller may deliver the goods. Is the seller entitled to get the goods back on the ground that the contract is void? In other words, what right of restitution exists as between the parties to an illegal contract? The general answer is that no such right exists. The rights of parties are governed by a special rule formulated in the maxim ex turpi causa non oritur actio. This maxim as to turpis causa is otherwise expressed in the saying, in pari delicto potior est conditio defendentis. An illegal contract is a turpis causa within the meaning of this principle. The maxim embodies a special and more far-reaching principle, applicable exclusively to cases of illegality. It means that no person can claim any right or remedy on the basis or ground that he has been a party to an illegal contract. If the illegal contract is an essential constituent of his cause of action he cannot succeed. The general consequence of that maxim is that the right of restitution is excluded in respect of all acts of performance of a contract void for illegality. This rule is subject to a number of real or apparent exception which require consideration. The first exception to the rule that there is no restitution in the case of an illegal contract exists where the contracting parties, though both guilty of taking part in an illegal transaction, are not in pari delicto. This is so where the illegal contract has been procured by some form of oppression, undue influence, or abuse of a position of influence or power. The second exception arises when the law thinks fit to allow a locus poenitentiae to one or both of the parties in consideration of the fact that the illegal purpose of the contract has not yet been fulfilled. It is considered that the ends of justice and public policy will best be served by allowing a party to repent before it is too late, and to prevent the completion of the illegal purpose by reclaiming property delivered or money paid by him in pursuance of it. The third exception is that in which there exists between the parties the relation of principal and agent or trustee and beneficiary. In such cases public policy requires that the rule of turpis causa shall be excluded in favour of the more important and imperative rule that agents and trustees must faithfully perform the duties of their office. The forth exception is the rule of class-protecting. The maxim ex turpi causa non oritur actio has no application to a tenant in Rent Act or to a borrower in Moneylenders Act, because these laws protect the tenant or borrower.