二重賣買에 대한 새로운 理解

Generally effect of second sale of double sale is discussed centering around that of real property. Even though few scholars assert the second sale is always good under the principle of freedom of contract, almost all the scholars and precedents hold the second sale is null and void if the second sale contravenes good morals and other social order. According to the latter view, the first sale becomes impossible to perform if the owner transfer the title of property to the second purchaser unless if the second sale contravenes good morals and other social order. According to the latter view, the first sale becomes impossible to perform if the owner transfers the title of property to the second purchaser unless the second sale contravenes good morals and other social order. Double sale of a thing raises the following several difficult problems. The first is whether the sold property is restorable to the owner for the reason of unjust enrichment through null and void contract. A person who without any legal ground derives a benefit from the property of another and thereby causes loss to the latter should return such benefit to the latter(Civil Act §741). On the other hand, Civil Act §746 principally restricts the obligee’s right of return if the performance has been made for illegal cause and exceptionally grants the right if such illegal cause exists only on the part of the person enriched. Lots of scholars regard the concept of contravening good morals in Civil Act §103 in the same light with illegal cause in Civil Act §746. Then how can we explain the ground of the right of return based on Civil Act §103 despite the Civil Act §706? The more important problem ensued is even the subsequent purchaser in good faith should cancel the registration of his title under the principle of absolute null and void effect of juristic act. The writer argues the null and void effect of second sale should not be applied to the subsequent purchaser in good faith. The ground of this argument bases on the equalization of null and void effect contravening Civil Act §103 with the proviso of Civil Act §406 (1) which provides the comparative effect of obligor’s fraudulent act prejudicing obligee’s claim. Scholars who assert the characteristic of second sale as tort permit restitution, but their argument is not clear in respect of its means. For its implement, the writer suggests the subsequent purchaser’s direct claim of cancellation by the first purchaser. This article contains several argument. One of them is writer’s argument should be applied to the contributor’s sale of contributed property taking advantage of the unregistered state.