不當得利制度素為法律人所孰悉,且亦受到法院實務之廣泛運用,但傳統見解對於其利益之概念及運用,卻存在許多不妥當之處,本文除將其一一指明外,亦嘗試提出「利益浮動性」之新觀點,重新安排利益適當之內涵,避免前述傳統見解之缺點,且簡化利益之認定,清理不當得利請求權之效力體系,使現行不當得利法更能符合台灣人民之法經驗。 在獲利返還責任上,依照「利益浮動性」之觀點,傳統見解之爭議將不復存在,退步言之,在採取傳統見解下,「利益大於損害時,以損害為準;損害大於利益時,以利益為準」法則之適用並不能完全符合法律文義,且亦不具備逾越法文義之法規範目的,故經本文比較分析後,「利益大於損害時,以損害為準;損害大於利益時,以利益為準」法則實應考慮廢止適用!期待藉由本文之研究,未來在實務上能破除此一通說及實務見解習以為常、想當然爾之偏見,真正落實不當得利法「取除不當利益取得」之精神,讓利益受領人不再「不當得利」!
Lawyers are familiar with unjust enrichment system, and which is widely used in judicial practice. However, under the traditional view there are many of irregularity in the benefits’ concept and application. This paper not only point out the mistake of traditional view, but also try to put forward a new aspect-“Fluctuation of Benefits”. By the Fluctuation of Benefits, it could rearrange the appropriate content of benefits, avoid the foregoing disadvantages of the traditional view, simplify the identification of benefits, clear the effectiveness system of unjust enrichment claims, so that the existing unjust enrichment law may more in line with the law experience of the people of Taiwan. In the liability for the restitution of benefits, according to the Fluctuation of Benefits the controversy under the traditional view will cease to exist. Even in taking the traditional view, the principle of “comparisons between benefits and damages” does not fully comply with the legal context as well as the purpose of legal norm. Therefore, by this comparative analysis, the principle of “comparisons between benefits and damages” should really be considered the abolition of application. Look forward, this paper hope that in the future the court decisions will get rid of the traditional accustomed prejudice and truly implement the legal spirit of unjust enrichment-"removing improper benefits ", so that benefit recipients are no longer "unjust enrichment".