善意占有人使用收益返還或償還義務之全部免除 善意不當得利受領人現存利益返還或償還義務 論證科學性 規範矛盾 特別規定說 法律上原因說 恣意禁止原則 適當性原則 合憲性法律適用 Bona fide possessor Bona fide recipient Obligation to return or compensate usages and profits Obligation to return or compensate existing interests Scientific method of argumentation Contradiction in norm Theory of special regulation Theory of legal ground Principle of prohibition of arbitrariness Principle of adequateness Application of law conform to constitution