自然之债源流考评

A Review of the Origin of Natural Obligations

自然之债是经由诉讼不能实现的债,债务人的履行或者承诺履行将激活债对债务人的强制力,债务人一旦自动履行即不得请求返还。自然之债是债的"亚类"。用"自然"加"债"来表达有两个含义:一是它不同于一般的作为法定之债的民事债,无论是债因还是效力;二是它不同于非债,不是纯粹的社会、道德或者宗教义务。用"自然之债"将"债"与"自然"连接可以体现出,这一类债的债务人可以拒绝履行,但一旦履行它就是债的履行而非不当得利或者赠与。这一点同罗马人区分契约与准契约的思路如出一辙。罗马人将"准"与"契约"相连,就将介于契约与侵权之间的地带统一起来。同样,"自然之债"也统一了处在法定义务与纯粹的社会义务之间的灰色地带。

Natural obligations cannot be achieved through litigations.The debtors＇ obligations can only be activated by debtors＇ performance or promises to perform.Debtors cannot claim for restitution once the obligations have been voluntarily performed by themselves.In fact,the natural obligation is a subsidiary obligation.There are two meanings of combining ＂nature＂ and ＂obligation＂：firstly,it differs from general legal obligations,either in cause or effectiveness;secondly,it is not a social,moral or religious duty,and thus is alien from non-debt.In the connection of ＂obligation＂ and ＂natural＂,debtors burdened with such obligations may refuse to perform,but once the prestation being made,it would compose formal performance of the obligation itself rather than unjust enrichment or donation.Based on this perspective,it is the same with the distinction between quasi-contract and contract in Roman.In fact,Roman had unified the different regions between contact and tort when they linked ＂quasi＂ to ＂contract＂ .Similarly,＂natural obligations＂ have also unified the grey areas between legal obligation and pure social duty.