On Unjust Enrichment "no Legal Reason"

Unjust Enrichment is very important in the civil law system. The precondition of researching Unjust Enrichment is how to understand the"no legal reasons"correctly. The criteria for whether the legal reasons are lack was always unclear. For the special propose of understanding the Unjust Enrichment correctly, I give a answer to the questions of what is"no legal reasons"and how to judge it. I hope that my thesis is able to provide a more detailed and structured parsing for it.Apart from introductory remark and conclusion, the dissertation consists of three parts.In the first part, I explained"no legal reasons", introduced and commented on the"unionism"and"non-unionism". In my opinion, we should adopt the views expressed by the latter. The Unjust Enrichment should be classified to two types: the Payment Unjust Enrichment and the Non-Payment Unjust Enrichment. And the standard of"no legal reasons"should be fixed separately for each type.The second part is the"no legal reasons"of the Payment Unjust Enrichment. After analyzing the payment,the Theory of Cause,the causa of payment and so on, the paper concluded that the"no legal reasons"of the Payment Unjust Enrichment means lacking objective causa of payment. Then under different Model of Real Right Alternation, the paper discussed the relationship between lacking objective causa of payment and the Payment Unjust Enrichment. In order to understand this judging criteria better, I laid out it through analyzing the legal relationship of the credit. The third section addressed in the Non-Payment Unjust Enrichment.The"no legal reasons"has a unified criterion lacking the entitlement for holding the property interests. In general, no rights means lacking the entitlement for holding the property interests. But, under legal access system, the standard of weather the entitlement for holding the property interests is lack, need to be determined in another way. So, the paper used the Acquisition in good faith system and Accession system as examples, to give an elaborative discussion.