In Germany, the opinion is commonly held that the general provision of § 812 (1) BGB, according to which the one enriched has to restore what he acquired without legal cause to the one at whose expense the enrichment occurred, is the basis of two different claims. This attitude is of ancient origin; it can be traced back to the general rule stated by Pomponius on the one hand and the distinction between two types of claims for restitution in roman-common law on the other. Nevertheless, the separation of the two types of claims is nowadays regarded as an unquestionable dogmatic truth. Both theory and practice divide the general clause into two different formulas. The article shows that it is indeed reasonable to distinguish restitution following unjustified performance from restitution following unlawful interference with another?s property. At the same time it refutes the commonly held opinion which, concentrating on the concept of performance (Leistung), separates two different claims of unjustified enrichment. The two forms of claims of unjustified enrichments can rather be described as two sides of the same coin. To distinguish them may not mean to separate them.
European Review of Private Law