Die Rückabwicklung gegenseitiger Verträge als einheitliches Problem

Phillip Hellwege has developed a uniform system for unwinding mutual contracts, a system which could be applied in English, Scots, and German law and which could serve as a model for the harmonization of European private law. In English and Scots law, the reasons why one party to a mutual contract may ask to have the contract unwound are well known. The causes of action in unjust enrichment have been, at least in the past decade, another main point of interest. They allow each party to claim back his performance once it has been decided that the contract is void, frustrated or has been rescinded or terminated. However, two questions have hitherto been neglected: how exactly is the contract unwound, and what happens if one of the parties is not able to restore what he has already received?
These questions have been a source of controversy in German law for over a century, and a generally accepted answer to them has not yet been found. It is the author's opinion that the problem of all three countries is that they recognize more than one regime governing the process of unwinding mutual contracts, and that this multitude of regimes can lead to discrepancies if one of the parties is not able to return what he has received. The author then proves that a uniform approach was known to English, Scots, and German legal history. Against this background, he has developed a uniform regime for unwinding mutual contracts which could be applied in English, Scots, and German law and which could serve as a model for the harmonization of European private law.