In the common law ofEnglandandUnited States, agreement is enforceable if it is shown that it is made for valuable “return”: that is a profit provided by a party seeking enforcement of the agreement. Thus, the presence of a profit is a precondition for the validity of all contracts unless they are under seal. Profits can be looked at as a price paid by the other party. It takes the form of some rights, profits or benefits accruing to the one party or some detriment or loss suffered by the other.
In Civil law system, a lawful cause is a precondition for the validity of contracts. Classically, the cause is the immediate and direct end which a contracting party has in incurring its obligations. In this sense it has never been used to distinguish between agreements and contracts. French writers distinguish between cause of contract and cause of obligation. The cause of obligation of one party is the performance of the other party obligation, and so if the other party is in default, no return exists to the other, then the other has the right not to perform and shall be discharged from its obligations.
It seems that the two concepts, return and cause of obligation have similar functions, but they differ; while return plays its role mainly at contract formation, cause of obligation plays its role at contract performance.
"The Concept of “Return” in Contracts,"
UAEU Law Journal: Vol. 2008:
33, Article 4.
Available at: https://scholarworks.uaeu.ac.ae/sharia_and_law/vol2008/iss33/4