Date of Award


Degree Type


Degree Name

Doctor of Juridical Science (S.J.D.)

First Advisor

Bruce W. Frier

Second Advisor

John A. E. Pottow

Third Advisor

Nicolas Cornell


The aim of this dissertation is to study the practice and theories regarding the law of illegality, in the context of contract and unjustified enrichment.

Illegality (and immorality) is universally seen as a ground for invalidating contracts. It is widely acknowledged that the courts have the "prerogative to limit enforcement of contracts that transgress the boundaries of public policy". In both Common Law and the Civil Law systems, it is usually in the law of contract that the problem of illegality is dealt with. An illegal contract is invalid, but it may be performed, either in full or in part. The ensuing problem is whether a party who performs an illegal contract is entitled to restitution from the recipient of the performance. Related to illegality defense in contract law, there is an inevitable problem of in what circumstances the illegality doctrine forecloses a claim for restitution under the law of unjustified enrichment.