The Restatement (Third) of Restitution and Unjust Enrichment

Alone among the great restatements of the common law published by the American Law Institute in the 1930’s and 40’s, the 1937 Restatement of Restitution boldly asserted the existence of a new third branch of the common law of obligations to stand alongside contract and tort. The organizing thesis of the Restatement was that hitherto ignored bodies of common law, known then as the law of quasi-contract, and of equity, centring on the use of the constructive trust, could be unified and restated as a coherent legal subject resting on an underlying principle against unjust enrichment. The new Restatement (Third), of Restitution and Unjust Enrichment builds on the foundation of the 1937 Restatement and offers an up-to-date account of American law on this subject which is equivalent both in its essentials and in most of its details to the restitutionary law of the Canadian common law provinces. The Restatement (Third) follows the basic analytical structure of the subject adopted in 1937 in terms of the scope of the subject, and the relationship between the underlying general principle and the detailed substantive liability rules. The Restatement (Third) includes modernized and integrated treatments of restitutionary remedies and defences. Throughout, it achieves a more effective integration of common law and equitable doctrines than was accomplished by its 1937 predecessor