This work investigates the central question of whether a unified law of restitution or unjust enrichment exists within the current legal framework. Robert L. Stevens, a legal scholar, challenges the prevailing academic consensus by arguing against the existence of a singular, cohesive doctrine of restitution. He utilizes a comparative analysis of established legal precedents to demonstrate how restitutionary principles are inextricably linked to and derived from existing categories of contract, tort, equity, and property law.

Legal scholars frequently cite this text for its rigorous challenge to the taxonomy of modern private law. Experts highlight the book as a significant contribution to the ongoing debate regarding the structural integrity of restitutionary claims.