Restitution : A New Start?

In this paper I argue that something has gone wrong with the law of restitution for unjust enrichment. I aim to explain what I think has gone wrong, and to propose the beginning of a solution. I argue that scholars and courts have equivocated between seeing unjust enrichment as a cause of action, which can be applied directly to the facts to determine whether a defendant is liable, and seeing it as a principle, whose role is only to say something about the justification for some legal rules. Many of the arguments that have been made over the last thirty years presuppose that unjust enrichment operates as a cause of action, even though they do not say so expressly. I argue that it cannot be a cause of action, which undermines a great deal of the scholarship and which means, in turn, that the causes of action remain to be described. The second part of the paper begins that task