Manfred Max Kaufmann (LL.M. 1987)
In recent years, Canadian courts have accepted the doctrine of unjust enrichment as a rationale underlying the law of restitution. This thesis adopts this approach, and examines its impact on questions adhering to the recovery of money mistakenly paid. The discussion is restricted to situations where no contractual obligations existed between the parties.
After an introduction in chapter one, chapter two examines precisely what the doctrine of unjust enrichment predicates. Three particular aspects of the recovery of money mistakenly paid are then tackled: the action of the rightful payee, the availability of a remedial constructive trust and the defence of change of position.
British and American law provide a background for the discussion. It will be seen that, with respect to restitutionary law, Canadian law has left its British ancestor behind and follows more the American model. The results arrived at are contrasted with the answers which a civil law code, more precisely, the German Civil Code, provides for the questions under review.
The doctrine of unjust enrichment, according to this thesis, call for the abolition of the action of the rightful payee. The doctrine does not necessarily entail the recognition of constructive trusts to remedy an unjust enrichment. However, the remedial constructive trust is a useful remedy for a mistaken payer and, if the payee has become bankrupt, the only one. Finally, it is argued that the recognition of change of position as a defence follows necessarily from the recognition of the unjust enrichment doctrine.