ABSTRACT
The law of unjust enrichment presents a different way of thinking about private law from the concepts of equity. A claimant may bring an action for unjust enrichment where the defendant has been 'enriched' as a result of some 'unjust factor' at the claimant's expense. By contrast, Birks had no truck with ideas of 'justice' in the general sense of that word. The concept of 'unjust enrichment' in his scheme meant a list of unjust factors which were set out in advance in a rigid taxonomy. In essence, the purpose of subrogation was to act as a remedy where the defendant was unjustly enriched at the claimant's expense by using property to discharge a debt. Birks claimed that knowing receipt was a doctrine which effected unjust enrichment in some circumstances so as to effect restitution of property which had been transferred away from a trust in breach of that trust.
