**Change of date: this lecture was originally scheduled for May 31st.** 


Lecture 3: “Unjust Enrichment”—the Potion that Induces Well-meaning Sloppiness of Thought


From about 1990, the courts of England and Wales began to signal that the law of restitution might be reducible to a single principle, that of unjust enrichment. Fuelled by Lord Steyn’s adoption in 1998 of the academician’s naive 4-stage test for unjust enrichment, there has since 2007 been very rapid expansion of the concept. Australian law has been heading in the opposite direction. So, English courts now seem ready to scrutinise all potential increases in another’s wealth where the claimant can establish a sufficient involuntary connection to that increase. This lecture argues that the English legal system is making a very serious mistake. Unjust enrichment is both too broad and too narrow to be a satisfactory legal concept. Citizens involuntarily increase one another’s wealth in innumerable ways in their day-to-day interactions and the law should not start from an assumption that such increases need to be justified. The paper argues that in general there needs to be either a (traceable) transfer of property involved, or a request for services. At the same time, in many, if not most, of the standard restitutionary fact patterns enrichment is either absent or irrelevant (as a driver of the law). Forcing the law of restitution into a template of unjust enrichment is calculated to disform the law. English case law has got to the point where carefully considered decisions of appellate courts before 1990 are being ignored in every direction.

Commentator: Professor Rob Stevens

Chair: Professor Louise Gullifer

Peter Watts is a Professor of Law at the University of Auckland. He is the General Editor of Bowstead & Reynolds on Agency (20th ed, Sweet & Maxwell, 2014). His other books include Directors' Powers and Duties (2nd ed, LexisNexis, 2015) and Watts, Campbell and Hare (Company Law in New Zealand (2nd ed, LexisNexis, 2015). He is a barrister at Bankside Chambers in Auckland and a door tenant at Fountain Court Chambers, The Temple, London. He is a Queen's Counsel and a Fellow of the Royal Society of New Zealand. In 2016, he is a Leverhulme Visiting Professor to the University of Oxford.


Three Leverhulme Trust Lectures are to be delivered at the University of Oxford in May 2016 by Professor Peter Watts.

Lecture 1: Wk 3 TT (10 May), The Cube, 5:30pm

Lecture 2: Wk 4 TT (17 May), The Cube, 5:30pm

Lecture 3: Wk 6 TT (31 May), The Cube, 5:30pm