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 a field of law. 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.

Presented by Professor Lionel Smith, Faculty of Law, McGill University

Professor Smith is the William C. Macdonald Chair in the Faculty of Law at McGill University, Canada and is a visiting professor at Oxford University. He is interested in all aspects of fundamental comparative private law. He is particularly engaged with how private law understands aspects of unselfish behaviour, and he has an active research agenda in the law relating to trusts, fiduciary obligations, gifts, and unjust enrichment, in civil law and in common law. 

Lionel is a titular Member of the International Academy of Comparative Law. He is also a member of the American Law Institute, the European Law Institute, and the International Academy of Estate and Trust Law. He is a non-practising member of the Bar of Alberta. In 2017 he was appointed Visiting Professor at the Faculty of Law, University of Oxford.

He is author, co-author or contributor to a number of leading works including: The Law of Tracing (Oxford University Press, 1997) ;Waters' Law of Trusts in Canada, 4th ed. (Carswell, 2012); Commercial Trusts in European Private Law(Cambridge University Press, 2005; paperback, 2009); Oosterhoff on Trusts: Text, Commentary and Materials, 7th ed. (Carswell, 2009) and  The Law of Restitution in Canada: Cases, Notes and Materials(Emond Montgomery, 2004). He is also the editor of three works on comparative trust law and has written numerous articles, book chapters, notes and reviews in leading international journals.  

A full biography can be found here.

About Australian Centre for Private Law Events

The mission of the ​Australian Centre for Private Law is to foster the development and understanding of the private law through advanced theoretical, doctrinal, empirical and historical research, and the dissemination of that research through education and professional outreach. By supporting the work of its Fellows, the ACPL seeks to promote research in all areas of private law and to establish itself as a research centre of national and international importance. The core initiatives of ACPL are:

Research: To advance a deeper understanding of the structure, principles and policies of the private law through advanced theoretical, comparative, and empirical analysis.

Education: To promote, facilitate and disseminate the results of that research for the benefit of Australia’s social and economic fabric.

Professional Outreach: To engage the judiciary and members of the legal profession in discussion about the values, goals and methods of private law and the respective roles of the judiciary, the legal profession and the academy in the interpretation and reform of private law.

The ACPL embraces all branches of private law, including the law of contract, torts, trusts, equity, property, unjust enrichment, including theoretical and jurisprudential dimensions and contextual applications thereof.


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