"Unjust Enrichment in Commercial Law" is a comprehensive collection of essays edited by Simone Degeling and James Edelman. The book is a significant contribution to the field of commercial law, particularly focusing on the complex and evolving area of unjust enrichment. Here is a detailed overview of the book:

Key Themes

1. Unjust Factors: The book delves into the core of any unjust enrichment claim, examining the unjust factors that can trigger restitutionary mechanisms. These factors include mistake, duress, failure of consideration, and others like ignorance, free acceptance, and exploitation of weakness.
2. Mistake and Voluntariness: A significant theme is the concept of voluntariness and its relationship to causation in the context of mistaken payments. Chief Justice Marilyn Warren discusses the archetypal unjust factor of mistake, highlighting the importance of voluntariness in determining restitutionary principles.
3. Failure of Consideration: The book also explores whether failure of consideration can be considered an unjust factor, thereby triggering restitutionary mechanisms, even in circumstances where a valid and enforceable contract exists. This theme is extensively discussed by McLure J, who questions the reasoning of the High Court in Roxborough.

Plot Summary

The book is structured around a series of essays presented at the Restitution in Commercial Law Conference in Sydney in August 2007. These essays are contributed by leading minds in the field, including judges from the House of Lords, the High Court of Australia, and intermediate Australian appellate courts, as well as leading practitioners and professors of law from across the Commonwealth.

The chapters cover a wide range of topics, including:

• Established Unjust Factors: Chapters examine well-established unjust factors like mistake, duress, and failure of consideration, which fall into two distinct categories: imperfect consent and policy.
• Controversial Issues: The book addresses many of the controversial issues at the cutting edge of unjust enrichment, providing insights into the complex and evolving nature of this area of law.
• Evolution of Law: The book reflects on the incremental progression and "gap filling" that will occur in this area of law in the years to come, as noted by Chief Justice Marilyn Warren.

Critical Reception

The book has received positive reviews for its comprehensive and insightful analysis of unjust enrichment in commercial law. Lord Rodger's chapter highlights the relatively recent development of unjust enrichment as a legal concept and notes that its analysis will continue to mature over the coming decades.

The book is described as an indispensable guide through this area of law for all commercial practitioners. It is praised for bringing together a series of essays that address many of the controversial issues in unjust enrichment, making it a valuable resource for legal scholars and practitioners alike.

Conclusion

"Unjust Enrichment in Commercial Law" by Simone Degeling and James Edelman is a seminal work in the field of commercial law. It provides a detailed examination of the complex and evolving area of unjust enrichment, covering both established and contentious issues. The book's comprehensive analysis and insightful contributions from leading legal minds make it an essential resource for anyone working in this area of law.