Taxonomy in Private Law — Furor in Text and Subtext

Abstract

This article starts with an overview of the debates over classification in private law that took place in the latter period of Peter Birks’s career. It does so by setting out the Birksian taxonomy and by collecting various extracts from Birks’s voluminous output, then contrasts those extracts with the views of a selection of his most prominent critics. The article next turns to a defence of Birks’s project and its aims of promoting rationality, the confinement of discretion, and modesty of function in the common law. The greater part of the article is devoted to showing how, in tort law particularly, New Zealand common law has lost its modesty and is intruding on personal freedoms. Instead of requiring an undertaking before a party becomes liable for nothing more than causing damage to another’s wealth, liability is being imposed from without by fudging the boundaries between contract and tort, and by using as tools nothing much sharper than “justice and fairness”. The final section of the article then turns to criticise, on similar grounds, the concept of unjust enrichment as promoted by Birks himself.

Keywords: Private law, contract, tort, restitution, unjust enrichment, taxonomy, classification