Long live the law of unjustified enrichment — A response to Jansen

• Jurisdiction: South Africa
• Citation: 2019 Acta Juridica 371
• Pages: 371-394
• Author: Du Plessis, J.
• Published date: 24 December 2019
• Date: 24 December 2019

371

Long live the law of unjustied

enrichment – A response to Jansen*

JACQUES DU PLESSIS†

The law of unjustied enrichment is a prominent feature of the legal

landscape of many civil-law systems and of German law in particular.

However, resorting strongly to historical arguments relating to the

development of German law, Nils Jansen has argued that the strands

of material united under its law of unjustied enrichment are too

disparate to warrant its recognition as a distinct eld of law. The purpose

of this essay is to explore the basis for and implications of Jansen’s

argument. This is done mainly by adopting the perspective of South

African law, which shares many features of the civil-law background

of German law. The exploration commences with a brief examination

of Jansen’s argument, followed by an inquiry into what it entails to

locate rules in various elds of law. Thereafter, the implications of his

argument for South African law are considered. It is concluded that

the view that certain rules should be (exclusively) located in some

elds of law because they serve policies or values that ‘belong’ to those

elds is problematic. Furthermore, it is not apparent why Jansen sets

such a high standard for uniformity in the application of the general

principles of the law of unjustied enrichment, compared to other

areas of law. And nally, it is doubtful what practical benets could arise

from his proposed alternative approaches, for example, relocating part

of its subject matter to a ‘law of performances’.

* I am g rateful for the comments of the participants in the ‘Private law in a

changing world’ seminars held at Edinburgh University on 12 April 2018 and at

the University of Cape Town on 26 October 2018, as well as for the reports of the

anonymous referees. A special word of thanks goes to Helen Scott for the invitation

to contribute to these seminars and to this collection of essays. The nancial support

of the National Research Foundation is acknowledged with gratitude.

† BComm LLM LLM (Stell) PhD (Aberdeen); Distinguished Professor of Law,

Stellenbosch University.

2019 ACTA 371

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372 PRIVATE LAW IN A CHANGING WORLD

I INTRODUCTION

A decade has passed since the appearance of Danie Visser’s Unjustied

Enrichment.1 A key feature of this pioneering work is the extent to

which it draws on what Reinhard Zimmermann has called the

modern civilian approach to the law of unjustied enrichment,

an approach especially exemplied by German law.2 Subsequently,

various South African and Scottish commentators have joined Visser

in arguing that these comparative insights could be instructive in

delineating the contours of local enrichment law.3 However, drawing

strongly on historical perspectives, Nils Jansen has expressed doubts

about the tenability of a unied law of unjustied enrichment in the

German-speaking civil-law systems, and has asked whether it is time

to say farewell to the eld.4 The fact that a prominent German scholar

has posed such a question, and is understood to have answered it in

the armative,5 is undoubtedly relevant to those who have argued

that developments in modern civil law, and especially in German law,

are instructive to other jurisdictions that share its civilian roots. The

potential signicance of Jansen’s views has already been considered

further aeld, and has resonated with some common-law scholars

who are sceptical about the coherence of a ‘law of unjust enr ichment’.6

1 D Visser Unjustied Enrichment (2008).

2 R Zimmer mann ‘Unjustied enrichment: The modern civilian approach’

(1995) 15 Oxford Journal of Legal Studies 403.

3 See eg R Zimmer mann ‘A road through the enrichment-forest? Experiences

with a general enrichment action’ (1985) 18 Comparative and International Law

Journal of Southern Africa 1; N Whitty ‘Rationality, nationality and the taxonomy

of unjustied enrichment’ in D Johnston & R Zimmermann (eds) Unjustied

Enrichment – Key Issues in Comparative Perspective (2002) 658; R Evans-Jones

Unjustied Enrichment vol 2: Enrichment Acquired in Any Other Manner (2003) 34–8

(and the exposition there of the views of MacQueen, Hogg, Reid and Blackie);

Visser Unjustied Enrichment (n 1) 36–46, 72–84; D Visser ‘Enrichment’ in

W Joubert (founding ed) The Law of South Africa vol 17 3 ed (2018) para 210;

J du Plessis ‘Labels and meaning’ (2014) 18 Edinburgh Law Review 416; J du Plessis

The South African Law of Unjustied Enrichment (2012) 10–15.

4 N Jansen ‘Farewell to unjustied enrichment?’ (2016) 20 Edinburgh Law Review

123; N Jansen ‘Gesetzliche Schuldverhältnisse: eine historische Strukturanalyse’

(2016) 216 Archiv für die civilistische Praxis 112.

5 See eg S Hedley ‘Farewell to unjustied enrichment? – A common law

response’ (2016) 20 Edinburgh Law Review 326; E Clive ‘Farewell to unjustied

enrichment?’ posted on the Edinburgh Private Law News blog (blog now removed;

copy of post on le with author).

6 See Hedley (n 5) 328; R Stevens ‘The unjust enrichment disaster’ (2018) 134

Law Quarterly Review 574 at 600.

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