The idea of a legal obligation

• Jurisdiction: South Africa
• Published date: 24 December 2019
• Date: 24 December 2019
• Citation: 2019 Acta Juridica 35
• Author: None
• Pages: 35-56

35

The idea of a legal obligation

NILS JANSEN*

Justinian once dened ‘obligation’ as a vinculum iuris, ie a legal bond

between the debtor and his creditor. Although this concept is still

an aspect of modern legal thinking, it cannot capture all aspects of

obligations in modern law. In fact, the traditional Roman concept

of obligatio does not appropriately account, inter alia, for the modern

principle of freedom of assignments. This essay, therefore, analyses the

history of the concept of obligatio, reecting in particular on the law

of assignment, the law of delict and unjustied enrichment. A result

of this history is that obligations, as far as the creditor’s position is

concerned, are today regarded also as proprietary rights.

I INTRODUCTION

In his early paper on Denition and Theory in Jurisprudence, HLA

Hart emphasised that legal concepts do not refer to objects existing

independently of our legal language. No ‘property’, or ‘contract’, or

‘consideration’, or even a ‘right’ exists independently of our systems

of law. Rather, legal systems are constituted by the conceptual

structure of our legal languages. It follows that legal concepts do

not correspond to the law in the same way as the concept of an

‘apple’ corresponds to apples. The meaning of legal concepts does

not correspond to an independent reality1 because their objects are

institutional facts that are brought about by jurists who coin such

concepts. The realities about which jurists are thinking have thus

been made by former generations of jurists. Young lawyers study

the meaning of those concepts in order to understand what their

law is about. I regard this as an evident insight, which is nevertheless

of great importance for the doctrinal jur ist: on the one hand, those

concepts create Denkzwänge – they set conceptual boundaries to

our legal thinking, and lawyers often nd it dicult to imagine

alternatives. Thus, for a German lawyer, those things that the

common lawyer addresses as a ‘consideration’ simply do not exist.2

* Professor of Civil Law, Institute of Legal History, University of Münster, Germany.

1 HLA Har t Denition and Theory in Jurisprudence (1953) 5.

2 Yet, it would be too simplistic to assume that new elements of legal doctrines

come into the world only with a new word being coined for them. Often, jurists

nd a concept for a legal idea only after having discussed it for some time. Thus,

2019 ACTA 35

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36 PRIVATE LAW IN A CHANGING WORLD

On the other hand, like every human institution, such concepts are

not xed for all time. They can be, and sometimes need to be, re-

designed in order to t in with social, economic or legal change.

I think that this basic insight into the nature of legal concepts

is helpful in understanding the idea of a doctrinal, or legal,

‘construction’. Today, constructive approaches to jur isprudence do

not seem to be particularly fashionable. They evoke ideas of alleged

nineteenth-century formalism, or of Begrisjurisprudenz. But such

a view may be misleading. Indeed, Rudolf von Jhering, who gave

powerful expression to the idea of a Constructionsjurisprudenz,3 made

it quite clear that the point of such an approach to legal doctrine

was to understand doctrinal concepts as tools to be designed by

jurists. And, in his later work, Jher ing complemented this basic idea,

showing that the main aspect of a convincing legal construction

was the purpose of the concept being considered.4 If the doctrinal

conception of a concept such as ‘property’, ‘right’, or ‘obligation’ is

to regard it as a construction in this sense of a purposively designed

tool, jurists will assume that its precise contours are not naturally

given. They will ask whether it needs to be improved to perfor m its

function in their legal world appropriately.

A symposium honouring Danie Visser is an ideal occasion to

analyse, with those remarks in mind, the idea of a legal obligation.

Obligations, particularly non-contractual obligations, have been

the focus of Danie’s work, and Danie has never been content

the German Obliegenheiten are much older than the word ‘Obliegenheit’. Yet, even

before they coined the modern concept, jurists were perfectly able to discuss the

relevant ideas in their language; cf on those discussions on contr ibutory negligence,

N Jansen in MSchmoeckel, JRückert & RZimmermann (eds) Histor isch-kritischer

Kommentar zum BGB (2003/2007/2013) §254 [48]. Otherwise, they would not

have been able to think about this idea.

3 Rvon Jhering ‘Unsere Aufgabe’ (1857) 1Jahrbücher für die Dogmatik des heutigen

römischen und deutschen Privatrechts; see also the Introduction to Jhering’s Der Geist

des römischen Rechts auf den verschiedenen Stufen seiner Entwicklung, TeilI 2 ed (1866).

On Jhering’s programme and his theory of a legal construction, seeN Jansen &

M Reimann ‘Begri und Zweck in der Jurisprudenz. Ein Geburtstagsblatt für

Rudolf von Jhering’ (2018) Zeitschrift für Europäisches Privatrecht 89–129, 95–106.

4 Rvon Jhering Der Zweck im Recht volI 2 ed (1884); volII (1883); see Jansen &

Reimann ‘Begri und Zweck’ (n3) 109–12. Jhering was never a Begrisjurist who

would not have teleologically reected the concepts and rules under consideration;

and he never stopped working doctrinally on the Roman heritage. Indeed, with

his last major work, Der Besitzwille. Zugleich eine Kritik der herrschenden juristischen

Methode (Jena 1889), he wanted to give a doctrinal example for his teleological

method: loc cit, ix, 364.

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