Abstract

Justinian once defined ‘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, reflecting in particular on the law of assignment, the law of delict and unjustified 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.