Christian von Bar 
Benevolent Intervention in Another’s Affairs [PDF ebook] 

In all legal systems of the European Union the law of contract and the law of tort form the main pillars of the law of obligations. Legal history and comparative law show, however, that it is not possible to cope with these two bodies of rules alone – even if their scope of application is generously conceived. Another part of the law of obligations, alongside the law of unjustified enrichment, which to some extent lies “between” contract and tort and fills the gaps that those areas of the law leave behind, is subject of this Book. The Study Group on a European Civil Code has drafted Principles relating to the unsolicited and voluntary undertaking of another’s affairs on the basis of a reasonable ground for intervention: “Principles of European Law: Benevolent Intervention in Another’s Affairs”.
In continental European legal systems the law on voluntary management of another’s affairs developed from the Roman law concept of negotiorum gestio. While distinguishable in its contemporary form from its historical origin, its Latin nomenclature remains current for many lawyers in continental Europe and Scotland. Consistent with that, the Latin term features throughout both as an umbrella term for the current national laws and as a collective label for the European Principles set out and explained in the text.
The Common Law does not recognise an independent relationship of legal obligations derived from a (beneficial) voluntary and benevolent intervention in another’s affairs. English and Irish law has only functional equivalents scattered across diverse legal constructs. As a result, the English legal language does not yet possess a native term for the legal obligation arising by operation of law out of the management of another’s affairs. The Study Group has opted for “Benevolent Intervention in Another’s Affairs” as a suitable description. No practical consequences result from that, save that in the English version of the articles the person acting is called an “intervener”, rather than the gestor.