Datio ob rem and datio ob causam – the purpose of performance in Roman law
Summary This paper deals with one of the most important unjustified enrichment claims in Roman law, the condictio causa data causa non secuta concentrating on the crucial issue of the purpose of performance. In Roman law the purpose of performance was denoted by the term res as a part of datio ob rem (giving for a purpose) or causa as a part of datio ob causam (giving on a basis); however, in the secondary literature there is a dispute over the exact meaning of those terms and their mutual relationship. Some scholars identify res with the counter-performance which was expected from the recipient. Others consider this interpretation of res as too narrow, because datio ob rem was applied not only where the giver expected counter-performance but also when he tried to achieve other goals, including that not associated with the recipient’s behaviour at all. In order to find a solution to that long-lasting dispute the article analyses typical examples of cases described in the sources as datio ob rem or datio ob causam.