THE CONCEPT OF ‘CAUSA’ IN THE SOURCES OF ROMAN LAW RELATED TO UNJUSTIFIED ENRICHMENT
In this paper I analyze the meaning of causa in the sources of Roman law in fourth, fifth, sixth and seventh title of the twelfth book of Digest’s. The aim of my study is to participate in the contemporary discussion on several crucial issues of Roman conception of unjustified enrichment. In my opinion research into the concept of causa can contribute to the better evaluation of the theories on causa condictionis, causa dandi, causa retinendi, the theory that datio sine causa was the central concept of Roman unjustified enrichment, as well as the theory that datio was a basic precondition of the application of condictio. I come to a general conclusion that causa had several different meanings: a) causa as an qualification of the fact that a benefit is in the hands of another person; b) causa which related to the legal basis of acquisition of a benefit; c) causa which related to the way in which a benefit was acquired; d) causa as a motive or an objective of the performance; e) causa which related to the basis of a promise of performance; f) causa which justified the retention of a benefit. Neither of the abovementioned meanings of causa corresponds to the causa condictionis understood in the abstract way as a ground for claims common to all condictiones, a common idea of the remedy for the recovery of an unjust enrichment. Only the last meaning related to the conception of causa retinendi. The theory that datio sine causa was the central concept of Roman does not seems to be justified.