The Principle of Unjust Enrichment. Roman Law Tradition and Modern Debate about the European Private Law. Wojciech Dajczak Uniwersytet im. Adama Mickiewicza w Poznaniu Civilian Tradition and Modern Debate about the Principles of Private Law Roman law – the part of ancient history and an elment of european legal experience Ancient history Principles of law } In quoque, qui non debitum accepit ab eo qui per errorem solvit, re obligatur: nam proinde ei condici potest si PARET EUM DARE OPORTERE, ac si mutuum accepisset. } He also who received something that was not due from a person who paid him through mistake, is liable under a real obligation, a personal action can be brought against him under the formule „ If it appears that he was required to give”. Civilian Tradition and Modern Debate abot the Principles on Private Law Unjustified enrichment in the CFR project – comparative and historic perspective Unjustified enrichment in the CFR project – comparative and historic perspective Unjustified enrichment in the CFR project – comparative and historic perspective Unjustified enrichment in the CFR project – comparative and historic perspective The normative nature of principle of unjustified enrichment in ancient Roman law The normative nature of principle of unjustified enrichment in ancient Roman law The normative nature of principle of unjustified enrichemt in ancient Roman law } The meaning of the discussed rule came down to the fact that it could be perceived as a clue resulting from the observation of experience and from a notion of the nature of law, which inspired one to seek accurate premises of granting condictio. Judicature defines premises of liability for unjustified enrichment which are unknown to the code – the example of France Judicature defines premises of liability for unjustified enrichment which are unknown to the code – the example of France General clause of restitution of unjustified enrichment on the example of BGB General clause of restitution of unjustified enrichment on the example of BGB } Interpretation of the German Supreme Court is a continuation of an attitude expressed in particular in Pomponius’s dictum – nam hoc natura aequum est neminem cum alterius detrimento fieri locupletiorem. } This is an attitude of openness to liquidation of previously unidentified cases of unjustified enrichment. English debate on the factors of an obligation for unjustified enrichment } Moses v. Macferlan [1760] } … obligation to reverse unjustified enrichment resulted from aequo et bono. } In English law there was no dogmatic concept of unjustified enrichment as a source of obligation. English debate on the factors of an obligation for unjustified enrichment English debate on the factors of an obligation for unjustiefied enrichment } „no basis” theory } The English law should uniformly adopt lack of bases to retain enrichment known from the Roman law tradition } The development of English common law over last 20 years is a clear step in the direction pointed out by Pomponius’s words. The rule of restitution of unjustified enrichment from the perspective of a comparative and historical discussion The rule of restitution of unjustified enrichment from the perspective of a comparative and historical discussion Unjustified enrichment in the CFR and traditon of roman law