ABSTRACT
In civil law systems, a distinction is made between non performance of a contract and change of circumstances, the latter being dealt with often under the expression clausula rebus sic stantibus (as long as things remain in the same state)254 or imprévision (change of circumstances).255 The distinction fell somewhat into disuse in the 19th century because it contravened the fundamental principle of pacta sunt servanda (contracts must be kept),256 but re-emerged with the devastating inflation experienced throughout Europe at the beginning of the 20th century. German law responded by recourse to the good faith clause in the BGB and to the notion of Wegfall der Geschäftsgrundlage (disappearance of the underlying basis of the contract) allowing readjustment or termination.257 French law adopted a much more limited approach: in private law pacta sunt servanda as expressed in Art 1134 of the Code civil took precedence and only in public law might adjustment be possible.258
