Theory of Circumstances Change in Islamic Jurisprudence and Iran's Law

Although, some lawyers have opinion that the theory emerges from the maxim of " Re bus sic stanti bus", which means everything will be as was the conclusion of the Contract, but must accept that this theory is existed by economic crisis of the last century. On the basis of the theory, if in a long term Contract, in the effect of Change of circumstance, which were unforeseeable for parties, the Coasts of the contract becomes so expensive that lose the balance of the Contract, for allocating of heavy unfair responsibility on one of the parties, this theory comes into.The theory is bring into legal systems of many Courtiers and some conventions as Vienna, UNCITRAL, UNIDOIT, I.C.C and principals of European Contracts. Iran’s law system has not any legislation about applying this theory and courts object to invoke to it on basis of stability of contract and Islamic law; in sprite of; some lawyers have been tried to find an equivalent for it; but expressly this system don’t try to create a principle for contract which is effected in change of circumstances. In this article; the author tries to introduce the scope of the theory in Iran and Islamic law and in the end some proposals are demonstrated.