Lawyers and specialists of fiqh consider unanimously that contracts can be invalidated if its conditions are illegal. It has been accepted by the civil law. The problem is to determine the exact conditions that can lead to annulment of the contract. Traditionally, basic reasons for annulment are: consensus (ejma) renunciation to what is required to fulfill the contract, opposition to Quran and Islamic Tradition, corruption, lack of necessary condition. None of these are free from critics. Recently, the two jurists Molaqqeq-e Esfahani and Mohaqqeq-e Iravany proposed a new analysis of this problem, by linking annulment of the contract to the existence of two incompatible intentions in it. Because it is not possible to make the two intentions agree with each other, the contract is invalid. This papers aims to show the significance of the theory of these two scholars.
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