Criteria for Qualification of the Contract Based on Analysis of the agreement of Contracting Parties in Iranian Law, Ja'fari jurisprudence and French law

The most important issue in the distinction between validity and invalidity, as well as the conditions, rules, and effects of a contract, is determining the nature of the contract or, in other words, describing the contract. The basic question of this article is what criteria can be used to achieve a correct qualification. To describe the contract, the most reliable way is to analyze the content of the contract concluded by the contracting parties, regardless of their chosen title. To achieve the nature intended by the contracting parties through the analysis of the content of the contract, the basic issue is which part of the contracting parties' contract is effective in identifying the nature of the contract. To achieve this goal, in this article, using the descriptive-analytical method, the viewpoints presented in Ja'fari jurisprudence, Iranian law, and French law were analyzed and examined. Some jurists consider the inherent effect of the contract to be decisive, some consider the basic obligation and some consider the subject of the contract to be effective, but it seems that the most important criterion is the essential elements or elements that make up the nature of the contract. Therefore, to describe a contract, first of all, it is necessary to determine the essential elements of the contract, after determining the essential elements of nominate contracts and separating them from conditions and provisions, by finding the essential elements of one of the nominate contracts in the agreement of parties, the contract is described with that title. If the contract of the contracting parties does not include any of the essential elements of nominate contracts, it should be considered an innominate contract. The most important source of the law is the substantive elements, but the law alone cannot determine the substantive elements, therefore, it is necessary to introduce the customary law and jurisprudential sources as the nature of the contract.