Theoretical foundations and legal documents of balance theory in Imami jurisprudence, Iranian contract law and International CISG and PECL documents

According to the theory of balance, it is necessary to observe justice in the contractual rights of the parties to the exchange contracts, to maintain the economic balance of the contract, and in the philosophy of law, full presentation of each person's rights, without the intervention of others, indicates exchange justice. Distributive justice, in its comprehensive sense, also requires the balance of rights of the parties in a reciprocal contract. This theory is acceptable in Iranian jurisprudence and law, citing the right to imprisonment, the rule of loss of goods before receipt and some legal options, and in transnational legal documents, with its numerous effects. Therefore, in this article, with the descriptive method of survey method (field finding) and comparative and sometimes descriptive causal-comparative method, while examining the jurisprudence and contract law of Iran, two important international documents "International Trade Convention" and "Principles" "European contract law" and its underlying legal systems define "reciprocity of obligations" as the main and common basis.reciprocity of obligations" as the main and common basis.