Historical evolution of the concept of just price and of contractual rescission due to "laesio ultradimidium"

Abstract

The Latin concept of iustum pretium first appeared in post-classical Roman Law in the Constitutions CJ.4.44.2 and CJ.4.44.8 of Diocletian and Maximian. These laid down the possibility of the rescission of contracts of sale due to laesio ultradimidium. Previously, during the classical period, the pricing criteria had been merely based on the willingness of the parts involved to determine a price between themselves with the only requirement being that the price be settled, definite, real and true. The concept of iustum pretium evolves historically through Canon Law, the Fuero Real (Royal decrees drawn up by Alfonso X in the 13th century), las Partidas (a seven-part legal code laid down by Alfonso X), the Costumbres de Tortosa (a legal body of work compiled in the late 13th century), the Ordenamiento de Alcalá (a collection of laws enacted by Alfonso XI in the 14th century) and the Novísima Recopilación (1805 compilation of laws). This notion of contract rescission due to laesio ultradimidium is not included in the current Civil Code as it was removed in the 1851 Civil Code project. Nowadays, only the Catalan Civil Rights Compilation and the Fuero Nuevo laws of Navarra recognize contract rescission due to legal lesion and apply, respectively, the market value and real value, identified with the just price, to determine the existence of said lesion. The jurisprudence of the Spanish Supreme Court does not require the price to be just, but to be settled. This price can be determined either through comparison to another certain price or at the discretion of the person in question without the need to quantify it at the time of drawing up the contract.