Page 65 - Latent Defect or Excessive Price?Exploring Early Modern Legal Approach to Remedying Defects in Goods Exchanged for Money - Bruijn

MEDIEVAL IUS COMMUNE
has been introduced for the common good. People frequently need something which the other has. Sales functions as an instrument to allocate those needs in a just way. Seeing that a contract which of necessity serves the interests of both parties should not be more detrimental to one than to the other, sales requires equality of value of the things transacted. To ensure that equality, the thing's value had to be determined. In order to do so, coinage was invented with which every thing's just price could be expressed. If the amount paid for a thing equalled its just price, the contract met the demands of fairness in exchange.
'And therefore, if the price exceeds the quantity of value of the thing, or conversely, if the \[value of the\] thing exceeds the price, the equality of justice is destroyed. As a consequence, considered on its own, it is illicit to sell for more or buy for less than the thing is worth'.129
Thus, the just price (justum pretium) became a vehicle to incorporate medieval normative theory with regard to what was considered fair and acceptable behaviour in commerce. If one only succeeded in formulating principles to determine what price was to be considered just, the right correspondence between price and thing sold, as required by Aquinas' contract theory, could conveniently be established.
Aquinas and later theologians would explain the requirement for a just price in commutative contracts with reference to C. 4.44.2.130 However, there is an important difference between the Roman law text and the views adhered to in moral theology. According to C. 4.44.2, the seller131 cannot rescind the sale as long as the deviation from the just price is not enormis. Aquinas contends that the Roman law adage that 'it is
129 Aquinas, Summa Theol., vol. 9, IIaIIae, q. 77, a. 1, resp., p. 147: 'Si autem fraus deficit, tunc de emptione et venditione dupliciter loqui possumus. Uno modo, secundum se. Et secundum hoc emptio et venditio videtur esse introducta pro communi utilitate utriusque: dum scilicet unus indiget re alterius et e converso, sicut patet per Philosophum, in 1. Pol. Quod autem por communi utilitate est inductum, non debet esse magis in gravamen unius quam alterius. Et ideo debet secundum aequalitatem rei inter eos contractus institui. Quantitas autem rerum quae in usum hominis veniunt, mensuratur secundum pretium datum: ad quod est inventum numisma, ut dicitur in V Ethic. Et ideo si vel pretium excedat quantitatem valoris rei, vel e converso res excedat pretium, tolletur iustitiae aequalitas. Et ideo carius vendere aut vilius emere rem quam valeat est secundum se iniustum et illicitum'; quoted by Baldwin, Medieval Theories, p. 72.
130 Gordley, 'Equality', p. 1638
131 According to the Gloss, the choice between price compensation or rescission of the contract was
reserved for the party which had caused the prejudice, i.e. either the buyer who had bought to cheap or the seller who had sold to high. See Gloss Elegerit to C. 4.44.2: 'Est ergo in potestate emptoris. Et idem dico econtra emptore decepto esse in potestate venditoris...'.
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