[Footnote 2: This opinion was accepted by all the later writers, e.g. Gerson, De Cont., ii. 5; Biel, op. cit., IV. xv. 10: 'Si pretium excedit quantitatem valoris rei, vel e converso tolleretur equalitas, erit contractus iniquus.']
[Footnote 3: Desbuquois, 'La Justice dans l'Echange,' Semaine Sociale de France, 1911, p. 167. Gerson says: 'Contractus species est justitiae commutativae quae respicit aequalitatem rei quae venditur ad rem quae emitur, ut servetur aequalitas justi pretii; propter quam aequalitatem facilius observandum inventa est moneta, vel numisma, vel pecunia,' De Cont., ii. 5.]
The conception of the just price, though based on Aristotelian conceptions of justice, is essentially Christian. The Roman law had allowed the utmost freedom of contract in sales; apart from fraud, the two contracting parties were at complete liberty to fix a price at their own risk; and selfishness was assumed and allowed to be the animating motive of every contracting party. The one limitation to this sweeping rule was in favour of the seller. By a rescript of Diocletian and Maximian it was enacted that, if a thing were sold for less than half its value, the seller could recover the property, unless the buyer chose to make up the price to the full amount. Although this rescript was perfectly general in its terms, some authors contended that it applied only to sales of land, because the example given was the sale of a farm.[1] However, the rescript was quoted by the Fathers as showing that even the Roman law considered that contracts might be questioned on equitable grounds in certain cases.[2] The distinctively Christian notion of just price seems to have its origin in a passage of St. Augustine;[3] but the notion was not placed on a philosophical foundation until the thirteenth century. Even Aquinas, however, although he treats of the just price at some length, and expresses clear and categorical opinions upon many points connected with it, does not state the principles on which the just price itself should be arrived at. This omission is due, not to the fact that Aquinas was unfamiliar with these principles, but to the fact that he took them for granted as they were not disputed or doubted.[4] We have consequently to look for enlightenment upon this point in writings other than those of Aquinas. The subject can be most satisfactorily understood if we divide its treatment into two parts: first, a consideration of what constituted the just price in the sale of an article, the price of which was fixed by law; and second, a consideration of what constituted the just price of an article, the price of which was not so fixed.
[Footnote 1: Hunter, Roman Law, p. 492.]
[Footnote 2: Ashley, op. cit., p. 133.]
[Footnote 3: 'Scio ipse hominem quum venalis codex ei fuisset oblatus, pretiique ejus ignarum ideo quiddam exiguum poscentem cerneret venditorem, justum pretium, quod multo amplius erat nec opinanti dedisse' (De Trin., xiii. 3).]
[Footnote 4: Palgrave, Dictionary of Political Economy, tit. 'Justum
Pretium.']
§ 2. The Just Price when Price fixed by Law.
Regarding the power of the State to fix prices, the theologians and jurists were in complete agreement. According to Gerson: 'The law may justly fix the price of things which are sold, both movable and immovable, in the nature of rents and not in the nature of rents, and feudal and non-feudal, below which price the seller must not give, or above which the buyer must not demand, however they may desire to do so. As therefore the price is a kind of measure of the equality to be observed in contracts, and as it is sometimes difficult to find that measure with exactitude, on account of the varied and corrupt desires of man, it becomes expedient that the medium should be fixed according to the judgment of some wise man…. In the civil state, however, nobody is to be decreed wiser than the lawgiving authority. Therefore it behoves the latter, whenever it is possible to do so, to fix the just price, which may not be exceeded by private consent, and which must be enforced.'…[1] Biel practically paraphrases this passage of Gerson, and contends that it is the duty of the prince to fix prices, mainly on account of the difficulty which private contractors find in doing so.[2]
[Footnote 1: De Cont., i. 19.]