It is probably correct to say that the canonical teaching on just price was negative rather than positive; in other words, that it did not so much aim at positively fixing the price at which goods should be sold, as negatively at indicating the practices in buying and selling which were unjust.  ‘The doctrine of just price,’ according to Dr. Ryan, ’may sometimes have been associated with incorrect views of industrial life, but all competent authorities agree that it was a fairly sound attempt to define the equities of mediaeval exchanges, and that it was tolerably successful in practice.’[1] The condition of mediaeval markets was frequently such that the competition was not really fair competition, and consequently the price arrived at by competition would be unfair either to buyer or seller.  ‘This,’ according to Dr. Cunningham, ’was the very thing which mediaeval regulation had been intended to prevent, as any attempt to make gain out of the necessities of others, or to reap profit from unlooked-for occurrences would have been condemned as extortion.  It is by taking advantage of such fluctuations that money is most frequently made in modern times; but the whole scheme of commercial life in the Middle Ages was supposed to allow of a regular profit on each transaction.’[2] There might be some doubt as to the positive justice of this or that price; but there could be no doubt as to the injustice of a price which was enhanced by the necessities of the poor, or the engrossing of a vital commodity.[3] Merely to buy up the whole supply of a certain commodity, even if it were bought up by a ‘ring’ of merchants, provided that the commodity was resold within the limits of the just price, was not a sin against justice, though it might be a sin against charity.[4] If the authorities granted a monopoly, they must at the same time fix a just price.[5] A monopoly which was not privileged by the State, and which had for its aim the raising of the price of goods above the just price was regarded with universal reprobation.[6] ‘Whoever buys up corn, meat, and wine,’ says Trithemius, ’in order to drive up their price and to amass money at the cost of others is, according to the laws of the Church, no better than a common criminal.  In a well-governed community all arbitrary raising of prices in the case of articles of food and clothing is peremptorily stopped; in times of scarcity merchants who have supplies of such commodities can be compelled to sell them at fair prices; for in every community care should be taken that all the members should be provided for, and not only a small number be allowed to grow rich, and revel in luxury to the hurt and prejudice of the many.[7] Thus the doctrine of the just price was a deadly weapon with which to fight the ‘profiteer.’  The engrosser was looked upon as the natural enemy of the poor; and the power of the trading class was justly reckoned so great, that in cases of doubt prices were always fixed low rather than high.  In other words, the buyer—­that is to say, the community—­was the subject of protection rather than the seller.[8]