[179] It may be of interest to recall the mediæval attitude toward monopolistic exactions, as summarily stated by St. Antoninus, who was archbishop of Florence in the first half of the fifteenth century: "When monopolist merchants agree together to preserve a fixed price, so as to secure an unlimited profit, they are guilty of sinful trading." He maintained that they should not sell above the market price, and should be prevented from so doing by law. See his "Summa Theologica," III, 8, 3, iv, and II, 1, 16, ii. Present day moral theologians lay down the same doctrine, and in addition condemn the characteristic monopolistic methods as unjust. See Tanquerey, "De Justitia," nos. 776, 777; Lehmkuhl, "Theologia Moralis," vol. I, no. 1119. [180] Clark, "The Problem of Monopoly," p. 35. [181] Final Report, p. 361. [182] Report on the Petroleum Industry, pp. 22, 23. [183] "Papers and Proceedings," pp. 158-194. [184] Op. cit., pp. 20, 251. [185] Op. cit., pp. 254-265. CHAPTER XIX THE MORAL ASPECT OF STOCK WATERING In the last chapter we saw that a monopoly has no right to gains in excess of the competitive rate of interest on its capital, except in so far as these have been derived from superior efficiency. Now superior efficiency is clearly present whenever the monopolistic concern obtains surplus gains by selling its product at competitive prices, or at the prices that would have prevailed under competition. Evidently the surplus in such a case is due to the greater productivity of the monopoly as compared with the average productivity of competitive concerns. When, however, the monopoly charges prices above the competitive level, its surplus gains cannot all be attributed to unusual efficiency. A part if not all of them are the result simply of the power to take; consequently they are immoral.