5. Above all they must protect their tenants, the agriculturists, and be very careful not to demand more than the net product. The Physiocrats never go the length of advising them to give to their tenants a portion of the net product, but they impress upon them the importance of giving them the equivalent of their annual expenditure and of dealing liberally with them. It does not seem much, but it must have been something in those days. “I say it boldly,” writes Baudeau, “cursed be every proprietor, every sovereign and emperor that puts all the burden upon the peasant, and the land, which gives all of us our sustenance. Show them that the lot of the worthy individuals who employ their own funds or who depend upon those of others is to none of us a matter of complete indifference, that whoever hurts or degrades, attacks or robs them is the cruellest enemy of society, and that he who ennobles them, furthers their well-being, comfort, or leisure increases their output of wealth, which after all is the one source of income for every class in society.”[59] Such generous words, which were none too common at the time, release the Physiocrats from the taunt of showing too great a favour to the proprietors. In return for such privileges as they gave them they demanded an amount of social service far beyond anything that was customary at the time. II So far we have considered only the Physiocratic theory. But the Physiocratic influence can be much more clearly traced if we turn to applied economics and examine their treatment of such questions as the regulation of industry, the functions of the State, and the problems of taxation.[60] I: TRADE All exchange, the Physiocrats thought, was unproductive, for by definition it implies a transfer of equal values. If each party only receives the exact equivalent of what it gives there is no wealth produced. It may happen, however, that the parties to the exchange are of unequal strength, and the one may grow rich at the expense of the other.[61] In giving a bottle of wine in exchange for a loaf of bread there is a double displacement of wealth, which evidently affords a fuller satisfaction of wants in both cases, but there is no wealth created, for the objects so exchanged are of equal value. To-day the reasoning would be quite different. The present-day economist would argue as follows: “If I exchange my wine for your bread, that is a proof that my hunger is greater than my thirst, but that you are more thirsty than hungry. Consequently the wine has increased in utility in passing from my hands into yours, and the bread, likewise, in passing from your hands into mine, and this double increase of utility constitutes a real increase of wealth.” Such reasoning would have appeared absurd to the Physiocrats, who conceived of wealth as something material, and they could never have understood how the creation of a purely subjective attribute like utility could ever be considered productive.