As to the sterile class, it produces nothing, and so, unlike the preceding class, it can only get its necessaries second-hand from the productive class. These may be got in two ways: a milliard from the agricultural class in payment for manufactured goods and another milliard from the landed proprietors. The latter milliard being one of the two which the landed proprietors got from the agriculturists, has in this way described the complete circle. The 2 milliards obtained as salaries by the sterile class are employed in buying the necessaries of life and the raw material of industry. And since it is only the productive class that can procure these necessaries and raw materials, this 2 milliards passes into the hands of the agriculturists. The 2 milliards, in short, return to their starting-point. Adding the milliard already paid by the landed proprietors to the 2 milliards’ worth of products unsold, the total of 5 milliards is replaced in the hands of the productive class, and so the process goes on indefinitely.[43] This _résumé_ gives but a very imperfect idea of the vast complexities and difficulties involved in tracing the growth of revenues—an evolution which the Physiocrats followed with the enthusiasm of children. They imagined that it was all very real.[44] The rediscovery of their millions intoxicated them, but, like many of the mathematical economists of to-day, they forgot that at the end of their calculations they only had what they had assumed at the beginning. It is very evident that the table proves nothing as to the essential point in their system, namely, whether there really exist a productive and a sterile class.[45] The most interesting thing in the Physiocratic scheme of distribution is not the particular demonstration which they gave of it, but the emphasis which they laid upon the fact of the circulation of wealth taking place in accordance with certain laws, and the way in which the revenue of each class was determined by this circulation. The singular position which the proprietors hold in this tripartite division of society is one of the most curious features of the system.