Thus far, for sake of simplicity, and not to depart from the usage of other writers, we have considered the revenues as practically identical with the money flowing into the treasury. Services rendered without pay do not belong to our subject.But still it is not quite accurate to identify the public revenues with the moneythat flows into the treasury. Money is here, as in private households, but the representative of wealth. When the government compels its subjects to pay contributions of classes one and two, taxes and fees, it does so in order to obtain control of wealth which it takes from the people to consume for a public purpose. But in the case of contractual revenues the matter is quite different. Here the government simply sells, for money, wealth : material things, privileges, or services which it has brought into existence. The transaction is a simple sale. This is partly true of some fees. The money that flows into the treasury simply takes the place of actual wealth already created or being created by the government. The important thing to note is that prices result in little or no increase in the amount of wealth in the hands of the government, unlike the other cases, but a mere change in the form of the wealth already owned. It is not wealth taken from the people to be consumed by the government; but wealth created by the government is turned into money so that it may be more conveniently consumed. Nothing is taken from the people at all, for they receive back the equivalent of their money in wealth, over which they then have control as owners. In the case of compulsory revenues the matter is different because they receive back nothing tangible, but simply enjoy the common or specialbenefits of good government. These benefits are of the same character exactly as the benefits which accrue to the individual when he consumes his own wealth. They are "reproductive," the same sense that the consumption of bread by the worker is reproductive. That is in no sense at all. Just as the aim of all production in the economic world is consumption or the satisfaction of wants, so the end and aim of the compulsory collection of revenues is consumption by the State. Sometimes, to be sure, the government turns these funds into permanent forms of wealth which are slowly consumed; as, for example, roads. Sometimes, too, the government adds to the effective power of the wealth before consuming it, or uses it to produce new wealth; but yet so far as the individual is concerned, he has parted with his property in a way which leaves him benefited, to be sure, but in exactly the same position as when he spends the same amount for some gratification. Quite the contrary is his position when he buys a piece of china made by the government, for then he has the equivalent of his money. The government, too, is no richer than before, but has its wealth in a form which better suits it.1 Frequently the government uses the wealth created directly without first turning it into money. This wealth is as much a part of the revenues as any that is sold.

We may now change our terminology slightly, and say that there are three sources of public revenues : the first is collected from all the citizens by compulsion, on the ground that certain expenditures are necessary and confer a common benefit upon all ; these are taxes. The second is collected by compulsion from certain persons on the ground that they are specially benefited by some expenditures ; these are fees. And lastly, the State creates wealth for itself. The wealth thus created constitutes a part of the revenue of the government belonging to the third class. This, whether sold or not, is contractual revenue.

1 Cf. Stein, Finanzwissenschaft, II., 138.