See. 7] INCOME 115 figure as income in future years. We have already observed that to count a new dwelling or piano as income this year, and its use as income in succeeding years, is a species of double counting as well as a confusion of capital and income. Both of these errors are repeated in any concept of social income which includes at once additions to the world’s wealth, and the income which this very wealth subse- quently yields. §8 When a wrong road is once taken, it almost inevitably happens that it leads those who follow it further and fur- ther astray. Economists, having selected a wrong idea of income to start with, naturally found it so ill suited to their purposes that, in each problem to which they at- tempted to apply it, some special interpretation or amend- ment became necessary, until, instead of one concept, they became possessed of a miscellaneous assortment® of concepts! They have been compelled not only to dis- sociate money-income and real-income, but also to disso- ciate the income of the individual and the income of society. When it is understood that the entire and only contribution to the income stream which any given instrument of capital can make consists in the services which that instrument renders, it will be found that all subsidiary meanings of income are simply incomes from particular instruments or groups of instruments. If the instrument in question is a private carriage, the services which it brings forth, as events desirable to its owner, are the acts of conveying him from one place to another. These are primary or natural-income. If the in trument is a public carriage, the services which it brings forth, as events desirable to its owner, are the pay- ments of fares. These are money-income.? If the group of ! The reader who cares to study them in detail will find a collee- tion of definitions in the Appendix to Chapter VIL 21t should be borne in mind that the income is not the money iteelf, which is a concrete commodity, but the bringing in of the money, which is an abstract service.