Consumption may affect capacity for production. — Satisfaction may be increased by increasing goods, or desires for available goods, 292. — Unsatisfied desire an evil, 293. — Definition of necessaries, 297. — Desire for them ultimately diminishes scarcity, 298. — The time element, 298. — The interests of other people, 299. — High desires increase efficiency, foresight, and altruism, 300.

I. Luxury defined as consumption which does not increase capacity for labor, 298. — Superfluities include consumption necessary for business connection, 300. — Short and long periods, 301. — Capacity for labor varies with consumption of necessaries, 301. — Classification of commodities, 302. — II. Demand for necessaries inelastic because (a) their consumption benefits both present and future, 304. — (b) Capacity for labor is limited, 306. — A tax on luxuries would divert labor to production of capital, also lessening demand, 307. — Labor would become more productive and real wages would rise, 308. — Wealth would be increased, 309; and transferred to people whose effective desire of accumulation is strong, 310. — III. Possible decrease in quantity of labor expended, 314. — Self-development not labor, 315. — Leisure, defined as time not devoted to labor, is either necessary or superfluous, 316. — Annual product varies inversely with superfluous leisure enjoyed, and might be either decreased or increased, 318. — Rise of wages might check fall of interest; convergence of altruism and foresight, 319.

I. Capital defined as wealth produced by labor and destined to satisfy wants in the future, 547. — The possibility of interest due to the fact that capital saves labor, 550. — Concrete illustration of the saving, 551. — II. Illustration of the circumstances which may affect the rate of interest under hypothetical conditions, the main conclusions of the present essay being suggested. — Capital quantitatively expressed in terms of labor multiplied by the time intervening between labor and enjoyment, 553. — III. Circumstances affecting the demand for capital: (a) The opening of new lands, 557. — (b) Inventions, 560. — Under certain conditions the ultimate effect of these circumstances is opposite to their immediate effect, 561. — (c) Variations in the aggregate consumption of society, 563. — Effect of such variations on the supply of capital, 564. — Supply of capital also affected by the quantity of labor expended, 567; which for a given population depends on the amount of leisure enjoyed and on the efficiency of labor, 568. — Conclusion on ultimate causes permanently affecting the rate of interest. — Why capital has always been able to earn interest, 569.