11. Such being the everlasting law of

human existence, the essential work of the political economist is to determine what are in reality useful or life-giving things, and by what degrees and kinds of labour they are attainable and distributable. This investigation divides itself under three great heads;—the studies, namely, of the phenomena, first, of Wealth; secondly, of Money; and thirdly, of Riches.

These terms are often used as synonymous, but they signify entirely different things. "Wealth" consists of things in themselves valuable; "Money," of documentary claims to the possession of such things; and "Riches" is a relative term, expressing the magnitude of the possessions of one person or society as compared with those of other persons or societies.

The study of Wealth is a province of natural science:—it deals with the essential properties of things.

The study of Money is a province of commercial science:—it deals with conditions of engagement and exchange.

The study of Riches is a province of moral