Though a simple book can be written on selected topics, the central doctrines of economics are not simple and cannot be made so.

In every age poets and social reformers have tried to stimulate the people of their own time to a nobler life by enchanting stories of the virtues of the heroes of old.

In the absence of any short term in common use to represent all desirable things, or things that satisfy human wants, we may use the term Goods for that purpose.

Producer's Surplus is a convenient name for the genus of which the rent of land is the leading species.

I admit that these terms and the diagrams connected with them repel some readers, and fill others with the vain imagination that they have mastered difficult economics problems, when really they have done little more than learn the language in which parts of those problems can be expressed, and the machinery by which they can be handled. When the actual conditions of particular problems have not been studied, such knowledge is little better than a derrick for sinking oil-wells erected where there are no oil-bearing strata.

Political Economy or Economics is a study of mankind in the ordinary business of life.

The hope that poverty and ignorance may gradually be extinguished derives indeed much support from the steady progress of the working classes during the 19th century.