116. It is not an object to diversify industry, but to multiply and diversify our satisfactions, comforts, and enjoyments. If we can do this by unifying our industry, in greater measure than by diversifying it, then we should do, and we will do, the former. It is not a question to be decided _a priori_, but depends upon economic circumstances. If a country has a supremacy in some one industry it will have only one. California and Australia had only one industry until the gold mines declined in productiveness, that is, until their supreme advantage over other countries was diminished: they began to diversify when they began to be less well off. The oil region of Pennsylvania has a chance of three industries, the old farming industry, coal, and oil. It will have only one industry so long as oil gives chances superior to those enjoyed by any other similar district. When it loses its unique advantage by nature it will diversify. The “strongest” nation is the one which brings products into the world’s market which are of high demand, but which cost it little toil and sacrifice to get; for it will then have command of all the good things which men can get on earth at little effort to itself. Whether the products which it offers are one or numerous is immaterial. All the tariff has to do with it is that when the American comes into the world’s market with wheat, cotton, tobacco, and petroleum, all objects of high demand by mankind and little cost to him, it forces him to forego a part of his due advantage (§§ 125, 134). (_F_) THAT MANUFACTURES GIVE VALUE TO LAND. 117. This doctrine issued from the Agricultural Bureau. It has been thought a grand development of the protectionist argument. It is a simple logical fallacy based on some misconstrued statistics. The value of land depends on supply and demand. The demand for land is population. Hence where the population is dense the value of land is great. Manufactures can be carried on only where there is a supply of labor, that is, where the population is dense. Hence high value of land and manufacturing industry are common results of dense population. The statistician of the Agricultural Bureau connected them with each other as cause and effect, and the New York _Tribune_ said that it was the grandest contribution to political economy since “the fingers of Horace Greeley stiffened in death”; which was true.