It now became the purpose of the leading statesmen to encourage a nation-wide trade by removing the local restrictions that surrounded the individual towns. The town economy had been carried on with little or no money, since the producer dealt directly with the consumer and paid him in his product. But for a national economy, money was necessary, and statesmen planned to secure the money by raising tariff walls around the country, and encouraging the exportation, and discouraging the importation of goods in such a way as to encourage the importation of money. This was the essence of the mercantile system, which was not without merit in its day, but which later degenerated into an abuse and which has been widely criticized in recent time as though it had always been lacking in merit. With the development of national economy the producer produced no longer for the consumer but for the market. Each section of the country produces now not all that it needs, but what it can produce advantageously, and it relies upon other sections of the country to satisfy its needs through an exchanging of commodities. To sum up the development: in the days of household economy, blood relatives cooperated to produce what they needed. At the stage of town economy, those who lived in the neighborhood of the same town cooperated to make a living, while in the third stage, the whole nation cooperates with that end in view. And while nation is often hostile to nation in matters of trade there is also a growing cooperation among nations, so that all the time we are becoming more dependent upon others for our living. But as we become more and more dependent upon our neighbors we gain in our ability to secure the things for which men labor; we are enabled to secure a better living with less effort than was necessary when our independence was greater.