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Of the nature and reason for trade (in general)
This matter, commonly called commodities, is partly native and partly foreign: native, that which is to be had within the territory of the Commonwealth; foreign, that which is imported from without. And because there is no territory under the dominion of one Commonwealth, except it be of very vast extent, that produceth all things needful for the maintenance and motion of the whole body; and few that produce not something more than necessary; the superfluous commodities to be had within become no more superfluous, but supply these wants at home, by importation of that which may be had abroad, either by exchange, or by just war, or by labour: for a man's labour also is a commodity exchangeable for benefit, as well as any other thing And there have been Common-wealths that having no more Territory, than hath served them for habitation, have neverthelesse, not onely maintained, but also encreased their Power, partly by the labour of trading from one place to another, and partly by selling the Manifactures, whereof the Materials were brought in from other places.
Hobbes, Lev XXIV 4