The Wealth of Nations by Part 4 Chapter 9 Page 25

place of the merchants, artificers, and manufacturers whom the inhabitants of those countries ought to find at home, but whom, from some defect in their policy, they do not find at home.

It can never be the interest of those landed nations, if I may call them so, to discourage or distress the industry of such mercantile states by imposing high duties upon their trade or upon the commodities which they furnish. Such duties, by rendering those commodities dearer, could serve only to sink the real value of the surplus produce of their own land, with which, or, what comes to the same thing, with the price of which those commodities are purchased. Such duties could serve only to discourage the increase of that surplus produce, and consequently the improvement and cultivation of their own land.