The Wealth of Nations by Part 4 Chapter 5 Page 74

dealer or shopkeeper, who would have bought them by wholesale. If he valued them lower, he lost a part of the profit of his manufacturing capital. When again he sold them from his shop, unless he got the same price at which a shopkeeper would have sold them, he lost a part of the profit of his shopkeeping capital.

Though he might appear, therefore, to make a double profit upon the same piece of goods, yet as these goods made successively a part of two distinct capitals, he made but a single profit upon the whole capital employed about them; and if he made less than his profit, he was a loser, or did not employ his whole capital with the same advantage as the greater part of his neighbours.

What the manufacturer was prohibited to do, the farmer was in some measure enjoined to do; to