The Wealth of Nations by Part 4 Chapter 5 Page 77

work a good deal cheaper, so the other can commonly afford his goods somewhat cheaper than if his stock and attention were both employed about a greater variety of objects. The greater part of manufacturers could not afford to retail their own goods so cheap as a vigilant and active shopkeeper, whose sole business it was to buy them at wholesale and to retail them again. The greater part of farmers could still less afford to retail their own corn, to supply the inhabitants of a town, at perhaps four or five miles distance from the greater part of them, so cheap as a vigilant and active corn merchant, whose sole business it was to purchase corn by wholesale, to collect it into a great magazine, and to retail it again.

The law which prohibited the manufacturer from exercising the trade of a shopkeeper endeavoured to force