The sneaking arts of underling tradesmen are thus erected into political maxims for the conduct of a great empire; for it is the most underling tradesmen only who make it a rule to employ chiefly their own customers. A great trader purchases his good always where they are cheapest and best, without regard to any little interest of this kind.

Chapter III, Part II, p. 530. - The Wealth of Nations (1776) - Book IV