The propensity to truck, barter and exchange one thing for another is common to all men, and to be found in no other race of animals.
Adam SmithTo found a great empire for the sole purpose of raising up a people of customers, may at first sight appear a project fit only for a nation of shopkeepers. It is, however, a project altogether unfit for a nation of shopkeepers; but extremely fit for a nation whose government is influenced by shopkeepers.
Adam SmithThe liberal reward of labor, therefore, as it is the necessary effect, so it is the natural symptom of increasing national wealth. The scanty maintenance of the laboring poor, on the other hand, is the natural symptom that things are at a stand, and their starving condition that they going backwards fast.
Adam Smith