All is more or less proper to serve as a common measure, in proportion as it is more or less in general use, of a more similar quality, and more easy to be divided into aliquot parts. All is more or less applicable for the purpose of a general pledge of exchange, in proportion as it is less susceptible of decay or alteration in quantity or quality.
"Reflections on the Formation and Distribution of Wealth". Book by Anne Robert Jacques Turgot (§ 39), 1766.
