The Wealth of Nations by Part 2 Chapter 2 Page 18

even with regard to an individual, it is still more so with regard to a society. The amount of the metal pieces which are annually paid to an individual, is often precisely equal to his revenue, and is upon that account the shortest and best expression of its value. But the amount of the metal pieces which circulate in a society can never be equal to the revenue of all its members.

As the same guinea which pays the weekly pension of one man to-day, may pay that of another to-morrow, and that of a third the day thereafter, the amount of the metal pieces which annually circulate in any country must always be of much less value than the whole money pensions annually paid with them. But the power of purchasing, or the goods which can successively be bought with the whole of those money pensions as they are successively paid,