Money is a piece of wealth like the others, "a compressed form of the net work done by other individuals", and "one of the most highly compressed and mobile forms". What a unit of money holds is a claim on the work of others. The measure asks whether a thing can hold that claim steady: whether the work one unit stands for stays the same over the years, and whether the thing meets the other standards given. Above all, its value must be "natural rather than asserted": it must keep its value even "if the entity that issues it were to vanish".
From The standard for money.
