“There can be no doubt that besides the regular types of the circulating medium, such as coin, notes and bank deposits, which are generally recognised to be money or currency, and the quantity of which is regulated by some central authority or can at least be imagined to be so regulated, there exist still other forms of media of exchange which occasionally or permanently do the service of money. Now while for certain practical purposes we are accustomed to distinguish these forms of media of exchange from money proper as being mere substitutes for money, it is clear that, other things equal, any increase or decrease of these money substitutes will have exactly the same effects as an increase or decrease of the quantity of money proper, and should therefore, for the purposes of theoretical analysis, be counted as money.”

Anytime there is a re-defining of history proven natural law issues into legal positivism's administrations, liberty is lost. I believe Hayek's theoretical analysis here encompasses barter. Barter being a foundation of commerce. Barter uses money (gold and silver coin by weights and measures) as well as any other specie of value. To expand money's definition to all elements of exchange is to broaden the probability for larceny, despotism and tyranny. Sea shells, commodities, labor, etc. can all be lawfully and freely used as a media of exchange but, that does not necessarily make them money.

Keynesian economics embraced by the socialistic machine of slavery and usury. Ludwig von Mises, and the Misesian branch of Austrian economics is a much better school of thought, concerning there should be no governmental intrusion. Consumer Sovereignty, and Economic Freedom of the individual.