those are both good points: legal tender laws and Gresham’s Law, and taxes . Incidentally they are the exact same points that somebody on an e-mail list just made, so independent verification.
the other point that was made there was that e.g. the dollar has a severe advantage because it is currently being used and has been used in the past, whereas gold would have to start anew. Rothbard wrote this about it:
From “The Case for Genuine Gold Dollar:”
There is a crucial difference, however, between money and all other goods and services. All other goods, whether they be postal service or candy bars or personal computers, are desired for their own sake, for the utility and value that they yield to consumers. Consumers are therefore able to weigh these utilities against one another on their own personal scales of value. Money, however, is desired not for its own sake, but precisely because it already functions as money, so that everyone is confident that the money commodity will be readily accepted by any and all in exchange. People eagerly accept paper tickets marked “dollars” not for their aesthetic value, but because they are sure that they will be able to sell those tickets for the goods and services they desire. They can only be sure in that way when the particular name, “dollar,” is already in use as money.
Hayek is surely correct that a free market economy and a devotion to the right of private property requires that everyone be permitted to issue whatever proposed currency names and tickets they wish. Hayek should be free to issue Hayeks or ducats, and I to issue Rothbards or whatever. But issuance and acceptance are two very different matters. No one will accept new currency tickets, as they well might new postal organizations or new computers. These names will not be chosen as currencies precisely because they have not been used as money, or for any other purpose, before.
Hayek and his followers have failed completely to absorb the lesson of Ludwig von Mises’ “regression theorem,” one of the most important theorems in monetary economics.[6] Mises showed, as far back as 1912, that since no one will accept any entity as money unless it had been demanded and exchanged earlier, we must therefore logically go back (regress) to the first day when a commodity became used as money, a medium of exchange. Since by definition the commodity could not have been used as money before that first day, it could only be demanded because it had been used as a nonmonetary commodity, and therefore had a preexisting price, even in the era before it began to be used as a medium. In other words, for any commodity to become used as money, it must have originated as a commodity valued for some nonmonetary purpose, so that it had a stable demand and price before it began to be used as a medium of exchange. In short, money cannot be created out of thin air, by social contract, or by issuing paper tickets with new names on them. Money has to originate as a valuable nonmonetary commodity. In practice, precious metals such as gold or silver, metals in stable and high demand per unit weight, have won out over all other commodities as moneys. Hence, Mises’ regression theorem demonstrates that money must originate as a useful nonmonetary commodity on the free market.
But one crucial problem with the Hayekian ducat is that no one will take it. New names on tickets cannot hope to compete with dollars or pounds which originated as units of weight of gold or silver and have now been used for centuries on the market as the currency unit, the medium of exchange, and the instrument of monetary calculation and reckoning.[7]