It remains to say a few words on a double standard. In some countries a gold or a silver coin is a legal tender for the payment of debts. The expression legal tender arises only on the payment of a contract to pay money, of a debt; it means that the law will declare the debt to have been paid, if the legal tender, money, has been given. A double standard gives the debtor the choice of paying in gold or silver coin as he pleases. Now if the value of the metal given in the metal market is the same, whether gold or silver has been offered, the contract is justly fulfilled, and neither party has an advantage over the other. The law fixes the relative quantities of the two coins or metals which may be given. In England it says that twenty shillings and one sovereign are the same money. But unfortunately the law cannot secure that the metallic value of either silver or gold will remain unchanged; if there is an alteration in the value of either, it is plain that twenty shillings may be worth more or less than a sovereign. A debtor will always choose to pay in the coin which is cheapest, which it costs him less of his wealth to obtain. If silver becomes cheaper than gold, the English gold sovereign will be sold abroad to buy silver, which will be brought to the English Mint to be coined, and debts will be paid with it with a profit. Hence the practical rule has been laid down that the inferior currency will expel all others from a country, that is, the money whose metal is valued too highly in the coin in the proportions established between the coin of both metals will be sought by all debtors, because they can purchase it with a profit with the metal which is introduced in the coin. In England the proportion of twenty shillings to the pound has long existed, in spite of many fluctuations in the metallic value of silver. The banishment of the gold has been prevented by the declaration that silver shall not be a legal tender beyond forty shillings. This has kept shillings a purely subsidiary money - over-valued, with too little silver in them to be a twentieth part of a golden sovereign, but not so little, and they not so numerous, as to make it worth while for coiners to manufacture them out of honest silver. A double standard seems to me unsupported by adequate reasons, and it entails the injustice that a debtor is enabled by it to pay his creditor with a smaller value of metal than was contracted for.*
* See Appendix A, page 173.