were accustomed to look upon silver as the metal for fixed and constant value.451 In any event, he sees that the increase of silver must be attended by a corresponding increase in business activity, if its value is not to depreciate,452 and he cannot be accused of the error of the mercantilists, that a country is impoverished by the export of money.453 He must also have understood clearly the importance of stability of value in a currency, since he deems it necessary to show that the increased output of silver will not decrease its value, and that silver is the least changeable of the monetary metals.454 Despite his enthusiasm for his thesis, which causes him to exaggerate the stability of silver, he does not fail to grasp the direct effect of supply and demand upon it,455 just as upon gold456 and other commodities.457 He shows also some understanding of the quantitative theory of the relation between gold and silver.458 It need hardly be added that, in strong contrast to Plato, his attitude toward the precious metals, especially silver, is very favorable.459
EXCHANGE
Xenophon presents no theory of exchange,460 though he is frankly interested in the advance of commerce and trade. In his opinion, the greater their development, the better it is for the city of Athens.461 He is full of practical suggestions to stimulate commercial activity.462 So assured is he of the prime importance of extensive commerce to a nation, that, in the spirit of modern commercialism, he insists upon the necessity of peace for its sake.463 To his mind, increased trade means not only material advantage, but social and political as well, in that greater prosperity, more labor, and a better distribution will mean greater satisfaction, and hence less danger of revolution in the state.464 He entertains none of the prejudice of the other Socratics against the money-makers’ art, a fact which may well be a warning against the too ready acceptance of their attitude as the usual verdict of the Athenian citizens.465 In his practical suggestions for the development of commerce there is a hint of the protective principle. He