Plato is not blind to the ethical aspects of the problem of slavery. In his first healthy state (ὑγιείνη), slavery and war are conspicuously absent, and it is the natural inference that the author believed these to be necessary evils of the more complex state.[[179]] He appreciates the dangers of absolute power, even in private life, and believes that few men can stand the strain.[[180]] He conceives human nature as a unity that defies absolute division into separate classes.[[181]] Though he does not renounce slavery in the Republic, he would limit, it to the barbarians and to those who seem unfit for the higher life.[[182]] It plays a remarkably small part in his first state, and it would seem that his idealism is here struggling against what he feels to be an economic necessity. In the Laws, he frankly accepts the necessity, and puts even agriculture, as well as the other industries, into the hands of slaves.[[183]] However, they are not to be treated as animals, but as rational men, in whom a proper usage may develop a certain degree of morality and ambition for good work.[[184]] To be sure, his purpose is economic rather than ethical—to make the slaves satisfied with their lot, and thus better producers.[[185]] He makes no mention of freedom as a reward for good behavior, though he elsewhere provides for the existence of freedmen in the state, and stipulates that they shall not become richer than their former masters.[[186]]
MONEY
As Plato was the first of extant Greek thinkers to grasp the principle of the division of labor, so he was the first to give any hint as to the origin of money. He states that it came into use by reason of the growth of necessary exchange, which in turn resulted from increased division of labor.[[187]]
The function of money he defines somewhat indefinitely by the term “token of exchange,”[[188]] an expression suggestive of Ruskin’s definition “a ticket or token of right to goods.”[[189]] It seems to imply that money is not itself a commodity to be trafficked in. In the Laws, he specifies more clearly the functions of this symbol. It acts as a medium of exchange and as a measure of value.[[190]] The latter office is performed by reason of the fact that money is a common denominator of value, changing products from incommensurable (ἀσύμμετρον) and uneven (ἀνώμαλον) to commensurable and even.[[191]]
Since Plato did not consider money to be a commodity to be bought and sold, and since he did not appreciate its productive function as representative capital, his theory of interest was superficial. His attitude toward it was somewhat similar to that of many people today toward speculation in futures in the stock market, as a practice contrary to public interest and policy. The application of the term τόκος to interest by Plato[[192]] and Aristotle, as though interest were the direct child of money, is probably only a punning etymology, and not intended seriously. It can therefore hardly be used, as it often is, to prove the superficiality of the theory of the Socratics. Plato, however, would have no money-making by usury,[[193]] nor indeed any loaning or credit at all, except as an act of friendship.[[194]] Such contracts should be made at the loaner’s own risk,[[195]] and held legal only as a punishment for breaking other contracts.[[196]] He calls the usurer a bee that inserts his sting, money, into his victims, thereby beggaring them and enriching himself.[[197]]
Such strictures against interest were common in mediaeval Europe, reappeared in Ruskin,[[198]] and are implied in the present opposition, in some quarters, to so-called “unearned income.”[[199]] The motive in mediaeval times, however, was distinctively religious, and was also partly due to the absence of a developed capitalism. With Ruskin and modern theorists, on the other hand, the objection is, at bottom, socialistic. The motive of the Socratics was essentially moral and political.
Plato’s other error concerning money, as above observed, was that it need possess no intrinsic value for domestic use. He looked upon gold and silver as causes of degeneration in state and individual,[[200]] and would therefore have put a ban on them for use within the state.[[201]] To his mind, a mere state fiat was sufficient to give currency and value.[[202]] This doctrine has also often recurred in the history of economic thought, as in Ruskin and the Greenback party of a generation ago.[[203]] The error, however, was not so grave in Plato’s case, for he, at least, recognized the need of the precious metals for international purposes.[[204]] Moreover, in his proposed state of such limited extent, the problem would have been far simpler, and he would have distinguished between actual conditions and possibilities in Greece and his admittedly more or less utopian ideal.
EXCHANGE
Exchange in Greek economy held a very minor place, compared with its dominant importance in modern theory. It was discussed chiefly in a negative manner, as the object of the moral and aristocratic prejudice of Greek thinkers. We find, however, some appreciation of its true place in the economic life of a state. Plato divides trade, ἀλλαγή or ἀγοραστική, into αὐτοπωλική, which sells its own products, αὐτουργῶν, and μεταβλητική, which exchanges the products of others. He further divides the latter into καπηλική, the exchange within the state, which he calls one-half of all the exchange, and ἐμπορική, foreign commerce.[[205]] He finds its origin in the division of labor, and in the mutual interdependence of men and states.[[206]] He understands the necessity of the reciprocal attitude in international, as well as in private, exchange, and thus has a clearer insight than the mercantilists and some modern statesmen. A state must raise a surplus of its own products, so as to supply the other state from which it expects to have its own needs satisfied.[[207]]
Since a tariff on imports played little part in Greek life, except in so far as it was imposed for sumptuary or war purposes,[[208]] the perplexing modern problem of the protective tariff scarcely came within the horizon of Greek thinkers. Plato would prohibit the import of certain luxuries, as a moral safeguard. He divides merchandise into primary and secondary products, and would not permit the import of the latter.[[209]] Elsewhere, however, he legislates against imposts upon either imports or exports, though unconscious of the significance of his suggestion.[[210]]