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