CHAPTER VI ARISTOTLE

This does not mean that the traders must receive the same in return (τὸ ἀντιπεπονθὸς κατ᾽ ἰσότητα), but an equivalent, or proportional requital (τὸ ἀντιπεπονθὸς κατ᾽ ἀναλογίαν).⁷¹⁶ It is this fact of proportional requital that makes exchange, and indeed human society, possible.⁷¹⁷ The meaning is illustrated by a proportion in which the producers bear the same relation to each other as their products.⁷¹⁸ By joining means and extremes, the exchangers are brought to a basis of proportional equality (τὸ κατὰ τὴν ἀναλογίαν ἴσον).⁷¹⁹ Thus is determined how many shoes, the shoemaker’s product, must be given for a house, the builder’s product, and the prices of the two commodities are justly settled, with relation to each other.⁷²⁰ It is very necessary for just exchange, that such proportional equality be effected before the requital or actual transfer takes place. Otherwise one will gain both superiorities (ἀμφοτέρας τὰς ὑπεροχάς), and equality becomes impossible,⁷²¹ since the cost of production of things is very diverse.⁷²² Indeed, the arts themselves could not exist, unless the advantage to the consumer were similar in quantity and quality to the cost to the producer.⁷²³