Book I: Chapter X
We have now determined what was before doubtful, whether or no the art of getting money is his business who is at the head of a family or a state, and though not strictly so, it is however very necessary; for as a politician does not make men, but receiving them from the hand of nature employs them to proper purposes; thus the earth, or the sea, or something else ought to supply them with provisions, and this it is the business of the master of the family to manage properly; for it is not the weaver's business to make yarn, but to use it, and to distinguish what is good and useful from what is bad and of no service; and indeed some one may inquire why getting money should be a part of economy when the art of healing is not, as it is as requisite that the family should be in health as that they should eat, or have anything else which is necessary; and as it is indeed in some particulars the business both of the master of the family, and he to whom the government of the state is entrusted, to see after the health of those under their care, but in others not, but the physician's; so also as to money; in some respects it is the business of the master of the family, in others not, but of the servant; but as we have already said, it is chiefly nature's, for it is her part to supply her offspring with food; for everything finds nourishment left for it in what produced it; for which reason the natural riches of all men arise from fruits and animals. Now money-making, as we say, being twofold, it may be applied to two purposes, the service of the house or retail trade; of which the first is necessary and commendable, the other justly censurable; for it has not its origin in [1258b] nature, but by it men gain from each other; for usury is most reasonably detested, as it is increasing our fortune by money itself, and not employing it for the purpose it was originally intended, namely exchange.
And this is the explanation of the name (TOKOS), which means the breeding of money. For as offspring resemble their parents, so usury is money bred of money. Whence of all forms of money-making it is most against nature.