This sort of barter is not contradictory to nature, nor is it any species of money-getting; but is necessary in procuring that subsistence which is so consonant thereunto.

But this barter introduced the use of money, as might be expected; for a convenient place from whence to import what you wanted, or to export what you had a surplus of, being often at a great distance, money necessarily made its way into commerce; for it is not everything which is naturally most useful that is easiest of carriage; for which reason they invented something to exchange with each other which they should mutually give and take, that being really valuable itself, should have the additional advantage of being of easy conveyance, for the purposes of life, as iron and silver, or anything else of the same nature: and this at first passed in value simply according to its weight or size; but in process of time it had a certain stamp, to save the trouble of weighing, which stamp expressed its value.
[1257b] Money then being established as the necessary medium of exchange, another species of money-getting spon took place, namely, by buying and selling, at probably first in a simple manner, afterwards with more skill and experience, where and how the greatest profits might be made.
For which reason the art of money-getting seems to be chiefly conversant about trade, and the business of it to be able to tell where the greatest profits can be made, being the means of procuring abundance of wealth and possessions: and thus wealth is very often supposed to consist in the quantity of money which any one possesses, as this is the medium by which all trade is conducted and a fortune made, others again regard it as of no value, as being of none by nature, but arbitrarily made so by compact; so that if those who use it should alter their sentiments, it would be worth nothing, as being of no service for any necessary purpose.

Besides, he who abounds in money often wants necessary food; and it is impossible to say that any person is in good circumstances when with all his possessions he may perish with hunger.
Like Midas in the fable, who from his insatiable wish had everything he touched turned into gold.

For which reason others endeavour to procure other riches and other property, and rightly, for there are other riches and property in nature; and these are the proper objects of economy: while trade only procures money, not by all means, but by the exchange of it, and for that purpose it is this which it is chiefly employed about, for money is the first principle and the end of trade; nor are there any bounds to be set to what is thereby acquired.

Thus also there are no limits to the art of medicine, with respect to the health which it attempts to procure; the same also is true of all other arts; no line can be drawn to terminate their bounds, the several professors of them being desirous to extend them as far as possible.