[St. Thomas Aquinas] did not merely assert that Usury is unnatural, though in saying that he only followed Aristotle and obvious common sense, which was never contradicted by anybody until the time of the commercialists, who have involved us in the collapse.
The modern world began by Bentham writing the Defence of Usury, and it has ended after a hundred years in even the vulgar newspaper opinion finding Finance indefensible.
But St. Thomas struck much deeper than that. He even mentioned the truth, ignored during the long idolatry of trade, that things which men produce only to sell are likely to be worse in quality than the things they produce in order to consume. . . .
[F]or trade, in the modern sense, does mean selling something for a little more than it is worth, nor would the nineteenth century economists have denied it. They would only have said that he was not practical; and this seemed sound while their view led to practical prosperity. Things are a little different now that it has led to universal bankruptcy.
–Chesterton, Saint Thomas Aquinas: The Dumb Ox