St Thomas Aquinas, the Angelic Doctor, called Aristotle 'THE Philosopher'. Here is his view of usury, which Thomas proved is a sin.[1258b]  （for it is not in accordance with nature, but involves
31 March 2022
Aristotle on Usury
men's taking things from one another. As this is so, usury is most reasonably hated, because its gain comes from money itself and not from that for the sake of which money was invented. For money was brought into existence for the purpose of exchange, but interest increases the amount of the money itself (and this is the actual origin of the Greek word: offspring resembles parent, and interest is money born of money); consequently, this form of the business of getting wealth is of all forms the most contrary to nature. And since we have adequately defined the scientific side of the subject, we ought to discuss it from the point of view of practice; although, whereas the theory of such matters is a liberal study, the practical pursuit of them is narrowing. The practically useful branches of the art of wealth-getting are first, an expert knowledge of stock, what breeds are most profitable and in what localities and under what conditions, for instance, what particular stock in horses or cattle or sheep, and similarly of the other animals also (for the farmer must be an expert as to which of these animals are most profitable compared with one another, and also as to what breeds are most profitable on what sorts of land, since different breeds flourish in different places); secondly, the subject of agriculture, and this again is divided into corn-growing and fruit-farming; also bee-keeping, and the breeding of the other creatures finned and feathered  which can be used to furnish supplies. These then are the branches and primary parts of wealth-getting in the most proper sense. Of the kind that deals with exchange, the largest branch is commerce (which has three departments, ship-owning, transport and marketing: these departments differ from each other in the fact that some are safer and others carry larger profits); the second branch is money-lending, and the third labor for hire, one department of which is that of the mechanic1 arts and the other that of unskilled labourers who are useful only for bodily service. And there is a third form of wealth-getting that lies between the latter and the one placed first since it possesses mediate an element both of natural wealth-getting and of the sort that employs exchange; it deals with all the commodities that are obtained from the earth and from those fruitless but useful things that come from the earth—examples are the felling of timber2 and all sorts of mining; and of mining itself, there are many classes since there are many sorts of metals obtained out of the earth. The3 most scientific of these industries are those which involve the smallest element of chance, the most mechanical those in which the operatives undergo the greatest amount of bodily degradation, the most servile those in which the most uses are made of the body, and the most ignoble those in which there is the least requirement of virtue as an accessory. But while we have even now given a general description of these various branches, yet a detailed and particular account of them, though useful for the practice of the industries, would be illiberal as a subject of prolonged study. There are books on these subjects by certain authors, for example, Charetides of Paros.