Aristotle condemns usury because it is the most extreme and dangerous form of chrematistic acquisition, or the art of making money for its own sake. As we have seen above, in discussing the legitimacy of commerce, buying cheap and selling dear was one form of chrematistic acquisition, which could only be justified by the presence of certain motives; and usury, according to the philosopher, was a still more striking example of the same kind of acquisition, because it consisted in making money from money, which was thus employed for a function different from that for which it had been originally invented. 'Usury is most reasonably detested, as the increase of our fortune arises from the money itself, and not by employing it for the purpose for which it was intended. For it was devised for the sake of exchange, but usury multiplies it. And hence usury has received the name of [Greek: tokos], or produce; for whatever is produced is itself like its parents; and usury is merely money born of money; so that of all means of money-making it is the most contrary to nature.'[1] We need not pause here to discuss the precise significance of Aristotle's conceptions on this subject, as they are to us not so much of importance in themselves, as because they suggested a basis for the treatment of usury to Aquinas and his followers.[2] [Footnote 1: Aristotle, _Politics_, i. 10.] [Footnote 2: Cleary, _op. cit._, p. 29.] In Rome, as in Greece, the philosophers and moralists were unanimous in their condemnation of the practice of usury. Cicero condemns usury as being hateful to mankind, and makes Cato say that it is on the same level of moral obliquity as murder; and Seneca makes a point that became of some importance in the Middle Ages, namely, that usury is wrongful because it involves the selling of time.[1] Plutarch develops the argument that money is sterile, and condemns the practices of contemporary money-lenders as unjust.[2] The teaching of the philosophers as to the unlawfulness of usury was reflected in the popular feeling of the time.[3] [Footnote 1: Cleary, _op. cit._, p. 29.] [Footnote 2: _De Vitando Aere Alieno_.] [Footnote 3: Espinas, _op. cit._, pp. 81-2; Roscher, _Political Economy_, s. 90.] § 2. _Usury in the Old Testament_.