[Footnote 1:  Op. cit., p. 14; Espinas, op. cit., p. 80.]

The teaching of Aquinas upon economic affairs remained the groundwork of all the later writers until the end of the fifteenth century.  His opinions on various points were amplified and explained by later authors in more detail than he himself employed; monographs of considerable length were devoted to the treatment of questions which he dismissed in a single article; but the development which took place was essentially one of amplification rather than opposition.  The monographists of the later fifteenth century treat usury and sale in considerable detail; many refinements are indicated which are not to be found in the Summa; but it is quite safe to say that none of these later writers ever pretended to supersede the teaching of Aquinas, who was always admitted to be the ultimate authority.  ’During the fourteenth and fifteenth centuries, the general political doctrine of Aquinas was maintained with merely subordinate modifications.’[1] ‘The canonist doctrine of the fifteenth century,’ according to Sir William Ashley, ’was but a development of the principles to which the Church had already given its sanction in earlier centuries.  It was the outcome of these same principles working in a modified environment.  But it may more fairly be said to present a system of economic thought, because it was no longer a collection of unrelated opinions, but a connected whole.  The tendency towards a separate department of study is shown by the ever-increasing space devoted to the discussion of general economic topics in general theological treatises, and more notably still in the manuals of casuistry for the use of the confessional, and handbooks of canon law for the use of ecclesiastical lawyers.  It was shown even more distinctly by the appearance of a shoal of special treatises on such subjects as contracts, exchange, and money, not to mention those on usury.’[2] In all this development, however, the principles enunciated by Aquinas, and through him, by Aristotle, though they may have been illustrated and applied to new instances, were never rejected.  The study of the writers of this period is therefore the study of an organic whole, the germ of which is to be found in the writings of Aquinas.[3]

[Footnote 1:  Ingram, op. cit., p. 35.]

[Footnote 2:  Op. cit., vol. i. pt. ii. p. 382.]

[Footnote 3:  The volume of literature which bears more or less on economic matters dating from the fourteenth and fifteenth centuries is colossal.  By far the best account of it is to be found in Endemann’s Studien in der Romanisch-canonistischen Wirthschafts- und Rechtslehre, vol. i. pp. 25 et seq.  Many of the more important works written during the period are reprinted in the Tractatus Universi Juris, vols. vi. and vii.  The appendix to the first chapter of Reseller’s Geschichte also contains a valuable account of certain typical