We shall therefore deal in the first place with the right of private property, which we shall show to have been fully recognised by the mediaeval writers. We shall then point out the duties which this right entailed, and shall establish the position that the scholastic teaching was directed equally against modern socialistic principles and modern unregulated individualism. The next point with which we shall deal is the exchange of property between individuals, which is a necessary corollary of the right of property. We shall show that such exchanges were regulated by well-defined principles of commutative justice, which applied equally in the case of the sale of goods and in the case of the sale of the use of money. The last matter with which we shall deal is the machinery by which exchanges are conducted, namely, money. Many other subjects, such as slavery and the legitimacy of commerce, will be treated as they arise in the course of our treatment of these principal divisions.
In its ultimate analysis, the whole subject may be reduced to a classification of the various duties which attached to the right of private property. The owner of property, as we shall see, was bound to observe certain duties in respect of its acquisition and its consumption, and certain other duties in respect of its exchange, whether it consisted of goods or of money. The whole fabric of mediaeval economics was based on the foundation of private property; and the elaborate and logical system of regulations to ensure justice in economic life would have had no purpose or no use if the subject matter of that justice were abolished.
It must not be understood that the mediaeval writers treated economic subjects in this order, or in any order at all. As we have already said, economic matters are simply referred to in connection with ethics, and were not detached and treated as making up a distinct body of teaching. Ashley says: ’The reader will guard himself against supposing that any mediaeval writer ever detached these ideas from the body of his teaching, and put them together as a modern text-book writer might do; or that they were ever presented in this particular order, and with the connecting argument definitely stated.’
[Footnote 1: Op. cit., vol. i. pt. ii. p. 387.]
The teaching of the mediaeval Church on the subject of property was perfectly simple and clear. Aquinas devoted a section of the Summa to it, and his opinion was accepted as final by all the later writers of the period, who usually repeat his very words. However, before coming to quote and explain Aquinas, it is necessary to deal with a difficulty that has occurred to several students of Christian economics, namely, that the teaching of the scholastics on the