[Footnote 3: _Op. cit._, p. 27. Espinas thinks that the influence
of Aristotle in this respect has been exaggerated. (_Histoire des
Doctrines Économiques_, p. 80.)]

In support of the account we have given of the development of economic
thought in the thirteenth century, we may quote Cossa: 'The revival
of economic studies in the Middle Ages only dates from the thirteenth
century. It was due in a great measure to a study of the _Ethics_ and
_Politics_ of Aristotle, whose theories on wealth were paraphrased by
a considerable number of commentators. Before that period we can only
find moral and religious dissertations on such topics as the proper
use of material goods, the dangers of luxury, and undue desire for
wealth. This is easily explained when we take into consideration (1)
the prevalent influence of religious ideas at the time, (2) the
strong reaction against the materialism of pagan antiquity, (3)
the predominance of natural economy, (4) the small importance of
international trade, and (5) the decay of the profane sciences, and
the metaphysical tendencies of the more solid thinkers of the Middle
Ages.'[1]

[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