In order to understand what we intend to say about exchanges in our time, we state the beginning of the last chapter of de usuries, whose words are the following:
Gregorius IX, in the final chapter of de usuries: Nauiganti, vel eunti ad nundinas certam mutuans pecuniae quantitatem, eo quod suscepit in se periculum, recepturus aliquid ultra sortem, usurarius est censendus.
The reason why Gregory IX decided the opposite (even though there was disbelief) was not the reason put forth by the gloss (by Panormitanus and the others) but by the need to put an end to veiled or covert usuries carried out as insurances because many, in seeing that canon law forbade usuries in general but did not prohibit nautical ones (and this one seemed licit because of the danger that the lender took on), took to lending by assuming the risk whether there was danger or not and whether what was lent went through sea or land.
By the same ruling, it has been ordered not long ago in these kingdoms and in those of Portugal that there shall be no exchange from one city in the kingdom to another because it is presumed that there are veiled usuries, as we will explain later.
Also, not only are the other usuries forbidden today by canon law, but even those known as nautical (21) (as the ones mentioned above such as Hostiense (22) stated), which here nobody contradicts, with which Salyceto (23) agrees, and which saying Ioan de Ananias (24) declares he shares, concluded that this text corrects a chapter of civil law.