Liber II, Pars III — Quot sunt species commutationum, et qua fuit necessitas invenire denarios. Cap. IX.

Liber II, Pars III — Quot sunt species commutationum, et qua fuit necessitas invenire denarios. Cap. IX.

If we consider the statements of the philosophers in the first book, it is clear that they are political. All exchanges can be reduced to three types. The first type is the exchange of goods for goods. For example, grain can be exchanged for wine, or for barley, or for other necessities that fulfill physical needs. Another type is the exchange of goods for currency. The third type is the exchange of one currency for another. For instance, when silver coins are exchanged for gold coins, or vice versa. Or, the coins of one region are exchanged for the coins of another region. So, to understand how such exchanges had to be introduced, we need to know that if there were only the community of a household, which is the primary community, no exchange would be necessary. For in a household, the head of the family governs, and it is his responsibility to provide for everyone in the household; therefore, every exchange made for the household's needs is done by the head of the family, either directly or through intermediaries, for it is the head of the family who must alleviate all domestic needs. But when there is no buying, selling, or exchange of the same thing among themselves, it is rightly said that it is stated in the first book. In the first community, which is the household, it is evident that there is no need for the work of exchange; therefore, because of other communities, an exchange system has been introduced. However, there are other communities beyond the household. Such as the community of a village, or a city, or the entire kingdom, and province, or even of different kingdoms or different jurisdictions. Sometimes, indeed, the necessities for life are not found in the whole kingdom at once, which is why some must travel through various parts of the world and through different kingdoms and regions, seeking spices and other things that are needed for life. Because of the different appearances of the stars and planets, some regions have warm areas while others do not, and vice versa. For this reason, it's necessary for people from the same village, city, or province to communicate and interact with one another, as well as with those from different provinces and kingdoms. Therefore, because of these communities, three types of exchanges have been introduced. For while it might suffice for the community of a village or city to exchange goods for goods, it was necessary to introduce a system of exchange for the entire kingdom. Again, if the exchange of goods for money sufficed for the entire kingdom, it was still necessary to introduce not only the exchange of goods for goods or goods for money but also money for money in the exchanges between different kingdoms and provinces. In ancient times, as the philosopher indicates in the first book of Politics, people lived simply and exchanged goods for goods. For example, if one person had an abundance of wine and another had an abundance of grain, they would exchange wine for grain, and through such exchanges, they would provide for their needs. However, this method, as he says, is still preserved among many barbarian nations that, lacking the use of money, only exchange the goods themselves. This method might work in a single village or town, but it can't be easily applied across an entire kingdom or province, especially if that province is large. For wine, grain, and other goods we need for life are too heavy to be transported easily over long distances. Therefore, it was necessary to find something that was portable, beautiful, and useful, so that provisions could be obtained. Among such things, silver and gold are the most beautiful metals, and they are useful and honorable; from them, vessels can be made that are useful to people, and having such vessels seems to bring honor and glory. Initially, exchanges were made based solely on the weight of metals: if someone wanted to acquire a certain amount of wine, they had to give a corresponding weight in silver or gold, or even another metal, as was customary among the people and kings of that time. But because it was difficult to weigh metals in every transaction, whether buying or selling, to ensure that buyers and sellers were satisfied with the weight, a mark was engraved on the metals, like the image of a ruler or some other public symbol, so that through its inspection, one could know the weight and value of that metal. Thus, the denarius and coin were invented as a sort of guarantor for us, so that we could immediately receive supplies to meet our needs according to its value. In an entire kingdom, to prevent people from being overly burdened when moving from one part of the kingdom to another with heavy provisions, the denarius was invented, which is easily portable; through its exchange, provisions can be obtained. Therefore, the exchange of goods for money could work in one kingdom or province, but in different kingdoms where various rulers dominate, the same coins aren't used by people living in different provinces, except for the exchange of goods for goods and goods for coins. Thus, it was necessary to find a way to exchange coins for coins. It’s clear how many types of exchanges there are, how they were invented, and what the necessity was for creating money. Therefore, it is fitting for a prudent head of a household. And it’s important for a wise manager to understand how such exchanges came about and what purpose they serve, so that by knowing, he can better provide for his household.