U is for Usury

German woodcut of Italian bankers. Photo from medium.com

Usury was denounced by the Catholic church in the Middle Ages, a potential route to heresy and excommunication. But royalty, the church, and the merchants needed bankers. The bankers found ways around restrictions. The Medici thrived on banking, but it proved to be their downfall, or their rise depending on how you look at it. Lending to people in charge seems to have an inherent risk, usury or not.

Criminal Interest

Usury is defined as charging an “exorbitant” interest according to Webster’s. But there’s that third dictionary definition, listed as Obsolete. Usury was once defined as charging any interest at all. It varied with the century.

There were banks in Rome, which might charge from 5-12% interest. There were banks in the 6th century Byzantine Empire, because Emperor Justinian set loan rates, which varied by the venture: 4% for “exalted personages,” 7% for business loans, and 12% for maritime loans. The Council at Nicea centuries earlier had banned interest but for clergy, not everybody.

Yet a few centuries later, between the time of Charlemagne (750 CE) to the Black Death (1350), usury was more strictly banned. First, the Catholic church said that usury was banned to everybody, that you could not have a transaction where more was returned than was given. Even in a simple transaction, like selling a cow, the farmers had to find a just price, where they would only receive what it cost.

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T is for Trionfi

Visconte-Sforza deck, Photo from wikipedia.

Playing cards came from Italy. Or France. Or Islam. Or China. The Internet will give you all those answers. But, in Europe, the first cards used were called trionfi also called tarot or tarock, and they reflected the 78-card tarot deck which became familiar to cartomancers across the centuries. At the time, they weren’t used for divination. Later folks claim they went back to the pharoah’s Egypt which has been disproved. No one seems to know why the Mamluk Egyptians had them, but they weren’t from Hermes Trismegistus.

The Milanese tarocchi, @1500. Photo from wikipedia.

When They Weren’t Riding Horses, They Needed Other Pastimes

The oldest surviving European decks came out of Milan from the early part of the 1400s. They are named the Visconti-Sforza deck, after Fra Lippo Visconti who commissioned them and his son, Francesco, of whom his later son tried to get Leonardo to build a bronze statue of horse. See L is for Leonardo. (I’m getting late in the alphabet–everybody seems to know everybody else).

The cards were exquisitely painted, sometimes with jewels. (What did a 14th century glue gun look like?) They even painted members of the duke’s family, which makes them historical documents. No complete deck has survived; multiple museums have incomplete decks.

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S is for Summa di Arithmetica

Pacioli also created a font. This Majuscule seems especially appropriate.

Having just spent the past two months analyzing a 1494 accounting textbook, it seems natural to devote one my alphabetic letters to the greatest math teacher of the Renaissance age–Luca Pacioli. I stumbled upon him and his work last year for the letter “P,” so I’m not going to rehash his biography.

Luca Pacioli woodcut from Summa, his 1494 600-page math textbook.

Nor will I tell you the secrets of my 35-page treatise on how this chapter on double-entry bookkeeping for Florentine wool merchants reveals their pious contract with heaven and the Catholic church. Feather Beds and Jesus may just be my next book, who knows? What I will talk about is why this work was so revolutionary, despite accusations of plagiarism and critics calling it of “little or no value.” Boo on them!

Free the Numbers!

If numbers give you a headache, I apologize in advance. But we have to talk about numbers. Perhaps you aren’t crazy about multiplying large numbers, like 9876 * 6789. That’s what calculators are for. Now imagine that it’s the year 1490 CE, and you’re still using Roman numerals, and you don’t have a calculator. You have to multiply IXDCCCLXXVI * VMDCCLXXXIX. Can you imagine? There were, apparently, ways to multiple Roman numerals that involved writing them in columns, doubling and halving, then crossing out odds and evens. You would be desperate to find an easier way. Welcome to Hindu-Arabic numerals.

Pacioli’s explanation on how to multiply 9876 & 6789, from Summa.
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