'Double Entry: How the Merchants of Venice Created Modern Finance,' by Jane Gleeson-White. (Courtesy W.W. Norton & Company)

Introducing Double Entry: How the Merchants of Venice Created Modern Finance, a new book by Jane Gleeson-White, Lewis Lapham (via Bloomberg) writes that Leonardo da Vinci learned math from a mathematics encyclopedia by Luca Pacioli, released in 1494, that had a section on double-entry bookkeeping, which helped pave the way for modern capitalism. Mr. Pacioli, who was a Franciscan Friar, also helped Leonardo create his theory of proportion.

From the story:

"After learning the subject from Pacioli’s book, Leonardo da Vinci got him a job in Milan as the first Chair of Mathematics. There, he helped Leonardo develop linear perspective for the “Last Supper,” while the artist gave Pacioli insight on the golden ratio for his next book.

"When the French army of Louis XII invaded Milan in October 1499, Pacioli was dragged from his lodgings and his mathematical models destroyed by soldiers who deemed them the devil’s work."

It's Friday. Why not sit back and listen to the podcast of Mr. Lapham in conversation with Ms. Gleeson-White?