Pacioli’s “Summa” in San Francisco

Setting up to give the talk under the watchful eye of Picasso

On April 24, SUMOP visited San Francisco’s new arts complex in the old dockland area to give a short talk about the background and importance of Luca Pacioli’s 1494 book Summa de arithmetica, geometria, proportioni et proportionalita. The occasion was a public showing of one of the few remaining first edition copies of the book by Christie’s, who are auctioning the book in New York in June. Giving a talk with a life-sized painting of Picasso behind me and original paintings by Renoir and Monet to my left (the total estimated value of all three at auction is $27M) was a new experience for me.

But I got an even greater thrill from spending a few moments before the event taking a close look at the book that initiated the modern commercial world by providing business leaders and financiers with the modern accounting methods necessary to run large organizations. Without the methods described in Pacioli’s book (which Christie’s expects to fetch between $1M and $1.5M), there would not be a financial system to give those paintings their much greater financial value. (Clearly, while I share with many the appreciation of fine art, the value I put on brilliant mathematical innovations is not mainstream.)

For a greatly expanded, written version of my talk, see the forthcoming May 1 issue of my regular Devlin’s Angle commentary for the Mathematical Association of America. (The April 1 post had a preview of the Christie’s event.)

Here are a few photos from the event. Two of the pictures show me examining one of the examples of double-entry bookkeeping in the textbook that first taught that method to the world.