Experts are questioning claims that illustrations in "De ludo schaccorum," an unpublished treatise on chess, were created by Italian Renaissance artist Leonardo da Vinci.

As reported by the Associated Press on April 14, 2008, scholars are engaged in a lively debate to determine if illustrations in De ludo schaccorum (On the Game of Chess) (ca. 1500) by Luca Pacioli (1445-1514/17) were designed by Leonardo da Vinci (1452-1519).

De ludo schaccorum Recovered

The long lost leather-bound De ludo schaccorum is part of the 22,000-volume library that belonged to northeastern Italy's Count Guglielmo Coronini (d. 1990). The collection is overseen by the nonprofit Fondazione Palazzo Coronini Cronberg of Gorizia. Bibliophile Duilio Contin discovered the priceless manuscript in 2006. After a year-long examination, architect and sculptor Franco Rocco determined that the book's design and 114 red and black chess problem diagrams are by the hand of Leonardo, Luca Pacioli's friend, student and associate.

Luca Pacioli

Franciscan friar Luca Pacioli, born in Borgo San Sepolcro, Tuscany, was one of Renaissance Italy's foremost mathematicians. An itinerant tutor educated in Venice and Rome, he settled in 1496 at the Milanese court of Duke Ludovico Sforza (1452-1499), where he taught Leonardo mathematics.

During his illustrious career, Pacioli wrote a number of books, including:

• Summa de arithmetica, geometria, proportioni et proportionalita (1494), a seminal work on double-entry accounting;
• De viribus quantitatis (1496-1508), a collection of mathematical problems, magic tricks and proverbs;
• Geometria (1509), a translation of the same work from Elements by Greek mathematician Euclid (ca. 325-265 B.C.); and
• De divina proportione (1496-98, published in 1509), a description of proportion in mathematics, art and architecture, including a discussion of perspective in painting. Its "see-through" illustrations of geometrical solids such as a dodecahedron were drawn by Leonardo da Vinci while he painted the Last Supper (ca. 1495-98).

Guilty by Association?

After Leonardo's collaboration with Luca Pacioli on De divina proportione, the French troops of King Louis XII (r. 1498-1515) invaded Milan, forcing the two to flee south to Mantua. While the pair enjoyed the patronage of Francesco Gonzaga and Isabella d'Este, the prominent mathematician penned his De ludo schaccorum and dedicated it to the royal couple.

Franco Rocco's attribution of the manuscript's illustrations to Leonardo da Vinci is based on:

• the artist's documented association with Pacioli;
• the presence of the golden ratio of proportion in the drawings, used by Leonardo in many of his compositions; and
• a similarity in design shared by the queen playing piece and drawings for a fountain in the master's Codex Atlanticus (1478-1518).

However, a healthy amount of critical skepticism from established Leonardo scholars has checkmated Mr. Rocco and his conclusions. Leading the opposition is Martin Kemp, professor emeritus of Oxford University and distinguished author of numerous studies on the artist. The respected curator of highly acclaimed museum exhibitions about the master has dismissed Rocco's assertions as baseless hypotheses. According to Dr. Kemp, no archival evidence exists for Leonardo's supposed interest in chess. Alessandro Vezzosi, director of the Leonardo Museum in Vinci, Italy, also is awaiting more concrete documentation from Rocco to substantiate his claims.

Luca Pacioli's De ludo schaccorum is the subject of a June 2008 conference in Gorizia.

Sources:

• Levenson, Jay A. (ed.), et al. Circa 1492: Art in the Age of Exploration (exh. cat.). Washington, D.C.: National Gallery of Art, 1991, 243-246.
• Nicholl, Charles. Leonardo da Vinci: Flights of the Mind. New York: Penguin Publishers, 2005, 267, 297, 303-307, 337, 347-348, 387.