René Descartes

“It was the Great Train Robbery of French intellectual life: thousands of treasured documents that vanished from the Institut de France in the mid-1800s, stolen by an Italian mathematician. Among them were 72 letters by René Descartes, the founding genius of modern philosophy and analytic geometry.” And now, says Patricia Cohen in a New York Times report, one of the letters has turned up — at a tiny college in Pennsylvania.

Finding it after hundreds of years proved a simple affair: a scholar from Utrecht University who was cruising the internet “noticed a reference to Descartes in a description of the manuscript collection at Haverford College in Pennsylvania.” The scholar contacted the school and that was that.

In the letter — dated May 27, 1641 — Descartes discusses the publication of Meditations on First Philosophy, “a celebrated work whose use of reason and scientific methods helped to ignite a revolution in thought,” says Cohen. “The document, experts say, reveals just how much Descartes tailored his writings to answer his contemporary critics. Frequently suspected of heresy, Descartes sent copies of his arguments to well-known theologians to gauge their opinions and answer their objections within his text.”

So how did the letter get to Haverford? It was donated in 1902 by someone whom, says Cohen, “bought the letter without knowing that it was stolen.” There is no explanation of how it’s known that the long-ago donor didn’t know, but in any event Haverford president Stephen G. Emerson immediately “contacted the Institut de France (coincidentally on Feb. 11, the anniversary of Descartes’ death in 1650) and offered to return the item.”

As to how it was stolen in the first place:

The letters were among thousands of documents stolen by Guglielmo Libri, an Italian count and mathematician who served as secretary of the Committee for the General Catalog of Manuscripts in French Public Libraries in the 1840s. After learning that he might be arrested, Libri fled to London in 1848 with a collection of 30,000 books and manuscripts, including those by Descartes, Galileo, Fermat, Leibniz, Copernicus and Kepler and other scientific and mathematical giants.

Claiming to be a political refugee, Libri was welcomed in Britain even though French courts eventually convicted him in absentia in 1850 and sentenced him to 10 years in prison. Libri raised money by selling his collection, and put a total of 7,628 lots up for sale at two auctions in 1861.

The letter is the 45th of the 72 stolen Descartes letters to be recovered.