A New Mystery Asks: Who Killed Descartes?

East Sider Andrew Pessin draws on historical fact to spin a tale of intrigue about the murder of the famous philosopher


“Cogito ergo sum” – I think, therefore I am. Many of us recognize this famous phrase by the seventeenth-century philosopher, mathematician and scientist René Descartes. But most of us are less familiar with Descartes’ unusual life and mysterious death, the subject of The Irrationalist: The Tragic Murder of René Descartes, a new work of historical fiction that is also a gripping murder mystery.

Author, scholar and East Sider Andrew Pessin has been researching Descartes for the past ten years and was inspired to write The Irrationalist by Richard Watson’s biography of the renowned philosopher and mathematician. Despite his fame, Descartes was not well liked. In fact, German academic Theodor Ebert proposed in 2010 that Descartes’ death may not have been due to natural causes.

In the novel, Descartes’ prickly personality, reclusive nature and brilliant insights unfold against a richly detailed background. The story begins with his murder. We then meet the man investigating his death: Adrien Baillet, a Jesuit priest and real person who wrote the first biography of Descartes. A bumbling but likeable character, Baillet is ill suited for his assignment but easy to root for. The novel draws on Baillet’s and Watson’s biographies in addition to Ebert’s work and letters written by Descartes.

As we travel with Baillet through the years and through France, the Netherlands and Sweden, we learn about the philosopher’s past. The meticulous descriptions of actual locations and historical figures weave a tapestry against which Descartes’ numerous detractors – personal, intellectual, political and religious – emerge as possible suspects.

Like many great murder mysteries, there is a dramatic plot twist at the end. Pessin has taken some liberties, although of course there is no proof that the novel’s denouement is less accurate than any other theory about Descartes’ death.

A philosophy professor at Connecticut College, Andrew has written seven books, two of them works of fiction, and starred as the Genius in a 1994 series of skits on the Late Show with David Letterman called “The Strong Guy, the Fat Guy, the Genius.” He lives with his family on the East Side.