“This was exhilarating,” Mr. Bos wrote in an e-mail message. “Seeing Descartes’ handwriting appear on my screen took my breath away.” Descartes, the author of “Cogito, ergo sum ...

The famous saying "I think, therefore I am" was the cornerstone of the philosophy of Rene Descartes, who died 375 years ago this month at the age of 53. His groundbreaking ideas shaped Western ...