Most Americans probably have only a vague notion of Rene Descartes, the 17th-century French philosopher and mathematician, as the guy who declared, "Cogito ergo sum" ("I think, therefore I am"). It's ...

Some of us do our best thinking in the shower, others do it while on the toilet. Renee Descartes, he pondered most deeply while ensconced in a baker's oven. The man simply needed to be convinced of ...