In asking for a relic of Descartes, the chevalier de Terlon was standing at the crossroads of the ancient and modern. He was applying to a modern thinker - the inventor of analytic geometry, no less - a primitive tradition that extends back not only to the institutionalization of Christianity in the fourth century, when Christians first broke into the tombs of saints to gather relics, but farther still, beyond the horizon of recorded history. The request is all the stranger for the fact that the man whose remains were treated in this quasisaintlike way would go down in history as the progenitor of materialism, rationalism, and a whole tradition that looked on such veneration as nonsense.