The 17th century thinker René Descartes is seen as the father of modern philosophy: A man who was entirely original, whose work marked a clear divide from earlier thinkers, and who laid the foundation for modern thought with his focus on self-knowledge of the individual mind.
But that narrative is “unquestionably false,” says Christia Mercer, a philosophy professor at Columbia University. Indeed, “people in his period did not think Descartes was the father of anything,” she adds. Though the philosopher was renowned in his day for his work on physics and natural philosophy, it wasn’t until the 19th century that historians portrayed Descartes as a major break with the past. This idea has endured in part because, while historians searched for the great male thinkers who might have influenced Descartes’ ideas, they missed the female philosopher who came before him: Teresa of Ávila.