Princess Elisabeth’s Cautions and Descartes’ Suppression of the Traité de l’Homme

Why did Descartes not publish his chief physiology work during his lifetime? Descartes considered that the physiological and medical conclusions that could be drawn from his philosophy were fundamental to his intellectual project, and an apparently complete work was circulating among friends in 1641 but was only published more than a decade after his death, as De Homine (1662) and Traité de l’Homme (1664). This paper argues that Princess Elisabeth’s careful consideration of his physiology raised questions about whether the common interpretation of his philosophy as dualistic was correct, implicating it in some of the most dangerous arguments of his generation. Her questions served as a warning, in a moment when the personal papers and even the liberty of the Frenchman were threatened. Descartes had no interest in becoming a medical Galileo, and listened to the princess, leaving the work unpublished.