Abstract
Harry Frankfurt has argued that Descartes’s madness doubt in the First Meditation is importantly different from his dreaming doubt. The madness doubt does not provide a reason for doubting the senses since were the meditator to suppose he was mad his ability to successfully complete the philosophical investigation he sets for himself in the first few pages of the Meditations would be undermined. I argue that Frankfurt’s interpretation of Descartes’s madness doubt is mistaken and that it should be understood as playing the same role as his more famous dreaming doubt. I focus my discussion around four questions: (Q1) What does the meditator have in mind when speaking of madness?, (Q2) Why does the meditator so quickly dismiss the madness doubt but take seriously the dreaming doubt?, (Q3) Does the madness doubt have the same scope as the dreaming doubt?, and (Q4) Why does the meditator bring up the madness doubt at all?