Descartes on unknown faculties and our knowledge of the external world

Descartes introduces his skeptical arguments, in the First Meditation, in an order of increasing strength. First, the narrator-meditator notices that judgments concerning the nature of small and distant objects are unreliable; later, that even sensory judgments about large and close objects are in doubt-this after considering an argument related to madness and another related to dreaming; finally, that no judgments resist doubt-the renowned Deceiver Hypothesis is introduced, a skeptical device intended to undermine not only the judgment that an external, corporeal world exists, but even the most certain judgments in mathematics.1 For each of these skeptical problems (with the exception of the madness worry), Descartes provides an argument in the later (epis-temologically constructive) Meditations that is its complement. In this paper, I focus on the complementary pair that concerns the problem of the existence of the external, corporeal world.