Look at your hands, feel the weight of your device, glance around the room. What if none of it is there? This episode unpacks René Descartes' evil demon, the 17th-century thought experiment from Meditations on First Philosophy designed to strip away everything we think we know. We explain his method of systematic doubt as a factory reset of the mind, his escalation from unreliable senses to the dream argument to a deceiving God who could make two plus three come out wrong, and why he still needed the demon: his comfortable everyday beliefs kept sneaking back in, so he required a relentless psychological tool to hold them at bay.

Drawing on scholar Zeno Vendler, we connect the demon to the Jesuit spiritual exercises of Ignatius of Loyola and the instruction agere contra, go against, and describe it as a philosophical weight vest. We then cov ...