Recent research in Baroque Scholastic and early modern meditational exercises has demonstrated similarity between Descartes’s Meditations and St. Teresa of Ávila’s El Castillo Interior. While there is growing agreement on the influence of Catholic meditations on Descartes, the extent of Teresa’s role is debated. Instead of discussing the full extent of Teresa’s influence, this paper concentrates on one example of the considered influence: the skeptical scenario of demonic deception, having clear anticipation in Teresa’s work where the exercitant faces off against (...) deceiving demonic forces, which confound and temporarily halt the meditative progress. The paper analyzes Teresa’s use of deceptive demons and its influence on the Cartesian Evil Demon scenario, while contrasting both with a discussion of demonic deception in the late Medieval and Baroque Scholastic context, arguing that demonological discussions in 1500s allowed both Teresa’s and Descartes’s deceivers to not only cause diversions but to make the deception laborious to resist. (shrink)