This course is intended to build on and extend students’ existing knowledge and interests in cognitive science and philosophy of mind. The topic is Delusions. We will investigate a number of sensory delusions, and sensory disorders. The goal is to discover what these glitches tell us about the architecture of cognition. We will also raise theoretical questions about the methodology this approach to studying cognition uses, and philosophical questions about the nature of perception. Can we reliably learn about “normal” minds from studying their breakdown? Is there such a thing as veridical perception, or is all perception in some sense illusion? What is the difference between illusion and delusion? Are delusions beliefs? What is the difference between neurological and psychiatric diagnoses?