Long before Freud or cognitive science, James Sully undertook something radical for 1881: treating human error not as a curiosity, but as a window into the mind itself. Illusions: A Psychological Study argues that perceptual mistakes are not failures of reasoning but fundamental features of how the human brain constructs reality. Sully examines illusions ranging from the sensory to the cognitive, from the physiological mechanisms that trick our eyes to the psychological processes that lead us to believe things that are not so. He proposes that these errors reveal the hidden architecture of normal perception, that by understanding how we go wrong, we can understand how we ever go right. This is a work of remarkable intellectual ambition, written when psychology was just becoming a discipline in its own right. It remains fascinating for anyone curious about the history of how we came to study the mind, and more importantly, about the strange, fallible, often deceived creatures we are.
