Bedeviled: A Shadow History of Demons in Science

Canales writes the history of imaginary beings in science — Maxwell's demon sorting molecules, Laplace's demon predicting the universe, Descartes's evil genius deceiving the thinker — and shows that these thought experiments were never mere illustrations but active tools that shaped the development of thermodynamics, information theory, quantum mechanics, and artificial intelligence. Each demon was introduced to test the limits of a theory and ended up revealing something the theory could not contain. The book connects figures from Leibniz through Boltzmann and Szilard to Landauer and Bennett, tracing how the demon concept migrated from physics to computation as the relationship between information and entropy became clear. Canales's approach — taking metaphorical constructs seriously as drivers of scientific progress — is itself a demonstration of how conceptual tools do real intellectual work. The result is an unusual history of physics told through its own fictional characters.