The Ratio Club, founded in 1949, was an informal British dining society that brought together a unique mix of young professionals from diverse disciplines—psychiatrists, psychologists, physiologists, mathematicians, and engineers—who shared a keen interest in understanding the emerging field of cybernetics. The club was named after the Latin word ratio, meaning “reason” or “calculation,” reflecting its focus on the study of feedback, control systems, and information processing in both biological and mechanical contexts. Meetings were typically held monthly in London, often over dinner, where members would present papers, discuss recent scientific developments, and debate ideas in a collaborative, interdisciplinary atmosphere. The Ratio Club was instrumental in fostering early British cybernetics, particularly by promoting dialogue between the sciences of mind and machine at a time when such cross-disciplinary interaction was rare.

Many of the club’s members went on to have significant influence in their respective fields. Figures such as W. Ross Ashby, Grey Walter, Alan Turing and Horace Barlow were central to discussions about neural networks, brain function, and feedback mechanisms, shaping early ideas in systems theory and artificial intelligence. The informal setting encouraged free-flowing conversation and experimental thinking, which allowed members to explore speculative and theoretical concepts without the constraints of formal academia. Although the club dissolved in 1958, its impact persisted, as the ideas and collaborations that emerged helped lay the groundwork for modern cognitive science, computational neuroscience, and AI research, bridging the gap between human and machine understanding in an era of rapid scientific change.