Cybernetics is an interdisciplinary framework for studying systems of control, communication, and adaptation in both living organisms and machines. It introduced foundational concepts such as feedback—the process by which a system uses its outputs to regulate future behavior—and homeostasis, the system’s ability to maintain internal stability amid external changes. A key principle in the field is Ashby’s law of requisite variety: to handle environmental disturbances effectively, a system needs enough internal complexity to match what it faces. Cybernetics also introduced a shared conceptual language, termed “cyberspeak” by Slava Gerovitch, for describing the behavior of humans, animals, and machines in terms of information processing and regulation. Prominent figures include Norbert Wiener, who defined cybernetics as the study of control and communication in animals and machines, and William Ross Ashby, who investigated adaptive behavior and built the homeostat, an early model of self-regulating systems. Beyond its historical significance, cybernetics profoundly influenced the functionalist view in philosophy of mind, particularly the idea of multiple realizability: the notion that mental or computational states can be instantiated in different physical systems, provided the same functional organization is preserved. While the field eventually fragmented into various specializations, its core ideas persist in fields such as artificial intelligence, neuroscience, systems theory, and robotics. The cybernetic dream of explaining both minds and machines using the same abstract principles continues to drive modern research into intelligence and cognition.