Cybernetics is defined as "the science of control and communication, in the animal and the machine" in a word, as the art of steersmanship; and this book will interest all who are interested in cybernetics, communication theory and methods for regulation and control. W. Ross Ashby (1903-1972) was an English psychiatrist and a pioneer in cybernetics, the study of complex systems. His two books, "Design for a Brain" and "An Introduction to Cybernetics," to be the landmark works for this subject. This book introduces exact and logical thinking into the nascent discipline and were highly influential. Contents include: What is new Change,the Determinate Machine,the Machine with Input,stability,the Black Box,Quantity of Variety,Transmission of Variety,Incessant Transmission,Regulation in Biological Systems,Requisite Variety,The Error-controlled Regulator, Regulating the Very Large System and amplifying regulation.