Short works

Books : reviews

W. Ross Ashby.
An Introduction to Cybernetics.
Chapman and Hall. 1956

Cybernetics has been defined as “the science of control and communication, in the animal and the machine”&mdasah;in a word, as the art of steersmanship; and this book will appeal to all who would learn something of cybernetics, communication theory and methods for regulation and control.

The author has specialised for many years In the applications of cybernetics to blological systems, and his treatment is quite new and much simpler and clearer than that generally used. Many workers in the biological sciences are interested in cybernetics and would like to apply its methods and techniques to their own speciality but have been prevented from taking up the subject by an impression that its use must be preceded by a long study of electronics and pure mathematics. The author is convinced, however, that this impression is false and that a great deal can be done, especially in the biological sciences, by the use of quite simple techniques, provided they are used with a clear and deep understanding of the principles involved. This book is intended, therefore, to provide such an introduction. Starting from common-place and well-understood concepts it proceeds step by step, to show how these concepts can be made exact and how they can be developed until they lead into such subjects as feed-back, stability, regulation, ultrastabillty, information, coding, noise, and other cybernetic topics.

Throughout the book no knowledge of mathematics is required beyond elementary algebra. An important feature is the number of carefully graded exercises, with hints and explanatory answers, so that the reader, as he progresses, can test his grasp of what has been read. The book is mainly intended as a self-inetructor but will also be found valuable as supplementary reading for a course in communication theory.

W. Ross Ashby.
Design for a Brain: 2nd edn.
Chapman and Hall. 1960

Design for a Brain has as its basis the fact that the nervous system behaves adaptively and the hypothesis that it is essentially mechanistic; it assumes that these two data are not irreconcilable.

The book proceeds by first developing an adequately rigorous logic of mechanism, considering such topics as dynamic system, stability and homeostasis. It then applies this logic to the behaviour of living organisms, and shows that we may deduce that certain types of behaviour must be produced by certain types of mechanism.

Since this book was first produced, understanding of brain-like mechanisms has improved immeasurably. For this reason the book was later considerably revised and much of the content matter was rewritten, the new version presenting the material in an altogether clearer, simpler and more cogent form.

At the time when the book was first written, information theory was just beginning to be known. Since then its contribution to our understanding of the logic of mechanism has been so great that a separate treatment of these aspects has been given in a companion volume by the same author, An Introduction to Cybernetics.