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           Ashby's book "Introduction to Cybernetics"
                                                                 Author
W. Ross Ashby (1956): An Introduction to Cybernetics, (Chapman & F. Heylighen,
Hall, London): now available electronically.
                  ----------------------------                   Date
                                                                 Oct 14, 2003
[ashby-big] Principia Cybernetica has selected Ashby's           (modified)
"Introduction to Cybernetics" as a classic book that deserved to Jun 8, 1999
be published again electronically. The original version has been (created)
out of print for many years. A few copies may still be found in
libraries or ordered through the [externalli]Amazon bookshop.            Home
However, we believe that the book is so important that it should         [up]
reach an as wide audience as possible. The best medium to         Reference material
achieve that seemed to be the world-wide web. This publication           [up]
has been made possible largely through Mick Ashby, the author's       Principia
grandson, who has convinced the copyright holders (the Ashby         Cybernetica
estate) that they should allow us to produce an electronic        Electronic Library
version.
                                                                          Up
W. Ross Ashby is one of the founding fathers of both cybernetics  Prev. [4arr] Next
and systems theory. He developed such fundamental ideas as the           Down
homeostat, the law of requisite variety, the principle of        --------------------
self-organization, and the principle of regulatory models. Many
of these insights were already proposed in the 1940's and
1950's, long before the presently propular "complex adaptive
systems" approach arrived at very similar conclusions. Whereas
the concepts surrounding the complexity movement are often
complicated and confused, Ashby's ideas are surprisingly clear
and simple, yet deep and universal.

[WRAshby195]

Photo: W.R. Ashby, dec. 1955, Stanford (Copyleft. 2002. No
Rights Reserved)

This elegance of thought is illustrated in particular by the
present book, which is still the only real textbook on
cybernetics (and, one might add, system theory). It explains the
basic principles with concrete examples, elementary mathematics
and exercises for the reader. It does not require any
mathematics beyond the basic high school level. Although simple,
the book formulates principles at a high level of abstraction.
For more concrete and extensive illustrations of systems
principles, you may refer to our other electronic books, "The
Macroscope" and "The Phenomenon of Science". For a similar
abstract, high-level, but technically simple approach, this time
to physics, you can check "Representation and Change".

The electronic version of Ashby's book has been formatted as a
PDF file (1.9 Mb), with two pages of the original book per
printed A4 page. This format, although it can be read on-screen,
is basically meant for printing out. The print-out will be
similar to the original book, including the original figures,
formulas, answers to exercises, table of contents and index. You
can read or print it with the [externalli]free PDF reader from
Adobe.

Table of Contents

1: WHAT IS NEW
The peculiarities of cybernetics
The uses of cybernetics

PART ONE: MECHANISM
2: CHANGE
Transformation
Repeated change
3: THE DETERMINATE MACHINE
Vectors
4: THE MACHINE WITH INPUT
Coupling systems
Feedback
Independence within a whole
The very large system
5: STABILITY
Disturbance
Equilibrium in part and whole
6: THE BLACK BOX
Isomorphic machines
Homomorphic machines
The very large Box
The incompletely observable Box

PART TWO: VARIETY                                                --------------------
7: QUANTITY OF VARIETY                                                Discussion
Constraint                                                       --------------------
Importance of constraint                                         
Variety in machines                                                * Mechanisms of
Transmission from system to system                                   Intelligence,
Transmission through a channel                                       Comment by John
9: INCESSANT TRANSMISSION                                            Waters
The Markov chain
Entropy                                                             Add comment...
Noise
                                                                          _
PART THREE: REGULATION AND CONTROL
10: REGULATION IN BIOLOGICAL SYSTEMS
Survival
11: REQUISITE VARIETY
The law
Control
Some variations
12: THE ERROR-CONTROLLED REGULATOR
The Markovian machine
Markovian regulation
Determinate regulation
The power amplifier
Games and strategies
13: REGULATING THE VERY LARGE SYSTEM
Repetitive disturbance
Designing the regulator
Quantity of selection
Selection and machinery
14: AMPLIFYING REGULATION
What is an amplifier?
Amplification in the brain
Amplifying intelligence

REFERENCES
ANSWERS TO EXERCISES
INDEX

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