Cybernetics, then, is indifferent to the criticism that some of
The machines it considers are not represented among the machines
Found among us. In this it follows the path already followed with
Obvious success by mathematical physics. This science has long
Given prominence to the study of systems that are well known to
Be non-existent— springs without mass, particles that have mass
But no volume, gases that behave perfectly, and so on. To say that
These entities do not exist is true; but their non-existence does not
Mean that mathematical physics is mere fantasy; nor does it make
The physicist throw away his treatise on the Theory of the Mass-
Less Spring, for this theory is invaluable to him in his practical
Work. The fact is that the massless spring, though it has no physi-
Cal representation, has certain properties that make it of the high-
Est importance to him if he is to understand a system even as
Simple as a watch.
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The biologist knows and uses the same principle when he gives
To Amphioxus, or to some extinct form, a detailed study quite out Of
Proportion to its present-day ecological or economic importance.
In the same way, cybernetics marks out certain types of mech-
Anism (S.3/3) as being of particular importance in the general the-
Ory; and it does this with no regard for whether terrestrial
Machines happen to make this form common. Only after the study
Has surveyed adequately the possible relations between machine
And machine does it turn to consider the forms actually found in
Some particular branch of science.
In keeping with this method, which works primarily with the
Comprehensive and general, cybernetics typically treats any
Given, particular, machine by asking not “what individual act will
It produce here and now?” but “what are all the possible behav-
Iours that it can produce?”
It is in this way that information theory comes to play an essen-
Tial part in the subject; for information theory is characterised
Essentially by its dealing always with a set of possibilities; both its
Primary data and its final statements are almost always about the
Set as such, and not about some individual element in the set.
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This new point of view leads to the consideration of new types
Of problem. The older point of view saw, say, an ovum grow into
A rabbit and asked “why does it do this”— why does it not just stay
An ovum?” The attempts to answer this question led to the study
Of energetics and to the discovery of many reasons why the ovum
Should change— it can oxidise its fat, and fat provides free energy;
It has phosphorylating enzymes, and can pass its metabolises
Around a Krebs’ cycle; and so on. In these studies the concept of
Energy was fundamental.
Quite different, though equally valid, is the point of view of
Cybernetics. It takes for granted that the ovum has abundant free
Energy, and that it is so delicately poised metabolically as to be, in
A sense, explosive. Growth of some form there will be; cybernetics
Asks “why should the changes be to the rabbit-form, and not to a
Dog-form, a fish-form, or even to a teratoma-form?” Cybernetics
Envisages a set of possibilities much wider than the actual, and then
Asks why the particular case should conform to its usual particular
Restriction. In this discussion, questions of energy play almost no
Part— the energy is simply taken for granted. Even whether the sys-
Tem is closed to energy or open is often irrelevant; what is important
Is the extent to which the system is subject to determining and con-
Trolling factors. So no information or signal or determining factor
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A N I N T R O D UC T I O N T O C Y B E R NE T I C S
W H A T I S NE W
May pass from part to part without its being recorded as a signifi-
Cant event. Cybernetics might, in fact, be defined as the study of sys-
Tems that are open to energy but closed to information and
Control—systems that are “information-tight” (S.9/19.).
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The uses of cybernetics. After this bird’s-eye view of cyber-
Netics we can turn to consider some of the ways in which it prom-
Ises to be of assistance. I shall confine my attention to the
Applications that promise most in the biological sciences. The
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