The W. Ross Ashby Digital Archive contains scans of original documents including a card index to his original notebooks, biographical (from his wife) and autobiographical material, a complete collection of aphorisms, a note on the 2004 Ashby Centenary Conference at University of Illinois, Urbana and some letters. The grand children who brought this project to fruition are to be congratulated on producing a standard setting archive site.
We reproduce below some 50 of aphorisms which first appeared in
Ashby's writings on Cybernetics "Mechanisms of
Intelligence" Intersystems Publications 1981 edited
by Roger Conant ISBN 1127197703
Thanks to the Ashby family for letting us extend
this collection three times to more than 150 aphorisms, many of Theorem status.
The Ross Ashby
site continues to be extended.
Some 25 notebooks, autobiographical writing and other
material are available at the British Library.
The famous Law of Requisite Variety is usually
stated "Variety absorbs Variety" but in his
to Cybernetics" (now available on line at
Cybernetica) he states it "picturesquely":
"only variety in R can force down variety due to D;
only variety can destroy variety" (p.207). R
and D are regarded here as players in a game but
often R is a regulator and D a disturbance in Ashby's
This was extended with Roger Conant (Int. J. Systems Sci.,1970 Vol.1, No. 2, 89-97) in the famous theorem "Every good regulator of a system must be a model of that system". If a table is to persist, for example, it must contain a model of itself. This dynamic model is produced by the form of the object and its accumulated internal stresses and strains.
Dr Horace Townsend has made a Java applet
simultation of Ashby's Homeostat
with a virtual four pen chart recorder. This is not a
concurrent machine but doubtless will evoke the
character of this object still central to our
understanding of the wide applicability of the
What Ashby Says...
Science is the Observer's Digest.
The Cyberneticist observes what might have
happened but did not.
A System is a set of variables sufficiently
isolated to stay constant long enough for us to
Division of the world's system into Natural and
Man-made died with Darwin.
Man is not the measure: first comes the
measure, then we see where he falls; so far the
result has always been humiliating.
Man pays for his knowledge with humiliation.
On Self Repair
The fault cannot be in the part responsible for
The scientist does not believe in events
without causes, not even when they happen in the
Introspection is the output of the verbalising
By the time sexual reproduction has been
achieved, the main difficulty of evolution is
The brain is merely Nature's latest means of
The goals of a species, such as Homo, are what
natural selection has driven it to.
The species is fundamentally aimless (it finds
its goals as it goes along).
The goals in evolution are what a species has
been forced to.
On Essential Variables
Poor M. Jourdain! He now has to understand that
he has been behaving homeostatically all his life,
when he thought he was merely minding his business.
For two thousand years psychology was a simple
description of Man's highest faculties--most of
which he does not posses.
The scientist does not believe in effects
without causes, not even when they happen in the
That homo has a brain, no more entitles him to
assume he knows how he thinks than possession of a
liver entitles him to assume that he knows how he
A man no more knows how he thinks, just because
he has a brain in his skull, than he knows how he
makes blood, because he has marrow in his bones.
On The Brain
The brain is natures latest and ferocious
instrument of self preservation.
Remember: The brain has no brain inside to
To think is to act--inside the brain.
On the Brain as controller
The brain controls nothing--it transmits.
On Organisation in the Brain
The brain organizes nothing--it acts.
The brain has no gimmick, just five billion
years of research and development.
The brain knows nothing of how it ought to act
it knows only what it does.
The test of a brain is its achievement of a
Note for the sociologist:
The brain uses compulsion throughout.
On the "absolute" Brain
Every brain is also an anti-brain.
On the "brain-like" mechanism
No system is brain like - every system is brain
like - as you please.
Natural selection insists that neuronic
details shall be irrelevant for whole
Natural selection insists that the nature of
the parts shall be irrelevant for the
The neurone is the one unit that, in
psychology, is quite devoid of interest, it is too
small to be visible in the man's action, and too
large to be sufficient in memory.
The neurone is the one unit that, in behaviour,
is quite devoid of interest today it is too small
to be noticeable in a man's action, and too gross
to carry a trace of memory.
No mammal will ever understand the mammalian
The man who talks today of probability in the
brain is usually trying to return to the days when
everything in the brain was so delightfully vague.
On Learning the unforseen
No man knows what to do against the really
All wisdom is wisdom after the event.
When a machine breaks, it changes its
Every system changes its mind by breaking.
The educated brain is the wreckage left after
the experiences of training.
On Adult Adaptation
The adult brain is the wreckage left by the
experiences of childhood.
On Memory: the value of Experience
Don't appoint, as the President's driver, an
Englishman who has spent thirty years learning to
drive on the left.
A system that stores its memories away from
their site of action must do much work remembering
where it put that memory.
There is no memory in the present - only a
state of affairs
On the "brain like" control mechanism
A mechanism is "brain-like" so far as it is
effective: there is nothing more.
The only people who talk today of "real"
intelligence are those who hope to find a meaning
for the adjective later.
Intelligent is as intelligent does.
The drive to equilibrium forces the emergence
That the brain matches its environment is no
more surprising than the matching of the two ends
of a broken stick.
Change the environment to its opposite and
every piece of wisdom becomes the worst of
For every bump of the phrenologist there exists
an environment that demands a depression.
Everyone is World Champion at some game
(although some of the games have not yet been
An Intelligence Test measures the degree to
which Tester and Subject think alike.
Is there a general intelligence? A universal
weapon is as likely.
Every piece of wisdom is the worst folly in the
The test measures only the degree to which
Subject and Composer think alike.
A man can be a pure logician only if it makes
him feel good.
Every skilled dramaticist understands the
inexorable logic of the emotion.
On Artificial Intelligence
He who would design a good brain must first
know how to make a bad one.
Pattern-recognition is a throwing away of
Any device that can lose information can
Deduction is the running-down of a determinate
Newton arrived at F = ma after a part-random
search, the apple arrived at the ground by pure
The general purpose computer is freer than the
Whether a computer can be "really" intelligent
is not a question for the philosophers: they know
nothing about either computers or
Today's digital computer is organized like an
army of a million men that can only get two into
action at a time.
Today's digital computer has a group velocity
that is about a millionth of its wave velocity
It is an open question which has the richer
organization: a living cow or a working silo.
Which biological organization proved more
resistant to the Spaniards: the Aztecs of Mexico or
the jungle of the Amazon?
Can a system be self-organizing? No system can
permanently have the property that it changes
On Requisite Variety
Man adapts by conquering the reducible, the
irreducible is impregnable.
We have broken into the Aladdin's cave of
brain-like mechanisms; we find we can have anything
we like--provided we pay for it!
On Localisation of Memory
Any system that stores its memories away from
the site of action must do much work in remembering
where it has put that memory.
A magician is a man who does not show all that
Every prediction is an operation on the past
A "Genius" is a man who shows the public only
the results of his labours.
To be a thing is to behave in a certain way
when explored with mechanical forces.
No man knows what to do against the purely
A long sequence of symbols each form a ????
On the self-organising system:
• No locomotive can be self-pushing.
• No cat can be self-washing
• No animal can be self-observing
• No man can be self-punishing
Today, those who don't know what "intelligence"
means must give way to those who do.
From every faculty there is an environment that
We cannot read the book of God, only the
Random choice is an abrogated choice.
"Random" means "you do the choosing".
We show only the intelligence there is in the
The computer can do more than the trained
The rule for decision is: Use what you know to
narrow the field as far as possible: after that, do
as you please.
Any system that achieves appropriate selection
(to a degree better than chance) does so as a
consequence of information received.
To recognise a class is to throw away
Some say that a first requirement is that it
shall weigh 45 ounces.
On adapting to a changing world
No system adapts to the changing: it can adapt
only to what is constant.
To speak of human behaviour, and then to speak
of the neuron, is to show that one has not yet
developed a sense of proportion.
Only the environment can design a brain.
On making an artificial brain
Man's brain contains no blue print for brains
against non-human environments.
On the brain's secret
The secret of the mammalian brain is that it
has long and slavishly fashioned itself to its
To refer to the head-ganglion of Homo sapiens
as "Man's brain" is to appeal to our lowest
Only the incorrigibly sentimental speak of
"Man's brain". Those who wish to stay clean -
headed speak of the "head ganglion of Homo
The liver is the brain of the inner world.
Brain to the inner world is the liver.
On the ethics of a system
A computer knows no ethics, only its set
It is only within the memory of living men that
psychology turned from studying how man ought to
think, to how he does actually think.
Any gibbon, as it throws itself on parabolic
arcs from branch to branch, demonstrates its
knowledge of Newtonian dynamics.
What Homo knows at any moment, of the actual
future is absolutely nothing.
As every machine goes to equilibrium, it
Functionally, the behaviour is the brain.
"Help one another" is the selfishness of the
"Logic" and "logical" are so degraded today
that they convey no useful information. They are
still used chiefly because they look well, either
by the **** or by the unthinking
Every dynamic system has its preferred modes of
vibration, perhaps simple, perhaps complex.
Rhapsodise as you will, a law of nature is just
Instincts of Homo
This species is peculiar in that members make
an ever-increasing habit of attacking and
exterminating weaker groups of their own species.
On the evolution of Homo sapiens
For ninety nine hundredths of this time (before
any traces of town dwelling) he improved chiefly in
his efficiency in killing big game and other
branches of his own species.
The specially human part of the brain has been
evolved for the chase and for tribal warfare. The
final evolution allowed armies of continental size
to massacre on a continental scale.
Every one of the faculties boasted of by Man
can become a humiliating or fatal embarrassment
when the environment is not the usual type.
The man who speaks today of free will is merely
a ***** confusionist
The man who talks of free will in the 60's is
trying to pump fog into a situation that he fears
Man can remember only those things that natural
selection has arranged that he should.
A concept is that which survives, is
stable under a sequence of operations
The brain takes information from where it is
useless and moves it to where it is useful.
The heart is a mechanical pump - love lies
elsewhere- the brain is an information -
When the brain is a convection channel it is as
selfish as the heart is unfeeling, when it
In the 60's, to introduce the topic of ???? is to
introduce fog into a clarifying situation.
The application of quantitative methods to the
brain will squeeze the remaining superstitions from
our ideas about it.
The whole function of the brain is summed up in
As God has to monitor his actions*, so must the
brain monitor it. *And he saw the light that it was
On decision processes
The brain decides nothing - it acts
Of what use is the brain? - "To think with" is
to reveal oneself as mediaeval and pre-Darwinian.
On the mystery of the brain
"But that", said Mr Hick contemptuously, "can't
be the explanation - there's no mystery in it."
On the laws of thought
The machine that can produce all trajectories
has no laws.
The product set has no constraints.
On Brain processes
Life-processes (in species or brains) use only
the additive methods - for the combinatorial there
has not been time enough.
In this universe, the life-time of a planet is
only sufficient to allow its evolved life-form to
explore the possibilities of additive adaptation.
On adaptation as a whole to a whole
All our adaptations are collections of nearly
independent bits life is too short to alow us to
explore the really holistic.
On Man's God-like intelligence
Intelligence is a specialisation to the
environment that is (?) complexly / aggregately.
An organism should be as intelligent as its
environment- no more, no less.
Every mechanism generates improbabilities (Not
only natural selection).
Among systems in a net, the struggle for
existence is inevitable.
The law of the brain is : What will be, will
On long-term planning in the brain: Man's
ability to plan
The brain is wholly opportunist, no less when
it proposes a long term plan.
On Progress in adaptation
A brain can improve till it fits in its
Organisation exists mostly in the eye of the
The brain knows only the present and what it
can construct from the present.
Man lives by surviving.
Which showed the best power of survival when
attacked by the Spaniards: that bio-organisation
calle the Amazon jungle: or that bio-organisation
called the Aztecs?
Which out-fought the Spaniards - the Aztec
civil organisation, or that bio-organisation called
the Amazon Jungle ?
The digital computer of today is like a
centipede with a million legs, each of which can go
forward in a microsecond but as it can move only
one pair at a time the whole animal is easily
outrun by the tortoise
When we take the ordinates of a wave function
and use them to compute their exact values a moment
later, we are (1) demonstrating that the science of
quantum physics use determinate systems. (2)
treats the system as determinate.
Every operation seeks the state that makes it
A "machine" is a shadow of simple
"The time it takes increases exponentially" is
a mathematical way of saying it can't be done.
If my sympathy with another's sufferings proves
the reality of the other's feelings then the
pattern of light and shade that I call a "weeping
heroine" on the cinema screen is genuinely feeling.
A man can report what happens in his brain only
so far as the events reach the verbalising
Every dramatist knows the inexorable logic of
Disorder never proceeds to order so milk can
never separate into buttermilk and cream.
On the subjective
How to test whether you're dreaming - kick the
fellow in front of you and see who feels the
I am therefore I think.
On error controlled servo
The error controlled servo - mechanism is a
brain without eyes.
Whatever vibrates is a musical instrument:
whatever is stable is a mechanical brain - the
difficulty lies in making a particular one.
Is your life achieving the full potentialities
of carbon ?
John Ashby writes "Some checking remains to be
completed". The source is Ross Ashby's hand-written
card index. Some ambiguities and near duplicates remain.