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posted on April 25, 2022 | General Stories
A Cybernetic View of Stone Sculpting

I modified this
story from an earlier version

published in a scientific journal, Cybernetics
and Human Knowing
, in 2009.  Cybernetics is the
study of how complex systems use information to
themselves. Here I portray sculpting in
that light, somewhat enlarged and
more fully illustrated
than before.

The linguistic challenges
of describing what paintings, drawings,
and photographs can illustrate inspired the
saying that “a picture is worth a thousand words”.
In scarcely more words than that, I will describe
what it is like to create 3D sculptural forms in
stone by movements of my body,
by the tools
of that trade and
informed in several

I discuss
only a
few issues here,
each of them pointing to
cybernetic nature of sculpting as a

human activity.  Given that objective, I
emphasize the actions through which
sculptures evolve, and not just the
static “statues” them-

Sculptures are
the frozen endpoints of long,

complex generative processes, and
we need to think about how
they come to be.

Some component
actions are well-understood physical
and physiological mechanisms.  How muscles
and tools work.  Physical qualities of
stone.  Safety factors, and
so on.

Other components,
like artistic imagination and
creativity, are far from understood.
Yet we must recognize their importance
and imagine how they function in
sculpting as a whole.


Perceiving Form

An effective aid to
visualization of 3D form is to run
your fingers over the surfaces of sculptures.
Gently and sensitively, everywhere and
in all directions, touching with
your eyes closed.

that builds correctly scaled forms
into your body, mind, and imagination.
That also happens during sculpting, and
the size and shape of the stone changes
Even imagining
sculptures in this
does that.

Form is the
of contact
with stone.


Listening to the Wind
is 45 inches tall.  I carved it in
banded green sedimentary mudstone.  It
rests in a lovely green garden bower in all
seasons and all kinds of weather.

Heart of Anima
is a smaller indoor sculpture
of igneous basalt, 19
inches high.

Sculpting Stone

the whole, integrated
phenomenon of sculpting
those stones.

To begin,
think of them simply as
stones, each
having evolved
through natural erosive action, much
as other stones do, then through
the active,
intentional agency
of a human body and

of what these stones may
remind you of, or what you think
they may represent to the sculptor, regard
them simply as forms, and imagine how
the action of carving them might
have unfolded.

In that light,
notice a
 similarity between
these particular sculptures.  In both
finished forms, surfaces
swoop smoothly
through space, and intersections between
them are similarly-swooping curves
that hold the surfaces in place
in perception

Another similarity is
that the slightly
earlier versions,
lighted only by fields of laser light, are
not yet smooth
at the finest scales. Over broad
regions of gently changing
form, they are al-
ready smooth.  But at the far finer scale of
surface  texture, they are still rough,
complex, and chaotic

If you examine the
images closely, you will
some of that roughness
as local
irregularities in the
of the
laser lines.

When I first
encountered those stones
they were boulders.  Now they
are works of art. What happened?
What processes unfolded
during their evo-

I will address
this question indirectly, by
describing what it is like to use two
very different methods of shaping stone.
By the definition of subtractive sculpting,
both methods are destructive.  
They make
rocks smaller by removing parts of them,
and that is the fundamental operation
in carving stone, wood, or
soap, regardless of the

One method
disrupts the crystalline
structure of the stone, crumbling
it violently into sand, dust, and gravel.
The other rubs it away slowly, gently,
even sensuously, and removes
only dust
or mud.

and its close cousin eroticism
depend on meanings we find in
forms, and on actions through which
we form them.  In that sense,
we can say
that those meanings guide the actions
that produce the forms.  We can
also say that the actions
produce meanings.

reinforce each other,
iteratively and recursively,
during the work. 
Here I
just want you to
imagine the



Utility companies
use jackhammers to break up
roadways and sidewalks.  
pneumatic hammers are smaller
and carve stone, b
ut basically
they are the same.  

Hammers come in
a range of sizes, remove 
stone in each cycle of action than
jackhammers, and afford far
control of the tool.

Compressed air sends
a piston forcefully forward.  It
strikes a metal chisel held loosely in
the snout of the hammer, the chisel leaps
forward, collides with the stone, and
bounces back to contact the
piston, several times
a second.

A bushing tool is
one of many types of chisels.  It
presents 4, 9, 16, or more sharp, pyramidal
points of tungsten carbide to the stone with each
strike, carrying the momentum of the metal
tool and leaving up to that
many craters.

A tool bounces
violently against a surface,
pointed straight in, rotating freely
about its axis.  Collisions knock the high
parts down, pushing the surface inward,
toward simplicity and integration in
the cases we will consider here.

A heavy bushing
tool in a big pneumatic hammer, used
with much air at high pressure, can degrade
granite quickly but without much precision. It
can also jar the body that guides it and cause
unplanned fractures in the stone, so it
pays to use it sensitively.

To give you a
sense of the destructive
power of these tools, that big
4-point bushing tool in the picture

is about 2 cm square at the face. It
concentrates a lot of force onto
those four points,
and the
hammer kicks like
a horse.

At the other end
of the spectrum, tiny, many-
pointed bushing tools in
tiny hammers,
used with little air, lightly frost
finished surfaces.  Used
enough, they do almost
nothing to the


can such
violent methods
such gentle forms?

When used to accomplish
what I call integrating or resolving
form, bushing tools pound down parts that
are “high”, relative to ideal, imaginary surfaces
that lie beneath the surface, and don’t touch those
that are “low”.   
In subtractive sculpting, getting
rid of low places means pounding every-
thing else down to that level,
which is a drag and a

How anyone can
imagine forms like these, sometimes
wholly without specific reference to objects
in the real world, is beyond our scope here.  It
is also beyond my understanding, though
I have experienced it every day of
my life and so have you.

However we do
it, “seeing” differences
between real and imaginary
surfaces identifies high places
and tells sculptors what
to take away.


Aids to Visualization
of Form

Rembrandt used
strong directional lighting
in paintings, chiaroscuro,
to emphasize
the orientation and curvature of surfaces
and illustrate texture.  That kind of lighting
is a common aid for artists, wild
animals, and other beings.

sculptures for the blind
remind us of the power of  fingertips
to make the shapes of the world real for
us.  His insights into the power of reflections
from highly integrated, highly reflective
surfaces to expand the perceptual
and emotional sizes  of  sculpt-
ures  are 

The structured laser lighting
illustrated just
below is a sensitive diag-
nostic tool.  It reveals form especially effectively
when objects rotate in the light, when the
light scans across them, or when obser-
vers move relative to the forms
and to the sources of


In those first figures,
Listening to the Wind
Heart of Anima are nearly finished.
But close inspection of the images
reveals remaining irregu-
larities in both pieces.

In this detail of
Listening to the Wind, you
see a small set of grooves left by
a rasp.  Once identified as a local
roughness by that and other
methods, it was easy to


Tools as
Probes for Information

Pneumatic hammers
are not just agents of erosion,
but rich sources of at least three kinds
of information about form.  Each of
them is invaluable to sculptors
as they work.

This is
the essence of


First, by maintaining
a constant average distance between a
sculptor’s body and a stone, pneumatic hammers
function as compressible sensory appendages.
They are sensitive probes that “measure”
surfaces, mapping them out in
sculptors’ minds.

Pneumatic hammers
are two-handed implements that
take many
muscle groups to control.  These
remembered patterns of contact between tool and
stone engage sculptors’ entire bodies and minds.
All of this happens as surfaces recede,
changing shape under the
rain of blows

Second, as long as
the bushing tool strikes normal
to the surface and the surface is flat,
all points strike simultaneously, produce
equal craters, and the tool bounces
straight back into the

A surface normal
at any point on a surface is a vector
perpendicular to the tangent plane at that point.
Always, it is directed “straight in” or “straight out”.
Sets of normals representing entire surfaces
as arrows pointing in or out are called
vector fields of normals.

Otherwise, only
some points strike the stone.
They make fewer, deeper craters,
and the process sounds and
feels quite different.

Attending to
sensations like these informs
slight adjustments of angle in real time,
maintaining the relationship between the
tool and the stone and keeping the
work going in a sensitively
controlled way.

And, because the tool
must keep moving over the surface of
the stone to keep it from digging in, its shifting
position and orientation are sensitive measures of
variation in the curvature of the surface.  That
engages the entire body in sensing,
mapping, and changing
the form in real

A third source
of information follows from the
fact that normals and tangents are per-
pendicular at every point. Those measures
are interconvertible mathematically, but
they mean different things to sculptors
and we experience them

A vector field of
normals is the set of directions
from which we “push” stone surfaces
inward.  A field of tangents, fused into
a dynamically changing sense of form, is
a perceptual tension that unifies dif-
ferent parts of surfaces and
resists the pushing.

Given the richness
and immediacy of these bodily-felt
images, the details of carving collapse
experientially into unbroken series
of actions that “push” surfaces
inward to meet their

We don’t need
to think about any of
that to do it.


Abrasion happens when
hard, rough materials slide over softer
ones under inward, normally-directed pressure.
The harder and sharper the abrasive and the greater
the pressure, the deeper the scratches it leaves. The
faster it moves, the more stone it removes
and the more quickly the
work proceeds.

Anyone who has
sanded furniture is aware of the
effort of scratching away hard material with
rough pieces of paper, and may have experienced
the wasted effort of using fine abrasives to
impart a polish before removing
coarse scratches.

Abrasives of
appropriate stiffness bridge across
low places and plane away the high, averaging
out local variation in topography and integrating whole
surfaces into unified perceptual wholes. This planing away
of promontories is an automatic result of stiffness that
requires no conscious thought other than to
select an appropriate backing.

The principle is
the same with curved stone as
with flat wood: to remove coarse scratches
by making successively finer ones until they
disappear, then possibly continuing to
the limits of the technology.

The harder the
parent material, the finer the
scratches it can hold and the higher
the polish it can take.

The finest scratches in
my polished Heart of Anima sculpture,
in basalt, are less than a thousandth the width of
the coarsest ones through which I did the final
shaping – – they are much finer than can
be seen without magnification.

If a surface
is ready for it, each succeeding
stage of abrasion takes less time and
effort than the one before, but it takes
inordinately more effort if the
surface is not ready.

I spent at least three
full weeks sanding Heart of Anima
at the coarsest stages of abrasion, when
I was still shaping, and less than a day
at the finest stage when I was
only polishing.

Crafting forms like these
by hand-powered, hand-directed
abrasion requires sculptors to “move” the
forms they create into being, as if dancing with
figments of their own imagination. Since abrasives
slide over surfaces, this would be a trivial insight
if the objective were just to smooth surfaces,
but it is not.  The objective is to
change their shapes.

This means removing
more material from some places
than others.  In turn, it means
modulating the process.

The relevant
variables, given the nature of the
abrasive and the stone, are velocity and
pressure at any moment and frequency of
abrading any portion of surface.  Each
of those variables can be varied
continuously by

Those factors
determine how fast abrasion
removes stone, but consider the pattern
of action that removes it. As with percussion,
abrading stone is rich with information about
form. In both cases, using that infor-
mation makes the action

As with percussion,
three kinds of information
are especially important.


“rubbing on rocks”
with sandpaper affords a direct,
bodily-felt sense of form.  This is the
integrated locus of contact.  This is exactly
what happens with bushing tools, but
from closer contact and much
more precisely.

Doing this
engages entire bodies, minds,
and imaginations in several ways.
I often lose conscious awareness
of anything but the

Sometimes, even the
stone disappears from view and
only form and movement exist
for me.  That experience
is sublime.

performing the unbroken
series of acts of sculpting feel curvature
during each and every stroke.  They feel it as
patterns of velocities and accelerations of
their fingers, hands, arms, and other
body parts, in relation to each
other and to the stone.

Humans and
many other species are acutely
sensitive to kinesthetic measures like these.
It’s how we keep our balance when we walk,
how we grasp, hit the ball when we swing,
and get our forks in our mouths instead
our lips.  It affects how animals fare
in encounters, whether they
are predators or prey.

to our bodies speak to us
in that way while we work helps
us discover and correct irregularities
of curvature that are invisible
under all but the best


During the week of my
40th birthday, in late February 1982, I
made a commitment:  to behave as if sculpting
were my life’s work. I was fully occupied in research
at the time, and my work in education had not yet
begun to peak.  Starting then, I applied the same
sense of purpose in sculpting as well, and
that made all the difference.

What did
doing that entail?

For one thing,
committing to work at sculpting
and not just play with it committed me to reflect
more mindfully on my own sculpting practice.
That helped me see sculpting as a complex,
interconnected, cybernetic system worthy
of my interest in its own right, just
because it is so interesting.

It also helped
me sculpt more

Becoming more aware and
mindful made me even more aware,
recursively. It helped me experience sculpting
more vividly, and with a greater sense of
presence than before. Being more
mindful itself made the
sculpting better.

Since the very
moment of that commitment, I’ve
been intensely aware of the process of sculpting,
while I sculpt.  I reflect often on the complexity,
the connectivity, and the multidimension-
ality among the component processes
of sculpting, whether or not I am
sculpting at the moment.

Gradually, I
learned literally to “feel” how
the work was going.  Particularly
important was to learn to feel connections
between my ongoing physical and
mental experience and what
that does to the stone.

Driven by
the power of
sculpting is now part of me;
it is
of my bones and
in my bones.


I owe much to
Humberto Maturana for the
perspective I take here, most of it gained
in workshops and personal conversations over
a 25-year period.  Though I read what he wrote,
his most important influence on my thinking
was always through relationships
between his spoken word and
his body language.

He was a
great storyteller.

Given my
emphasis on the physicality
of sculpting here, it seems especially
appropriate that Maturana’s ideas
have perturb my understanding
in such physical

In the published
version of this article, I
thanked journal editor Pille Bunnell
for inviting me to be the featured artist
for an issue of Cybernetics and Human Knowing,
and to write the article.  She also allowed me
to write
in more experiential than scholarly
voice and
to not worry about the
cybernetic literature.

At the same time,
she was also an
valuable coach on
the language and
concepts of cybernetics. And as
had been for me before, she was

a brilliant editor.

I still thank Pille
for all those things.

Edited August 2022

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