The Act of Creation (95 page)

 

 

The main distinguishing features of associative and bisociative thought
may now be summed up, somewhat brutally, as follows:

Habit                              Originality
Association within the confines    Bisociation of independent
of a given matrix                  matrices
Guidance by pre-conscious or       Guidance by sub-conscious
extra-conscious processes          processes normally under restraint
Dynamic equilibrium                Activation of regenerative
potentials
Rigid to flexible variations       Super-flexibility
on a theme                         (reculer pour mieux sauter)
Repetitiveness                     Novelty
Conservative                       Destructive-Constructive

 

And thus we are back where we left off in the first book; the circle
is closed.

 

 

 

 

 

APPENDIX I:
ON LOADSTONES AND AMBER
I have compared (Book One,
X
) the constructive
periods in the evolution of science to river-estuaries in which previously
separate branches of knowledge merge in a series of bisociative acts. The
present appendix is meant to illustrate the process by a few salient
episodes from the history of magnetism and electricity -- two fields of
study which, until the beginning of the nineteenth century, had developed
on independent lines, and seemed to be in no way related. Their merging
was due to the discovery of unitary laws of a previously unsuspected
kind underlying the variety of phenomena, and took physics a decisive
step forward towards a universal synthesis.

 

 

 

The Greeks, fortunately perhaps, had not paid much attention to the
antics of loadstones and amber; they had shrugged them off as freak
phenomena. Aristotle had hardly anything to say about them -- had
he laid down the law on magnetism and electricity, as he did in other
domains of physics, the story might have been different. As it happened,
both sciences started from scratch in the seventeenth century; just at
a time when scholasticism had to yield to the empirical approach. This
smoothed their path of progress -- but even so, progress was neither
smooth nor continuous.

 

 

Apart from some casual references in earlier sources, the first landmark
in the history of magnetism in Europe is a manuscript, dated 1269, by
a French crusader, Petrus Peregrinus from Picardy. It gives a detailed
description of two types of mariner's compass (which apparently had been
in use for at least a century): a magnetized needle either floating on
a stick in a bowl of water, or turning on a vertical axle. Peregrine
further described his experiments with a spherical loadstone which he had
fashioned, defining its poles and the attractive and repellent properties
of its surface; yet he shared the contemporary belief that the source of
the 'virtue' which attracted the compass needle was located in the sky --
in the Polar Star or the Great Bear.

 

 

During the next three hundred years no further progress seems to have
been made -- except for some improvements of the compass and attempts
to measure magnetic declination, caused by the puzzling discovery that
the direction of the needle deviated at different places to different
degrees from the direction of the Polar Star.

 

 

The next landmark is Dr. William Gilbert of Colchester, court physician
to Queen Elizabeth, the first great English experimentalist. Gilbert
put both magnetism and electricity on the map -- or rather, on two
separate maps; his influence on his younger contemporaries, Kepler
and Galileo, was enormous. Gilbert's fundamental discovery -- in fact
the only important discovery made in the whole history of magnetism as
an independent science -- is again one of those which, in retrospect,
appear deceptively simple. He found that the power which attracted the
magnetic needle was not in the skies but in the earth: that the earth
itself was a huge spherical loadstone. He arrived at this conclusion by
making, as Peregrine had done, a spherical magnet, and exploring the
behaviour of a minute compass-needle on its surface. As he moved the
needle over his globe, he saw that it behaved exactly as the needle of
the mariner's compass behaved on a sea journey -- both with regard to its
north-south alignment and to its 'dip', which increased the closer the
needle approached either of the poles. He concluded that his spherical
loadstone was a model of the earth which therefore must be a magnet.*
So the secret of the compass-needle was solved by ascribing magnetic
properties to the earth -- there remained only the secret of the nature of
magnetism itself. Gilbert's book,
De Magnete
, was published
A.D. 1600 -- the same year in which Kepler joined forces with Tycho
de Brahe to lay the foundations of the new astronomy; the symbolic year
which, like a watershed, divides medieval from modern philosophy. Gilbert,
born in 1544, stood, like Kepler, astride the watershed: with one
foot in the brave new world of experimental science, the other stuck in
Aristotelian animism. His descriptions of how magnetism works are modern;
his explanations of its causes are medieval: he regards the magnetic
force as a living emanation from the spirit or soul of the loadstone. The
earth, being a giant loadstone, also has a soul -- its magnetic virtue --
and so have the heavenly bodies.

Magnetic force is animate, or imitates the soul; and in many things
surpasses the human soul while this is bound up in the organic
body.' [1] The actions of the magnetic virtue are 'without error
. . . quick, definite, constant, directive, motive, imperant, harmonious
. . . it reaches out like an arm clasping round the attracted body
and drawing it to itself. . . . It must needs be light and spiritual
so as to enter the iron' -- but it must also be a material, subtle
vapour, an ether or effluvium. Even the earth's rotation is somehow
connected with magnetism: 'In order that the Earth may not perish in
various ways, and be brought from confusion, she turns herself about
by magnetic and primary virtue. [2]

Thus Gilbert's book, which enjoyed uncontested authority for the next
two hundred years, postulated on the one hand action at a distance,
but asserted on the other the existence of an effluvium or ether which
passes 'like a breath' between the attracting bodies. It was also a
major factor in creating semantic confusion: the word 'magnetism',
which originally referred to the properties of a type of ore mined in
Magnesia, a province of Thessaly, came soon to be applied to any kind of
attraction or affinity, physical, psychological, or metaphorical ('animal
magnetism', 'Mesmerism', etc.). But as long as the study of the behaviour
of magnets remained an isolated field of research, no further progress
could be made. In 1621 van Helmont, and in 1641 Athanasius Kircher,
published books on the subject which added nothing new to it, but dwelt
at length on the alleged wound-healing properties of magnets; Kircher's
book carried a whole section on the 'magnetism' of love, and ended with
the dictum that the Lord is the magnet of the universe. Newton took no
interest in magnetism except for some remarks in the third book of the
"Principias" [3] to the effect that the magnetic force seemed to vary
approximately with the inverse cube of the distance; while Descartes
extended his theory of cosmic vortices to cover both magnetic and
electric phenomena. The main subjects of interest were the variations
in the positions of the earth's magnetic poles which, to the navigators'
distress, were found to wander around like floating kidneys. This led to
the kind of controversy characteristic of most periods of stagnation in
the history of science; thus one Henry Bond of London town, a 'Teacher
of Navigation', published in 1676 a book,
The Longitude Found
,
based on the theory that the magnetic poles lagged behind the earth's
daily rotation. This thesis was torn to pieces in another book,
The
Longitude Not Found
, by Peter Blackborough.
Even the great Halley went haywire where magnetism. was concerned:
he proposed that the earth was a kind of solar system in miniature,
with an inner core and an outer shell, both of them magnetized, and a
luminous fluid between them to provide light for the people living on the
surface of the inner core; this luminous effluvium escaping through the
earth's pores gave rise to the aurora borealis. Halley was the greatest
astronomer and one of the leading scientific minds of the age, who
had published the first modern magnetic chart in Mercator's projection,
based on his own patient observations; but his wild speculations indicate
that the element of the fantastic was firmly embedded in the concept of
magnetism -- as it still is in our day. Children are still fascinated by
compasses and magnets, governed by a force more mysterious than gravity --
because the latter is taken for granted from earliest experience whereas
magnetism cannot be sensed, and not only attracts but also repels. No
wonder that this unique phenomenon, while considered in isolation,
had led those who studied it round in circles in a blocked matrix.
But although, for nearly two centuries, the study of magnetism made no
progress, Gilbert's work had a fertile influence on other branches of
science. The loadstone became the archetype of action-at-a-distance,
and paved the way for the recognition of universal gravity. Without
the demonstrable phenomena of magnetic attraction, people would have
been even more reluctant to exchange the traditional view that heavy
bodies tended towards the centre of the universe, for the implausible
suggestion that all heavenly and earthly bodies were tugging at each other
'with ghostly fingers' across empty space. Even the magic properties
attributed to magnetism, and the very ambiguity of its concept, proved
to be unexpectedly stimulating to the tortuous line of advance which
led via Mesmerism and hypnosis to contemporary forms of psychiatry.
The next turning point is Coulomb's discovery, in 1785, that the inverse
square law applied to magnetism too, as it applied to gravity. It must
have looked at the time as if these two kinds of action-at-a-distance
would soon turn out to be based on the same principle -- as Kepler and
Descartes thought they were; as if a great merger ofsciences were in the
offing. But that synthesis is still a matter of the future; instead of
merging with gravity, magnetism entered into a much less obvious union
with electricity.
The first mention of electricity on record occurs in the fragments
of the
History of Physics
by Theophrastus, the successor of
Aristotle at the head of the Athenean Lyceum. He innocently remarks
that when amber is rubbed it acquires the curious virtue of attracting
flimsy objects. The Greek word for amber is
elektron
. Although the
Greeks were not interested in the elektron's virtues, "Forever Amber"
would be an appropriate motto for modern science.
For two thousand years little more is heard of electricity, until we
again come to Dr. Gilbert, who demonstrated that the peculiar properties
of amber were shared by glass, sulphur, crystals, resin, and a number
of other substances, which he accordingly called 'electrics'. To account
for electric attraction he created the concept of an electric effluvium,
as distinct from the magnetic effluvium -- but with an equally lasting
influence on further developments.
During the next century, advance again was slow. Members of the Italian
Academia del Cimento (a short-lived forerunner of the Royal Society)
continued Gilbert's experiments, and added a few observations to
them. The main events of the century were the discovery of electric
repulsion and the construction, by Guericke, of the first machine for
the continuous production of electricity. The machine consisted of
a sulphur ball, the size of a child's head, which was rotated on an
axle while the experimenter's hand was pressed against its surface,
thus generating a frictional charge. Guericke also discovered, and
described, the phenomena of electrical conduction and induction --
but nobody paid any attention to them, and they had to be rediscovered
in the next century. This illustration of discontinuity in progress was
followed, almost immediately, by yet another one. In the first years of
the eighteenth century an Englishman, Hawkesbee, invented a new machine
to produce electricity by replacing Guericke's sulphur sphere with one of
glass -- which was a vast improvement, but again passed unnoticed. The
glass-friction machine was re-invented and improved in the 1740s;
the sphere was replaced by a cylinder, pads were used instead of the
hand, and the machine was equipped with insulated wire conductors -- the
conductivity of metal having been meanwhile discovered by Gray and Du Fay,
who also made the basic distinction between conductors and insulators.
The fact that the electric virtue produced by this machine could be
carried by wires over distances of hundreds of feet led to the concept
of a flow or
current
-- the electric effluvium was now regarded
as a kind of liquid, or liquid fire, flowing through the wire. But the
phenomena of electric repulsion led Du Fay to assume two kinds of electrio
fluid -- like kinds repelling, unlike kinds attracting each other, on the
analogy of magnetic poles. Benjamin Franklin did not like the idea of two
fluids; he believed that the polarity could be explained by a surplus or
a deficiency of a single fluid, designated by a plus and a minus sign --
a rather unhappy suggestion which, to this day, is apt to confuse the
minds of hopeful students. A further complication arose from the fact that
while the electric fluid was demonstrably unable to flow across insulating
substances such as glass or air, it nevertheless induced electric charges
on the other side of the insulator; so one now had to assume that there
were two kinds of electricity: the first a fluid running through a wire,
the second an etheric effluvium acting at a distance.
Thus by the middle of the eighteenth century the whole science was in a
state of confused and creative anarchy -- as cosmology and mechanics had
been a hundred years earlier, before Newton. 'We cannot follow the twists
of theory in the minds of these men', Pledge wrote about Franklin and
his contemoraries [4]; yet they went happily ahead, theorizing in dirty
kitchens and experimenting with kites, lightning rods, luminous discharges
in vacuum tubes, detonating inflammable spirits, electrocuting birds,
mice, and occasionally themselves. I have mentioned before (p. 204) the
sensation created by the discovery of the condenser in the shape of the
Leyden Jar -- due to accidental shock; a few years later, the expression
'an electrifying effect' had already gone into metaphorical use. According
to the "Oxford Dictionary", armies were the first to be 'electrified'
-- by courage (Burke); theatre audiences came next (Emerson). Typical of
the happy confusion was Gray's theory, which he confined to the secretary
of the Royal Society on the day before his death, that the planets were
moved round the sun by a simple electric force. To demonstrate this, a
small pendulum weight was held on a string over an electrically charged
globe, and lo! the weight began to describe circles and ellipses round
the globe, always in the correct direction from west to east -- due,
of course, as was later proved, to small unconscious jerks which the
experimenter imparted to the string.
The first indirect intimation of the shape of things to come was
the demonstration (around 1780) by Cavendish and Coulomb that the
action-at-a-distance type of electricity (i.e. the electrostatic field)
was governed by the same inverse square law as magnetism and gravity.
Thus mathematics entered into the study of electricity and magnetism,
although their physical nature was anybody's guess. The mathematical
tools were ready, in the shape of differential equations which French
mathematicians of the eighteenth century -- Lagrange, Laplace, Legendre
-- had worked out for gravity and mechanics; then Poisson lifted the
basic equations of the gravitational potential out of their original
frame of reference, and applied them first to the electrostatic, then to
the magnetic field. He was able to import these rules of the game from a
foreign playing-field by the bold move of substituting 'electric charge'
and 'magnetic pole strength' for 'gravitational mass' in the equation --
and it worked. Newton's inverse square law, Lagrange's and Poisson's
equations, were among the first striking instances revealing the unity
of mathematical laws underlying the diversity of phenomena.
In the meantime, Luigi Galvani, Professor of Anatomy at the University
of Bologna, had spent some fifteen years working on a theory of
'animal electricity'. On September 20th, 1786, he recorded one of his
experiments, which was to make history. He attached a nerve-muscle
preparation of a dissected frog to a copper hook and hung the hook
on an iron railing. Whenever one of the frog's legs touched the iron,
it jerked away and contracted violently. Now it was already known that
electric discharges from Leyden Jars or lightning rods caused muscles to
contract; but since the iron railing could not be a source of electricity,
Galvani drew the logical conclusion that the electricity which caused the
contraction was generated in the muscle itself under the stimulus of the
metallic contact. Like so many neat and logical deductions it happened to
be wrong; but it was an error which proved to be as immensely fruitful as
Columbus' or Kepler's errors. The muscle convulsion had indeed been an
electrical phenomenon; however, as Volta was soon to prove, the current
had been generated not inside the muscle but by the contact of the two
different metals, copper and iron -- the prototype of the Voltaic battery
(the frog's leg touching the railing closed the circuit). Galvani's
theory had been a wrong move in the right direction, for the experiment
did demonstrate the sensitivity of certain living tissues to
minute electric currents; after a few decades of the usual detours,
Sömmering compared nerves to electrical telegraph wires; and from the
middle of the nineteenth century onwards electric phenomena played an
increasing part in physiology, until finally the electro-chemisty of
living tissues became a single, integrated matrix.