Associative skills, on the other hand, even of the sophisticated kind which require a high degree of concentration, do not display the above features. Their biological equivalents are the activities of the organism while in a state of dynamic equilibrium with the environment -- as distinct from the more spectacular manifestations of its regenerative potentials. The skills of reasoning rely on habit, governed by well-established rules of the game; the 'reasonable person' -- used as a standard norm in English common law -- is level-headed instead of multi-level-headed; adaptive and not destructive; an enlightened conservative, not a revolutionary; willing to learn under proper guidance, but unable to be guided by his dreams.
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 o
n 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 contr
acted 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.
In the domain of inanimate matter, the Voltaic battery, inspired by Galvani's frogs, led to a parallel synthesis of electricity and chemistry. The battery gave the experimenters for the first time ample supplies of electric current -- which neither the friction machines nor the Leyden Jar had been able to do. It taught them not only that the chemical interaction of metals produced electricity; but also that an electric current sent through certain chemicals led to their decomposition. In 1806 Davy tentatively suggested that chemical affinity had an electrical basis. But nearly a century had to pass until, in 1897, Thompson discovered that a certain type of electrical discharge -- the so-called cathode rays -- consisted of particles smaller than atoms; and that in these particles 'matter derived from different sources such as hydrogen, oxygen, etc. -- is one and the same kind, this matter being the substance from which the chemical elements are built up'. [5] Thompson's 'elementary corpuscles' were later named 'electrons'.