Cover image for Critical mass : how one thing leads to another
Critical mass : how one thing leads to another
Ball, Philip, 1962-
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First American edition.
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New York : Farrar, Straus and Giroux, [2004]

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520 pages : illustrations ; 24 cm
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HM585 .B35 2004 Adult Non-Fiction Non-Fiction Area

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Are there any "laws of nature" that influence the ways in which humans behave and organize themselves? In the seventeenth century, tired of the civil war ravaging England, Thomas Hobbes decided that he would work out what kind of government was needed for a stable society. His approach was based not on utopian wishful thinking but rather on Galileo's mechanics to construct a theory of government from first principles. His solution is unappealing to today's society, yet Hobbes had sparked a new way of thinking about human behavior in looking for the "scientific" rules of society. Adam Smith, Immanuel Kant, Auguste Comte, and John Stuart Mill pursued this idea from different political perspectives. Little by little, however, social and political philosophy abandoned a "scientific" approach. Today, physics is enjoying a revival in the social, political and economic sciences. Ball shows how much we can understand of human behavior when we cease to try to predict and analyze the behavior of individuals and instead look to the impact of individual decisions-whether in circumstances of cooperation or conflict-can have on our laws, institutions and customs. Lively and compelling, Critical Mass is the first book to bring these new ideas together and to show how they fit within the broader historical context of a rational search for better ways to live.

Author Notes

Philip Ball majored in chemistry at the University of Oxford and received a Ph.D. in physics from the University of Bristol. He is now a writer and consulting editor for Nature

Reviews 4

Publisher's Weekly Review

Ball (an NBCC award finalist for Bright Earth) enthusiastically demonstrates how the application of the laws of modern physics to the social sciences can greatly enrich our understanding of the laws of human behavior: we can, he says, make predictions about society without negating the individual's free will. He opens his lucid and compelling study with an account of Thomas Hobbes's mechanistic political philosophy and shows how Adam Smith, Kant, Auguste Comte and John Stuart Mill expanded on Hobbes's scientific but anti-utopian theories of government and society. Ball notes a return to such a scientific view of the social sciences in the past two decades, and he examines the application of physical laws to economics, politics, even the inevitable synchronization of a theater audience's applause. First, he exhaustively details the development of key concepts in contemporary physics, such as self-organization, phase transitions, flocking behavior, chaos, bifurcation points, preferential attachment networks and evolutionary game theory. Next, he shows how social scientists apply these concepts to the study of human organization. Ball's primary assertion is that we must attend to the relationship between global phenomena and local actions. In other words, noticing the impact of individual decisions on laws and institutions is more worthwhile than trying to predict the behavior of individuals (as Ball's discussion of the logic of voting habits makes all too clear). Ball's carefully argued disagreements with conventional economic theory make for particularly engaging reading. Nonspecialist readers who enjoy a steep learning curve will relish the thought-provoking discussions Ball provides. Photos, illus. Agent, Russ Galen. (June) (c) Copyright PWxyz, LLC. All rights reserved

Choice Review

This delightful, readable book draws analogies and bridges gaps between laws of physics and human behavior. Science writer Ball explains how scientific studies prove useful in increasing understanding of issues in social science, using mathematics (like statistics) to simulate human behavior. A large variety of interesting topics are covered, among which are crowd movements, optimum positioning of walkways among buildings, design of museum display rooms, control of urban systems and the physics of traffic, "the wave" in stadium crowds, and rhythmic clapping prevalent in many Eastern European countries. He usually starts with an explanation of the science underlying the analogy and then investigates such topics as the ways in which the Allied and Axis powers could have grouped themselves for WW II, and how financial crises relate to critical points in statistical mechanics. He shows that power laws seem to drive both nature and society functions. The section on the use of game theory about how humans (should?) react to help and harm has direct interest in the current world situation. Some 17 pages of notes, a 13-page bibliography, and a 16-page index round out this fascinating book, appealing to both scientists and humanists at every level. ^BSumming Up: Highly recommended. General readers; upper-division undergraduates through professionals; two-year technical program students. W. E. Howard III formerly, Universities Space Research Association

Booklist Review

In this wide-ranging investigation of pioneering attempts to explain social behavior by applying formulas borrowed from physics, Ball explains how maverick social theorists are now using discoveries about molecular motion and crystal formation to predict the behavior of various human groups, including crowds of soccer fans and clusters of pedestrians. Ball acknowledges that past political arithmeticians have often dehumanized their subjects by adopting mechanistic assumptions about individual psychology and have sometimes legitimated totalitarian rulers by giving them a putatively scientific charter. But Ball's numerous detailed examples of the new social physics show how statistical models from physics can yield highly reliable predictions for large-group outcomes without abridging the unpredictable freedom of individual choice. These same examples teach that a consistent physics of society yields not an ideological straitjacket stipulating how people should act but rather a detailed portrait of how people do act. Because the new social physics can help managers and policy makers in dozens of fields, this accessibly written book will attract a very diverse audience. --Bryce Christensen Copyright 2004 Booklist

Library Journal Review

What can physics have to say about how people behave in groups, how networks such as the Internet evolve, and why the stock market fluctuates, among other questions? According to Ball (Designing the Molecular World; contributor, Nature and New Scientist magazines), a lot. The application of physical methods to social problems isn't particularly new, as the author demonstrates, beginning with Hobbes's attempt at a scientific explanation of politics. The development of statistical measurements of society paralleled the growth of statistical physics; as Ball puts it: "physical science and social science were the twin siblings of a mechanistic philosophy and when it was not in the least disreputable to invoke the habits of people to explain the habits of insensate particles." With that in mind, Ball explores recent applications of statistical physics toward a study of social physics. He draws on a wide body of contemporary literature that includes physical approaches to traffic, economics, group dynamics, and politics. While the physical application to the social sciences is not alien, as physics explains the behavior of particles and phase transitions, can it explain human behavior? Ball goes further to suggest that whatever we may make of individual behavior, "once we become part of a group we cannot be sure what to expect"; there are social forces affecting one's behavior that the individual cannot understand, e.g., something as mundane as clapping after a performance (why does it get louder and softer?). Ball has written an elegant synthesis that goes a long way toward illuminating why physicists are exploring social questions and the implications of their work. Highly recommended for both academic and public library science collections.-Garrett Eastman, Rowland Inst., Harvard Univ. (c) Copyright 2010. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.



Critical Mass: How One Thing Leads to Another By Philip Ball Farrar, Straus & Giroux ISBN: 9780374281250 Critical Mass ONE RAISING LEVIATHAN THE BRUTISH WORLD OF THOMAS HOBBES A work on politics, on morals, a piece of criticism, even a manual on the art of public speaking would, other things being equal, be all the better for having been written by a geometrician. --Bernard Fontenelle, secretary of the Académie Française, late seventeenth century "I perceive," says I, "the world has become so mechanical that I fear we shall quickly become ashamed of it; they will have the world be in large what a watch is in small, which is very regular, and depends only on the just disposing of the several parts of the movement. But pray tell me, madame, had you not formerly a more sublime idea of the universe?" --Bernard Fontenelle (1686) The most complete exposition of a social myth often comes when the myth itself is waning. --Robert M. Maclver (1947) It is no longer very useful to ask the question "Who governs Britain?" Discuss. --Exercise in Stephen Cotgrove's Science of Society (1967) Brothers will fight and kill each other ... men will know misery ... an axe-age, a sword-age, shields will be cloven, a wind-age, a wolf-age, before the world ends.1 T his is how the Norsemen envisaged Ragnarok, the Twilight of the Gods; but in political exile in France in 1651, Thomas Hobbes must have thought that he had lived through it already. At Naseby and Marston Moor, Newbury and Edgehill, the stout yeomanry of England had hacked one another to bloody ruin. Oliver Cromwell reigned as Lord Protector of a country shocked to find itself a republic, its line of monarchical succession severed by the executioner's ax. The combatants in the English Civil War, unlike those in France's Revolution or America's blood-soaked battle of North against South, had few clear ideological distinctions. The Royalists fought under the king's banner, but the Roundheads also claimed allegiance to "King and Parliament." For all his presumptuous arrogance, Charles I had no desire to live outside the constitution and laws of the land. Both sides were Anglican and wary of Papists. There were aristocrats in the Parliamentarian ranks and common folk among the Cavaliers. Many of those who slaughtered one another might have found little to dispute had they wielded words instead of swords. Such a conflict could be nothing but a prescription for confusion once the beheading of the king brought it to an end. Embarrassed by the power with which fate had invested him, Cromwell searched in vain for a constitutional solution that would guarantee stability. Such was the might his troops, the formidable Ironsides, gave him that as Lord Protector he could experiment more freely than any British ruler before or since--although this was a freedom Cromwell would happily have relinquished had he felt able. Time and again he created parliaments on which to shed some burden of authority, only to dissolve them once he found them unworthy of the responsibility. In the turmoil of those times, none could be certain that friends would not become foes, or old opponents emerge as allies. The Presbyterian Scottish Parliament, whose fierce antagonism to Charles I had precipitated the conflict between Parliament and Crown in the 1630s, was by 1653 fighting against Cromwell with Charles II as its figurehead. Cromwell himself expelled from the House of Commons the Parliament he had fought to instate, and struggled to maintain control of the monstrous army he had created. After Cromwell's death in 1658, this militia restored Parliament and longed for an end to the Protectorate. John Lambert led the troops to victory over a Royalist uprising in 1659 even as he plotted to restore Charles II to thethrone (and conveniently make him brother-in-law to Lambert's daughter). Yet in the end it was by defeating Lambert that George Monk, a former Royalist, restored a Parliament in 1660 that he knew would crown the exiled king. What could the common people possibly have craved more than stability? Twenty years of war and changing fortunes had convinced them that only a monarchy would supply it; and Charles II, who had narrowly escaped the tender mercies of the Ironsides just eight years previously, found a loyal army and a joyous population awaiting his return from France. There is no way to understand the extraordinary quest on which Thomas Hobbes (1588-1679) embarked without acknowledging its historical setting. Centuries of monarchical rule over a hierarchical society had been graphically dismembered with the fall of the ax on January 30, 1649. A system of governance previously upheld by divine and moral imperatives had been revealed as arbitrary and contingent. Almost every political idea that was to follow in later centuries was voiced then, in seventeenth-century England, and many of them were put into practice. Soldiers and laborers became Levelers and Diggers, advocating socialist principles of equality and an end to individual ownership of land. Cromwell himself seems to have toyed with the notion of a freely elected democratic government, yet he spent much of his Protectorate heading a military dictatorship. Charles I had dissolved Parliament and had instigated an absolute monarchy in the years before the Civil War. Which of these systems should a society adopt? The issue was a burning one. Although war between nations was regarded almost as a natural state of affairs, it might hardly pain the common person beyond the imposition of new taxes and levies. But internal strife was agonizing. The Civil War in England, conducted on the whole with restraint toward civilians, was bad enough; but the Thirty Years' War that ravaged Europe from the early part of the seventeenth century killed one in every three inhabitants of many German states. For Hobbes and many of his contemporaries, civil peace was worth almost any price. England's miseries were a symptom of broader changes in the Western world. The feudal system of the Middle Ages was waning before the rise of a prosperous middle class, and from the ranks of this vigorous and ambitious sector came many of the Parliamentarians, who no longer felt obliged to submitto every royal whim. The monarchy, with its councillors and Star Chamber, harked back to the medievalism of Elizabethan society, but the spirit of the age cleaved to something more democratic, however limited in scope. The Reformation of Luther and Calvin had split Europe asunder; no longer did a single Church rule all of Christendom. The backlash to the assault on ecclesiastical tradition--prompted not only by Luther's heresy but by the. humanism of the Renaissance--gave birth to the Counter-Reformation, the Council of Trent, the Jesuits, and a ruthless Inquisition. The greater the religious diversity, it seemed, the greater the intolerance. Emerging from this ferment were ideas about the nature of the world that were ultimately to prove as challenging as any of the proclamations that Luther allegedly nailed to the church door in Wittenberg. Copernicus had been fortunate to develop his heliocentric theory--the idea that the Earth revolves around the sun--in the early sixteenth century, before the Counter-Reformation, and his first manuscript, circulated around 1530, even received papal sanction. But by 1543, when the full treatise was published after his death, it was prefaced with a note through which the editor, Andreas Osiander, hoped to evade ecclesiastical condemnation by indicating that the new view of the celestial bodies should be regarded simply as a convenient mathematical fiction. How Galileo fared against papal authority when he placed the same idea on firmer footing is the stuff of legend. The Inquisition condemned him in 1616 and forced him to recant in 1633. But by the middle of the seventeenth century, with René Descartes revitalizing the ancient Greek atomic theory and Isaac Newton soon to be admitted to Trinity College in Cambridge, the banishment of magic and superstition by mechanistic science seems in retrospect inevitable. Hobbes's masterwork, Leviathan, was an attempt to develop a political theory out of this mechanical worldview. He set himself a goal that today sounds absurdly ambitious, although at the dawn of the Enlightenment it must have seemed a natural marriage. Hobbes wanted to deduce, by logic and reason no less rigorous than that used by Galileo to understand the laws of motion, how humankind should govern itself. Starting with what he believed to be irreducible and self-evident axioms, he aimed to develop a science of human interactions, politics, and society. It is hard now to appreciate the magnitude not just of this challenge in itself but of the shift in outlook that it embodied. There has never been anyshortage of views on the best means of governance and social organization. Almost without exception, proposals before Hobbes (and many subsequently) were designed to give the proposers the greatest (perceived) advantage. Emperors, kings, and queens sought to justify absolute monarchy by appealing to divine covenant. The Roman Catholic Church was hardly the first theocracy to set itself up as the sole conduit of God's authority. In Plato's Republic, one of the earliest of utopian models, cool and self-confident reasoning argued for a state in which philosophers were accorded the highest status. The rebellious English Parliament of the early 1640s demanded that the king transfer virtually all governing power to it. One could always find an argument to put oneself at the top of the heap. Hobbes was different. What he aimed to do was to apply the method of the theoretical scientist: to stipulate fundamental first principles and see where they led him. In theory any conclusion was possible. By analyzing human nature and how people interact, he might conceivably have found that the most stable society was one based on what we would now call communism, or democracy, or fascism. In practice, Hobbes's reasoning led him toward the conclusion that he had probably preferred at the outset, from which we may reasonably suspect that his method was not as objective as he would have had the world believe. Nonetheless, its claim to have dispensed with bias and to rely only on indisputable logic is what makes Leviathan a landmark in the history of political theory. But it is something more. Hobbes's great work is seen today as historically and even philosophically important, but political science has become a very different beast, and no one seriously entertains the notion that Hobbes's arguments remain convincing. Nor should they, in one sense--for as we shall see, his basic postulates are very much a product of their time. Yet Leviathan is a direct and in many ways an astonishingly prescient antecedent to a revolutionary development now taking place at the forefront of modern physics. Scientists are beginning to realize that the theoretical framework which underpins contemporary physics can be adapted to describe social structures and behavior, ranging from how traffic flows to how the economy fluctuates and how businesses are organized. This framework is not as daunting as it might sound. Contrary to what one might imagine from the popular perception of modern physics, we do not have to delve into the imponderable paradoxes of quantum theory, or themind-stretching revelations of relativity, or the origins of the universe in the Big Bang, in order to understand the basic ideas involved. No, this is an approach rooted in the behavior of everyday substances and objects: water, sand, magnets, crystals. But what can such things possibly have to say about the way societies organize themselves? A great deal, as it happens. Hobbes had no inkling of any of this, but he shared the faith of today's physicists that human behavior is not after all so complex that it cannot occasionally be understood on the basis of just a few simple postulates, or by the operation of what we might regard as natural forces, For Hobbes, contemplating the tumultuous political landscape of his country, the prime force could not be more plain: the lust for power. THE LEVIATHAN WAKES Thomas Hobbes (Figure 1.1) had never been able to take anything for granted. His father was a poorly educated and irascible vicar, a drunkard who left his family when Thomas was sixteen and died "in obscurity." This put his son to little inconvenience, since from a young age Thomas was supported and encouraged by his wealthy and altogether more respectable uncle Francis, a glover and alderman of Malmesbury. Francis watched over the boy's education, helping to nurture a clearly prodigious intellect: by the time the fourteen-year-old Thomas won admittance to Magdalen College at Oxford, he had already translated Euripedes' Medea from Greek to Latin. He so excelled at the university that when he graduated, he was recommended to the Earl of Devonshire as a tutor to the earl's son (who was only three years younger than Thomas). From such a position Hobbes was free to continue his studies of the classics. In his early twenties he acted as secretary to Francis Bacon (1561-1626), whose interests ranged from natural science and philosophy to politics and ethics. During this time until Bacon's death, Hobbes showed no evident inclinations toward science; but Bacon's rational turn of thought left a clear imprint on his thinking. It was not until 1629 that the forty-year-old Hobbes, a committed classicist, had his eyes opened to the power of scientific and mathematical reasoning. The story goes that Hobbes happened to glance at a book that lay open in a library, and was transfixed. The book was Euclid's Elements of Geometry , and Hobbes began to follow one of the Propositions. "By God, this is impossible!" he exclaimed, but was soon persuaded otherwise. As Hobbes's contemporary, the gossipy biographer John Aubrey, tells it, So he reads the Demonstration of it, which referred him back to such a Proposition; which proposition he read: that referred him hack to another, which he also read, and sic deinceps [so on], that at last he was demonstratively convinced of that trueth. This made him in love with Geometry.2 Hobbes was deeply impressed by how this kind of deductive reasoning, beginning with elementary propositions, allowed geometers to reach ineluctable conclusions with which all honest and percipient people would be compelled to agree. It was a prescription for certainty. The axioms of geometry are, by and large, statements that few people would have trouble supposing. They assert such things as "Two straight lines cannot enclose a space." We can typically convince ourselves of their validity with simple sketches. Other fields of inquiry struggle to muster analogous self-evident starting points. "I think, therefore I am" may have convinced Descartes that, as an axiom, it is "so solid and so certain that all the most extravagantsuppositions of the skeptics were incapable of upsetting it"; but in fact every word of the sentence is open to debate, and it has none of the compelling visual power of geometry's first principles. Hobbes was sufficiently enthused to attempt geometry himself, but he was never a master of the subject. Through clumsy errors he persuaded himself that he had solved the old geometric conundrum of "squaring the circle" (something that was later shown to be impossible). But that was not his principal concern. In the 1630s, the tensions between Crown and Commons led Charles I to dissolve Parliament and embark on an eleven-year period of "personal rule." In the midst of an unstable society, Hobbes wanted to find a theory of governance with credentials as unimpeachable as those of Euclid's geometry. This meant that he needed some fundamental hypothesis about human behavior, which in turn had to be grounded in the deepest soil of science. And there was one man who had dug deeper than any other. In the spring of 1636, Hobbes traveled to Florence to meet Galileo. The fundamental laws describing how objects move in space are called Newton's laws, since it was Sir Isaac who first formulated them clearly in his Principia Mathematica (1687). But the tallest giant from whose shoulders Newton saw afar was Galileo (1564-1642), who laid the foundations of modern mechanics. Galileo taught the world about falling bodies, which, he said, accelerate constantly as they descend (if one ignores the effects of air resistance). And with his law of inertia, Galileo went beyond the "common sense" view of Aristotle that objects must be continually pushed if they are not to slow down: on the contrary, said Galileo, in the absence of any force an object will continue to move indefinitely in a straight line at constant velocity. Aristotle's view is the commonsense one because it is what we experience in everyday life. If you stop pedaling your bicycle, you will eventually come to a standstill. But Galileo realized that this is because frictional forces act in nature to slow us down. If we can eliminate all the forces acting on a moving body, including gravity and friction, the natural state of the body is motion in an unchanging direction at unchanging speed. This was a truly profound theory, for it saw beyond the practical limitations of Galileo's age to a beautiful and simple truth. (An air pump that could create a good vacuum and thus eliminate air resistance was not invented until 1654.) Galileo's law of inertia is without doubt one of the deepest laws of nature.On meeting the great man, Hobbes became convinced that this must be the axiom he was seeking. Constant motion was the natural state of all things, including people. All human sensations and emotions, he concluded, were the result of motion. From this basic principle Hobbes would work upward to a theory of society. What, precisely, does Hobbes mean by this assumption? It is, to modern eyes, a cold and soulless (not to mention an obscure) description of human nature. He pictured a person as a sophisticated mechanism acted on by external forces. This machine consists of not only the body, with its nerves, muscles, and sense organs, but also the mind, with its imagination, memory, and reason. The mind is purely a kind of calculating machine--a computer. if you will. Such machines were popular in the seventeenth century: the Scottish mathematician John Napier (1550-1617) devised one, as did the French philosopher and mathematician Blaise Pascal (1623-1662). They were mechanical devices for adding and subtracting numbers; and this, said Hobbes, is all the mind does too: "When a man Reasoneth , hee does nothing else but conceive a summe totall, from Addition of parcels: or conceive a Remainder, from Subtraction of one summe from another ... For REASON ... is nothing but Reckoning ."3 The body, meanwhile, is merely a system of jointed limbs moved by the strings and pulleys of muscles and nerves. Man is an automaton. Indeed, Hobbes held that the ingenious mechanical automata created by some inventors of the era were truly possessed of a kind of primitive life. To him there was nothing mysterious or upsetting about such an idea. Others were less sanguine: the Spanish Inquisition imprisoned some makers of automata on the grounds that they were dabbling in witchcraft and back magic. What impelled Hobbes's mechanical people into action was not just external stimuli relayed to the brain by the apparatus of the senses. They were imbued also with an inner compulsion to remain in motion. For what is death but immobility, and which person does not seek to avoid death? "Every man ..." said Hobbes, "shuns ... death, and this he doth, by a certain impulsion of nature, no less than that whereby a stone moves downward."4 Mankind's volitions, therefore, are divided by Hobbes into "appetites" and "aversions": the desire to seek ways to continue this motion and to avoid things that obstruct it. Some appetites are innate, such as hunger; others arelearned through experience. To decide on a course of action, we weigh the relevant appetites and aversions and act accordingly. What Hobbes means by "motion" is a little vague, for he clearly does not intend to imply that we are forever seeking to run around at full tilt. Motion is rather a kind of liberty--a freedom to move at will. Those things that impede liberty impede motion. Even if a man sits still, the mechanism of his mind may be in furious motion: the freedom to think is an innate desire too. What room is there in this mechanical description for free will? According to Hobbes, there is none--he was a strict determinist. Humans are puppets whose strings are pulled by the forces at play in the world. Yet Hobbes saw nothing intolerable in this bleak picture. After all, he believed that he had arrived at this basic, indisputable postulate about human nature by introspection, by considering his own nature. The first puppet he saw was himself: "Whosoever looketh into himself, and considereth what he doth, when he does think, opine, reason, hope, feare, &c, and upon what grounds; he shall thereby read and know, what are the thoughts, and Passions of all other men, upon the like occasions."5 THE MECHANISTIC PHILOSOPHY If we shudder at this concept of humanity today, it is partly because we regard mechanical, clockwork devices as crude and clumsy. There are now many materialist scientists and philosophers who believe that the brain is a kind of vast and squishy computer whose secrets reside in nothing more than the extreme interconnectedness of its billions of biological switches. This view of the brain as a superior version of our most advanced cultural artifact is neither unusual nor eccentric. To the intellectuals of the seventeenth century the same was true of the clock, which as a reliable timekeeper was still a recent innovation. In that age there was nothing inelegant about a mechanical picture of humanity; on the contrary, it showed just how wonderfully wrought people were. Descartes said: And as a clock, composed of wheels and counterweights. observes not the laws of nature when it is ill made, and points out the hours incorrectly, than when it satisfiesthe desire of the maker in every respect; so likewise if the body of man be considered as a kind of machine, so made up and composed of bones, nerves, muscles, veins, blood, and skin, that although there were in it no mind, it would still exhibit the same motions which it at present manifests voluntarily.6 As above, so below. If mankind was a clockwork mechanism, so too was the universe. The planets and stars revolved like the gears of a clock, contrived by God the cosmic clockmaker. This set in train the debate about whether or not God's skill had left him any cause to intervene in the world once it was "wound," which culminated in an intemperate argument between Gottfried Leibniz and Isaac Newton (who seldom argued temperately). And if the universe was a clockwork mechanism, the way to understand it was to take it apart, piece by piece: to apply the reductionist methodology of science. It was precisely this approach that Hobbes chose to use to analyze the workings of society; he would resolve it into its constituent parts and descry in their motions the simple causative forces. This was his intention in Leviathan' s precursor De Cive (On the Citizen), published in 1642, which contained many of the same ideas: "For everything is best understood by its constitutive causes. For as in a watch, or some such small engine, the matter, figure, and motion of the wheels cannot well be known except it be taken asunder and viewed in parts."7 By this time Hobbes had joined other Royalist sympathizers in exile in Paris. He sensed what was in the air in England in 1640, when Charles I had been forced to reconvene Parliament in order to gather taxes to finance the suppression of rebellion in Scotland. So antiroyalist was the new "Short" Parliament, which had smoldered in banished discontent for eleven years, that the king rapidly dissolved it again, only to have to resurrect it once more when the Scottish army reached Durham on its march south. From there it was a downhill slide to the outbreak of civil war in 1642. Fearing that his political writings would draw censure (or worse) from the belligerent Short Parliament of 1640, Hobbes left for France. Thus, although Hobbes had formulated most of his ideas on "civil governments and the duties of subjects" before the war began, its impending prospect lent his efforts some urgency. He had originally intended to write a three-part thesis that began with traditional physics, extended these ideas to the nature of humankind, and only subsequently developed a "scientific"theory of government. But as he later explained, De Cive was hastened by circumstances: "My country some years before the civil war did rage, was so boiling hot with questions concerning the rights of dominion and the obedience due from subjects, the true forerunners of an approaching war; and this was the cause which ripened and plucked from me this third part."8 In France, Hobbes joined the circle of mechanistic French philosophers whose acquaintance he had made during his earlier European trip in 1634-1637. Among them were Marin Mersenne (1588-1648) and Pierre Gassendi (1592-1655), colleagues of Descartes and two of the most enthusiastic supporters of the mechanical worldview. In this supportive environment Hobbes refined his theory of human nature and carried it through to deduce the consequences for civic structure. Leviathan was published in 1651, and Hobbes presented it in exile to the fugitive Charles II, to whom he had once taught mathematics. There was to be no one, Royalist or Roundhead, who was pleased by what it said. THE UTOPIANS Hobbes was not the first to imagine a utopia based on scientific reasoning. The governing philosophers of Plato's Republic live simply and own no private property, but they have absolute power over the lower classes of soldiers and common people, with whom Plato is little concerned. His is a utopia for aristocrats only; the mob might as well be living in a totalitarian, if benevolent, state. But the word utopia comes from the imaginary land devised by the scholar and lawyer Thomas More (1478-1535). In More's book Utopia (1516), a sailor named Raphael Hythloday describes the eponymous island where he dwelt for five years after sailing there by chance. The meaning of the name is debated, but the common interpretation renders it as either "good place" or "no place." In More's Utopia everything is ideal. There is no ownership: everyone lives in identical houses, but the houses are exchanged every ten years to dispel any notion that individuals own their homes. All people of the same sex are dressed alike, and their clothing is simple and immune to fashion. Everyone works--enough but not too much--and they are offered noncompulsoryeducational lectures. All of the many religions are tolerated, and people live moderately and modestly. It is a vision on the one hand refreshingly liberal, equal, and just, and on the other terrifyingly bland and spiritless. When Francis Bacon drew up his own version of the perfect society, he made science its linchpin. New Atlantis was a book he never finished; it was published, incomplete, the year after his death. The title harks back to Plato, who mentions the fabled lost civilization several times in his dialogues. But Bacon employs the same conceit as More: European sailors are driven off course in the Pacific Ocean and find themselves at the previously unknown island of Bensalem (a Hebrew word meaning "son of peace," although the implication is that this is the "New Jerusalem"). It is a Christian society that dwells on Bensalem, welcoming, kind, and compassionate but also fiercely patriarchal and hierarchical. Central to the culture of Bensalem is Salomon's House, an institution devoted to science and the acquisition of new knowledge. The scientists (Fathers) dress and act rather like priests, and have access to vast resources for research. There are laboratories where nature is not only examined but also imitated and manipulated. Artificial environments resembling mines reproduce the conditions in which metals and minerals are formed; new living species are devised and created. "Neither do we this by chance," a Father explains, "but we know beforehand of what matter and commixture what kind of those creatures will arise."9 Salomon's House resembles in many ways a modern research institution, albeit one unfettered by any constraints on research ethics. Some might see in it the blueprint for biotechnological laboratories in which the stuff of life is cut up, spliced, and reconstituted. The Fathers take an oath of secrecy and reveal their inventions only if it suits them. One cannot imagine Bacon having much difficulty with the modern concept of gene patenting by private companies. But Bacon's Bensalem is essentially an arbitrary society--a vision of what its author considered desirable, and one devoted to, rather than derived from, scientific principles. This is why Hobbes's Leviathan is original. He does not describe a society ready-made and shaped by his own preferences, but builds it up, with careful logic, from his mechanistic view of how humans behave. We should take care with what we mean by that. Hobbes was not especially interested in psychology, or in deducing how people will respond to aparticular set of circumstances. He was pursuing a moral philosophy by asking whether a course of behavior is right . In this respect, the ground was prepared for him (and characteristically for the times, he does not acknowledge it) by the Dutch philosopher Hugo Grotius (1583-1645), whose Laws of War and Peace (1625) attempted to find the irreducible characteristics of human social existence. Grotius was not looking for scientific or mathematical laws as we would now understand them, but for "natural laws," which again might be better regarded as natural rights. With ruthless efficiency, Grotius stripped society of its more pleasant features--benevolence, he said, is all very well, but it is not fundamental There are only two things that people have a natural right to exercise in the company of their fellows: an expectation that they will not be subjected to unwarranted attack, and the freedom to defend themselves if they are. So long as people confine themselves to self-preservation and refrain from injuring others without cause, society is possible. This, said Grotius, is the "State of Nature," the most basic state of social existence. Civilization generally does rather better than that, encouraging courtesies and friendships and learning and the arts and so forth, but these are all optional extras, and society as such can exist without them. Thus Grotius's "minimal society" was a grim affair, and his concept of natural rights was not, as we might suppose today, a precondition of liberalism. But it was not at all obvious how even such a brusque, unfriendly society might be maintained. For who was to say when aggression was warranted and when it was not? If food is short, are you justified in killing your neighbor to preserve yourself? Are you justified in doing that preemptively, as an insurance policy against possible famine next year? Even if everyone agrees to recognize their fellows' natural rights, social stability doesn't necessarily follow, because there is no consensus about how to exercise them. In the hierarchical societies of medieval Europe this seldom became a problem, because people were accustomed to the idea that they should do as they were told by their superiors. They might resent this inequality, but it was rarely questioned. By the Renaissance those certainties had broken down--partly because of changes to the structure of society, partly because of religious unrest and the Reformation, partly because humanism had exposed people to new ways of thinking and there was more awareness of the sheer diversity of societies past and present. Society suddenly seemed to lack foundational principles or agreed behavioral norms. Hobbes realized that this relativism of opinions about how to exercise natural rights meant that in the end a "state of nature" was all about one thing: power. HOW TO BUILD A COMMONWEALTH The person without liberty is without power. Even the most humble and self-effacing of us wants a little power--to choose when we eat and sleep, where we live and with whom, what we may say and do. Many millions of people in the world lack some or all of these freedoms, but they are among those acknowledged internationally, in the Universal Declaration of Human Rights, as liberties that everyone deserves simply by virtue of being alive. Hobbes defined power as the ability to secure well-being or personal advantage, "to obtain some future apparent Good." People, he said, have some "Naturall Power" that enables them to do this, stemming from innate qualities such as strength, eloquence, and prudence. And they may use these qualities to acquire "Instrumentall Power," which is merely "means and Instruments to acquire more": wealth, reputation, influential friends. So Hobbes's model of society hinged on the assumption that people (if we say "men" we are not, in this context, being inaccurate) seek to accumulate power, up to a personal level of satiety that varies among individuals. It is a cold-blooded prescription, for sure. The Scottish political scientist Robert MacIver has complained that it neglects all that is good and worthy in man: "Hobbes ignored all the social bonds that spread out from the life of the family, all the traditions and indoctrinations that hold groups of men together, all the customs and innumerable adjustments that reveal the socializing tendencies of human nature."10 Doubtless that is so, and we may want to make the same complaint. The social historian Lewis Mumford condemns this kind of abstraction of society, saying that it reduces the individual to "an atom of power, ruthlessly seeking whatever power can command."11 It has to be admitted that this is precisely what Hobbes intended. Yet even the nineteenth-century Romantic Ralph Waldo Emerson seems to agree with the Hobbesian interpretation of human nature when he says "Life is a search after power." And in any event, we can agree or disagreewith Hobbes's wolfish view of humanity while nevertheless phrasing the valid question: Given these postulates, what follows? If men behave this way, what kind of society can arise and be maintained? Power is relative: the true measure is the amount by which one man's power exceeds that of the others around him. It follows, Hobbes said, that the quest for power is in fact a quest for command over the powers of other men. But how does one command the power of another? In the bourgeois market society that had come to dominate the cultural landscape of the mid-seventeenth century, the answer was simple: he buys it. One man pays another to act on his behalf and to submit to his will. This does not necessarily mean, as it might sound, simply that a powerful man may hire others to act as bullies, henchmen, and mercenaries. Rather, Hobbes had in mind the way a rich merchant employs workers to make and distribute his goods, or a craftsman takes on assistants to execute a contract. Yet his formulation is as icy as his model of man as machine: "The Value, or WORTH of a man, is as of all other things, his Price; that is to say, so much as would be given for the use of his Power."12 It is the ethic of the free market: buy out the competition. It is not obvious that a society in which appetites for power vary need in itself be an unsettled one: those with moderate ambitions might be happy enough to work for those with stronger desires. But Hobbes maintained that some men's appetites know no limits. Such power-hungry individuals destabilize a society in which less ambitious men might otherwise labor in harmony. "I put for a generall inclination of all mankind," he said, a perpetuall and restlesse desire of Power after power, that ceaseth only in Death. And the cause of this, is not alwayes that a man hopes for a more intensive delight, than he has already attained to; or that he cannot be content with a moderate power: but because he cannot assure the power and means to live well, which he hath present, without the acquisition of more.13 And so all are sucked into a perpetual power struggle. Unchecked, this leads to Hobbes's own vision of a State of Nature, in comparison with which Grotius's version--a crabbed, surly society--might sound positively idyllic. It is as bleak and frightening as you can get. Without any law or law enforcers, every man is open to violent exploitation by others. When everyone seeks to dominate his neighbor without restraint,says Hobbes, there is "no place for Industry ... no Culture of the Earth ... no Knowledge of the face of the Earth ... no Arts; no Letters; no Society; and which is worst of all, continuall feare, and danger of violent death; And the life of man, solitary, poore, nasty, brutish, and short."14 Who would not do all he could to escape such a state? But to proceed logically to a better way, Hobbes found it necessary to introduce two more postulates, which he elevated to the status of Laws of Nature. The first says that a man will not seek actively to harm himself or endanger his life, or to overlook ways of making it safer. Reasonable enough at first glance, this in fact accords us extraordinary percipience in seeing the consequences of the actions we choose, so that we will always make the choice most favorable to our self-preservation. But the second law is still more debatable: "That a man be willing, when others are so too, as farre-forth, as for Peace, and defence of himselfe he shall think it necessary, to lay down this right to all things; and be contented with so much liberty against other men, as he would allow other men against himselfe."15 In other words, men will, as a corollary of their instinct for self-preservation, be prepared to suppress their exploitative impulses and cooperate with one another. Only thus can peace and stability be brought to the State of Nature. But cooperation is not enough. For men's unceasing appetite for power will make them liable to defect from this contract the moment they see any advantage in doing so. We shall see later that Hobbes here essentially formulates, three hundred years ahead of time, one of the most influential behavioral dilemmas of the modern era. The solution, he reasons, is for men not simply to give up some of their natural rights to do as they please, but to transfer these rights to some authority that is then granted the mandate to impose the contract--by force if necessary. In whom should this authority reside? Hobbes felt that it did not greatly matter, so long as the authority was there. His fundamental postulates assume a degree of equality among men rarely voiced in seventeenth-century Europe: in the State of Nature, no man's status is greater than another's, although some have the advantage of greater "Naturall Power." But then the community elects some individual and confers on him absolute power. In effect they choose a monarch and thenceforth defer to him or her without question. This resolution is a peculiar mixture, for it amounts to the creation of a despotism by democratic means out of an anarchic state. Hobbes admits thatthe supreme authority could conceivably be an elected body, not an individual--a Parliament, in effect. But he suspects (and who can dispute it?) that with more than one head of state, internal power conflicts will arise sooner or later. The powers of Hobbes's elected monarch are absolute, stopping only at the right of individuals always to preserve their own lives. It is up to the sovereign, once elected, to decide how much of each man's power he must enlist to maintain the social contract. Even to a tyranny, says Hobbes, citizens owe an obligation of duty and submission. At the same time, this absolutism unites people into a cohesive unit, a Commonwealth: the Leviathan. It was a curious name to give to a supposedly desirable state of society--almost as though Hobbes positively wanted his readers to envisage a dreadful, oppressive regime. Leviathan is a fearsome sea creature mentioned in the Book of Job: If you lay a hand on him, You will remember the struggle and never do it again! Any hope of subduing him is false; The mere sight of him is overpowering ... When he rises up, the mighty are terrified; They retreat before his thrashing ... Nothing on earth is his equal--A creature without fear. He looks drown on all that are haughty; He is king over all that are proud.16 The message is plain--you disobey Leviathan's laws at your peril. Yet because it has freely elected to be governed this way, the population in some sense shares in the political structure that results. Leviathan is thus "one person, of whose acts a great multitude ... have made themselves every one the author"17--an image reinforced by the dramatic frontispiece to the first edition of the book, probably prepared by the artist Wenceslas Hollar (Figure 1.2). In personifying the State in this way, Hobbes was following a long tradition: in the fourteenth century, the Bishop of Rochester, Thomas Brinton, identified the prince as the head of the "body politic" and the laborers as the feet. Others took delight in anatomizing every member of society, from priests (chest or ears) to merchants (thighs) to judges (ribs). The justification for the Leviathan, says Hobbes, is "the Convenience, or Aptitude to Produce the Peace, and Security of the People." One can deplorehis proposed means of achieving these aims, but the objectives themselves are nevertheless enshrined in all democracies today. In explaining how a mass of selfish individuals can unite to create a sovereign nation, Hobbes gave form to the modern idea of the State. More than this, even: according to historian Frederick Nussbaum, "Hobbes discovered society."18 And thus Thomas Hobbes believed he had proved monarchy to be the best system of rule, using science and reason alone. He felt that those nations that had enjoyed prolonged civic stability, such as Imperial Rome, had by good luck or judgment hit on the ideal solution that science now revealed with inexorable logic. "The skill of making, and maintaining Commonwealths," he said, "consisteth in certain Rules, as doth Arithmetique and Geometry; not (as Tennis-play) on Practise onely."19 A CALCULUS OF SOCIETY One might think that Charles II would have been pleased with a treatise claiming to prove scientifically that kings were the best rulers. But he was not at all happy with Leviathan, for it proposed that the king comes from the ranks of ordinary men and is instated arbitrarily by election of the masses, like a common parliament! Whereas it was well known that kings ruled by divine decree, deriving their authority not from some social contract but from a heavenly one. To the Royalists, the book was pure treason. There was no comfort here for supporters of the parliamentary system either. Hobbes's supreme authority, whether an individual or a collective body, subsequently had the right to decide who would succeed it--democracy is exercised once and then relinquished. And to make matters worse, Leviathan offended the devout by lambasting those nations which "acquiesce in the great Mysteries of Christian Religion, which are above Reason."20 This was deemed by many to be a declaration of atheism. Hobbes endeared himself to no one. So it was a dangerous game that Hobbes now played. In the winter of 1651-1652, shortly after his book appeared, he retreated from the hostility of the exiled Royalists and returned to Cromwell's England, where the desire for peace and stability under the Protectorate had introduced a degree of tolerance. Hobbes made friends within the new regime, and he fitted in quietly enough until Charles II was restored to the throne in 1660. If there was one thing the Royalists, new and old, disliked more than Hobbes's political philosophy, it was his views on religion. He had become widely regarded as an atheist, especially by the dominant Anglican Royalists, and he might well have faced imprisonment if the bill to make Christian heresy a criminal offense had been passed by Parliament in 1666. The threat was ever present for the remainder of Hobbes's lifetime; but in spite of this, and decades of ill health notwithstanding, he survived to the truly venerable age of ninety-one. No nation chose to put the advice in Leviathan into practice. Indeed, according to the historian Richard Olson, "because they seemed to inspire both immorality and revolution, Hobbes's theories were generally feared and detested by all respectable persons."21 To the Scottish philosopher David Hume, "Hobbes's politics are fitted only to promote tyranny, and his ethics to encourage licentiousness."22 But because his ideas were argued with such compelling force and precision, they posed a challenge to all subsequent politicalphilosophers. You could be appalled by Hobbes, but you could not ignore him. Above all, Leviathan established the idea that there was room for reason in politics. Previous utopias were not deductive; their validity was simply asserted. In general they sought either to shore up the status quo or to portray a society conjured into existence from the author's imagination, with no explanation of how things got to he that way. The Leviathan, on the other hand, was at least ostensibly the product of mechanistic science. It was not something to be celebrated, but was a necessary evil, the only alternative to grim anarchy. The social contract proposed by Hobbes might sound like a forerunner of those advocated by John Locke (1623-1704) and Jean-Jacques Rousseau (1712-1778), but it is instead the reverse. To Locke and Rousseau, the power conferred upon the head of state comes with an obligation to serve the interests of the populace; for Hobbes, the common people are contracted to serve their ruler. For Hobbes, the principal fear was of anarchy; for Locke it was the abuse of power, which is why he saw the need for safeguards to avoid absolutism. But although apparently a proponent of autocracy, Hobbes also provides arguments that can be used to support both bourgeois capitalism and liberalism. Although he expressed an aversion to the way the mercantile society bred men whose "only glory [is] to grow excessively rich by the wisdom of buying and selling," which they do "by making poor people sell their labour to them at their own prices,"23 he saw bourgeois culture as largely inevitable, and sought a system that would accommodate its selfish tendencies without conflict. To this end he left it to the market to assign the value of everything, people included: "The value of all things contracted for, is measured by the Appetite of the Contractors: and therefore the just value, is that which they be contracted to give,"24 This free-market philosophy found voice in Adam Smith's Wealth of Nations in the following century. Those in Britain and the United States (and indeed elsewhere) who lived through the 1980s will recognize it as an attitude that did not wane with the Age of Enlightenment. A political scientist taking a chronological approach would chart the trajectory of Hobbes's thought via Locke to later thinkers who believed there could be such a thing as a "calculus of society." Along this path we woulduncover Jeremy Bentham's utilitarianism in the late eighteenth century, an attempt to harmonize the individual's pursuit of personal happiness with the interests of society. Bentham, like Locke, believed that reason alone could show how this might be achieved. His solution was the "greatest happiness" principle, which would guide society to an optimal state in which the sum total of human happiness was as large as it could possibly be, given the conflicts of interest that inevitably arise when each person seeks his or her own advantage. Bentham's utopia was quite different from Hobbes's: a democracy with equality for all, including votes for women. Bentham and the Philosophical Radicals, who included John Stuart Mill, paved the way for the socialism of Karl Marx. Marx, of course, was also determined to formulate a "scientific" political theory, one that in his case was strongly (and misguidedly) influenced by Darwinism. And so we might go on. But I shall not. These theories indeed seek a foundation in rationality, and we shall revisit them from time to time. But they are not scientific in the way that the real topic of this book is scientific. There are few political thinkers who have defined a social model with the logical precision of Hobbes, and none who have carried those precepts through to their conclusions in a truly scientific, rather than suppositional way. This is not by any means to denigrate such models; rather, it is simply to say that their approach is different. Political theorists tend to concern themselves with what they think ought to be; scientists concentrate on the way things are . The same is true of the new physics of society: it seeks to find descriptions of observed social phenomena and to understand how they might arise from simple assumptions. Equipped with such models, one can then ask what we would need to do in order to obtain a different result instead. Decisions about what is desirable should properly be in the realm of public debate--they are no longer scientific questions. In this sense, the science becomes, as it should be, a servant and guide, and not a dictator. How is it that physics has come to have the confidence, perhaps even the arrogance, to venture into social science? No one in recent decades has set out to construct a physics that would be capable of this. It just so happens that physicists have realized they have at their disposal tools that can be applied to this new task. These tools were not developed for that purpose; they were first developed to understand atoms. Carolyn Merchant, in her book The Death of Nature (1983), argues thatthe rise of mechanistic, atomistic philosophy in the seventeenth century sanctioned the manipulations and violations of nature that continue to blight the world today. The Utopian society envisaged by Thomas Hobbes, in which people are little more than automata impelled this way and that by mechanical forces and where scientific reasoning is the arbiter of social justice, sounds like a chilling place to live. It is hard to imagine how any model of society that regards the behavior of individuals as governed by rigid mathematical rules can offer us a vision of a better way to live, rather than a nightmarish Brave New Would. That. I suspect, is the instinctive objection that many will have to the notion of a "physics of society." But I hope to show that the new incursion of physics into the social, Political, and economic sciences is not like this. It is not an attempt to prescribe systems of control and governance, still less to bolster with scientific reasoning prejudices about how society ought to be run. Neither does it really imagine that people are so many soulless, homogeneous effigies to be shuffled this way and that according to blind mathematics. Instead, what physicists are now trying to do is to gain some understanding of how patterns of behavior emerge--and patterns undoubtedly do emerge--from the statistical melée of many individuals doing their own idiosyncratic thing: helping or swindling one another, cooperating or conflicting, following the crowd or blazing their own trail. By gaining such knowledge, we might hope to adapt our social structures to the way things are rather than the way some architect or politician or town planner thinks they ought to be. We might identify modes of organization that fit with the way we actually and instinctively behave. These are potential practical benefits of a genuinely inquisitive physics of society, but from such efforts emerges a broader message too. The message is this: collective actions and effects are inevitable. No matter how individualistic we like to think we are, our deeds are often the invisible details of a larger picture. This is not necessarily a description of impotence. Environmentalists and other activists like to entreat us to "think globally, act locally." But the physics of society shows that the reverse can take effect too: by concerning ourselves with nothing more than how we interact with our immediate neighbors, by "thinking locally," we can collectively acquire a coherent, global influence. The consequences of that--good or bad--are worth knowing. No scientific theory will show us how to build a utopia, but the search for a physics of society will benefit from our acknowledging the lessons of those quixotic attempts, like that of Thomas Hobbes. to do so in the past. These efforts to create a rational utopia show us the dangers of such a rigid program. Science provides not prescriptions but descriptions. With such understanding, we might hope to make our choices with clearer vision. Copyright © 2004 by Philip Ball Excerpted from Critical Mass: How One Thing Leads to Another by Philip Ball All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher. Excerpted from Critical Mass: How One Thing Leads to Another by Philip Ball All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.

Table of Contents

Introduction: Political Arithmetickp. 3
1 Raising Leviathan: The brutish world of Thomas Hobbesp. 9
2 Lesser Forces: The mechanical philosophy of matterp. 33
3 The Law of Large Numbers: Regularities from randomnessp. 48
4 The Grand AH-Whoom: Why some things happen all at oncep. 80
5 On Growth and Form: The emergence of shape and organizationp. 98
6 The March of Reason: Chance and necessity in collective motionp. 118
7 On the Road: The inexorable dynamics of trafficp. 156
8 Rhythms of the Marketplace: The shaky hidden hand of economicsp. 178
9 Agents of Fortune: Why interaction matters to the economyp. 204
10 Uncommon Proportions: Critical states and the power of the straight linep. 226
11 The Work of Many Hands: The growth of firmsp. 250
12 Join the Club: Alliances in business and politicsp. 270
13 Multitudes in the Valley of Decision: Collective influence and social changep. 295
14 The Colonization of Culture: Globalization, diversity, and synthetic societiesp. 337
15 Small Worlds: Networks that bring us togetherp. 352
16 Weaving the Web: The shape of cyberspacep. 372
17 Order in Eden: Learning to cooperatep. 402
18 Pavlov's Victory: Is reciprocity good for us?p. 429
19 Toward Utopia?: Heaven, hell, and social planningp. 449
Epilogue: Curtain Callp. 467
Notesp. 471
Bibliographyp. 489
Acknowledgmentsp. 503
Indexp. 505