During the twentieth century the physical sciences converged with biology in transforming the Newtonian world machine governed by eternal, universal, and mathematical laws into an evolving—indeed exploding—cosmos where uncertainty prevails, and human efforts at observation affect what is observed. This brings the mathematical sciences closer to the social sciences, and turns history into another kind of black hole from which no branch of knowledge can now escape.

Few historians have so far paid attention to this extraordinary intellectual transformation, but surely it is time for the historical profession to broaden its inherited aspiration to achieve “scientific” history through criticism of sources and the like, and try to connect human affairs with this revised scientific portrait of evolving reality by fitting the human career on earth into its cosmic, biological, and social context. My own ideas of how this might be done are unlikely to carry very far, but let me sketch them anyhow in hope of provoking others to do better.*

What makes us different from other forms of life is our capacity to invent a world of shared feelings and symbolic meanings and then act upon them in concert. Across the millennia of human life on earth, cooperative effort among larger and larger numbers of human beings proved capable of getting desired results more or less dependably. Moreover, agreed-upon meanings associated with any new skill or idea that worked better than previous ones tended to spread and alter the way humans did things. Shared meanings, in other words, were capable of rapid evolution, radically outpacing older biological processes of genetic mutation and selective survival. But the process of symbolic evolution does not appear to be fundamentally very different from biological evolution any more than biological evolution was fundamentally very different from the physical and chemical evolution of the cosmos that preceded and sustained it.

How did symbols arise and acquire such powers? How is agreement on symbolic meanings sustained among groups of human beings? And how do agreed-upon meanings that provoke unusually satisfactory actions cross cultural boundaries between different human societies? These are the critical questions for a satisfactorily scientific human history; or so it seems to me. Let me recklessly suggest a few tentative answers.

First, how did we acquire our strange—I am tempted to say magical—powers and learn to live within a symbolic universe of our own invention? I start by assuming that the processes propelling organic evolution apply to the human species as much as to any other life form. Accordingly, before fully human societies arose, I imagine that effective cooperation among a large number of individuals was a critical factor promoting the survival of our ancestors on the savannas of Africa, where human evolution seems to have centered. I also believe that the first notable innovation allowing large bands to stick together, which started proto-humans along an evolutionary path that diverged from the one followed by our closest relatives, the chimpanzees, was the invention of rhythmic voicing and dance.

As I argued in my book Keeping Together in Time, rhythmic voicing and dance had the effect of dissipating personal rivalries and enhancing a warm feeling of togetherness among participants, as community song and dance and other rhythmic exercises—aerobics, marching in step, grandstand cheering, and the like—still do. As a result, large bands, sustained by the emotional side effects of voicing and dance, were capable of cooperating more effectually. Indeed, those who engaged in such exercises had such great advantages that only bands that learned to dance and make sounds together were able to survive. Rhythmically voiced sound and dance thus became a distinguishing human trait since the members of no other species ever spontaneously invented this way to express themselves and strengthen social bonds in doing so.

Large bands, in turn, provided the setting within which voiced signals developed into articulate speech and grammatical languages, introducing another and very powerful way to make cooperation more exact and flexible among large numbers of persons. Language, needless to say, also became universal among human communities, and its power to shape consciousness and focus attention on some aspects of a situation, while dismissing others as trivial, meant that the continuing importance of song and dance for sustaining human communities was almost entirely obscured. Words do not easily describe the emotional affects of keeping together in time, and we still fumble when trying to explain what happens to human brains and bodies when we sing and dance. Nonetheless, it seems to me that the evolutionary advantages that accrued to human communities from the introduction of language were fundamentally similar to those previously arising from rhythmic voicing and dance: to wit, more effective cooperation across time and space and among larger numbers of persons than had been possible before.

The behavioral effects of language are familiar. First and foremost, it defined what ought to be done in daily life by reducing proper behavior to rules that are communicated to infants by voice and gesture and sustained among adults by gossip. Human societies thereupon became automated, so to speak, by custom. Effective response in different circumstances was usually guaranteed by conforming to traditional rules of behavior, and frictions were minimized because everyone knew what to expect of one another in all ordinary situations. Customary rules, expressed in words, therefore minimized quarrels, maximized effective cooperation, and allowed increasingly complex division of labor among indefinitely large numbers of individuals who spoke the same language.


But language also has a contrary power, facilitating invention of new kinds of behavior whenever experience disappoints expectation. This arises from the fact that language allows us to move to and fro in imagined time, remembering useful things from the past and planning what to do in the future. On the one hand, planning makes concerted action more precise, since by talking things over in advance, different roles can be assigned to different individuals and rules for sharing the results of specialized cooperative behavior can be laid down in advance. But acting consciously on the basis of verbally formulated rules and expectations has its pitfalls. Hopes and expectations can, and sometimes do, diverge from experience. Disappointment, in turn, invites (and sometimes compels) revising plans and altering behavior accordingly.

An impulse to innovate which still prevails among us thus arose, starting humankind on a path of technological and cultural change that tended to accelerate as knowledge and tools became more complex, powerful, and correspondingly prone to error. Abrupt increase in the variability of deliberately shaped stone tools, which set in sometime between 60,000 and 40,000 years ago, may be the archaeological residue of what happened when humans first began to use fully developed language to make plans, and, as a result, also started to make mistakes and then tried to correct them by deliberately altering the way they did things.

Language is so powerful and pervasive in human lives that it seems right to say that our ancestors became fully human only when they began to use language and act not on the basis of sensory stimuli alone but in accordance with plans and hopes and verbally formulated ideas about themselves and everything around them. A prolonged, tangled, and repetitive exchange of verbal messages still turns infants into human beings, as parents of any two-year-old can attest. And once the human plane of face-to-face verbal coordination of most everyday behavior had been achieved, major subsequent landmarks of our history depended principally on improvements in communication that allowed messages to travel farther and more accurately across time and distance than spoken words ordinarily do.

Always it was networks of messages, delivered in verbal form, supplemented by gesture and sometimes solemnized by ritual, that created and sustained local human communities; and the particular meanings, transmitted back and forth, defined relationships and expectations among participants. It was in small groups, whether hunting bands, pastoralists, or agricultural villages, that most people lived and died. This was where, until almost the day before yesterday, face-to-face communication assured biological and cultural continuity, even though an increasing proportion of these primary communities came to be incorporated into larger communication networks, centered in cities and sustaining what we call civilizations.

Civilizations brought strangers together and separated classes of people living side by side into distinct semi-autonomous groupings. Priests and rulers, warriors and artisans, merchants and travelers, masters and servants lived very differently from one another, yet all depended on exchanges of goods and services, regulated by customary rules on the one hand and, on the other, by demographic and material limits on supply and demand.

As compared to primary communities, urban-based civilizations were (and still are) tumultuous and unstable social structures, but they were also more powerful, coordinating the actions of larger numbers of persons partly by obedience to deliberate commands, and partly by negotiated, more or less voluntary, exchanges of goods and services. Larger numbers working together, whether willingly or unwillingly, deliberately or inadvertently, had the same effect that cooperation within larger bands of more or less undifferentiated individuals had had at the beginning of human history. In other words, civilized forms of society exerted power over the natural environs and over much larger human numbers than more homogeneous societies were able to do. Ever since the first civilizations arose, civilized social complexity therefore tended to spread, until in our own time almost all humankind is caught up in a single global system, exchanging messages furiously fast and upsetting traditional ways of life almost everywhere.

For all practical purposes, details of how small roving bands that experienced only sporadic outside contacts evolved into today’s One World are infinite, and the happenstance of surviving documentation means that much of what mattered most will never be definitely known. But an appropriately imaginative historian can hope to discern major landmarks in the civilizing process by focusing on breakthroughs in communication and transport that altered the range and flow of messages among human populations, and thereby accelerated the propagation of novelties far and wide that met human wishes or wants better than before. Here I can only sketch what I surmise to have been major steps of this process.


From the beginning, people walked and ran. This is what allowed hunters and gatherers to spread across most of the earth within as little as 50,000 to 60,000 years. From the start, adjacent bands encountered one another from time to time, and intermittent clashes over territorial boundaries were probably chronic. But bands also met peaceably on festival occasions to dance and sing, and used such occasions to exchange mates and information. Such gatherings constituted a sporadic genetic and communications network that allowed humankind to remain a single species despite its worldwide dispersion. Seepage from band to band could also propagate new techniques and ideas across long distances.

The spread of bows and arrows is one, partially known, example. Invented in Eurasia-Africa sometime between 30,000 and 15,000 years ago—no one yet can say where—bows spread very widely, and when Eskimos brought the device across the Bering Strait about 100 CE, bows began to spread through the Americas also. The process was still going on in 1492 when Europeans arrived in the Caribbean and encountered raiding parties of seafaring, bow-wielding Caribs from South America bent on attacking people in the Caribbean islands who lacked these formidable weapons.

Seepage by means of overland contact with neighbors—whether peaceable or violent—was comparatively slow, as the diffusion of archery shows. But when people first learned to use paddles and sails to propel rafts and boats, possibilities for long-range encounters opened up along the coasts of easily navigable seas. Almost certainly parts of Southeast Asia (and especially the offshore islands of Indonesia) were the principal sites of this breakthrough. A vague horizon for seafaring is established by the fact that people who reached Australia some 40,000 years ago (and perhaps even earlier than that) must have used some sort of flotation device to get there. But wooden rafts and ships seldom leave archaeological traces; and since melting glaciers subsequently raised sea levels substantially, early coastal settlements in Southeast Asia and everywhere else have been inundated.

Still, it seems clear that at an early time sailing vessels began to exploit the reversible monsoon winds to sail to and fro in Southeast Asia and along the shores of the Indian Ocean. Such seafaring was well developed by the time Sumerian records offer a glimpse of the sea network that connected the land of Sumer at the head of the Persian Gulf with Indus and Egyptian societies—and with a wider world of seagoing peoples beyond.

Sumerian cities, in fact, arose where this sea network connected up with a newer network of caravan portage. Donkeys, the first important caravan animal, were domesticated about seven thousand years ago; but since caravan management was almost as complicated as seafaring it presumably took a while for overland portage to become significant. But when local peoples learned that letting caravans pass for a negotiated protection fee assured a better supply of exotic and desirable items than plundering them did, overland portage across relatively long distances began to connect diverse populations more insistently than before. And it is surely not an accident that it was in Sumer, where an already ancient seagoing network intermeshed with a newly accessible hinterland, that the first cities arose between 4000 and 3000 BCE. Goods and ideas moved along these communications networks and, where they converged, the Sumerians were in an optimal position to pick and choose, elaborating and improving upon skills and knowledge coming from far and near.

Sumerian achievements, such as writing, metallurgy, wheeled vehicles, and an impressive religion, spread outward along the same networks. For example, on distant northern steppes Indo-European herdsmen accepted the Sumerian pantheon of seven high gods—sky, earth, thunderstorm, sun, moon, fresh water, and salt water. And, with subsequent adjustments, their Aryan, Greek, Latin, Celtic, German, and Slavic descendants carried this pagan pantheon with them into India and across Europe.

Similarly, wheeled vehicles, in the form of two-wheeled chariots, reached China by 1400 BCE and helped to consolidate the power of the Shang dynasty. But of all Sumerian innovations, their resort to writing was perhaps the most significant since it added a new dimension to information storage and retrieval. Being more capacious, enduring, and reliable than human memory, written records allowed priests and rulers to collect and disburse indefinitely large quantities of material goods according to deliberate rules. As a result, government became more powerful; commands became more enforcible, even at a distance; and coordinated effort among thousands and eventually millions of persons became routine.

Writing also assisted long-distance trade, as ancient files of letters exchanged between families of merchants in Anatolia and Assur show. Their caravans connected distant peoples and local rulers with the heartland of Mesopotamian civilization and assured relatively rapid transmission of information back and forth. Ships moving across the southern seas (and after about 5000 BCE through the Mediterranean as well) did the same. Human societies thereby acquired something resembling a nervous system, carrying messages, stimulating innovations, and accelerating social change all along their routes.

In due course, early centers of civilized complexity also arose in China and India and around the shores of the Mediterranean. From the start these new centers of civilizations were in slender contact with one another, and the Americas saw comparable forms of civilized society emerge about two millennia later. But the Eurasian-African web of communication always remained larger, more highly skilled, and more powerful than any other constellation of human societies. A few cursory remarks about how links connecting Eurasian populations with one another became inescapable and more efficient will show why that was so.

Caravans became more capacious when larger animals were induced to carry heavier loads: first mules, then camels. Domesticated camels only became available in suitably large numbers after about 200 CE, and by dint of their ability to cross deserts and feed on wild-growing forage along the way, transport by camel caravans became remarkably cheap and far-ranging. They brought much of Africa into regular contact with Eurasian peoples and made the deserts and grasslands of Central Asia and the Middle East into a highway that tied China, the Middle East, India, and Europe into a single interacting whole.

Shipping and navigation also improved across the centuries, following rather different technical paths in Pacific and Atlantic waters. Yet the upshot was similar after about 900 CE: all-weather Chinese and European ships started to sail routinely even across stormy seas, thereby reinforcing the interconnectedness of Eurasia-Africa that camel caravans sustained. Then, when European seamen deciphered the wind patterns of the Atlantic, within a single generation, between 1492 and 1522, they began to sail across all the oceans of the earth, and soon converted every inhabited coastline and its hinterland into a globally interacting whole.

Military technology and organization also played a parallel role by spreading information and establishing advanced practices wherever raiding parties or invading armies penetrated. Needless to say, warfare was destructive—always. But destruction sometimes cleared the way for reconstruction along more effective lines. This, it seems to me, is the basic upshot of political history, with which most historians have been principally concerned. The story is too long for me to enter into here, but it is clear that the Eurasian grasslands from Manchuria to Hungary became the seat of nomad horsemen whose cavalry raids into settled agricultural lands challenged civilized armed forces and governments from shortly before 700 BCE until the Manchu conquest of China in 1644 brought steppe conquests to an end. These same nomads, with their herds of domestic animals, were very hospitable to caravans as well. This meant that raid and trade supplemented one another throughout the Eurasian steppes and deserts; and the resulting exchanges among groups, both peaceable and violent, tended to accelerate the diffusion of new practices that somehow satisfied human wants and needs better than before.

Finally, what about truth and beauty? Religion? Science? Art? These dimensions of our lives also contributed to human satisfaction and survival and evolved across time in response to conscious choices. Precise formulations varied widely, and attachment to local tradition was usually very strong. But on the whole people still prefer truth to falsehood and beauty to ugliness whenever they recognize the difference. And every so often a new doctrine, a new system of thought, or some more modest rearrangement of signs and symbols—a new idea or style of art—struck home, and was accepted as being clearly better than anything previously known. The spread of the Sumerian pantheon among Indo-European tribesmen is an early example, and the spread of Newtonian astronomy around the earth is a more modern case in point.

Ideas, in fact, are among the most contagious aspects of human culture; even though, when translated into a new language and required to fit into a different social context, they have a chameleon capacity to change meaning, sometimes only slightly, sometimes radically. Technological innovations are almost as contagious as ideas, and they too alter their meaning and importance when crossing linguistic and cultural boundaries. Printing, for example, split European culture apart by juxtaposing Christian and classical pagan learning with a flood of new and often incompatible information about the wider world; whereas in China, where printing had originated several centuries before it reached Europe, the effect was to consolidate traditional literary and intellectual culture by assuring wider access to Confucian and other classical texts. This is an extreme example of how different contexts can alter the effect of a given technique. Nonetheless, it suggests that uniformity will never arise among human societies, however closely modern communications may connect them.

About the world-changing, destructive- constructive consequences of more recent advances in communication, much has been said and I forebear from comment on the formidable array, starting with printing and mechanically powered transport, swiftly followed by the instantaneity of electrical telegraph, radio, TV, computers, and the Internet. What is happening among us today is obviously drastic, with quite unforeseeable consequences. But consequences of intensified communication have been unforeseeable ever since dance and then language came on stream and initiated the restless changeability that comes from making mistakes and trying to repair them. We are therefore at one with our predecessors, immersed in a process we do not control and can only dimly understand—a process nonetheless that has made us and our agreed-upon systems of meaning the most disturbing, changeable, and quite extraordinarily powerful factor in upsetting the multiple levels of physical, chemical, biological, and social equilibriums within which we exist.

What a history to explore, reflect upon, and wonder about! And where does it go from here? The future of an evolving universe and of humankind’s extraordinary career on earth are both unknowable, but wondrous and awesome all the same. Finding out about the future, by living through it, hit and miss, is a daunting yet enticing prospect, for us and for our successors.

Perspicacious history of how we got where we are might even improve human chances of survival. Accordingly, to chart the principal landmarks in human change (which is as much as we are ever likely to be able to do), and bring the history of humankind into convergence with the other sciences, is an intellectual and moral imperative for the twenty-first century. Or so it seems to me. My own professional efforts have aimed in that direction. I invite others to persevere and make world history into a respectable branch of learning by correcting and extending what I and my contem-poraries have been able to patch together.

This Issue

June 29, 2000