The New Renaissance Computers and... | Buy

Chapter One

The Information Revolution

This has often been called the age of information, and for once a popular label is correct. Never before has information been produced at such a staggering rate, and the rate is increasing rapidly. This explosion of information was spawned by the extraordinary development of modern computer technology, and it has already revolutionized manufacturing and business, science and technology, schools, government, even some of our homes. But the changes have barely begun: The production and use of computers is still growing explosively.

To understand the significance of the information revolution that has been touched off by computer technology we need to investigate its historical parallels. A study of the effects of comparable inventions in the past can provide important insights into the revolutionary implications of computer technology today.

At first it might seem that no such parallels exist, that the computer revolution is unique in history. But it is not unique. At least three inventions in the past--language, writing, and printing--had effects that were very similar to today's computer revolution. Each of these inventions decreased the effort and cost required to produce, store, and distribute information, thereby causing an information explosion very similar to the one being created today by computer technology.

To understand the importance of these three inventions we need to place them in their proper historical contexts: Each is closely associated with the beginning of a fundamentally new form of human society. The invention of language is associated with the very beginning of the human race, the invention of writing with the beginning of civilization, and the invention of printing with the beginning of modern civilization.

These associations are highly suggestive. The most important dividing points in the history of civilization were each accompanied by an invention that caused an information explosion. This suggests a possible cause-and-effect relationship--that information explosions may have caused these transformations of civilization. If we can prove that such a relationship exists, the implications for civilization today would be profound: The computer could be the invention that will change civilization to a degree not seen since the Renaissance, the time of the last great revolution in information handling.

To show that such a causal relationship exists we need to show that civilizations generally are information-limited. In other words, we need to show that a limit on the production of information impeded progress in the period that preceded each information explosion: To do this we must study in detail the limits that are placed on a society by restrictions on the production of information.

The fundamental reason that civilization is limited by information is quite simple: Civilization is information. Most of the factors that characterize a civilization--its ethics and laws, its technology, its philosophy and religion, its literature and art--are forms of information. And civilizations are generally limited more by lack of information than by lack of physical resources. Classical civilization, for example, possessed all of the resources needed to create Morse's telegraph and Edison's phonograph. Ramses and Pericles failed to build telegraphs and phonographs only because they lacked the necessary information.

But information limitations have broader implications, beyond the simple lack of specific items of information. Information limits are quantitative as well as qualitative, and their quantitative study can lend broad insights into the patterns that mark the development of civilizations. Just as a quantitative limit on the production of steel restricts the output of automobiles and ships, a limit on the production of information restricts the number of things that a civilization knows how to do. A quantitative information limit restricts not only science and technology, but also such things as literature, politics, art, music, architecture, religion, law, ethics, history, and philosophy. Indeed, there is hardly an aspect of civilization that is not directly restricted by limits on information production. To understand these restrictions in detail we must quantify the information requirements of key elements of various civilizations and compare those requirements to the actual capacity of civilizations to produce information.

If information limits are so important, we might well wonder why they have not already been studied in some detail. There are probably two basic reasons. First, the very concept of information as a quantifiable substance is a very recent development. The quantitative theory of information was one of the great triumphs of twentieth-century science, developed by scientists and engineers who were trying to optimize radio and telephone communication. The theory is so new that even in the physical sciences many researchers are only beginning to understand its full implications for their fields. We should not be surprised that its implications for history and sociology have barely begun to be probed.

The second reason that information explosions have not generally received the attention they warrant is more subtle: No two of them are studied by the same scientific discipline. The first one is studied by anthropologists and linguists, the second one by archaeologists, the third by historians. It is difficult to recognize a recurring pattern from the study of a single instance, and few professionals have the breadth of knowledge necessary for proficiency in all the requisite disciplines. Thus each of these three inventions has generally been studied in isolation, and the recurring pattern of information explosions has remained relatively unexplored.

The vital importance of information to human civilization has not gone completely unnoticed, however. In the 1930s the French historian Henri Berr pointed out the epochal significance of the inventions of language, writing, and printing for the development of civilization (1934). Berr, unfortunately, seems to have been writing a little ahead of his time. The intimate connection among these inventions through their quantitative effect on the production of information could not have been completely understood prior to Shannon's development of a quantitative theory of information in the 1940s. And, more importantly, Berr had no way of knowing that the computer, the next critical invention that would have an explosive effect on information production, was only a decade away.

It might seem extreme to argue that the first of these critical inventions, the invention of language, was the only factor or even the principal factor that distinguished early humans from their prehuman antecedents. Defining the exact point of origin of the human race in the fossil record is somewhat arbitrary. Nevertheless the invention of language is a very good choice for the point that marks this critical juncture. Gould called language "the most widely cited common denominator and distinguishing factor of humanity" (1993, 321). Falk, an anthropologist at the State University of New York, puts it this way:

Various skills, including hunting, tool production, warfare and language have been advocated at one time or another as responsible for human brain evolution. Apes occasionally do all but one of these activities. They sometimes hunt, make tools, and fight, but they never engage in spoken language as we know it. If we wish to identify one prime mover of human brain evolution, ... it is language.... Human technology and social achievements required conscious thought, which is, and probably was, dependent on language. In other words, until they acquired language, our early ancestors may not have been truly human. (1984, 38)

The connection between the invention of writing and the dawn of civilization is even clearer. In the third millennium B.C. civilizations emerged almost simultaneously in four so-called "cradles of civilization": Egypt, Mesopotamia, the Indus Valley, and China. The single factor that distinguished these four cultures from their neighbors was the invention of writing. Other factors, such as metallurgy, commerce, and urbanization, were possessed in some degree by other cultures. Writing alone distinguishes civilization. As Gelb of the University of Chicago writes:

[M]any other great men--among them Carlyle, Kant, Mirabeau, and Renan--...believed that the invention of writing formed the real beginning of civilization. These opinions are well supported by the statement so frequently quoted in anthropology: As language distinguishes man from animal, so writing distinguishes civilized man from barbarian.... Writing exists only in a civilization, and a civilization cannot exist without writing. (1963, 221-22)

The relation between the invention of printing and the origin of modern civilization is particularly important because the information explosion that resulted from the invention of printing is the only one that can be studied in any detail. Yet historians have curiously neglected this critical invention. For example, W.H. McNeill's monumental survey The Rise of the West contains only a single reference to Gutenberg, and that reference is in a footnote to a chapter on the Far East (1963, 531). Eisenstein is one of the few scholars to study the effects of the invention of printing, and the almost complete absence of detailed study of those effects surprised her. She writes:

What were some of the most important consequences of the shift from script to print? Anticipating a strenuous effort to master a large and mushrooming literature, I began to investigate what had been written on this obviously important subject ... [but] there was not even a small literature available for consultation. Indeed I could not find a single book, or even a sizeable article which attempted to survey the consequences of the fifteenth-century communications shift. (1979, xi)

Eisenstein gives many reasons why historians tended to overlook the importance of printing. She mentions, for example, the difficulty of trying to assess the effects of printing by looking for new titles (with presumably revolutionary ideas) in the catalogs of books offered for sale by printers in the fifteenth century. Such studies missed the point that the catalogs themselves were novel. It was not the titles that were revolutionary but the fact that books were being advertised for sale (1979, 168).

Eisenstein describes the importance of printing to events such as the Copernican revolution in astronomy and the comparable revolution in anatomy and medicine in the time of Harvey. She writes:

We cannot ... study all aspects of the past, and intellectual historians may be well advised to leave many inventions ... to the specialist. To treat Gutenberg's invention in this way, however, is to miss the chance of understanding the main forces that have shaped the modern mind. (1979, 24-25)

The late Renaissance witnessed a number of singular and highly important events--the Copernican revolution, the discovery of the New World, the Reformation--that were crucial to the development of modern civilization. When these pivotal events are examined in detail a common thread can be found: books. As Gingerich put it:

The early 1500s were times of vast changes. Oceanic navigators opened new continents and an age of exploration. Da Vinci and Durer coupled mathematics with art to capture new harmonies of proportion and perspective. Martin Luther successfully set into motion a reformation of the church.... Meanwhile, the explosive spread of printing with movable type beginning in the 1450s fanned the sparks of all these movements, including the reform of astronomy. Without printing, Copernicus would have been deprived of the vast majority of his source materials. Even five decades earlier, he could not easily have found the requisite information that built his De Revolutionibus into the greatest astronomical treatise of its century. And without printing, his manuscript might have languished, virtually forgotten, on the shelves of the cathedral library. (1975, 202)

To understand how widely Copernicus's book was distributed in the sixteenth century, Gingerich has made an effort to track down and catalog all the existing copies of it. He was able to find 245, copies of the first edition (1543) and a similar number from the second edition (1566), and he estimates that he has accounted for about half of the total printing. Thus about 1,000 copies were in circulation in the sixteenth century, and the copies had a wide geographic distribution. One of them had traveled as far as Mexico by 1600 (Gingerich 1979). With the invention of the printing press, books suddenly became available in numbers that had been beyond the reach of earlier civilizations; ideas were able to reach a more widespread audience than ever before. Copernicus's book is just one example of the flood of information that became available after the invention of the printing press.

The importance of printing to the Reformation is equally clear. Here the obvious critical book was the Bible, the first book to be printed and still the record holder for volumes printed. In addition, Martin Luther made extensive use of the new printing press. As Dickens put it:

Between 1517 and 1520, Luther's thirty publications probably sold well over 300,000 copies.... Unlike the Wycliffite and Waldensian heresies, Lutheranism was from the first the child of the printed book, and through this vehicle Luther was able to make exact, standardized and ineradicable impressions on the mind of Europe. (1966, 51)

For the discovery of the New World, the critical books were works on geography and natural history. Columbus, for example, owned at least four of the newly printed books. They are preserved to this day and contain extensive marginal notes in his own handwriting. A single generation earlier it would have been inconceivable that the son of a Genoese weaver could be wealthy enough to possess several books. But Pliny and Marco Polo were at Columbus's bedside. Morison (1942, 92-95) has outlined in some detail the importance of these books not only for the development of Columbus's ideas about geography, but also for his ability to argue effectively in the famous debates with the Spanish geographers at Salamanca, who in fact had a much better idea than Columbus did of the true distances to Cipango and Cathay.

Thus the explosive effect of the sudden and unprecedented production of an abundance of information (not all of it correct) provides a simple explanation for many of the unparalleled accomplishments of the Renaissance. It is an explanation that does not require assumptions of the presence of unusual human genius during this time period. The anomaly that was responsible for many of the accomplishments of the late Renaissance lay not so much in human intelligence as in the quantity of information that was suddenly available to that intelligence. The printing press supplied talented people with the information that they vitally needed and, equally important, allowed them to communicate their ideas and discoveries quickly to thousands of their contemporaries. Is it any wonder that the first generation to produce books in any quantity would explode in a frenzy of exploration? That the generation that first produced abundant copies of Pliny and Marco Polo would seek out strange climes and new worlds? That the generation that printed a thousand copies of De Revolutionibus would ask questions about the nature of the universe?

Eisenstein has raised questions about the quality of the information produced by the early printing industry, pointing out that much of what was printed was misinformation (1986, personal communication). Early books contained errors ranging from descriptions of unicorns and dragons to the inaccuracies in Ptolemaic astronomy. But the quantity of misinformation dropped rapidly following the invention of printing. Serious reports of dragons were rare by the eighteenth century. Why? At least part of the answer lies in the development of scientific methods in the sixteenth and seventeenth centuries. But this begs the question. Why were scientific methods suddenly developed?

Consider that scientific methods are fundamentally a two-pronged attack on problems of information. One part of the scientific method involves verification of information by observation and experiment (such techniques are obviously responsible for much of the decline in misinformation following the invention of printing). The other part of the scientific method involves a search for patterns or underlying rules ("laws") that explain large bodies of observations. This, portion of the scientific method is, in essence, a technique for dealing with a large quantity of information by reducing it to a comprehensible pattern.

None of these techniques was particularly new. Observation, experimentation, and the discovery of patterns are probably as old as mankind itself. Yet the use of these techniques increased enormously in the sixteenth and seventeenth centuries, so much so that a "scientific revolution" is widely recognized to have occurred at that time. In other words, following the invention of printing we find, first, a massive increase in the production of information, and then an equally massive development and application of old techniques for refining that information. The scientific revolution of the sixteenth and seventeenth centuries can thus be seen as a necessary and even forced response to the large increase in the production of information that followed the invention of printing. The very quantity of newly produced information forced the development of techniques for dealing with large quantities of information. Those techniques are the processes that lie at the heart of modern scientific methods.

Eisenstein discusses a case that illustrates the direct impact of the sheer abundance of new information on the development of scientific methods in the sixteenth century. The case involves Tycho Brahe, who is rightly celebrated for producing superbly accurate new observations of the motions of the planets. His industrious pursuit of new data is frequently contrasted with "the 'almost hypnotic submission to authority' associated with reliance on Ptolemy and inherited data, manifested by all previous astronomers, including Copernicus" (Eisenstein 1979, 624). But the critical fact often overlooked is that Brahe possessed a printed set of Copernicus's newly published tables in addition to a newly printed copy of Ptolemy's tables. Brahe may have been the first person to ever possess two separate sets of computations based on two different theories (Eisenstein 1979, 624). And they did not match. Is it any wonder, then, that he ceased to rely on authority and turned to direct observation? What appears at first blush to represent a major and inexplicable change in basic philosophy can be seen as merely a natural reaction to the simple possession of an unprecedented quantity of information (none of it perfectly accurate) in the form of two sets of planetary tables.

These examples of the direct impact that the explosive growth in information production can have on the development of civilization do not, in themselves, provide a complete understanding of the quantitative aspects of the information limitations that marked the major watersheds of human history. To understand these information limitations we must first determine the quantities of information actually possessed by different levels of civilization. Then we must establish the minimal quantities of information that are required to perform certain tasks essential to those levels of civilization. Neither of these projects is easy. Both of them are possible only because the quantitative differences in the information requirements of different levels of civilization are so large that very rough estimates will prove to be both useful and revealing.

To construct these estimates we need to know a little about information theory. Like many pivotal discoveries, information theory is based on ideas so simple that they seem obvious rather than revolutionary. Claude Shannon was the first to recognize that the fundamental unit of information measurement is the quantity of information needed to decide between two alternatives. Shannon named this unit of information the "bit" (from BInary digiT). If one bit can decide between two alternatives, then two bits can decide among four alternatives by first dividing the four alternatives into two sets of two alternatives each. One of the bits then decides between the two sets, and the other one between the two alternatives within the selected set. Similarly, three bits can decide among eight alternatives, and so forth. Each additional bit doubles the number of choices that can be made. Because a letter of the alphabet is one of twenty-six alternatives (ignoring capitals), a letter contains a little less than five bits of information. This is only a small sample of information theory, but it is enough to allow us to make rough comparisons of the information content of various civilizations and thereby assess the effects of information explosions. It allows us to define an information explosion quantitatively as an increase of about two (or more) orders of magnitude in the production of information.

In order to evaluate the amount of information produced at various times in the past we need to distinguish five broad categories of civilization that differ principally by the method they use to store and handle information. It will be convenient to assign labels to them as follows:

Level 0--Pre-Language

Level 1--Language

Level 2--Writing

Level 3--Printing

Level 4--Computers

In evaluating the quantity of information available at each of these five levels it is the smallest quantity, the amount of information at Level 0, that is the most difficult to handle. Lacking language, each individual is essentially limited to the content of his or her own mind. But how much information can one mind contain? This quantity is so uncertain and variable that it might be best to simply label it h and try to set some bounds on it. We can set a lower bound on h by noting that epic poems such as the Iliad , which contain about 5 million bits, have been memorized. To get an upper bound, we might ask how many Iliads a person might reasonably memorize. A hundred seems unlikely. It seems plausible that h is within one or two orders of magnitude of 5 million bits.

In a Level 1 society (with language) individuals have available the information content of their own minds plus that of the rest of their village, clan, or tribe, perhaps 50 to 1,000 times h There is, however, considerable redundancy in this information. The knowledge of how to hunt or chip flint would be common to many individuals. Even allowing for this redundancy the amount of information available to an individual in a Level 1 society would be one or two orders of magnitude greater than that available in Level 0.

In a Level 2 society (with writing) the amount of available information took another quantum leap. The greatest accumulation of information in any Level 2 society was probably found in the library of Alexandria in Egypt in about the third or fourth century A.D. One scholar describes Byzantine records indicating that the library possessed 532,800 scrolls in the third century B.C. (Parsons 1952, 204). Ignoring questions about the accuracy of this number, we could use it as the basis of a rough estimate of the information content of the library if we could determine the information content of a scroll. A clue to this value is found in the tradition that Zenodotus, a librarian at Alexandria, divided the Iliad and the Odyssey into twenty-four books each, in part so that each book would fit comfortably on a scroll (Parsons 1952, 205). Thus if the Iliad contains 5 million bits, and a twenty-fourth part of this is a typical size for a scroll, then the great library contained about 100 billion bits ([10.sup.11] bits), one or two orders of magnitude more information than was available in a Level 1 society. Although the redundancy of the information contained in these volumes is difficult to quantify, it was probably less than the corresponding redundancy of the information available in a Level 1 society.

A Level 3 civilization (with printing) would have hundreds of libraries larger than the library at Alexandria; some of its libraries are larger by several orders of magnitude. The total amount of information available even in an early Level 3 civilization is so vast that an individual cannot begin to comprehend all of it. Leibniz (d. 1716) is said to have been the last individual to comprehend all known information, certainly an exaggeration. In a fully mature Level 3 civilization the daily publication output can exceed any single individual's comprehension.

A crude estimate of the quantity of information available in a Level 3 civilization can be obtained by starting with an almanac figure showing 10,000 new book titles published in the United States in 1950. If each book contains 5 million bits, and 1,000 copies are printed, and the copies have a shelf life of about 20 years, then [10.sup.15] bits will be available in books alone. Allowing one or two more orders of magnitude for other publications such as newspapers, periodicals, government publications, advertisements, and so forth, we arrive at about [10.sup.17] bits of information available in a Level 3 culture, about a million times more information than was available in a Level 2 civilization (even to a scholar who had access to the library in Alexandria).

Level 4 civilization will be marked by a rapid acceleration in the rate at which information is produced. For example, word processors and computerized typesetting machines will greatly enhance the productivity of the publishing process, and computerized measurement and control devices will multiply the rate at which observations and other raw information can be generated. Modern accelerator experiments in high-energy physics, for example, are expected to generate a quantity of data equivalent to the content of the library of Alexandria in about five minutes, on average (Butler and Quarrie 1996). But Level 4 will see an interesting twist in the growth of information resources: Mere increases in the total store of information will become relatively unimportant, because even a Level 3 civilization can generate information at a rate that far exceeds anyone's ability to make use of it. Electronic computers, however, are capable of creating a totally new dimension in an information explosion. Computers can multiply our ability to find, analyze, and make use of vast quantities of extant information, thereby circumventing the information limits that bedeviled Level 3 civilization.

We can make some rough estimates of the amount by which computer technology can increase our ability to find and utilize information. We do not need very accurate estimates to show that the increase is going to be very large indeed. Consider the total quantity of information available to a talented person without a computer. Suppose this individual has completed a speed reading course and can read 1,000 words per minute. One word is about five letters or 25 bits, so if this person spends six hours a day reading, seven days a week, for seventy years, he will have read about [2x10.sup.11] bits (roughly twice through the library at Alexandria). A modest home computer can read that many bits in a few days--a really fast computer, in minutes. Therefore even today's computer technology provides an increase of a factor of thousands to millions in total information availability. This estimate makes no allowance for such things as the use of indexes to enable an individual to sort through more information than he or she can read, or for the fact that a human reader generally employs more intelligence and judgment than a machine is able to employ. But even with these refinements, it remains clear that the computer will increase information availability by many orders of magnitude. Increases on this scale are completely unprecedented and are far greater than the increase associated with the change from Level 2 to Level 3 civilizations.

In order to fully exploit the capability of computers to search through and analyze information in great quantities, information "utilities" are needed to supply information to home or office computers at modest prices. Rudimentary versions of such utilities were first created in the 1970s. The recent explosive growth of the Internet exhibits not only the technological capabilities that are possible today but also the incredible level of demand that already exists for such services.

And this is only the beginning. These services have been in existence only for a short while. Soon whole libraries and eventually virtually all of the information produced by our civilization will be available in this form. Computers will be able to search out needed information and distribute it electronically to the home or office. Every individual in a Level 4 civilization will have instant access to a supply of information that will dwarf even the Library of Congress, and will have the electronic hardware and software needed to make effective use of such a quantity of information. The ability to easily find and utilize the entire information stock of a civilization will be the hallmark of a Level 4 civilization.

Thus the quantitative limits on information available at each level of civilization are approximately:

Level 0--Pre-Language: [10.sup.7] bits

Level 1--Language: [10.sup.9] bits

Level 2--Writing: [10.sup.11] bits

Level 3--Printing: [10.sup.17] bits

Level 4--Computers: [10.sup.25] (?) bits

These estimates need refinement. They may be in error by orders of magnitude; the last one is little more than a guess. The relative sizes, however, are probably accurate enough to allow us to begin to assess the information limitations of the different levels of civilization. Having defined these quantities, we are halfway toward an understanding of information limits. But the second part of the problem--identifying the tasks that are essential to a given level of civilization and estimating the amount of information required to perform those tasks--is considerably more difficult and will require an extensive study that can only be outlined here.

Consider the tasks that were actually accomplished at the various levels of civilization. Great literature, for example, has been created by civilizations at Level 1, in the form of epic poetry and sagas. Such literature can therefore be achieved by a civilization whose information limits are only a couple of orders of magnitude larger than the content of the literature itself. Operating a democratic system of government on a continental scale almost certainly requires the information capacity of the printing press, and is probably beyond the capability of a Level 2 civilization. And manned exploration of the moon is a task that exceeds the information capacity of a Level 3 civilization. The design, construction, and operation of a manned moon-rocket require the information processing capacity of electronic computers.

It will not be easy to construct a complete list of the features that characterize each level of civilization, the features whose information requirements we need to determine. A partial list for a Level 3 civilization would include such things as internal combustion engines, telephones and telegraphs, large-scale democratic governments, and universal literacy and education requirements. A similar list for Level 2 would include such things as large-scale autocratic governments, monumental architecture, and elementary mathematics. Level 1 would include such things as the use of tools, fire, and possibly agriculture and metallurgy. Obviously it will require a great deal of research and study to arrive at reasonably complete lists of features that characterize each level of civilization.

The quantity of information that is required to produce these particular features of civilization can be somewhat difficult to estimate, when both direct and indirect information requirements are considered. The information required to build an automobile, for example, goes far beyond the blueprints, diagrams, and specifications required to describe each part of the vehicle. The specifications for the size, shape, and strength of a piston are not very useful without information on how to obtain iron ore and produce steel. Despite these difficulties we should be able to estimate the direct information requirements of various tasks from the specifications and plans required for the task, and to make reasonable "overhead" assumptions that will account for the indirect requirements. Thus we should be able to make estimates that are sufficiently accurate to enable us to understand the limitations placed on civilization by limits on the amount of information produced.

To take a simplified example of such an estimate, let us try to calculate some of the information requirements for a large-scale democratic government system. Assume that we have a voting population of about 100 million, that two candidates are running for office, and that each has a 1,000-word (at 25 bits per word) statement of his or her views on critical issues. Further assume that each copy of the candidate's statement can be shared among ten voters. Simple arithmetic shows that more than [10.sup.11] bits are required for just two candidates in a single election (not even considering the indirect information requirements). This is roughly the size of the entire library of Alexandria, which represented centuries of accumulated information. It should be clear from this calculation that any large-scale democracy is going to have serious difficulties in a Level 2 civilization.

Similar calculations can be done for other critical elements of modern civilization. It should be easy to show that such things as communication networks, manufacturing complexes, and modern transportation systems have massive information requirements that exceed the information production capability of earlier civilizations. Imagine trying to run an airline without printed schedules and timetables, for example. Calculations of these information requirements are particularly important because they can be used to test, perhaps even falsify, the conjecture that civilizations are fundamentally limited by the quantity of information they can produce, store, and distribute. If, for example, it were shown that earlier civilizations had much larger information resources than I have estimated, or that the information requirements of modern civilization are much smaller, then it might be possible to demonstrate that civilizations are not really limited by restrictions on their information production.

Of course it is something of an oversimplification to say that civilization is limited by information, or, more generally, to say that civilization is information. But every statement that can be made about civilization is an oversimplification to some degree. The key point is not whether it oversimplifies, but whether this idea is sufficiently accurate and novel that it provides us with important new insights, as it does. Among other things, it provides a simple and natural explanation for vexing questions such as why the first industrial and scientific revolution occurred in western Europe rather than, for example, in the Arab civilizations. (In China, where the printing press was first invented, the concomitant information explosion was hampered by a number of factors, most obviously the absence of an alphabetic script.)

A number of other historical events are difficult to understand without a knowledge of quantitative information limitations. For example, the transition from ancient civilizations to the Dark Ages is usually described in terms of the destruction of classical civilization by barbarian invaders. But this explanation fails to provide a clear means of distinguishing between a civilized and a barbaric society, to explain why Theodoric the Goth, for example, should be considered more barbaric than Caligula or Commodus. From the standpoint of information limitations, however, the transition to the Dark Ages is seen as the most recent (possibly the last) example of the destruction of a Level 2 civilization by a Level 1 civilization. The few examples of the use of writing that are found during the aptly named Dark Ages (such as Bede, Charlemagne and Alcuin, and Alfred the Great) serve only to highlight the general absence of the written word that characterizes the information limitations of this period.

The medieval period is a time of gradual, halting progress back to a Level 2 civilization, complicated at the end by the first appearance of a Level 3 civilization. It is this double revolution that makes the Renaissance period difficult to understand and classify. The term "Renaissance" is itself a serious misnomer, for the Level 3 civilization that began here bears no resemblance to any classical civilization purportedly reborn.

One possible objection to classifying civilizations according to their quantitative information limits is that the levels defined are too broad--each level spans widely disparate types of civilizations. Is it reasonable, for example, to group Egypt of the twenty-third century B.C. with France of the twelfth century A.D.? Or are these cultures too dissimilar to be linked in any reasonable classification scheme? But an important function of a classification system is to point out connections that might not otherwise be obvious. The term "Bronze Age," for example, draws a link between Mycenaean Greece and Shang-dynasty China. And there are broad similarities between, for example, ancient Egypt and medieval France that make such a link reasonable. A visitor from Egypt's Middle Kingdom would have found much that was familiar in twelfth-century Paris: a hereditary monarchy; a warrior class that employed swords, bows and arrows and spears; and a religion that employed elaborate ceremony to ensure a pleasant life after death. The royal tombs at Fontevrault might surprise our visitor only in the use of bronze rather than gold for the coffin effigies. Such a visitor might even notice a parallel between the collapse of the "broken" pyramid at Meidum and the collapse of certain medieval cathedrals, notably the one at Beauvais. Engineering was strictly a trial-and-error affair in both cultures. The similarities between these Level 2 cultures appear far more striking than the differences, even though the two cultures are separated by thirty centuries.

If we were to continue this thought experiment by moving our Egyptian friend (or a medieval compatriot) into the next level of civilization we would find a radically different situation. Suppose we could, move our visitor only eight centuries further, into a phone booth in an airport sometime around 1930. He or she would be in a truly alien world, filled with totally unfamiliar artifacts such as telephones, airplanes, automobiles, and refrigerators. Even a simple flashlight would have no parallel whatsoever in our visitor's experience--its function would seem like magic no matter how painstaking the effort to analyze it or work with it. (Arthur C. Clarke, the noted science and science fiction writer, has proposed as "Clarke's Third Law" that any sufficiently advanced technology is indistinguishable from magic. We can now quantify "sufficiently advanced," and note that it requires approximately one information explosion.)

One might argue that the twentieth century has some unique quality that makes this last comparison unfair or at least unrepresentative of a general rule. Yet an individual from a Level 1 civilization (from the central Amazon, for example, or from 10,000 B.C.) would have about as much trouble understanding the great Pyramid or the cathedral at Chartres as Aristotle or Roger Bacon would have trying to understand a flashlight. As a general rule civilizations within any of these levels resemble each other far more than any of them resemble any civilization in another level. This is the fundamental rationale for proposing such a classification system.

Of course the quantity of information available at each of these levels was never constant. In a Level 1 civilization the quantity fluctuated roughly with the size of the tribe or clan. In a Level 2 civilization the quantity of information produced was not limited in principle, but limits were determined in practice by the difference between the rate at which information was produced and the rate at which it was destroyed. The human penchant for burning books and libraries kept the limit fairly low throughout much of history--so low that Level 2 societies often had little advantage over Level 1 societies. Tales of the destruction of Level 2 civilizations by Level 1 are common in history.

Level 3 civilization was fundamentally different in this respect. After the invention of printing the production of information increased rapidly and never reached an equilibrium. In other words, the rate at which information was produced nearly always exceeded the rate at which it was destroyed. The technical advantage that Level 3 civilizations held over earlier levels quickly became so great that I can find no recorded case of a Level 3 civilization being destroyed by one at Level 2 or lower. On the contrary, on each occasion in which such civilizations came in contact, as they did in the American continents and in India, the Level 3 civilizations invariably conquered or destroyed the earlier civilizations. Indeed, the first civilization to attain Level 3 very quickly conquered most of the world and relinquished control only after the rest of the world had also attained a good measure of Level 3 technology.

Note that I am not arguing for any form of technological determinism, that certain levels of information production would force the development of certain kinds of civilization. I am rather arguing the converse, that lack of information-production capacity will prevent the development of certain forms of civilization. Neither am I advocating a monocausal interpretation of history. Information production is only one element in the bewildering complexity of the development of civilization. Nevertheless, it is an important element, perhaps the most important element, and it is one whose time is ripe for study because the necessary theoretical tools have now been developed to a reasonable state of maturity.

What insights does an understanding of information limitations give us into the effects of the information explosion taking place today? Can we make any reasonable prognosis about the characteristics of a Level 4 civilization? Each of the three information explosions in the past produced a society that was largely unrecognizable to an individual from an earlier civilization. There is no reason to expect less from the fourth. In fact, this information explosion will be much larger and will take place much faster than the earlier ones. The difference between the twentieth and the twenty-first centuries may well be greater than the difference between the twentieth and the thirteenth (A.D. or B.C.).

Although making a forecast across such monumental change may seem hopeless, one historic figure did in fact make an extraordinary set of predictions that spanned just such different levels of civilization: Roger Bacon wrote about airplanes, submarines, horseless chariots, and other Level 3 wonders in the thirteenth century. Of course Bacon's remarkable prognoses were based more on wish than on hard evidence. Similarly accurate predictions about Level 4 civilization will probably be difficult to distinguish from wishful thinking.

One way to appreciate the full capability of a Level 4 civilization is to recognize that the Apollo moon landings were among the first (and presumably the simplest) examples of accomplishments that are possible only in a Level 4 civilization. What other tasks will lie within the capabilities of Level 4? Most of the problems facing our civilization today could be reduced or even eliminated with a massive influx of information. A partial list of those problems reads like a litany from the Apocalypse: famine, pestilence, poverty, war, illiteracy, intolerance. Level 4 civilization will be able to accomplish things such as observing cropland on a worldwide scale (from spacecraft) to monitor and alleviate the effects of drought, blight, locust plagues, and other age-old calamities. It will map the entire human genome (and probably many other genomes) and produce much better understanding of the functioning of biological systems. And these are just a couple of examples of the early accomplishments of Level 4. The full range is as far beyond our present imagination as our present civilization is beyond the medieval.

One of the most hopeful predictions that we can make about Level 4 civilization is that wars should be difficult or even impossible for Level 4 governments to conduct. War is already rare between two countries in which both have an unrestrained press. It is no accident that many of the wars fought in this century were launched by governments that kept tight control over the distribution of information, especially through the press. And such restraint on the press will be impossible in a Level 4 civilization, in which each home could have the equivalent of a printing press in the form of a small computer. War between nations in a Level 4 civilization may become as unthinkable as war between Virginia and Pennsylvania today. The antiwar movement could well match the achievement of the abolition movement of the last century.

Although Level 4 civilization will certainly solve some of the problems we face today, it will also undoubtedly have its own share of troubles. Crime, for example, will take on new and inventive forms, especially if electronic banking becomes standard. However, this discussion has focused on the gains and benefits conferred by computer technology rather than on the problems that will be experienced in a Level 4 civilization. It has done so for the most basic of reasons: Anticipating the problems that will occur in the future is a far more difficult task than forecasting the present-day problems that will be solved. The simple reason for the difficulty is that we generally have a deep familiarity with and understanding of today's problems that need to be solved, but at the same time we often lack even the context necessary to perceive the problems of the future. For example, although Roger Bacon wrote of airplanes, automobiles, and submarines, it would be preposterous to expect him to have anticipated, in the thirteenth century, the problems that would result from the successful attainment of his forecast, problems such as air pollution produced by automobile exhaust, acid rain, depletion of petroleum reserves, nuclear waste disposal, or deforestation of tropical rain forests. He lacked the necessary background and context even to conceive of these problems. As recently as the early twentieth century, Henry Ford did not anticipate the problems of automobile exhaust pollution, and Marie Curie would probably have been astonished at the problem of nuclear waste disposal.

There is therefore a broad variety of problems whose very context was technologically unimaginable only a generation or two ago. Consider the difficulties that would arise if parents had the ability to specify and alter the complete genetic makeup of their children. Such capabilities may become possible with computerized genetic engineering. This would not cause any great problem if, for example, all children turned out to have blue eyes, but what if all of them turned out to be male?

To take another example, computer technology raises serious problems concerning violations of personal privacy. Electronic mail can be intercepted, and electronic commercial transactions can be recorded and analyzed in ways that were inconceivable a generation ago. However, in addition to creating this problem, computer technology has provided a possible solution to it through the use of recently invented codes and ciphers that are believed to be mathematically unbreakable. A full discussion of the theory of these codes would take us far afield of the main point here. Good discussions can be found in Gardner (1989) and the references therein.

But perfect codes and ciphers, while they may alleviate problems related to privacy violations, can create other problems that may be more serious. Indeed, these codes may represent one of the most dangerous inventions of the century. Suppose, for example, they had been widely available during the Second World War, and Allied code breakers had been unable to break the Axis codes. The battle at Midway may well have been lost, and the war in Europe could have dragged on for years, perhaps into another Thirty Years' War. Or more likely, the war would have dragged on until large numbers of atomic bombs were employed. Thus there are good reasons why many are afraid of allowing this technology to become widely available. It could prove extremely useful to criminal, terrorist, and drug-smuggling organizations, and correspondingly frustrating to law-enforcement efforts.

Level 4 civilizations will also have to face problems brought on by rampant population growth. These problems are intertwined with the computer revolution because computer technology is revolutionizing medical techniques and thereby decreasing death rates. Population growth problems are so important and so intractable that they warrant a full discussion in a separate chapter (see chapter 10).

The key point here is that all technological revolutions create problems that literally cannot be imagined outside of the context provided by those very revolutions. By failing to focus on these problems I do not mean to imply that they are unimportant, only that I lack the context necessary to even conceive of most of them. The one prediction that we can make with some confidence about Level 4 civilization is that its troubles will be different from the troubles that preoccupy us today. Problems such as the long conflict between capitalism and Marxism that troubled so much of this century may soon be as forgotten as the Schleswig-Holstein question that convulsed another century.

Today we can catch only dim glimpses of the features of Level 4 civilization, much as Roger Bacon caught glimpses of Level 3. And although there may not be anyone alive now with the insight and perspicacity to match the good friar, we have the advantage that our predictions need cover only a few years rather than centuries. Such is the staggering pace of the changes that we face.