Bring out your dead

579 – 658

We’re now taking history less than one century per day.

Something major happened to Earth’s atmosphere in 535. We have reports from around the world of the sun being darkened or blotted out for more than a year, and evidence from tree rings and ice cores of an extreme cold spell. The culprit might have been dust thrown into the atmosphere by volcano or a comet. This on its own must have been bad news for the world’s population. But even more consequential was what happened starting seven years later. In 542, bubonic plague made an appearance in the Egyptian port of Pelusium, and rapidly spread around the Mediterranean, eventually reaching much of western Europe and Persia. (China seems to have gotten off more lightly.) It’s possible the epidemic had its origin among rodents in the east African Great Lakes region: disturbances to these populations after 535 may have contributed to the spread of plague, either up the Nile valley, or to trading towns on the Indian Ocean. Recent genetic evidence has confirmed that plague bacteria from this period are almost identical to those from the later, better known Black Death in the late Middle Ages. The plague struck repeatedly around west Eurasia for the next 200 years, before disappearing. The death toll must have been many tens of millions.755

Major movements of peoples would follow the plague in the sixth and seventh centuries. The Byzantine reconquest of most of the western Roman Empire, under Justinian, came undone as a new wave of Germanic barbarians, the Lombards, occupied Italy. The Anglo-Saxons expanded from the east of England to occupy most of present-day England. Slavs moved south to occupy most of the Balkans. And, most consequentially, Arabs under the banner of Islam occupied most of the Middle East and North Africa.

The selfish meme

310 – 404

In the first decades after the crucifixion of Jesus, the number of those who worshiped him as a resurrected savior was at most a few thousand, and probably many fewer. In 313, when Constantine issued the Edict of Milan mandating tolerance for Christianity, Christians numbered many millions. Thus, in two and a half centuries, Christian numbers had doubled at least ten times. On average, someone who lived to the age of seventy-five during this period could expect to live through an eight-fold increase in the numbers of Christians between her birth and her death.

Christianity began in confusion, controversy and schism and so it continued. A dominant orthodox church, with a recognizable ecclesiastical structure, emerged only very gradually and represented a process of natural selection — a spiritual survival of the fittest … The Darwinian image is appropriate: the central and eastern Mediterranean in the first and second centuries AD swarmed with an infinite multitude of religious ideas, struggling to propagate themselves. Every religious movement was unstable and fissiparous; and these cults were not only splitting up and multiplying but reassembling in new forms.

Paul Johnson A History of Christianity

If we’re going to apply Darwinian analogies to culture, we might want to distinguish between the selection of memes within people’s heads, and between them (intra- and inter-cephalic selection, if you will). Inside people’s heads, different ideas survive or fail depending on the benefits and costs they produce for their carriers, how well they fit with other ideas, and so on. Outside people’s heads, some ideas may spread because people work extra hard to propagate them. Christianity spread as rapidly as it did partly because it radically exalted the Spirit over the Flesh. As Clement (a relative moderate among early Christians) wrote “Our ideal is not to experience desire at all.” A consequence is that the new religion effectively sterilized a fraction of its hosts, who gave up on the normal business of marrying and raising children, and turned into cultural super-spreaders.

Two ways of life were given by the Lord to his church. The one is above nature, and beyond common human living; it admits not marriage, childbearing, property nor the possession of wealth. . . . Like some celestial beings, these gaze down upon human life, performing the duty of a priesthood to Almighty God for the whole race. . . . And the more humble, more human way prompts men to join in pure nuptials, and to produce children, to undertake government, to give orders to soldiers fighting for right; it allows them to have minds for farming, for trade, and for the other more secular interests as well as for religion.

Eusebius, quoted in Peter Brown The Body and Society: Men, Women and Sexual Renunciation in Early Christianity

Women were another important vector for the spread of Christianity. Pagans and Christians agreed they were over-represented among converts. Celsus, a pagan critic of Christianity, took a dim view of this, sounding like a modern critic of advertising for children: “Christians must admit that they can only persuade people destitute of sense, position, or intelligence, only slaves, women, and children, to accept their faith.” Tatian, a Christian apologist, was cheerier: “They say of us, that we gabble nonsense among females, half grown people, girls, and old women. Not so. Our maidens philosophize, and at their distaffs speak of things divine.”

Of course some of the same observations (e.g. regarding the overcoming of desire and religious celibacy) could be made about the spread of Buddhism during the same period, suggesting that there are general principles at work in the spread of religions, as in the spread of microorganisms.

For a sophisticated scholarly treatment along these lines of the interaction of selfish genes and selfish memes check out Mixed Messages: Cultural and Genetic Inheritance in the Constitution of Human Societies by Robert Paul. A lot of work on the coevolution of genes and culture has been done by mathematical modelers; Paul is something else, a long-time cultural anthropologist who brings wide knowledge and thick description of culture and symbolism to the topic.

Plagues and peoples

210 – 309

Every day on Logarithmic History we cover an interval 5.46% shorter than the preceding day. From covering the first 754 million years after the Big Bang on January 1, we’re down to one century worth of history today.

And it’s a bad century for both Rome and China. Rome goes through an economic crisis, with a huge currency devaluation. Political life goes to hell too. From 235-284 there are 20 Emperors; 18 of them die violently. The Roman Empire experiences multiple, destructive invasions by barbarians. Previously under the Pax Romana, most of the cities of the Empire, including Rome, had been unwalled; now there is a spate of wall-building. The empire recovers toward the end of the century, but in a more heavily militarized and authoritarian form. And in China the Han dynasty disappears entirely after 220, to be replaced by three kingdoms of barbarian origin.

This coincidence of catastrophes may be more than just bad luck. Put it this way: If we look at the Big Picture, going way back on our calendar, and turning for a moment from human history to the evolution of life, we can summarize biological evolution since the Cambrian as:

• A process of escalation, in which arms races among organisms are major drives of progressive evolution …

but …

• Now and then, a physical catastrophe punctuates the history of life, causing mass extinctions, from which living things slowly recover.

Returning to human history, we can summarize social evolution since the adoption of agriculture as:

• A process of escalation, in which conflicts between rival groups (matrilineal and patrilineal kin groups, empires, and – we will see – major religions) are drivers of increasing social complexity …

but…

• Now and then, a biological catastrophe – in the form of an epidemic of some new disease – punctuates human history, causing major population losses, and often political and social collapse as well (i.e. the “germs” in Guns, Germs and Steel).

One such catastrophe contributed to the collapse of New World societies in the face of Old World diseases after 1492. But the Old World too must have had its own earlier catastrophes as the great killer diseases – the diseases of civilization that need a minimum population to keep going – established themselves.

Epidemic disease may have made a major contribution to the fall of Rome and of Han China. Rome suffered two massive epidemics, one from 165-180, another from 251-266. It’s plausible (and some day geneticsts will tell us whether it’s true or not) that these epidemics represent the arrival of smallpox and measles in the West. There is also evidence from the current distribution of tuberculosis strains that the expansion of the Roman Empire, and trade across borders, helped to spread this disease. And we’ll run into bubonic plague in a few days time (Saturday, October 13). There may be a similar story to tell about China, also stricken by epidemics at this time. The opening of the Silk Road and of trade across the Indian Ocean allowed precious goods and new ideas to travel between civilizations. It also opened the way for lethal microorganisms.

In addition to “Guns, Germs and Steel,” a classic book here is William McNeill’s Plagues and Peoples. For the Roman empire, more up-to-date, and with a wealth of information, is The Fate of Rome: Climate, Disease, and the End of an Empire.

Enjoy it while it lasts

105 – 209 CE

If a man were called to fix the period in the history of the world, during which the condition of the human race was most happy and prosperous, he would, without hesitation, name that which elapsed from the death of Domitian [96 CE] to the accession of Commodus [180 CE]. The vast extent of the Roman empire was governed by absolute power, under the guidance of virtue and wisdom. The armies were restrained by the firm but gentle hand of four successive emperors, whose characters and authority commanded involuntary respect.

Edward Gibbon, The Decline and Fall of the Roman Empire, Chapter 3

Gibbon doesn’t include China in this assessment of the state of the world, but for that country too, under the Eastern Han dynasty, there was a period of stability and prosperity, lasting from the death of the usurper Wang Mang in 24 CE to the outbreak of the Yellow Turban peasant uprising in 184 CE. During this time, the Roman and Han empires so completely dominated their respective portions of Eurasia that they enjoyed relative peace. Toward the end of the second century CE, both empires had populations around 50-60 million; world population was perhaps 190 million. In the succeeding centuries both empires would experience major population declines and political collapse. As a result, the world’s total population may have declined as well.

Ian Morris’ attempt to quantify historical progress, set forth in his book The Measure of Civilization, tends to corroborate Gibbon. Roman diets and biological well-being may or may not have been very good, but their standard of living, measured by energy capture – the energy embodied in livestock, household goods, dwellings, public buildings, infrastructure, and so on – may have reached heights unmatched in the West for a millennium.

Of course Gibbon’s view is a retrospective one, and didn’t anticipate the vast rise in standards of living that eventually followed the industrial revolution.

(After this I’ll give dates as numbers without the “CE”.)

The historical Jesus

6 BCE – 104 CE

The historical Jesus will be to our time a stranger and an enigma. The study of the Life of Jesus has had a curious history. It set out in quest of the historical Jesus, believing that when it had found Him it could bring Him straight into our time as a Teacher and Savior. It loosed the bands by which He had been riveted for centuries to the stony rocks of ecclesiastical doctrine, and rejoiced to see life and movement coming into the figure once more, and the historical Jesus advancing, as it seemed to meet it. But He does not stay: He passes by our time and returns to His own … by the same historical inevitability by which the liberated pendulum returns to its original position.

Albert Schweitzer, The Quest of the Historical Jesus

Taking stories of the past seriously is not the same as taking them literally, as we’ve already seen in the cases of Crater Lake and the Exodus. By the time Albert Schweitzer wrote the words above, scholars of the New Testament, working for more than a century, especially in Germany, had pieced together an account of Jesus and his message very much at variance with millennia-old Christian doctrine.* It’s a testament to Schweitzer’s intellectual integrity that he – a believing Christian – followed the evidence where it took him. His general conclusions (although not all the details) are now very much the scholarly mainstream. Bart Ehrman summarizes in Jesus: Apocalyptic Prophet of the New Millennium:

Jesus is best understood as a first-century Jewish apocalypticist. This is a shorthand way of saying that Jesus fully expected that the history of the world as we know it (well, as he knew it) was going to come to a screeching halt, that God was soon going to intervene in the affairs of this world, overthrow the forces of evil in a cosmic act of judgment, destroy huge masses of humanity, and abolish existing human political and religious institutions. All this would be a prelude to the arrival of a new order on earth, the Kingdom of God. Moreover, Jesus expected that this cataclysmic end of history would come in his own generation, at least during the lifetime of his disciples. It’s pretty shocking stuff, really. And the evidence that Jesus believed and taught it is fairly impressive.

The study of the past – by biologists, geologists, physicists, and philologists – had a disturbing effect on the intellectual equilibrium of a Christian society. No doubt it will go on disturbing us, Christian or not.

* Some “New Atheists” not only  reject the Christian conception of Jesus as Messiah and Savior, but doubt whether he existed at all. From the “History for Atheists” blog, here’s a good discussion of why most scholars believe that Jesus really existed.

The forgotten revolution

252 – 127 BCE

103,049

Here’s where this number comes from: Take a sequence of symbols, (a b c d e f g h i j), say. Construct as many groups as you want by sticking parentheses around any two or more symbols or groups. For example, ((a b) c d (e (f g)) h i j). Or (a (b (c (d e f g) h) i) j). Or (a (b (c d e)) f g (h i j)). There are 103,049 ways of doing this with ten symbols, so 103,049 is the tenth Schröder number, named after the man who published this result in 1870. But it turns out that the same number is given in Plutarch – attributed to Hipparchus (190-120 BCE) – as the number of “affirmative compound propositions” that can be made from ten simple propositions. It is only in 1994 that somebody connected the dots, and realized that Schröder numbers had been discovered 2000 years before Schröder.

This is just one example of the very high level of mathematical, scientific, and technical accomplishment attained within the Hellenistic world — the world of Greek culture after Alexander. Lucio Russo calls Hellenistic science The Forgotten Revolution. A couple more examples from his book:

Everybody knows that Aristotle – and thus “the Greeks” – thought that heavy objects fall faster than light ones. Supposedly it took Galileo to prove him wrong. But in fact there is a clear statement in Lucretius (De Rerum Natura II:225-239) that objects of different weight fall at the same speed, unless air resistance kicks in; Russo argues that circumstantial evidence points to Hipparchus as the source.

Russo also argues that Hellenistic thinkers understood that gravity could account for the spherical shapes of the earth and planets, and that the balance between gravity and linear velocity could account for circular orbits. He shows that some strange passages in Vitruvius and Pliny about the sun making planets go around by shooting out triangular rays make sense if you assume the authors were looking at, but not understanding, vector diagrams of successive straight line motions bent into a circle by a centripetal pull.

Russo argues that scientific progress largely came to an end by 150 BCE, and the Roman period saw an actual decline in scientific understanding. Later writers like Ptolemy and Galen, often taken to represent the height of Classical learning, were derivative, and didn’t really understand their predecessors: a stark reminder that a civilization may avoid collapse, and even maintain a decent level of prosperity, but regress intellectually.

Asabiya and meta-ethnic frontiers

In 390 BCE an army of Gauls, 30 thousand strong, marched out of northern Italy into Latium, an area that included Rome. They defeated a Roman army, sacked and burned Rome, and left only after being paid a large tribute. This marked a turning point for Rome, which resolved never again to allow such a disaster. Over the next century, Romans used a mixture of coercion and consent to bind their Italian allies more closely to them. Attempted secession was punished. But those who accepted their position as allies were not simply crushed and plundered (as in many other empires) but granted some or all of the privileges of Roman citizenship in return for military contributions. Membership in the Roman confederation was attractive enough that many Italian states sought it voluntarily.

The history of Greece during this period is different. Greek city-states never united. In the aftermath of the bloody Peloponnesian war, different city-states went on fighting for supremacy, until they were finally conquered by an outside power, Macedonia.

Peter Turchin is an ecologist-turned-social scientist who thinks that the contrast between Rome and Greece illustrates some general Laws of History. According to Turchin, the rise and fall of empires is partly conditioned on the strength of “asabiya,” or social solidarity. (He borrows the term from the medieval Arab historian ibn Khaldun.) The strength of states depends not just on material factors like population size and wealth, but also on morale – on the willingness of citizens to work together for the common good (which includes punishing free-riders). Asabiya was high in early Rome; in Greece, by contrast, while individual city-states might evoke strong group feeling, there was little willingness to cooperate for the good of Greece as a whole.

Asabiya in turn (according to Turchin) develops especially along “metaethnic frontiers,” where very different cultures meet and clash. The illustration (by me, writing about matrilocal asabiya, not Turchin) shows the general idea. When culture changes little, or changes gradually, with distance (a), there is little basis for uniting independent polities (stars) into enduring larger units, and alliances (dotted lines) shift constantly. Along the metaethnic frontier (b), the opposite is true (solid lines show cohesive enduring units). Think Game of Thrones versus Lord of the Rings: it’s easier to get men and elves and dwarves to work together when they are fighting an army of orcs serving the Dark Lord.

Sometimes a metaethnic frontier develops where major religions or ideologies clash. But in the Roman case, the metaethnic frontier ran along the line dividing civilized Italians from barbarian Celts. Greece, by contrast, experienced a surge in fellow-feeling when Athens and Sparta fought together to defeat Persia, but this was too short lived to lead to a unified state.

Also worth reading is Empires of Trust, tracing parallels between the expansion of early Rome and of the United States – two immense states on the western frontiers of civilization. (The book is better than most comparing America and Rome.)

And here’s me, on slime mold asabiya.

The way and the word, continued

Continuing yesterday’s post: What accounts for the differences between classical Greek and early Chinese intellectual traditions? Below are a few things that might be involved; this is hardly a complete list.

Non-degenerate limit random variables

Here’s a nice little puzzle involving probability:

Take a bag with two marbles in it, one red and one green. Draw a marble at random. Put it back in the bag, and add another marble of the same color. Repeat: randomly draw one of the (now three) marbles in the bag, put it back, and again add a marble of the same color. Continue, adding a marble every time. What happens to the frequency of red marbles as the number of marbles in the bag goes to infinity?

Answer: When you carry out this procedure, the frequency approaches a limit. As the number of marbles grows larger, you sooner or later get, and stay, arbitrarily close to the limit. Now carry out the same infinite procedure a second time. This time you also approach a limit. But the limit this time is different! The first time, the limiting frequency might be .23748… . The second time it might be .93334… . If you keep on doing the infinite experiment a bunch of times, you’ll approach a different limit every time, with the various limits uniformly distributed over the interval [0,1]. These are non-degenerate limits. This is different from what you get when you flip a fair coin infinitely many times. The frequency of heads will always approach the same “degenerate” limit, .50000… .

A chance element like this is probably involved in the intellectual traditions of major civilizations. The first few great thinkers to come along have a massive influence on the direction of intellectual life, just as picking a red or green ball on the first round makes a big difference to the final limit. So Pythagoras’ and Plato’s obsessions with numbers and geometry as the keys to the universe have a disproportionate influence on later Western thought (allowing that the “Pythagoras” we know is encrusted with legends). Subsequent thinkers have progressively less and less influence, just as picking a green or red ball when there are already a hundred balls in the bag doesn’t make much difference in the ultimate limiting frequency.

Temperament

But there may be more systematic things going on. Daniel Freedman was a psychologist, white, married to a Chinese-American woman. While awaiting the birth of their first child, the couple found that relatives on the two sides of the family had very different ideas about how newborns behave. Freedman was sufficiently intrigued that he carried out an investigation of assorted newborns in a San Francisco hospital, including babies of Chinese and European origin.

It was almost immediately apparent that Chinese and Caucasian babies were indeed like two different breeds. Caucasian babies started to cry more easily, and once started they were more difficult to console. Chinese babies adapted to almost any position in which they were placed.. … In a similar maneuver … we briefly pressed the baby’s nose with a cloth, forcing him to breathe with his mouth. Most Caucasian and black babies fight this … by immediately turning away or swiping at the cloth. However … the average Chinese baby in our study … simply lay on his back, breathing from his mouth. … Chinese babies were … more amenable and adaptable to the machinations of the examiners. p. 146

This might seem like a minor curiosity, but it fits neatly with later work demonstrating East-West differences in adult cognitive styles. This raises the possibility that differences in temperament evident at a very early age might influence the evolution of intellectual traditions.

Coinage

Coined money apparently initially appeared in Lydia, in Asia Minor, around 600 BCE. It was quickly taken up by the Lydians’ Ionian Greek neighbors. And it is in Ionia too that we find the earliest philosophers. In Money and the Early Greek Mind, Richard Seaford argues that these developments are connected. The monetization of the Greek economy accustomed Greeks to the idea that a common impersonal material measure of value, relatively independent of individual control, underlay the multifarious goods and services produced by the polis economy. This led in turn to the pre-Socratic philosophers, who were obsessed with finding the one impersonal natural element – water, air, number – of which the whole heterogeneous variety of the natural world was made.

In Athens, the expansion of a monetary economy led to a curious insult – opsophagos, or fish-eater. What made this an insult is that fish were sold in the marketplace. They were a mere commodity, free of the ritual and taboos that surrounded the sacrifice and distribution of animal flesh. The fish-eater was a rich man indulging the pleasures of consumption free from the constraints of tradition and decorum. And his conspicuous consumption offended not only tradition but the spirit of democracy. Better that he spend his wealth on the public good.

In traditional China, by contrast, coins, and later paper money, would challenge but never break the hold of state patriarchy. And Spartans too recognized the subversive potential of money. Sparta used iron bars for money, precisely because they were inconvenient.

The way and the word

523 – 384 BCE

Over the course of the mid to late first millennium BCE, Greeks and Chinese developed impressive intellectual traditions that would profoundly influence later civilization. These traditions differed a lot. In content:

The fundamental concepts at play in Greece and China were strikingly dissimilar. The Greeks focused on nature and on elements, concepts that seem familiar and obvious to those educated in modern science.  They invented the concept of nature to serve distinct polemical purposes – to define their sphere of competence as new-style investigators and to underline the superiority of naturalistic views to … traditional beliefs. … Chinese investigators had a very different set of fundamental concerns, not nature and the elements, but the tao, ch’i, yin–yang, and the five phases. Where Greek inquirers strove to make a reputation for themselves as new-style Masters of Truth, most Chinese Possessors of the Way, had a very different program, namely to advise and guide rulers. … To that end they … redefined existing concepts … to produce a synthesis in which heaven, earth, society, and the human body all interacted to form a single resonant universe.

Geoffrey Lloyd and Nathan Sivin. The Way and the Word: Science and Medicine in Early China and Greece, p. 241

And in style of engagement:

Ancient Greek culture encouraged disagreement in natural philosophy and science as in every other field; the Chinese emphasized consensus. Success in debate was how you made your name in Greece, in a way that has no analogue in China.

Ibid. p.  247

What accounts for these differences? A few thoughts tomorrow.

State patriarchy and the Ancient City

671 – 524 BCE

The period leading up to historical times saw the rise of patrilineal descent groups (and maybe some transitions from matrilineal descent) across Eurasia. Different civilizations found different ways of accommodating these groups. In China, patrilineal clans go as far back as we have any historical records, back to the Shang dynasty. Confucius (551-479 BCE) in some ways represented a break with this past. He thought a wise prince should select ministers based on their ability rather than their lineage. But China could never be governed by bureaucrats alone, and Chinese states found themselves depending on extended families and clans to help rule the country. The Confucian state exalted filial piety, obedience to one’s elders, and ancestor worship along with obedience to the Emperor. When an official told Confucius “In my country there is an upright man named Kung. When his father stole a sheep, Kung bore witness against him,” Confucius replied, “The upright men in my community are different from this. The father conceals the misconduct of the son. The son conceals the misconduct of the father. Uprightness is to be found in this.” The resulting social compact – Arthur Wolf, an anthropologist of China, calls it “state patriarchy” – was extraordinarily resilient. In days to come we will see how it kept bouncing back from one disruption after another, like one of those heavy-bottomed dolls you just can’t keep knocked over.

By contrast, the classical city-states of Greece and Rome went through a series of social revolutions early in their history where both kings and patrilineages lost their exalted position. This argument was developed back in the nineteenth century by the French historian Numa Denis Fustel de Coulanges. In his book The Ancient City, Fustel showed how ancestor worship and clan loyalty gave way to civic institutions. For example in Athens the democratic reformer Cleisthenes (570-508) replaced old-style subdivisions of the populace based on descent with new subdivisions based on residence. For a time, the classical city-state commanded intense loyalty from its citizens, and displayed an exceptionally high level of military effectiveness.

China’s revolution against the old order of elders, extended family, and clan waited until the twentieth century, and took a horrific toll on the population. Even today some of the old ways persist. The putative patrilineal descendants of Confucius, more than two million strong, have recently been updating their genealogies, have recently been updating their genealogies.