Ubiquity tells the story of dynamic complex systems. It explains how some systems in the world organize themselves on the edge of instability which can lead to catastrophic outcomes like earthquakes, forest fires, financial crashes, and more.
The Notes
- “Life is understood backwards but must be lived forwards.” — Søren Kierkegaard
- “Men wiser and more learned than I have discerned in history a plot, a rhythm, a predetermined pattern. These harmonies are concealed from me. I can see only one emergency following upon another…and only one safe rule for the historian: that he should recognize in the development of human destinies the play of the contingent and the unforeseen….The ground gained by one generation may be lost by the next.” — H.A.L. Fisher
- Humans are terrible at predicting the future and great at coming up with an explanation for why something happened after the fact…even when there is no consensus as to why. In other words, humans have an innate ability to see patterns that don’t exist to find meaning and make sense of history. And, at times, attempt to use those same patterns to incorrectly predict the future.
- Ex: Historians still come up with new causes for WWI, there’s no consensus on its cause.
- Ex: “The crash of 1987 was such a storm of mass emotion that ‘market as machine’ theorists worked overtime explaining the drop and figuring out how to ‘fix’ the system. The theory that gained the most credence was that the crash was caused by so-called portfolio insurance computer programs, which in essence sold stocks as the market went lower… Unfortunately for the theory, it does not explain very well why markets around the world crashed simultaneously or why the decline stopped. It is at an utter loss to explain why many indexes around the world that had no computer trading fell further than the Dow Jones Industrial Index. It also ignores the fact that throughout 1986 and 1987, market observers in an equally serious tone had continually explained why a stock market crash was impossible because of ‘safeguards that are in place,’ safeguards such as portfolio insurance.” — Robert Prechter Jr.
- “The art of being wise is the art of knowing what to overlook.” — William James
- “This book is about a terrific step along the scientific road of learning what to overlook. It is about the discovery of a profound similarity not between triangles or moving objects, but between the upheavals that affect our lives, and the ways in which the complicated networks in which they occur—economies, political systems, ecosystems, and so on—are naturally organized.”
- “Predicting the long-term future of any chaotic system is practically impossible, and a chaotic process looks wildly erratic even if the underlying rules are actually quite simple.”
- Most ecosystems, economies, organisms, etc. are complex systems. Complex systems are chaotic. Much of the time the complex system sits at equilibrium — where all its underlying forces are in balance. Disequilibrium (instability) creates the chance for upheaval in the system.
- “The key idea is the notion of the critical state, a special kind of organization characterized by a tendency toward sudden and tumultuous changes, an organization that seems to arise naturally under diverse conditions when a system gets pushed away from equilibrium.”
- “There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.” — Mark Twain
- “Time and again, history has proved a very bad predictor of future events. This is because history never repeats itself; nothing in human society…ever happens twice under exactly the same conditions or in exactly the same way.” — Richard Evans, In Defense of History
- “To trace something unknown back to something known is alleviating, soothing, gratifying and gives moreover a feeling of power. Danger, disquiet, anxiety attend the unknown—the first instinct is to eliminate these distressing states. First principle: any explanation is better than none… The cause-creating drive is thus conditioned and excited by the feeling of fear…” — Friedrich Nietzsche
- Power Law – a relationship between two things in which a change in one leads to a relative change in the other. “A power law, with its scale-invariant form, implies that large events are just magnified copies of smaller ones, and that they arise from the same kinds of causes.”
- Sandpile Game
- Per Bak, Chao Tang, and Kurt Weisenfeld created a sandpile game to better understand what causes an avalanche.
- The game drops one grain of sand at a time until it grows into a giant pile to see how long before it triggers a collapse.
- They found that there was no way to predict which grain of sand would trigger an avalanche or its size.
- The sandpile naturally configured itself into a critical state where any grain of sand could trigger an avalanche of any size at any time.
- Bak et al, found a power law, after counting how often avalanches of each size occurred, in that as the size of the avalanche doubled, it was twice as unlikely to occur.
- “In this simplified setting of the sandpile, the power law also points to something else: the surprising conclusion that even the greatest of events have no special or exceptional… What makes one avalanche much larger than another has nothing to do with its original cause, and nothing to do with some special situation in the pile just before it starts. Rather, it has to do with the perpetually unstable organization of the critical state, which makes it always possible for the next grain to trigger an avalanche of any size.”
- Freezing Game
- Tom Witten and Leonard Sanders created a simple game to mimic the freezing process of copper.
- They found that a in molten state, copper particles follow a random path. But as one particle solidifies, the molten particles following a random path will miss it or hit it and stick. As more particles hit it and stick it grows into a cluster.
- They learned:
- Clusters grow into complex shapes that make every cluster unique.
- The clusters also had a hidden simplicity. The clusters have a property known as self-invariance or self-similarity i.e. the shapes look similar at different scales, despite each being unique.
- Earthquakes
- “Since my first attachment to seismology, I have had a horror of predictions and predictors. Journalists and the general public rush to any suggestion of earthquake prediction like hogs toward a full trough.” — Charles Richter
- Iben Browning predicted an earthquake would hit the midwest U.S. — the New Madrid fault — between December 1st and 5th, 1990. States prepared for the worst, closed schools, and set up an emergency response. Yet, the U.S. Geological Survey said the prediction had no merit. The quake never happened.
- Brian Brady predicted two quakes — 9.8 and 8.8 — would hit Peru in August 1981 and May 1982 and a foreshock of 7.5 or more would occur in June 1981. None of it happened. Brady retracted his prediction after the foreshock failed to appear.
- Japanese scientists predicted a “great Tokai earthquake” in the late 1970s due to the “pattern” of time between quakes in that area. Didn’t arrive.
- William Bakun predicted a quake in Parkfield, California, on the San Andreas fault, after noticing a “pattern” of earthquakes occurring in the area on an average of once every 22 years. Bekun believed it was a cyclical process. The U.S. Geological Survey agreed, and issued its own Parkfield prediction, in 1985, that a quake would hit sometime in the next 5 to 6 years. It never hit.
- Earthquakes are hard to predict: “After a century of research, virtually all quakes still come completely unannounced.”
- “Earthquake prediction research has been conducted for over 100 years with no obvious successes. Claims of breakthroughs have failed to withstand scrutiny. Extensive searches have failed to find reliable precursors…reliable issuing of alarms of imminent large earthquakes appears to be effectively impossible.” — Robert Geller
- The Earth’s crust is a complex system of 8 major plates, and numerous smaller plates, made up of different types of rocks with different properties, being pushed about by the Earth’s mantle and made more complicated by how each plate interacts with one another. The plates are under constant stress. As the stress builds, a segment along the fault hits its threshold, and the plate slips. What happens next determines the size of the earthquake. The earthquake could stop at a single slip or the slip could create instability in nearby areas of the fault and lead to further slipping.
- “Earthquakes in the real world tend to be accompanied by foreshocks and aftershocks, which is another way of saying that large earthquakes tend to cluster together in time, and that the longer you wait without seeing one, the longer you will probably have to wait.”
- Gutenberg-Richter Law:
- “This law reveals that larger quakes take place less frequently than smaller, and what’s more, that the precise numbers follow a relationship known to mathematicians as a power law—a special mathematical pattern which has a simplicity that stands in shocking contrast to the overall complexity of the earthquake process.”
- The bigger the earthquake, the rarer it is.
- Richter scale measures the energy of an earthquake. It’s exponential. When a magnitude goes up by one, the energy goes up by 10.
- “The Gutenberg-Richter law boils down to one very simple rule: If earthquakes of type A release twice the energy of those of type B, then type A quakes happen four times less frequently. Double the energy, that is, and an earthquake becomes four times as rare. This simple pattern—a power law—holds for quakes over a tremendous range of energies.”
- “Catastrophic earthquakes, then, strike in a very real sense for no reason at all. There is an explanation for why there are such earthquakes in the first place: it is the very fact that the Earth’s crust is tuned to be in a critical state, and lives on the edge of upheaval. But there is no explanation—other than a simple narrative telling, after the fact, of which rocks slipped and in what sequence.”
- “It appears that, at many levels, our world is at all times tuned to be on the edge of sudden, radical change, and that these and other upheavals may all be strictly unavoidable and unforeseeable, even just moments before they strike. Consequently, our human longing for explanation may be terribly misplaced, and doomed always to go unsatisfied.”
- Forest Fires
- Bruce Malamud et al studied a century of forest fires in the U.S. and Australia to see how large the typical forest fire was.
- They did not find a “typical” size. Instead, they found a pattern with a power law: as the size of the forest fire doubles, it becomes about 2.48 times as rare.
- “Fires spread as they do because any forest has the organization of the critical state, and how far any particular fire goes is largely a matter of chance.”
- Yellowstone Effect — forests with very few fires, grow denser over time, but the higher density increases the likelihood that the next fire could be catastrophic.
- The unintended consequence of a “zero tolerance” approach to forest fires by the U.S. Forest Service is that forests age, ground debris accumulates, and forests enter a state of instability. The forest was no longer in a critical state and the next match could be catastrophic.
- “Fires are an indispensable component of the natural dynamics that keep forests in that state, so by suppressing them, the Forest Service has instead driven the forests into an even more unstable state, a supercritical state, with a high density of burnable material everywhere.”
- Managed burns reduce old growth and debris and the possibility that a forest reaches a supercritical state and harder to trigger a catastrophic fire.
- Self-Organized Criticality
- A property of a complex dynamic system that naturally tunes itself toward criticality.
- It explains forest fires, grasshopper outbreaks, measles epidemics, traffic jams, solar flares, financial markets, and more.
- “Self-organized criticality seems to show up only in things that are driven very slowly away from equilibrium, and in which the actions of any individual piece are dominated by its interactions with other elements.”
- Mass Extinction Events
- Fossil records show catastrophic extinction events 440, 365, 250, 210, and 65 million years ago.
- The most recent, 65 million, wiped out the dinosaurs and 75% of all species on Earth. The KT boundary separates two geological time periods marked by the extinction event. It’s believed that a comet or asteroid struck Earth near the Yucatan Peninsula because iridium, ruthenium, and rhodium — common in comets and asteroids — are found across the KT boundary. What they don’t know is why some species survived while others died out.
- The event that struck 250 million years ago wiped out 95% of all species.
- “The Big Five extinctions are merely the most obvious of the sudden disruptions. In between, the record shows countless smaller mass extinctions. Life on Earth seems to suffer sporadic and catastrophic episodes of collapse.”
- “Not every extinction is part of a mass extinction. Evolutionary biologists estimate that some few billion different species have evolved at one time or another during the course of life’s history. Only a few tens of millions exist today, however, which means that 99 percent of all species in history are now extinct. Extinction is so natural an event in evolution that, as someone once said, ‘To a first approximation, everything is extinct.’ As it turns out, only 35 percent of all species died out as part of a mass extinction. The “background” extinctions account for nearly two-thirds of all extinctions.”
- “The alteration of background and extinction regimes shapes the large-scale evolutionary patterns in the history of life.” — David Jablonski
- “That pattern includes two phases, the intervals of background extinctions, in which species disappear at a low rate, and episodes of high rates of extinctions, including major biotic crises. Most biologists agree that the prevailing force in times of background extinctions is natural selection, in which competition plays an important part.” — Richard Leakey and Roger Lewin
- Jack Sepkoski
- Cataloged groups of marine invertebrates from when they came into being to when they went extinct. Sponges and corals make up the largest part of the fossil record. His catalog presents a condensed view of how life changed over the past 600 million years.
- Pull of the Recent — only a tiny number of organisms at any time end up as fossils. The most recent fossils are most likely to remain intact through today.
- Monograph Effect — the only species we know about are those that have 1) ended up as fossils and 2) were discovered. Most species are undiscovered. Any record keeping of any kind will look like sudden bursts in the number of species when it’s really a blip.
- Signor-Lipps Effect — the error rate when dating fossils is relative to the number of fossils available to you. Fewer fossils lead to a greater error in estimating the species extinction.
- Lipps-Signor Effect — fewer fossils increase the error rate when estimating the origination of a species.
- Sepkoski’s record shows that the extinction of species followed a normal evolutionary process interspersed by sudden cataclysmic events.
- “The distribution of extinctions according to their size (this being taken as the number of families that went extinct) follows our old friend the power law. In fact, the pattern of regularity is in this case identical to that for earthquakes: if you double the size of the extinction under consideration, you find that such events become four times as rare. And this power-law regularity extends from extinctions involving just a few families all the way up to the worst events that wiped out thousands.”
- Peter Yodzis studied different ecosystems. The theory goes that removing a predator should result in an increased number of its prey. Yodzis found that the ecosystems are so complex that the effect of removing a predator is unpredictable. Species are linked in numerous indirect ways that lead to unforeseen consequences when removing one species from the ecosystem.
- Since it’s impossible to know the impact of the extinction of one species on an ecosystem, it could have a minimal effect or it could set off a cascade that wipes out another species, and another, leading to mass extinction.
- “If ecosystems live in a critical state, then large upheavals should be expected, and we should expect to find scale-free distributions everywhere.”
- Stuart Kaufman studied molecules and found that some act as catalysts that speed up the chemical interactions with others. He found that as he increased the number of molecules it created an autocatalytic set — a positive feedback loop where the collection of molecules catalyzed on its own. The number of molecules does not have to be large to create this feedback loop.
- “Evolution accomplishes its ends through the triple action of variation, selection, and replication.”
- Kaufman turned his attention to evolution and created a game that mimicked evolutionary change. His game showed that an evolutionary change in a single species could have little to no effect on an ecosystem or it could trigger an evolutionary chain reaction in every other species in the ecosystem. It was impossible to predict the size of the impact. The game produced long periods of little evolutionary change interrupted by massive bursts of activity.
- Kaufman adjusted his game for the existence of food chains: “The food chain naturally organizes itself into a critical state in which the extinction of just one inconspicuous species near the bottom can trigger an avalanche of further extinctions of any size. And most impressively, extinctions become precisely four times less likely each time the size is doubled, in excellent agreement with the real fossil record.”
- The final complication relates to external shocks. Ecosystems tend to adapt to its immediate environmental conditions. In other words, species don’t prepare in advance for ice ages, asteroids, etc. The impact of any external shock is unpredictable. It could lead to minor extinction events or massive events.
- Critical State Universality:
- Phase Transitions — the process of transition between one state and another like changing from gas to liquid or liquid to solid.
- “In the late 1960s physicists discovered that there is a universal organization for substances in a critical state. Remarkably, while there are thousands of different substances all complicated by their own specific details, the critical state is in every case much the same. So the world is immeasurably simpler than it might have been. The lesson is this: When it comes to understanding something in a critical state, most of the details simply do not matter.”
- Leo Kaufman found that the only thing that seemed to matter was the shape of the element and the physical dimension it existed in.
- “So forget the atomic masses and the electrical charges of the particles involved. Forget whether those particles are atoms of oxygen, nitrogen, krypton, nickel, or iron. Forget even whether they are made of single atoms or are more complicated molecules made of several or even a hundred atoms. Forget everything, in fact, about the kinds of particles and how strongly or weakly they interact with one another. None of these details affects the organization of the critical state even a tiny bit. This is critical state universality.”
- “The miracle of universality is that any two substances, real or imaginary, that fall into the same class will necessarily have exactly the same critical-state organization, regardless of how utterly dissimilar they may otherwise seem to be.”
- Economies and Markets
- “It is a conventional joke that there are as many different opinions about the future of the economy as there are economists. The truth is quite the opposite. Economic forecasters…all say more or less the same thing at the same time; the degree of agreement is astounding. The differences between forecasts are trivial relative to the differences between all forecasts and what happens….what they say is almost always wrong….the consensus forecast failed to predict any of the most important developments in the economy over the past seven years—the strength and resilience of the 1980s consumer spending boom, the depth and persistence of the 1990s recession, or the dramatic and continuing decline in inflation since 1991.” — John Kay
- “In 1993, the Organization for Economic Cooperation and Development (OECD) analyzed forecasts made between 1987 and 1992 by the governments of the United States, Japan, Germany, France, Italy, and Canada, as well as by the International Monetary Fund (IMF) and the OECD itself. The conclusion? Not only were each of these organizations’ predictions abysmally inaccurate, but they would have made better predictions for inflation and gross domestic product if they had scrapped all their “sophisticated” economic models and simply guessed that the numbers in each year would be unchanged from the last.”
- “When they are predicting anything that involves money, economists, prominent investors and the reporters who quote them haven’t been wrong on occasion: they’ve been unerringly errant.” — John Rothchild
- Predicting the economic future is impossible.
- “According to the numbers, sudden upheavals are very far from being highly unlikely, and may indeed even be inevitable. In direct conflict with everything the efficient market hypothesis stands for, large fluctuations in market prices seem to result from the natural, internal workings of markets, and so flare up from time to time even if there aren’t any ‘sources of structural fragility,’ or sudden alterations of the fundamentals to set them off. And the reason may be quite simple: markets are not even remotely close to being in equilibrium.”
- Benoit Mandelbrot studied cotton prices and found that prices not only followed a random walk but the price changes had no typical size and followed a power law.
- Gene Stanley studied the fluctuations in the S&P 500 and found that price changes were 16 times less likely each time you doubled the size of the fluctuation. There is no typical fluctuation in the S&P 500.
- “This power law implies that there is no such thing as a typical fluctuation, and so no reason to think that the largest swings either up or down are in any sense unusual. The idea that sudden and terrifically large changes need explaining doesn’t seem to hold up; in conflict with our intuition, even these are merely business as usual.”
- Similar power law forms are found in the fluctuations of individual stocks, foreign stock markets, and currency markets.
- “You can even look at the fluctuations in this volatility—that is, at how vigorously and erratically the market flits between its times of wildness and calm. Here again, researchers have found a scale-invariant power law: the market doesn’t have a typical wildness in its fluctuations. Even its volatility is itself highly volatile.”
- The belief that investors/speculators are rational agents is undone by the advertising industry. Humans can be manipulated, influenced, and biased, and act on those biases, which can then influence others.
- “It is hard to deny that people get swept up in a craze and became interested when they know that others are interested. This is not rational decision making, but human beings influencing one another nonrationally.”
- “All economic movements, by their very nature, are motivated by crowd psychology. Without due recognition of crowd-thinking…our theories of economics leave much to be desired….It has always seemed to me that the periodic madnesses which afflict mankind must reflect some deeply rooted trait in human nature….It is a force wholly impalpable…yet, knowledge of it is necessary to right judgement on passing events.” — Bernard Baruch
- Markets and economies operate in a critical state where the underlying factors sit at the edge of imbalance but any one factor or mood can trigger instability and magnified volatility. Because of that, it’s impossible to predict how big the next bull market will be or how big the next downturn will be. All we do know is that catastrophic market events are less likely than minor ones.
- “Despite the confident predictions of bulls and bears, and despite what you may read in the newspapers, mathematical analysis indicates that no matter what the market has just done over the past week, month, or year, prices are still just as likely to go up in the near future as down. But this only hints at the true flagrancy of the market’s unpredictability, or, shall we say, its upheavability. The power law for price fluctuations indicates that even the rough magnitude of the upcoming change is unforeseeable. In a market organized to the critical point, even the great stock market crashes are simply ordinary, expected events, although it is true that we should expect them infrequently. Even though there are no indicators whatsoever, the market may fall by 20 percent tomorrow. Such events need not be triggered by anything exceptional.”
- Social Networks
- Six Degrees of Separation — Stanley Milgram ran a social experiment by sending letters to random people in Kansas and Nebraska with instructions that it should be sent to a stockbroker friend of his in Boston (with no address for his friend). He found that it took about six steps for the letter to reach his friend. Each of us is connected by a chain of acquaintances of no more than six people.
- Six Degrees of Kevin Bacon — is a game based on six degrees of separation played by randomly choosing an actor, connecting that actor to another actor in the same film, and repeating that process until you arrive at Kevin Bacon.
- All social networks have this small world character that links everyone into a close connection of a few steps.
- Small world character helps explain the speed at which infectious diseases and ideas spread.
- “Financial markets are wild at heart, seemingly because the opinions or expectations of one investor can affect those of another. The small-world character of the social and business relationships among traders in financial markets simply adds to the ease with which such influences can be amplified immensely. It may, in fact, make it even easier for the wild fluctuations of the critical state to rip through the markets.”
- City Populations:
- Follow a power law where for every city of a certain size, there are four cities with populations half that size. This is true in the U.S. and worldwide.
- There is no normal size of a city and no way to predict how big a “new” city will become.
- Patterns can also be found inside cities in which areas people choose to live.
- Similar patterns can be found in demographics around wealth. For every amount of wealth, there are four times as many people who have half that amount of wealth. Ex: for every billionaire, there are four times as many half-billionaires.
- Science
- “Science is the belief in the ignorance of experts.” — Richard Feynman
- Thomas Kuhn found that scientists were often closed-minded, quick to reject, or ignored ideas that contradicted their views.
- “Scientists aren’t superhuman, and, when doing science, they aren’t even all that different from anyone else. They suffer the usual human biases and blindnesses, and often “want” the world to turn out to be one way rather than another. None of this implies that science does not work. Indeed, it seems to work, and spectacularly well.”
- Paradigms — “Accepted examples of actual scientific practice—examples which include law, theory, application, and instrumentation together—providing models from which spring particular coherent traditions of scientific research.” — Thomas Kuhn
- Normal scientific work tries to extend the ideas and allow for a better understanding of things that fall within a particular paradigm. But not all ideas fit neatly into a paradigm. Those ideas are what can lead to scientific revolutions and a new paradigm.
- “Normal science repeatedly goes astray. And when it does—when, that is, the profession can no longer evade anomalies that subvert the existing tradition of scientific practice—then begin the extraordinary investigations that lead the profession at last to a new set of commitments, a new basis for the practice of science. The extraordinary episodes in which that shift of professional commitments occurs are…scientific revolutions. They are the tradition-shattering complements to the tradition-bound activity of normal science.” — Thomas Kuhn
- For science to advance it needs anomalous ideas that overcome the inertia of the old guard.
- Citations of scientific papers follow a power law — as the number of citations doubles, the number of papers with that many citations falls by about eight. There is no “typical” number of citations for scientific papers. There is no way to predict how important any one paper might become.
- “In every paradigm, scientists discover a logical structure that makes sense of a portion of the world and gives them an intellectual foundation to which they cling until the discrepancies and inconsistencies grow so unsettling as to force them to break with tradition and alter some of their cherished ideas.”
- War
- “They fight and fight and fight; they are fighting now, they fought before, and they’ll fight in the future… So you see, you can say anything about world history… Except one thing, that is. It cannot be said that world history is reasonable.” — Fyodor Dostoyevsky
- Leslie Richardson studied the 82 wars that occurred between 1820 and 1929. He found a power law whereas the number of deaths doubled, the wars of that size were four times less common.
- Other studies corrected for population and found a similar power in the size of wars. When adjusting deaths for population the power law says that wars become 2.6 times less frequent each time you double the number of deaths.
- There is no “typical” sized war and no way to predict how big any war will get.
- It suggests that the world is organized in a critical state and any conflict can trigger instability and war.
- History
- “In the law of gravitation, physicists find the principal explanation for the motion of the planets and the shapes of galaxies. But history is not like physics. In history, frozen accidents continually alter the playing field on which the future must unfold, and so the historian can only fall back on the telling of stories.”
- “The very use of language commits the historian, like the scientist, to generalisation… When Gibbon wrote of both the establishment of Christianity by Constantine and the rise of Islam as Revolutions, he was generalising two unique events. Modern historians do the same when they write of the English, French, Russian and Chinese revolutions. The historian is not really interested in the unique, but in what is general in the unique.” — Edward Hallett Carr
- Revolutions are founded on human distress and maladjustment but only arise by overcoming inertia.
- “The facts of history are indeed facts about individuals, but not about actions of individuals performed in isolation, and not about the motives, real or imaginary, from which individuals suppose themselves to have acted. They are facts about the relations of individuals to one another in society and about the social forces which produce from the actions of individuals results often at variance with, and sometimes opposite to, the results which they themselves intended.” — Edward Hallett Carr
- “It is always a mistake for the historian to try to predict the future. Life, unlike science, is simply too full of surprises.” — Richard Evans, In Defense of History
- “Nothing causes more error or unfairness in man’s view of history than the interest which is inspired by individual characters.” — Lord Acton
- “History is to a considerable extent a matter of numbers.” — Edward Hallett Carr
- “Among all civilized peoples the political sciences create, or at least give shape to, general ideas; and from these general ideas are formed the problems in the midst of which politicians must struggle, and also the laws which they imagine they create.” — Alexis de Tocqueville
- “Genius is the summed production of the many with the names of the few attached for easy recall.” — Edward O. Wilson
- “Writing history is like drinking an ocean and pissing a cupful.” — Gustave Flaubert
- “When you read a work of history, always listen out for the buzzing. If you can detect none, either you are tone deaf or your historian is a dull dog. The facts are really not at all like fish on the fishmonger’s slab. They are like fish swimming about in a vast and sometimes inaccessible ocean; and what the historian catches will depend, partly on chance, but mainly on what part of the ocean he chooses to fish in and what tackle he chooses to use—these two factors being, of course, determined by the kind of fish he wants to catch.” — Edward Hallett Carr
- “Cleopatra’s nose, had it been shorter, the whole face of the world would have changed.” — Blaise Pascal
- “If the smallest of details continually intrude on the larger picture, with the power to alter it radically, how is the historian to make sense of anything? Faced with this dilemma, it becomes doubly difficult for the historian to separate the significant historical facts from the background of all facts.”
- Historians have to struggle with the possibility their story about a chain of events may have been triggered by an accident or random occurrence. Despite our need to make sense of what happened, there is always a possibility of not knowing what set things off.
- “There is something in the nature of historical events which twists the course of history in a direction that no man ever intended.” — Herbert Butterfield
- “Human history is a bit like biological evolution: what there is in the present goes together in new ways to produce things in the future, the likes of which have never before existed.”
- “It is not chaos that historians should be turning to for instruction, but universality—the notable discovery that under very broad conditions, systems made of interacting objects of all different kinds show universal features in their behavior.”