Great Progress
The metrics that settle the argument
Child mortality is the most unforgiving of statistics. It measures the fraction of children who die before their fifth birthday — a brutal index of how well a society protects its most vulnerable. In 1800 that fraction was not a fraction at all but a near-certainty: one in three children, in many places one in two, never saw age five. Every family knew grief as intimately as life itself. Draw the world as a map shaded by child mortality in 1800 and the whole thing is blood red — every continent, every empire, every faith. Humanity lived in a constant state of loss, and had for its entire existence.
Redraw the map for 1950 and the picture fractures. The industrialized world — Western Europe, North America, Japan, Oceania — had cut child mortality below five percent. Antibiotics, vaccines, sanitation, and rising prosperity insulated their children from the epidemics and malnutrition that once claimed millions. But the rest of the globe still bled: across Africa, India, the Middle East, and Latin America, between a fifth and two-fifths of children still died young. The division was stark, and it was not racial or cultural or providential. Modernity saved lives, and its absence cost them.
Redraw it once more for 2015 and the transformation is unmistakable. In wealthy nations child mortality sits below one percent. Latin America, East Asia, and the Middle East approach survival rates once reserved for kings’ heirs. Even Sub-Saharan Africa, still the most burdened region, has fallen to a range of five to twelve percent — down from one-in-three only two generations before. From one-in-three to under one-in-a-hundred across most of the earth, in the span of two centuries: millions of lives spared, families unbroken, futures restored.
I lead with this number because it is the least disputable metric of progress we have. GDP can be gamed, happiness surveys can be argued with, and every composite index embeds someone’s weighting scheme. A dead child is not a modeling choice. Whether children live to grow up is a fact about the world, and the fact has moved in one direction, massively, everywhere.
The causes are neither mysterious nor ideological. Vaccines, antibiotics, oral rehydration therapy. Clean water, sanitation, nutrition. Maternal education and economic growth. Each step a practical intervention; together, a revolution in human destiny. The story is not finished — Sub-Saharan Africa and parts of South Asia still carry the heaviest burdens, where poverty, weak health systems, and conflict conspire against further gains. But humanity has demonstrated that child mortality is not fate. It is policy, technology, and will. For centuries death claimed children as a tax on life itself; in most of the world that tax has been abolished. Civilization’s scorecard is disputed on almost every line, but here the verdict is clear: progress is real, measurable, and monumental.
One Number for Civilization
Grant the child-mortality collapse and a broader question follows: how do you measure the level of a civilization as a whole? The usual answer is a dashboard — GDP per capita, literacy rates, technological capability, political stability, happiness indices — and the dashboard drowns you. Every metric offers something; their multiplicity obscures the trend and invites cherry-picking, which is precisely what the pessimists do for a living.
I propose a single robust proxy: life expectancy at birth.
Life expectancy is uniquely holistic. GDP can mask deep inequality; literacy says nothing about health or material security. Life expectancy implicitly integrates healthcare quality, nutrition, prosperity, technological sophistication, education, and institutional strength, because a society cannot sustainably raise it without improving most of those at once. It contains the child-mortality collapse as its largest single component and then keeps counting — through working life, into old age. And it naturally penalizes exactly the things that ought to be penalized: violent conflict, pandemics, oppression, and corruption all shorten lives directly. Societies that keep their people alive a long time turn out, with striking regularity, to be societies with functioning courts, competent engineers, honest enough officials, and stable enough economies. Societies that cannot are struggling with poverty, weak governance, and instability, whatever their monuments say.
The obvious objection is that life expectancy ignores freedom, happiness, and cultural richness. Narrowly, true. But sustained high life expectancy is hard to fake and hard to achieve by decree; in practice it implies significant personal autonomy, effective governance, and social trust — the same factors that correlate with subjective well-being and cultural vibrancy. A regime can build a skyline in a decade. It cannot make its population live to eighty without becoming, in most of the ways that matter, a decent place to live. Track this one number over time and across populations and you get the trajectory of civilization without the dashboard.
The Pharaoh’s Missing Luxury
Metrics measure progress from the outside. From the inside, the strange thing about progress is that its greatest products are invisible to the people who enjoy them.
We flatter ourselves that modernity’s luxuries are smartphones, jet travel, and AI, and we overlook the true apex of modern luxury: the long, hot, private, cheap shower. No king or emperor ever had it. The richest tyrants of history could summon armies but not hot water on demand in a private chamber. That miracle belongs to you.
Take it apart. Heat: your ancestors shivered through winters and feared cold as death’s herald; you step into a chamber where fire has been tamed and piped into water. Privacy: bathing was once communal, humiliating, or ritualized; now it is solitude at will, dignity preserved by tile and lock. Convenience: the richest pharaoh could not roll out of bed and be under cleansing warmth in thirty seconds, and you can — true luxury is not rare but repeatable, frictionless. Cheapness: you need not calculate whether one more minute under the water is decadent excess. The indulgence is guiltless because the infrastructure makes it scalable. Luxury, democratized.
You do not see the miles of pipe, the energy grid, the pumps and boilers, the generations of engineers and laborers who built this invisible empire for your convenience. All you see is water that obeys. That is what civilization is: miracles normalized into background noise. Lose the shower for a week — camping, a war zone, a broken heater — and you will remember what it was. Not hygiene: sanctuary.
This is wealth in the proper sense — accumulated capacity to satisfy human purposes, almost none of it appearing as anyone’s line item — and its invisibility is why the progress argument has to be made at all. Nobody feels grateful for the absence of cholera. The baseline resets within a generation, the miracle becomes plumbing, and the beneficiaries of the greatest enrichment in human history conclude that the system that produced it has failed them. Poverty is the default condition of mankind; wealth is the anomaly that needs explaining. So explain it.
The Rome Test
Here is a thought experiment that forces the explanation into the open. Suppose you could send a single document back to the Roman Empire in 27 B.C. — a codex of roughly a hundred pages, no smartphone, no magic, everything buildable with Roman materials, labor, and social structures. What is the smallest, most catalytic subset of modern knowledge that could trigger an industrial revolution nearly two thousand years early?
Working out what goes in the codex is a precise way of asking what actually causes progress, because every page spent on one thing is a page not spent on another. And the exercise delivers a sharp verdict: almost none of the budget goes to gadgets. It goes to four kinds of recursion.
First, and above everything, the method. Without a reliable way of generating and testing ideas, any single invention is brittle — a marvel that decays into ritual within a generation. The keystone pages teach the scientific method: truth comes from repeated, controlled observation, not from authority or tradition; experiments must be documented and reproducible; predictions that fail are discarded no matter who proposed them. Rome already had literate elites and superb engineers. What it lacked was the engine that turns tinkering into a systematic discovery process — the one technology that manufactures all the others.
Second, concentrated energy. Progress is, at bottom, a thermodynamic project: more work done per human muscle. The codex sketches the upgrade path from water wheels to heat engines — coke from coal, hotter furnaces, steel consistent enough for pressure vessels (a few pages suffice; the details are refinements the method will supply) — arriving at a low-pressure atmospheric steam engine that Roman metallurgy could actually build: boiler, piston, and beam, pumping water from mines, then a crank and flywheel to turn reciprocation into rotation, then line shafts driving mills, saws, and lathes. The lathes cut better engine parts, and the loop closes. Alongside it, a page of basic thermodynamics and a page of germ theory and sanitation — boil water, wash hands, separate sewage from drinking water, quarantine the contagious — because industrial growth requires a healthy, numerous workforce, and lower child mortality is the first dividend any civilization collects.
Third, information reproduction. A printing press — a screw press adapted to movable type, well within Roman carpentry — accelerates the spread of everything else. Mass-produced technical manuals, standardized weights and measures across the empire, results from Alexandria criticizing results from Gaul. Knowledge that cannot be cheaply copied dies with its keeper; knowledge that can be copied compounds.
Fourth, capital formation. The quietest pages matter most: double-entry accounting, the joint-stock company, an early patent system, broad literacy. Inventions do not fund, build, and deploy themselves. There must be institutions that let strangers pool resources for ventures none could attempt alone, ledgers that make ventures legible, and property rules that let an innovator capture enough of the value to bother. This is the machinery of turning wealth into capital, and without it the steam engine remains a temple curiosity — which is, roughly, what Hero of Alexandria’s actual steam toy remained.
The sections amplify each other: the method improves the engines, the engines power the presses, the presses spread the method, and the capital institutions fund the next round. Each yields visible gains within a generation, which buys the elite patronage that keeps the project alive. Given competent leadership, Rome plausibly goes from water wheels to locomotives and telegraphs in under two centuries.
That is the answer to what causes progress. Not any single gadget, and not resources — Rome had resources, and so does every poor country today. Progress is a self-amplifying stack: a method for finding truth, concentrated energy to act on it, cheap reproduction of information, and institutions that form capital. The Industrial Revolution happened when those four finally coincided, and the child-mortality map turned from red to pale wherever the stack was allowed to operate. The hot shower is simply what the stack looks like from inside, two centuries in.
The Curve Ahead
A trend is not a law. Anyone can plot two centuries of rising life expectancy and rule a line onward; the honest question is what Credence the extrapolation deserves, given everything that could break it — nuclear war, engineered pandemics, severe climate disruption, unaligned artificial intelligence.
Existential risks provoke exaggerated responses in both directions: dismissal, because the catastrophes have never happened, and paralysis, because their consequences would be unbounded. The framework I defend in deciding under uncertainty — Effective Decision Theory — cuts between them: condition on scenarios with realistically estimable probabilities, and refuse to let unresolvable tail cases dominate the calculation. Applied here, the reference class is instructive. Civilization has absorbed world wars, pandemics, depressions, and totalitarian regimes, and the life-expectancy curve records each as a notch, not a reversal; the underlying stack — method, energy, information, capital — kept compounding through all of them, because knowledge, once cheaply copied, is very hard to unlearn.
Weighing the tangible risks against that resilience, I assign roughly 75% Credence that global life expectancy at birth will be higher 25 years from now than it is today. Not 99% — the risks are real, and some are novel in kind. Not 50% — that would ignore two centuries of evidence about how this system behaves under stress. The number is a forecast, deliberately falsifiable, and it is the appropriate final form of the progress argument: not a mood, but a stated probability on a measurable outcome.
Optimism of this kind is not a temperament; it is a calibration. The same discipline that licenses it also polices it, and the place to see the policing in action is the doomsday prediction that already ran to completion — the peak-oil panic, the next chapter’s field guide to how confident catastrophism goes wrong, and the questions that tell you when it might finally be right.