For most of history, a child born anywhere on Earth had a strong chance of dying before age five, and most adults lived close to subsistence. Around 1800, by modern estimates, the large majority of humanity lived in what we would now call extreme poverty, and global life expectancy at birth was around thirty years. Today extreme poverty affects roughly a tenth of humanity, and global life expectancy is above seventy. No single cause produced that change, but almost every part of it runs through the transformation that began in the mills and mines of Britain. The Industrial Revolution is the hinge on which modern history turns.

The hockey stick

If you draw a graph of average income per person over the last two thousand years, the line is nearly flat for eighteen centuries and then shoots upward, like the blade of a hockey stick. Since 1800, average output per person worldwide has risen more than tenfold. Sustained growth made possible mass schooling, modern medicine, cheap food, and leisure time that earlier generations could not imagine. It also made possible industrial warfare on a scale never seen before. The same factories that made railways and fertilizer could turn out artillery shells and machine guns, as the world learned in 1914.

Growth changed family life as well. As incomes rose and child mortality fell, families in industrial countries began to have fewer children and to invest more in each one, a shift demographers call the demographic transition. Schooling replaced work as the main business of childhood.

The Great Divergence

Industrialization also opened huge gaps between nations. Countries that industrialized early became far richer than those that did not, and that wealth translated into military power and empire. By 1900 a handful of industrial states controlled much of the globe. The gap between the richest and poorest countries widened through the nineteenth and twentieth centuries, a pattern historians call the Great Divergence. In recent decades, the rapid industrialization of China, India and other countries has begun to narrow it, and the largest share of the world's manufacturing now happens in Asia.

New classes, new ideas

Industry created a large industrial working class and a confident middle class of owners and professionals, and with them new political ideas. Liberals celebrated free trade and individual enterprise. Socialists, including Karl Marx, who worked in London using Engels's knowledge of Manchester, argued that industrial capitalism exploited workers and would be overthrown. Conservatives worried about the loss of community and tradition. Many of the debates of modern politics, about wages, hours, unions, welfare and the role of the state, began as arguments about the factory system.

Environment

Burning coal released smoke that blackened cities and filled lungs, and it released carbon dioxide that accumulated invisibly in the atmosphere. Atmospheric carbon dioxide stood at roughly 280 parts per million before industrialization and now exceeds 420. The same fossil energy that lifted billions out of poverty is now the main driver of climate change, which is why the energy question begun in 1712 is still open.

Technology and work today

Debates over automation and artificial intelligence often echo the Industrial Revolution. Will new machines destroy jobs or create new ones? Who will capture the gains? The history suggests two lessons at once. In the long run, new technologies raised living standards enormously and created many kinds of work that no one could have predicted. In the short run, specific workers and communities, such as the handloom weavers, suffered real and lasting losses, and gains reached ordinary people only after decades of struggle, reform and new institutions. Both lessons are true, and policy works best when it takes both seriously. The handloom weavers are a sobering example: there were still hundreds of thousands of them in Britain in the 1820s, and within a generation their trade had nearly vanished, along with the incomes and status of the families who depended on it.

Worked example: was it progress?

A friend says the Industrial Revolution was a disaster: child labor, slums, slavery-grown cotton, pollution. Another says it was the greatest thing that ever happened to humanity. How do you weigh them?

• Count the gains honestly: income, health, literacy and life expectancy rose on a scale never seen before.
• Count the costs honestly: the suffering of early factory workers, enslaved people and colonized peoples was real and was not inevitable in its full extent.
• Ask what made the difference: the gains spread widely only when workers organized, reformers passed laws, and states invested in health and schools.
• Look forward: the task now is to keep the benefits while ending the damage, especially to the climate.

This is where the Industrial Revolution meets Universal Humanism. Universal Humanism holds that every person has equal dignity and that human ingenuity should serve everyone. The story of industry shows both sides of that challenge: an extraordinary expansion of human power, and a long fight to make sure that power served the many and not only the few. The Factory Acts, the Charter, the cooperatives and the unions were attempts to put human beings at the center of a machine age. That work is not finished, and every generation that meets a new technology has to take it up again.