World Religions › Modern
Secularization
19th century – today· Belief or practice· New movements & secular thought
Mostly agreed by scholarsMost historians agree; some details uncertain.
The long decline of religion's hold on government, science, education and personal life, strongest in Europe and East Asia.
See it on the World Religions map →What it is
From the 1800s, states took over schools, marriage law and welfare from churches, and science explained more of nature. Thinkers from Auguste Comte and Marx to Max Weber, who spoke of the 'disenchantment of the world', expected religion to fade. In much of Europe weekly church attendance fell steeply during the 1900s. Pew estimates about 1.9 billion people, roughly 24% of the world, were religiously unaffiliated in 2020, mostly in China, Japan, South Korea, Europe and North America.
Why it matters
It reshaped how modern states and societies work; whether it is universal or mainly a Western and East Asian pattern is one of sociology's biggest questions.
Sources and history
Census and survey data (Pew, World Values Survey, church attendance counts) document the trend; Weber, Émile Durkheim and later sociologists built theories to explain it.
Questions and debates
Peter Berger, once a leading secularization theorist, recanted in the 1990s, citing religious growth in Africa, Latin America and the US. Whether modernization always erodes faith is debated.
Inside this (5)
Connections (6)
▸The Enlightenment and religion helped launch SecularizationMostly agreed by scholars
The connection
Enlightenment writers made reason and evidence, not church authority, the test of truth. Deists like Voltaire accepted a creator but rejected miracles and clerical power, and a few, like Baron d'Holbach, were openly atheist. Revolutionary France briefly attacked the Church outright. These ideas set the pattern of separating knowledge and government from religion.
When and where
Mainly France, Britain, the Netherlands and Germany, about 1685–1815, through salons, the Encyclopédie (1751–72) and revolutionary France's de-Christianization campaign of 1793–94.
How do we know?
Enlightenment texts argue for this shift directly; measurable decline in belief and churchgoing comes mostly later, in the 1800s and 1900s.
Questions and debates
Scholars debate whether secularization began with the Enlightenment or earlier with the Reformation; Charles Taylor and others argue Christianity itself shaped the secular age.
▸Darwin's On the Origin of Species accelerated SecularizationMostly agreed by scholars
The connection
Natural selection explained life's apparent design without a designer, undercutting a leading argument for God, William Paley's 'watchmaker'. Many educated Victorians, Darwin among them, moved toward doubt, and science gained authority over questions of origins once answered by scripture. Many believers, though, accepted evolution as God's way of creating.
When and where
Britain and beyond from 1859; Thomas Huxley coined 'agnostic' in 1869, and Darwin described himself that way in an 1879 letter.
How do we know?
Victorian letters, memoirs and sermons record losses of faith after Darwin; later surveys link rejection of evolution with stronger religiosity, though not uniformly.
Questions and debates
Historians reject a simple 'war of science and religion': many clergy embraced evolution, and doubt had other causes too, such as biblical criticism.
▸Historical-critical Bible scholarship fueled SecularizationMostly agreed by scholars
The connection
If the Bible was written by many human authors over centuries, with contradictions, its authority as God's word came into question for many readers. Strauss's Life of Jesus, translated by George Eliot in 1846, became a byword for faith-shaking scholarship. Liberal churches adapted, but critical scholarship helped many educated Europeans drift from traditional belief.
When and where
German universities from the 1830s, spreading to Britain through translations and the controversial Essays and Reviews (1860), and to America by the 1880s.
How do we know?
Victorian memoirs often cite biblical criticism as a cause of lost faith; heresy trials, such as Charles Briggs's in the 1890s, show churches' alarm.
Questions and debates
Its effect is hard to separate from science, urbanization and politics; many leading critics remained devout believers who saw their work as serving faith.
▸Secularization was predicted by Marx: religion as 'the opium of the people'Mostly agreed by scholars
The connection
Marx watched religion losing ground among Germany's educated radicals, the Young Hegelians, and turned that trend into a prediction: once poverty and class rule were abolished, religion would wither away on its own. Communist states later tried to speed his forecast by policy, closing churches, temples and mosques.
When and where
Germany and Paris, 1843–44; Marx built on Ludwig Feuerbach's The Essence of Christianity (1841), which called God a projection of human nature.
How do we know?
Marx's essay states that 'the criticism of religion is essentially completed' in Germany and must now become criticism of politics.
Questions and debates
The forecast fared unevenly: religion revived in post-Soviet Russia and grew in China after 1980, while Western Europe secularized without revolution.
▸Friedrich Nietzsche: 'God is dead' diagnosed SecularizationMostly agreed by scholars
The connection
Nietzsche did not cause secularization; he described it. 'God is dead' meant that educated Europeans no longer truly believed, even if they kept churchgoing and Christian morals out of habit. He warned that this loss would eventually undermine the values built on faith, leading to nihilism unless people created new ones.
When and where
Italy, Switzerland and France, 1882–88, in The Gay Science (1882), Thus Spoke Zarathustra and On the Genealogy of Morals (1887).
How do we know?
His texts state the diagnosis directly; later thinkers, from Heidegger to the 1960s 'death of God' theologians, took it up.
Questions and debates
Whether his diagnosis was right is contested: Europe secularized slowly, while much of the world grew more religious in the following century.
▸Secularization led to Rise of the 'nones' (no religion)Mostly agreed by scholars
The connection
Secularization first showed in falling church attendance in Western Europe. By the 1990s it reached identity: people stopped naming any religion at all. In the US, nones grew from under 1 in 10 adults to about 3 in 10 by 2023–24, driven largely by younger generations raised with less religion.
When and where
Western Europe from the 1960s; the US from the early 1990s; South Korea and Japan; tracked by Pew and the General Social Survey.
How do we know?
Long-running surveys: the General Social Survey (since 1972), Pew's Religious Landscape Studies (2007, 2014, 2023–24), the European Values Study and censuses.
Questions and debates
Some sociologists reject secularization theory, and Pew found the US shift leveling off around 2019–2024; whether it resumes is unknown.