The Enlightenment is having a renaissance, of sorts. A handful of centrist and conservative writers have reclaimed the 17th-and 18th-century intellectual movement as a response to nationalism and ethnic prejudice on the right and relativism and “identity politics” on the left. Among them are Jordan Peterson, the Canadian psychologist who sees himself as a bulwark against the forces of “chaos” and “postmodernism”; Steven Pinker, the Harvard cognitive psychologist who argues, in Enlightenment Now, for optimism and human progress against those “who despise the Enlightenment ideals of reason, science, humanism, and progress”; and conservative pundit Jonah Goldberg, who, in Suicide of the West, argues in defense of capitalism and Enlightenment liberalism, twin forces he calls “the Miracle” for creating Western prosperity.

In their telling, the Enlightenment is a straightforward story of progress, with major currents like race and colonialism cast aside, if they are acknowledged at all. Divorced from its cultural and historical context, this “Enlightenment” acts as an ideological talisman, less to do with contesting ideas or understanding history, and more to do with identity. It’s a standard, meant to distinguish its holders for their commitment to “rationalism” and “classical liberalism.”

But even as they venerate the Enlightenment, these writers actually underestimateits influence on the modern world. At its heart, the movement contained a paradox: Ideas of human freedom and individual rights took root in nations that held other human beings in bondage and were then in the process of exterminating native populations. Colonial domination and expropriation marched hand in hand with the spread of “liberty,” and liberalism arose alongside our modern notions of race and racism.

These weren’t incidental developments or the mere remnants of earlier prejudice. Race as we understand it—a biological taxonomy that turns physical difference into relations of domination—is a product of the Enlightenment. Racism as we understand it now, as a socio-political order based on the permanent hierarchy of particular groups, developed as an attempt to resolve the fundamental contradiction between professing liberty and upholding slavery. Those who claim the Enlightenment’s mantle now should grapple with that legacy and what it means for our understanding of the modern world.

To say that “race” and “racism” are products of the Enlightenment is not to say that humans never held slaves or otherwise classified each other prior to the 18thcentury. Recent scholarship shows how proto- and early forms of modern race thinking (you could call them racialism) existed in medieval Europe, with near-modern forms taking shape in the 15thand 16thcenturies. In Spain, for example, we see the turn from anti-Judaism to anti-Semitism, where Jewish ancestry itself was grounds for suspicion, versus Jewish practice. And as historian George Fredrickson notes in Racism: A Short History, “the prejudice and discrimination directed at the Irish on one side of Europe and certain Slavic peoples on the other foreshadowed the dichotomy between civilization and savagery that would characterize imperial expansion beyond the European continent.” One can find nascent forms of all of these ideas in antiquity—indeed, early modern thinkers drew from all of these sources to build our notion of race. ...