On the Post-Enlightenment Evolution of Moral Universalism

Abstract Is humanity’s circle of moral concern expanding? I explore frequencies of morally universal language in 15 million book publications in American English, British English, French, Spanish, German and Italian from 1800–2000. In each language, morally universal terminology diminished markedly. This pattern also emerges in Chinese, Russian and Hebrew books. I test two prominent hypotheses predicting moral universalism, pertaining to reason and religiosity. Reason-based terminology indeed correlates positively with purely morally universal terminology—but also (and more strongly so) with morally communal terminology. These empirical patterns cast doubt on claims of (i) moral universalism expanding and (ii) reason being its main driver.