Atheism and freethought trace their roots to ancient Greek philosophy, with its emphasis on rational inquiry and curiosity about the workings of nature. Other sources included early Chinese Confucianism, ancient Indian materialists, and Roman Stoics, Epicureans, and Skeptics. Submerged during the Dark Ages, freethought re-emerged in the Renaissance. With the Enlightenment, rationalist and empiricist thinkers laid foundations for the modern scientific outlook. Utilitarians emancipated morality from religion, foreshadowing consequentialism. The late eighteenth and nineteenth centuries ushered in a golden age for freethought. With the turn of the twentieth century, this flame flickered, but an abiding tradition remained that decades later would emerge as secular humanism.

secularhumanism.org/what-is-secular-humanism/secular-humanism-defined/