Voltairine de Cleyre (1866–1912)

Freethought, she wrote, was "the right to believe as the evidence, coming in contact with the mind, forces it to believe. This implies the admission of any and all evidence bearing upon any subject which might come up for discussion." DeLamotte commments that "among the many subjects that came up routinely in late-nineteenth-century freethinking circles were marriage, sexuality, birth control, women's rights, race relations, labor relations … and the relation of the individual to the state."

Little wonder, then, that, as Paul Avrich puts it, "between the anarchist and free thought movements there was a close and longstanding affinity. Both shared a common anti-authoritarian viewpoint and a common tradition of secularist radicalism stretching back to Thomas Paine," who was, of course, well thought of by "atheists and anarchists alike. Nearly all anarchists were freethinkers, and many … first came to anarchism through the free thought movement, in which they constituted a militant left wing within the local clubs as well as the regional and national federations."