In 1927, Unitarian professors and students connected to the University of Chicago formed the Humanist Fellowship. It helped bring together non-theistic religious liberals and other modernists who wanted a human-centered alternative to traditional theism. The network soon became a base for publishing and coordinated organizing that shaped later Humanist statements and institutions.
In 1928, the Humanist Fellowship began publishing New Humanist magazine. The publication gave the growing movement a place to share ideas, argue for modern ethical and scientific worldviews, and coordinate across congregations and intellectual circles. This publishing platform later became the venue for the first Humanist Manifesto.
In 1933, "A Humanist Manifesto" (later called Humanist Manifesto I) was published with 34 signers, including philosopher John Dewey. It presented humanism as a modern, human-centered “religious” movement and laid out a set of affirmations about knowledge, ethics, and social responsibility. The document became a foundational reference point for later secular humanist organizing and later revised manifestos.
By 1935, the Humanist Fellowship evolved into the Humanist Press Association. This change reflected a growing emphasis on publishing and national coordination, including moving from New Humanist to successor publications. It helped keep the movement connected as it expanded beyond its early Chicago-centered roots.
In 1941, Curtis W. Reese and John H. Dietrich reorganized the Humanist Press Association into the American Humanist Association (AHA). The AHA aimed to organize humanism as a non-theistic and increasingly secular movement, while still engaging both religious and nonreligious humanists. It also began publishing The Humanist magazine as a key public-facing platform.
On 26 August 1952, humanists from multiple countries met in Amsterdam at the first World Humanist Congress and established the International Humanist and Ethical Union (IHEU). This created a permanent international umbrella organization to connect national humanist and ethical groups. The founding mattered because it turned humanism into a coordinated global movement rather than mostly national or local efforts.
In 1952, the World Humanist Congress ratified the Amsterdam Declaration (1952), often described as a foundational statement of “modern, ethical humanism.” It emphasized democracy, freedom of thought, and a human-centered ethics grounded in responsibility to society rather than supernatural authority. By giving the new international union a shared program, it helped member organizations coordinate around common values.
In 1965, a competition organized by what is now Humanists UK selected Dennis Barrington’s design—later known as the Happy Human—as a symbol for humanism. Over the following years it was adopted by many humanist organizations internationally. A shared visual symbol made public recognition and cross-border identity-building easier for the growing humanist movement.
In 1973, the AHA released Humanist Manifesto II, drafted by Paul Kurtz and Edwin H. Wilson, as a major update to the 1933 manifesto. The new text took a more “hardheaded” tone shaped by experiences of world war and totalitarianism, while pushing a strongly secular and human-rights-centered outlook. Its release drew wide media coverage and helped modernize humanist messaging for late-20th-century debates.
In 1973, Prometheus Books published Humanist Manifestos I and II as a combined print edition, helping circulate the documents beyond magazine readership. Book publication made the manifestos easier to assign in courses, collect in libraries, and distribute internationally. This supported the wider spread of secular humanist ideas through the 1970s and later decades.
From its 1952 start, the IHEU grew into a worldwide union of humanist and related organizations, eventually spanning many countries. It promoted humanism as an ethical philosophy emphasizing reason, freedom of thought, democracy, and human rights. This growth showed that organized secular humanism was becoming a lasting international movement, not only a set of national initiatives.
By 1999, the movement’s core “reference points” for many organizations were well established: the 1933 and 1973 manifestos, the 1952 founding of the IHEU, and the 1952 Amsterdam Declaration. Together, they provided both ideas (the manifestos’ program statements) and institutions (an international federation) that shaped how secular humanists organized, communicated, and worked on human-rights and secularism issues. This period closed with a mature, international humanist infrastructure ready for further updates in the 2000s.
Humanist Manifestos and International Humanist Organizations (1933–1999)