Humanist Manifesto I appeared in 1933, drafted by a group centered on the journal The New Humanist and signed by thirty-four people, several of them Unitarian ministers, who wanted to state Humanism as a positive philosophy rather than only a rejection of theism. It affirmed the universe as self-existing, human beings as a continuous part of nature, and religion as properly concerned with human welfare in this life rather than a supernatural one. Humanist Manifesto II followed in 1973, authored chiefly by Paul Kurtz and Edwin H. Wilson and published under the American Humanist Association's auspices, extending the first manifesto's claims into more explicit ethical and social territory, human rights, global governance, sexual freedom, in the language of the period.
Humanist Manifesto III, subtitled Humanism and Its Aspirations, was adopted by the American Humanist Association in 2003 as a shorter, deliberately less programmatic statement of the same underlying commitments, knowledge of the world derived by observation and reason, ethical values grounded in human need and experience, and a life of purpose found in service to human welfare rather than in the promise of an afterlife.
Outside the American organizational line, the International Humanist and Ethical Union, now Humanists International, adopted the Amsterdam Declaration in 1952 at its founding congress and revised it in 2002, stating the same broad humanist commitments as the official minimum position of its member organizations worldwide, a document distinct from the American Humanist Association's manifestos but built from substantially the same premises.