AHA spread to all states, and some prominent public figures such as Isaac Asimov, John Dewey, Erich Fromm, Paul Kurtz, Carl Sagan, and Gene Roddenberry became members. Humanist organizations from all continents formed the International Humanist and Ethical Union (IHEU), which is now known as Humanists International, and promotes the humanist agenda via the United Nations organizations UNESCO and UNICEF. Varieties of humanism Early 20th century naturalists, who viewed their humanism as a religion and participated in church-like congregations, used the term "religious humanism". Religious humanism appeared mostly in the US and is now rarely practiced. The American Humanist Association arose from religious humanism. The same term has been used by religious groups such as the Quakers to describe their humanistic theology. The term "Renaissance humanism" was given to a tradition of cultural and educational reform engaged in by civic and ecclesiastical chancellors, book collectors, educators, and writers that developed during the 14th and early 15th centuries. By the late 15th century, these academics began to be referred to as umanisti (humanists). While modern humanism's roots can be traced to the Renaissance, Renaissance humanism vastly differs from it. Other terms using "humanism" in their name include: Christian humanism; a historical current in the late Middle Ages in which Christian scholars combined Christian faith with interest in classical antiquity and a focus on human well-being. Ethical humanism"; a synonym of Ethical culture, was prominent in the US in the early 20th century and focused on relations between humans. Scientific humanism emphasizes belief in the scientific method as a component of humanism as described in the works of John Dewey and Julian Huxley. Scientific humanism is largely synonymous with secular humanism. Secular humanism was coined in the mid-20th century. It was initially an attempt to denigrate humanism but some humanist associations embraced the term. Secular humanism is synonymous with the contemporary humanist movement. Marxist humanism; one of several rival schools of Marxist thought, which accepts basic humanistic tenets such as secularism and naturalism but differs from other strands of humanism because of its vague stance on democracy and rejection of free will. Philosophy Immanuel Kant provided the basis of the humanist narrative. His theory of critical philosophy formed the basis of the world of knowledge, defending rationalism and grounding it in the empirical world. He also supported the idea of the moral autonomy of the individual, which is fundamental to his philosophy.