Atheist "Denominations" Explained

Atheist, freethinking, and humanist organizations have developed through splits, mergers, and ideological changes resembling those found in religious movements. Matt Baker uses a family-tree chart to illustrate these relationships, while stressing that atheism does not have denominations in the formal Christian sense.

The category “no religion” is the fourth-largest religious-affiliation category worldwide and the second-largest in the United States, according to the figures presented. Its size makes organized nonreligion an important subject alongside Christianity, Islam, Hinduism, Buddhism, and Judaism.

People reporting no religion are not necessarily atheists. The category also includes individuals who believe in God, maintain personal spiritual beliefs, or accept some form of higher power without identifying with an established religion.

The episode concentrates on atheists, freethinkers, and humanists rather than everyone without religious affiliation. These groups have more clearly defined philosophical positions and established organizations whose historical relationships can be traced.

Atheism, freethought, and humanism often describe overlapping aspects of the same worldview in contemporary Western societies. Baker argues that many people identifying as atheists also embrace freethinking and humanist principles without necessarily adopting those additional labels.

Atheism primarily concerns what exists. In Baker's description, contemporary Western atheists generally reject supernatural beings and regard reality as part of the natural world, including rejecting gods as conventionally understood by major religions.

Freethought primarily concerns how knowledge is obtained. Freethinkers emphasize scientific investigation, observation, evidence, and reason rather than accepting claims solely because they appear in religious scriptures, traditions, or supposed divine revelations.

Humanism primarily concerns morality and human welfare. Humanists argue that people can behave ethically without believing in God and that improving society is worthwhile because it benefits human beings, rather than because a deity commands it.

Atheistic ideas existed in ancient Greece and India, but most modern atheist movements trace their organizational and philosophical origins to the European Enlightenment. Baker places that intellectual period approximately between 1650 and 1800.

The Protestant Reformation and Scientific Revolution helped create the conditions for modern freethought. Both began during the sixteenth century and weakened the assumption that established religious authorities should determine what people could believe or know.

The Reformation challenged the Roman Catholic Church's position as the dominant intellectual and religious authority in Western Europe. Its consequences helped create an environment in which alternative religious and philosophical positions could develop.

The Scientific Revolution strengthened observation and experimentation as methods of obtaining reliable knowledge. This encouraged later thinkers to question explanations based on inherited authority and religious tradition.

Enlightenment thinkers increasingly questioned biblical reliability and whether God intervened in the ordinary operation of the universe. Nevertheless, Baker emphasizes that relatively few prominent Enlightenment figures openly identified as atheists.

Deism was more common than atheism among Enlightenment intellectuals. Deists believed that God created the universe but no longer intervened in its operation, allowing them to retain belief in a creator while rejecting traditional accounts of divine intervention.

Expanding religious freedoms in Europe and America made explicit rejection of belief in God increasingly possible. Over time, the term freethinker became associated with people who relied on science and reason while rejecting divine revelation as an authority.

The pansy became a symbol of the freethought movement because of its association with thinking. Its name derives from the French word pensée, meaning thought, and its downward-bending appearance was interpreted as resembling someone deep in contemplation.

The Golden Age of Freethought extended approximately from 1859 to 1914. Baker identifies Charles Darwin's publication of On the Origin of Species in 1859 and the outbreak of World War I in 1914 as the period's boundaries.

Several of the oldest surviving freethought organizations emerged during this Golden Age. Their early priorities included legal equality for nonbelievers, freedom from religious requirements, and the publication of secular ideas.

The National Secular Society was founded in Britain in 1866 by Charles Bradlaugh. Baker identifies it as the oldest freethinking organization founded explicitly within the modern secular movement.

Charles Bradlaugh challenged the requirement to swear religious oaths by requesting to make a secular affirmation instead. His insistence on affirming that he would tell the truth without invoking the Bible contributed to later legal changes governing oaths and affirmations.

The term secular was introduced into modern political and philosophical use by George Jacob Holyoake. It derives from the Latin saeculum, previously used in Christian contexts to distinguish worldly matters from sacred ones.

Early secularists preferred the term secular partly because atheist carried strong negative associations. Holyoake and Bradlaugh were primarily concerned with securing equal civil rights for people without religious beliefs rather than attacking religion itself.

George Jacob Holyoake helped establish the Rationalist Press Association to distribute freethinking ideas. Publishing offered a way to reach nonreligious audiences when freethinkers continued to experience social exclusion. The organization survives as the Rationalist Association.

The National Liberal League was among the earliest major American freethought organizations. It was subsequently reorganized as the American Secular Union, demonstrating how early American secular groups developed new institutional identities.

Robert G. Ingersoll became a leading figure in American freethought through his public speeches. His passionate advocacy of religious skepticism and intellectual independence earned him the nickname “the Great Agnostic.”

The term agnostic was coined by Thomas Henry Huxley during the nineteenth century. Huxley used it to express the position that people should not claim knowledge of matters for which they lack sufficient scientific grounds.

The Ethical Movement emerged alongside organized freethought and became an important predecessor of modern humanism. It emphasized moral conduct and social responsibility rather than requiring agreement on theological doctrines.

Felix Adler founded the New York Society for Ethical Culture. Adler was the son of a prominent Reform Jewish rabbi, illustrating the movement's connection to religious reform as well as secular philosophy.

Adler's Ethical Culture movement welcomed atheists, agnostics, deists, and even theists. Participation depended on commitment to independent thinking and ethical action rather than agreement about whether God existed.

The Ethical Movement emphasized “deed, not creed.” Its ambition was to create something resembling a new religion organized around ethical behavior rather than supernatural beliefs or mandatory religious doctrines.

Ethical societies spread throughout cities in the United States and Britain. American organizations eventually united under the American Ethical Union, while British organizations established the British Ethical Union.

The American Ethical Union survives under its original name, while the British Ethical Union evolved into Humanists UK. The British organization first adopted the name British Humanist Association before taking its current identity.

Conway Hall Ethical Society traces its institutional ancestry to South Place Chapel, established in 1787. It consequently claims an exceptionally long history and describes itself as the world's oldest freethought organization.

South Place Chapel was originally associated with Christian Universalism rather than freethought. Universalism later became connected with Unitarianism through the development of Unitarian Universalism.

South Place Chapel did not formally join the freethinking Ethical Movement until 1888. For this reason, Baker distinguishes its earlier religious ancestry from its secular history and maintains that the National Secular Society, established in 1866, deserves recognition as the oldest explicitly freethinking organization.

The word humanism originally referred to an intellectual movement associated with the Renaissance. Renaissance humanists revived and studied ancient Greek and Roman ideas, whereas twentieth-century humanism developed into a distinct philosophical and ethical worldview.

Modern organized humanism initially developed as an attempt to establish a human-centered alternative to traditional religion. Its early organizational expression overlapped with the Ethical Movement and retained some explicitly religious terminology.

The Humanist Fellowship, established in Chicago in 1927, was the first organization identified by Baker as using humanist in this modern organizational sense. It became an important starting point for American organized humanism.

The Humanist Fellowship published the first Humanist Manifesto in 1933. Now known as Humanist Manifesto I, it argued that scientific discoveries, economic developments, and expanding human knowledge required fundamental changes in established religious beliefs.

Humanist Manifesto I contained 15 affirmations expressing the principles of early religious humanism. Among them were the assertions that the universe was self-existing rather than created and that religious aspirations should be formulated according to scientific methods.

Thirty-four people signed Humanist Manifesto I, including numerous Unitarian ministers. Their participation helps explain why the original manifesto described humanism as a form of religion rather than explicitly rejecting religious identity.

The Chicago Humanist Fellowship eventually became the American Humanist Association. The organization continued the intellectual and institutional tradition established by the original fellowship and its 1933 manifesto.

A comparable humanist fellowship in Montreal eventually became Humanist Canada. Its first president, Dr. Henry Morgentaler, subsequently became widely known for his involvement in the Canadian abortion-rights movement.

Humanism underwent a significant change during the 1970s and 1980s, moving away from presenting itself as a new religion. Baker identifies the publication of Humanist Manifesto II in 1973 as a central turning point.

Humanist Manifesto II appeared forty years after the original manifesto and removed the earlier emphasis on religious humanism. Its language presented humanism more explicitly as a secular philosophical and ethical position.

The signatories of Humanist Manifesto II reflected a broader intellectual coalition than the first manifesto. They included DNA co-discoverer Francis Crick, science-fiction author Isaac Asimov, feminist Betty Friedan, Reconstructionist Rabbi Mordecai Kaplan, and psychologist B. F. Skinner.

Paul Kurtz was a driving force behind Humanist Manifesto II and its more secular orientation. He helped move organized humanism away from its earlier religious framing toward an explicitly secular intellectual movement.

Paul Kurtz established the Council for Secular Humanism. The organization brought the concepts of secularism and humanism together under one institutional identity.

Kurtz also founded the Committee for the Scientific Investigation of Claims of the Paranormal, commonly known as CSICOP. This organization extended scientific skepticism beyond conventional religious claims to subjects including ghosts, UFOs, psychic abilities, and other alleged paranormal phenomena.

Kurtz's work connected secular humanism with organized scientific skepticism. His organizations challenged both supernatural religious beliefs and extraordinary claims that lacked adequate scientific evidence.

The Council for Secular Humanism and the paranormal-investigation organization operated separately before being brought together under the Center for Inquiry. Baker dates their institutional consolidation to 1991 and presents it as a major development in organized secular humanism.

Paul Kurtz eventually lost his leadership position at the Center for Inquiry following an internal organizational struggle. Baker characterizes his departure as being effectively forced by a younger generation of leaders seeking control.

The American Humanist Association published Humanist Manifesto III in 2003. This completed a sequence of three major manifestos associated with the organization, following those of 1933 and 1973.

The Council for Secular Humanism developed two additional major statements of humanist principles. These were A Secular Humanist Declaration in 1980 and Humanist Manifesto 2000 in 2000.

Humanists International produced two major international declarations. The Amsterdam Declaration of 1952 and its 2002 successor expressed humanist principles through an international organization representing humanist groups around the world.

Baker identifies seven major humanist declarations and manifestos as the closest equivalents to creeds within organized Western atheism. They comprise the three American Humanist Association manifestos, two Council for Secular Humanism documents, and two Amsterdam Declarations.

Baker's doctoral research challenged the argument that atheists lack any shared positive worldview. He distinguished atheism itself, which need only involve nonbelief in God, from humanism, which contains an identifiable collection of ethical, philosophical, and intellectual commitments.

His central research hypothesis was that most contemporary Western atheists adhere to humanist principles even when they do not identify as humanists. The argument concerns a common worldview among atheists, not the existence of a formal atheist religion or universally binding creed.

Baker tested his hypothesis using 17,635 self-identified atheists. Participants rated their agreement or disagreement with statements drawn directly from the seven major humanist documents using a five-point Likert scale.

The survey found overwhelming agreement with the principal beliefs expressed in humanist declarations. Baker interpreted the results as evidence that contemporary Western atheists frequently share a coherent humanist worldview beyond simply rejecting belief in God.

Baker acknowledges that his research conclusion is controversial within atheist communities. Many atheists reject the idea that they follow creeds or subscribe to prescribed beliefs, maintaining that atheism itself means only lacking belief in God.

Most early organizations avoided using atheist in their official names. Instead, they adopted labels such as secular, rationalist, ethical, freethinking, or humanist because atheism carried considerable social stigma.

American Atheists was founded in 1963 by Madalyn Murray O'Hair. Its explicit adoption of the atheist label represented a departure from the naming practices of earlier secular organizations.

Madalyn Murray O'Hair became nationally controversial through her opposition to school-sponsored religious activities. Her activism, public reputation, and prominent legal battle contributed to her being described as “the most hated woman in America.”

O'Hair initiated legal action because she opposed requiring her son to participate in school prayers and Bible readings. Her case was combined with another similar dispute and ultimately reached the United States Supreme Court.

The Supreme Court ruled 8–1 in favor of the constitutional challenge to compulsory religious exercises in public schools. Baker presents the decision as a major victory against requiring students to participate in prayer or Bible reading.

O'Hair's son William, known as Bill, later rejected his mother's atheism and became a Christian. He eventually became a Baptist minister and social-conservative lobbyist, adopting religious and political positions sharply opposed to those of his mother.

Madalyn Murray O'Hair disappeared in 1995 alongside another son and a granddaughter. Their disappearance initially prompted suspicions that they had fled with money belonging to American Atheists while attempting to escape financial or tax problems.

Investigators eventually determined that O'Hair and her two relatives had been kidnapped and murdered. The perpetrator was identified as a former felon who had worked for American Atheists, contradicting the initial explanation that the family had voluntarily disappeared.

The bodies of O'Hair and her relatives were not discovered until 2001. The case demonstrated how initial suspicions surrounding the organization's finances had obscured the actual circumstances of the disappearances.

Atheist Alliance International developed from cooperation among local American atheist organizations into an international network. Its organizational expansion enabled atheist groups from different countries to participate in a common association.

Atheist Alliance International obtained special consultative status with the United Nations. Baker identifies this as an important example of organized atheism gaining representation within international institutions.

The New Atheist movement emerged during the early 2000s and adopted a more confrontational approach toward religion. Rather than concentrating principally on equal treatment for nonbelievers, its leading figures openly challenged religious beliefs and institutions.

Four writers became particularly associated with New Atheism: Richard Dawkins, Sam Harris, Christopher Hitchens, and Daniel Dennett. They were collectively nicknamed the “Four Horsemen” because of their prominence in the movement.

The September 11, 2001 terrorist attacks helped motivate the new wave of criticism directed at religion. Around the same period, the Four Horsemen published influential books arguing against religious beliefs and their consequences.

New Atheism represented a shift from defending atheists' civil rights toward actively promoting atheism and criticizing religion. Baker describes this as a more evangelistic approach, borrowing a term normally associated with the spread of religious beliefs.

Richard Dawkins established his own foundation in 2006 to promote science and challenge religious thinking. The organization became associated with public advocacy of scientific reasoning and secular perspectives.

The Richard Dawkins Foundation merged with the Center for Inquiry in 2016. The merger brought Dawkins's advocacy organization into an established institutional network encompassing secular humanism and scientific skepticism.

Dawkins and Daniel Dennett supported an initiative called the Brights, which attempted to establish a more positive identity for nonbelievers. The movement proposed using bright as an alternative to atheist, drawing an analogy with the adoption of gay as a positive identity term.

The Brights rebranding effort failed to achieve widespread adoption. Baker observes that, as of 2024, the term had not become a commonly accepted alternative to atheist.

The Freedom From Religion Foundation was founded by Anne Nicol Gaylor. Its leadership subsequently passed to her daughter Annie Laurie Gaylor and her daughter's husband, Dan Barker.

Dan Barker had previously been a Christian minister before becoming a prominent secular activist. His involvement illustrates how former religious leaders have also contributed to organized freethought.

The Freedom From Religion Foundation remains unusual among modern nonreligious organizations for emphasizing the identity of freethinker. Baker contrasts this with the greater popularity of the terms atheist and humanist among more recently established groups.

The term skeptic has increasingly replaced freethinker when describing people who prioritize evidence and scientific reasoning. Both terms emphasize testing claims through rational inquiry rather than accepting assertions based solely on religious revelation or tradition.

The Center for Inquiry operates within both the humanist and skeptical traditions. Its connection to CSICOP gives it an institutional role in examining paranormal claims as well as promoting secular humanist principles.

Michael Shermer founded the Skeptics Society, which publishes Skeptic magazine. The organization represents another major American branch of the organized scientific-skepticism movement.

Michael Shermer became the subject of serious allegations in 2013 involving rape and sexual harassment. Baker notes that Shermer was never criminally charged, and the allegations divided members of the atheist and skeptical communities.

The allegations against Shermer generated competing positions within atheist circles. Some members believed the women making the allegations, while others defended Shermer, creating significant disputes within the movement.

The controversy prompted broader discussion about women's experiences and representation in atheist communities. Baker observes that atheist organizations have historically tended to be male-dominated, making the allegations particularly consequential for internal discussions about gender.

Baker uses organizational controversies to challenge the assumption that secular groups are immune to problems commonly associated with religious institutions. He cites financial suspicions, leadership struggles, and sexual-assault allegations as examples of conflicts that can emerge wherever people organize around shared beliefs.

The James Randi Educational Foundation became another major institution associated with scientific skepticism. It was founded by magician and paranormal investigator James Randi, who used his knowledge of deception and illusion to scrutinize extraordinary claims.

The foundation operated the $1 Million Paranormal Challenge. It offered one million dollars to anyone able to demonstrate a supernatural or paranormal phenomenon under mutually agreed scientific testing conditions.

No claimant successfully collected the $1 million paranormal prize. Baker presents the challenge as a prominent example of skeptics demanding reproducible evidence rather than accepting extraordinary claims on testimony alone.

Several forms of modern Satanism belong on an atheist organizational family tree because they reject belief in a literal Satan. Baker explains that many Satanists use Satan as a symbol for challenging mainstream religious authority and emphasizing human autonomy.

The Church of Satan was founded in 1966 by Anton LaVey. Baker identifies it as a major example of atheistic Satanism, in which Satan does not represent a supernatural being believed to exist.

The Temple of Set broke away from the Church of Satan in 1975 but adopted a fundamentally different supernatural position. Its adherents believe in Set, identified with the ancient Egyptian deity, as a real being and the one true God.

The Temple of Set therefore differs from the atheistic Satanist organizations shown elsewhere on the chart. Although it shares institutional ancestry with the Church of Satan, its supernatural theology prevents it from being classified as atheist in the same sense.

The First Satanic Church also emerged as an offshoot of the Church of Satan. It is led by Karla LaVey, daughter of Church of Satan founder Anton LaVey.

The Satanic Temple was founded in 2012 by Lucien Greaves, according to Baker's chronology. Unlike the Temple of Set and the First Satanic Church, it is not presented as a formal institutional offshoot of the original Church of Satan.

The Satanic Temple regards itself as a modernized version of LaVeyan Satanism. It shares the symbolic use of Satan and the rejection of belief in a literal supernatural Satan, despite its independent organizational origins.

The Church of Satan, First Satanic Church, and Satanic Temple are all classified as atheistic organizations in Baker's chart. Their common rejection of a literal Satan distinguishes them from the supernatural beliefs associated with the Temple of Set.

The family tree reveals that nonreligious organizations do not share a single institutional lineage or philosophical emphasis. Secular societies originally emphasized civil equality, Ethical Culture promoted moral behavior, humanist organizations developed shared ethical principles, skeptical groups investigated extraordinary claims, and New Atheists adopted more direct criticism of religion.

The history also demonstrates that organizational ancestry and present beliefs are not always the same. Conway Hall evolved from a Christian institution into an ethical society, British Ethical Union became Humanists UK, the Center for Inquiry combined humanist and skeptical traditions, and the Temple of Set developed supernatural beliefs after separating from an atheistic Satanist organization.

Baker intends to combine his non-Christian organizational family trees with a simplified Christian denominational chart. The planned World Religions Family Tree poster would bring the historical relationships between major religious and nonreligious traditions into a single visual reference.