The thinkers worth knowing.
Authors, scientists, philosophers, and debaters who have shaped the conversation around religion, faith, and reason.
Looking for the female freethinkers specifically? Visit the Women & Atheism hub →
Christopher Hitchens
Author & Journalist
Arguably the most brilliant and entertaining critic of religion of his generation. His book God Is Not Great is essential reading — and his debates are unmissable.
Sam Harris
Neuroscientist & Author
One of the Four Horsemen of New Atheism. Harris brings a scientific and philosophical rigor to the question of faith, and isn't afraid to go where the argument leads.
Richard Dawkins
Evolutionary Biologist & Author
Author of The God Delusion and The Selfish Gene. Dawkins makes the scientific case against religion more clearly than almost anyone — and with remarkable patience.
Matt Dillahunty
Host, The Atheist Experience
A former seminary student turned atheist activist. Dillahunty is one of the most skilled live debaters alive — methodical, fair, and relentless.
George Pell
Former Catholic Cardinal
Included here not as an atheist, but as a case study. His debate with Dawkins and his subsequent conviction offer a sobering look at institutional religion.
Daniel Dennett
Philosopher & Cognitive Scientist
One of the Four Horsemen of New Atheism. Dennett brought a philosopher's rigour to the question of why religion exists — and whether we can outgrow it.
Carl Sagan
Astronomer & Science Communicator
Host of Cosmos and author of The Demon-Haunted World. Sagan made the case that science is our best candle in the dark — and that scepticism is a virtue, not a vice.
Alex O'Connor
Philosopher & YouTuber
Known online as Cosmic Skeptic, O'Connor is a young Oxford-trained philosopher making the secular case with clarity, nuance, and genuine intellectual humility.
Jordan Peterson
Clinical Psychologist & Author
Peterson occupies a singular position in these debates — not a theist, not an atheist, but a psychologist who argues that religious myths encode genuine truths about the human condition. His five-part debate with Sam Harris is essential viewing.
Ayaan Hirsi Ali
Author & Activist
Born in Somalia, raised Muslim, she fled a forced marriage and eventually renounced Islam — living under death threats ever since. Her memoir Infidel is one of the most important books on religion and women's rights ever written.
Bertrand Russell
Philosopher & Mathematician
The 20th century's most influential atheist philosopher. His 1927 lecture "Why I Am Not a Christian" and the Russell's Teapot analogy laid the intellectual groundwork for modern secular thought.
Stephen Fry
Author, Actor & Humanist
Best known in these circles for his 2015 RTE interview, where he was asked what he'd say to God: "Bone cancer in children? What's that about?" One of the most articulate voices for secular humanism.
William Lane Craig
Christian Apologist & Philosopher
Included here as the most formidable defender of theism. His Kalam Cosmological Argument is the most debated argument for God's existence in academic philosophy. Understanding his case makes the secular response sharper.
Dan Barker
Former Evangelical Preacher · FFRF Co-President
Spent 19 years as an evangelical minister and Christian songwriter before losing his faith through his own research. Now co-president of the Freedom From Religion Foundation. His book Godless is one of the most honest deconversion accounts ever written.
Julia Sweeney
Comedian, Actor & Author
Former Saturday Night Live cast member whose one-woman show "Letting Go of God" traces her journey from devout Catholicism to atheism with warmth, humor, and intellectual honesty. Her TED Talk has been watched millions of times.
Peter Boghossian
Philosopher & Author
Creator of "Street Epistemology" — a Socratic dialogue method for challenging faith-based reasoning. His book A Manual for Creating Atheists reframes the goal from winning arguments to changing how people evaluate evidence.
James Randi
Skeptic & Magician · 1928–2020
The Amazing Randi was the 20th century's greatest scientific skeptic. A former stage magician, he spent decades exposing faith healers, psychics, and con artists — and offered $1 million to anyone who could demonstrate the supernatural under controlled conditions. Nobody ever claimed it.
Megan Phelps-Roper
Author & Speaker
Raised in the Westboro Baptist Church — the most reviled hate group in America — she left at 26 after conversations on Twitter slowly cracked her certainty open. Her memoir Unfollow and her TED Talk are essential reading on how minds actually change.
Michael Shermer
Founder, Skeptic Magazine
Founded Skeptic magazine and the Skeptics Society, and spent decades as a Scientific American columnist. A former evangelical Christian, his books Why People Believe Weird Things and The Believing Brain explain the psychology of religious conviction better than almost any other source.
Lawrence Krauss
Theoretical Physicist & Author
Author of A Universe from Nothing, Krauss argues that the laws of physics allow a universe to emerge without a creator — directly challenging the cosmological argument at its core.
Aron Ra
Atheist Activist & YouTuber
Texas-based atheist activist and former state director of American Atheists. His YouTube series "Foundational Falsehoods of Creationism" is the most thorough takedown of creationist arguments available — essential viewing for anyone engaging with biblical literalism.
Madalyn Murray O'Hair
Founder, American Atheists · 1919–1995
Won the 1963 Supreme Court case that ended mandatory school prayer in America, founded American Atheists, and was the most visible atheist in the United States for thirty years. The reason organized U.S. atheism exists as a political force.
Emma Goldman
Anarchist, Feminist & Writer · 1869–1940
One of the most fearless critics of organized religion in early-20th-century America. Her essays The Failure of Christianity and The Philosophy of Atheism remain searing — and she was among the first to argue women's emancipation required rejecting religion.
Taslima Nasrin
Physician, Author & Activist · b. 1962
Bangladeshi doctor turned novelist, exiled since 1994 for writing about Islam's treatment of women. Has lived under fatwas and forced relocations for three decades — and still writes.
Francesca Stavrakopoulou
Biblical Scholar · b. 1975
Professor of Hebrew Bible at Exeter and one of very few senior biblical scholars in Britain who is also a public atheist. Her book God: An Anatomy reconstructs the very physical, embodied deity behind the biblical text.
Susan Blackmore
Psychologist & Writer · b. 1951
Spent twenty years investigating the paranormal before changing her mind and publicly breaking with parapsychology. Author of The Meme Machine — a sweeping theory of how culture, including religion, evolves through differential copying.
Greta Christina
Author & Blogger · b. 1961
One of the leading voices of atheist feminism. Her book Why Are You Atheists So Angry? names ninety-nine specific, documented grievances — and refuses to apologize for any of them.
Ophelia Benson
Editor & Writer · Butterflies and Wheels
Editor of the long-running skeptic site Butterflies and Wheels and co-author of Does God Hate Women? — a cross-religion examination of how faith traditions structure women's subordination.