Labels
Every person in this series rejected the authority of the religion they were born into, or grew up outside one, and said so in writing or in public. They did not all reach the same place. Each page carries one label for the furthest position the person reached, in their own words where they used one. Where the word is ours or their critics', a note beside the label says so. Many changed labels over a lifetime, and the chapter tells that story; the label marks the furthest point, not the whole road.
The rule for who is in the series at all is explained on Who is included.
A scale of belief about God
Six of the labels answer one question, what the person believed about God, and they can be read as a scale. It runs from an impersonal creator, through gods who take no interest in us and a God who is only nature, to suspended judgement, to the view that God cannot be known, to plain denial. The scale is a guide, not a ranking; the people at each end are not more or less admirable, and a life can move along it in either direction.
Deist
Believed in a creator, or a mind or power behind the order of nature, that neither hears prayer, nor judges, nor rewards and punishes, nor promises a life after death; and rejected revelation, scripture's authority, miracles and the churches. Deists whose God cared for human beings, as Voltaire's and Paine's did, are not in this series.
In this series (5): Uriel da Costa (he used no label), Constantin-François Volney (he named God as the ruler of nature's order), Mark Twain (in his private writings; he used no label), Thomas Edison (his "Intelligence that is running things"), Luther Burbank (his own word was "infidel")
Epicurean
Followed Epicurus in holding that gods may exist but neither made the world nor take any interest in it, and that death is the end of us and nothing to fear.
Pantheist
Used the word God for nature or the universe as a whole, and not for a person who wills, judges or answers prayer.
In this series (4): Baruch Spinoza (his phrase was "God, or Nature"), Abner Kneeland, Ernst Haeckel (his own word was "monism"), Albert Einstein (he spoke of "Spinoza's God")
Sceptic
Doubted every claim to certain knowledge, claims about the gods included, without settling into a plain denial.
In this series (5): Xenophanes (he proposed one god, unlike mortals), Lucian of Samosata, Jayarāśi Bhaṭṭa (the scholars' word, and a disputed one; he used no label), David Hume, H. L. Mencken (his own word was "skepticism")
Agnostic
Held that whether God exists cannot be known, and declined to claim either way. Thomas Henry Huxley coined the word in 1869; it was later applied to earlier thinkers who took the same position.
In this series (13): Protagoras (the word is later; the position is his), John Stuart Mill (raised without religion), Charles Darwin, Thomas Henry Huxley, Leslie Stephen, Robert G. Ingersoll, Andrew Carnegie (his own word was "evolutionist"), Winwood Reade (he used no label), Thomas Hardy (the word he pointed to; he never called himself an atheist), Clarence Darrow, Bertrand Russell, Jawaharlal Nehru (a word others gave him), Carl Sagan
Atheist
Said that there is no God, or that they did not believe in any god. Some used the word proudly; others avoided it and said the same thing in other words.
In this series (77): Diagoras of Melos (as ancient writers report), Theodorus the Atheist (as ancient writers report), Kazimierz Łyszczyński (in his manuscript, as the prosecution read it), Matthias Knutzen (in substance; his own word was "Conscientiarii"), Jean Meslier (in a testament kept secret until his death), Andō Shōeki (Kanō's description in 1928; his own word was "nature"), Denis Diderot, Baron d'Holbach (in books published anonymously), Yamagata Bantō (his own word: "there are no spirits"), Sylvain Maréchal, Arthur Schopenhauer (others' word; he objected to it), Richard Carlile (from about 1821; earlier a deist), Percy Bysshe Shelley, Harriet Martineau, Ludwig Feuerbach (others' word; his own were "anthropology" and "humanity"), Max Stirner (others' word; his own was "egoist"), Ernestine Rose, Vissarion Belinsky (in Dostoevsky's account), Mikhail Bakunin, George Holyoake (his own word for some years; later "secularist"), Ignacio Ramírez, Karl Marx (in substance; he used no label), Ludwig Büchner, Charles Bradlaugh, Friedrich Nietzsche (in substance; he wrote of atheism, not as a badge), Manuel González Prada, W. K. Clifford (in substance; he used no label), Annie Besant (from 1874; a Theosophist from 1889), G. W. Foote, Sigmund Freud, Francisco Ferrer, Voltairine de Cleyre, Emma Goldman, E. V. Ramasamy (Periyar) (he took the word only conditionally until the 1971 formula), Chen Duxiu (in substance; he used no label), Virginia Woolf ("there is no God", in her memoir), Diego Rivera (reported to have said in 1956 that he was a Catholic), Hu Shih, Abraham Kovoor (his own word was "rationalist"), Luis Buñuel, Goparaju Ramachandra Rao (Gora), Ayn Rand, Jean-Paul Sartre, Bhagat Singh, Katharine Hepburn, Simone de Beauvoir, Ismail Adham, Alan Turing (dated only by his biographer), Albert Camus (his own word was "unbeliever"), Richard Feynman, Madalyn Murray O'Hair, Isaac Asimov, Kurt Vonnegut, José Saramago, Barbara Smoker, Steven Weinberg (others' word), Richard Dawkins, Daniel Dennett, Stephen Hawking, Narendra Dabholkar, Salman Rushdie, Christopher Hitchens, Douglas Adams, Annie Laurie Gaylor, Penn Jillette, Ricky Gervais, Taslima Nasrin, Aron Ra, Sean Carroll, Sam Harris, Seth Andrews, Matt Dillahunty, Ayaan Hirsi Ali (from 2002; a Christian from 2023), Leo Igwe, Avijit Roy, Hemant Mehta, Mubarak Bala
Beside the scale
The other four answer different questions, so they sit beside the scale rather than on it. They concern what happens to the soul (materialist), what to put in religion's place (humanist), the authority of church and scripture when a person's view of God is not recorded (freethinker), and the people whose unbelief we know only from what their enemies charged them with (accused). Many atheists were also materialists and humanists; the label chosen is the one that best describes the person's own emphasis.
Materialist
Held that mind or soul is the working of the body and that nothing of a person survives death. Some said nothing at all about God; the question that mattered to them was the soul.
In this series (7): Ajita Kesakambali, Wang Chong (the word is later; he used no label), Fan Zhen, Julien Offray de La Mettrie, Claude Adrien Helvétius, Shibli Shumayyil (his own phrase was "the practical materialist philosophy"), Kōtoku Shūsui (others' word; he gave himself no label)
Humanist
Put human reason and human welfare in the place of religion, and chose that positive name over a word for what they did not believe.
In this series (5): E. M. Forster, M. N. Roy, Margaret Knight, Gloria Steinem, Stephen Fry
Freethinker
Rejected the authority of church and scripture and judged religion by reason. They left no sign of believing in a God who cares for human beings, but they also left no plain statement in their own words of what they did believe about God.
In this series (13): Prodicus of Ceos (ancient writers called him an atheist), Critias (ancient writers called him an atheist), Euhemerus (ancient writers called him an atheist), Jeremy Bentham (he used no label), Frances Wright (her own word was "infidel"), George Eliot (she used no label), Ernest Renan (his own word was "rationalist"), Ambrose Bierce (his own word was "infidel"), Marie Curie (she used no label), Margaret Sanger (her slogan was "No Gods, No Masters"), Lu Xun (he used no label), Zora Neale Hurston (she used no label), John Lennon (he used no label)
Accused
Known as an unbeliever only through the accusations of enemies: informers, prosecutors or refuters. Their own words either do not survive or do not say. The chapter weighs what the accusers had to gain.
In this series (2): Ibn al-Rawandi (known only through his refuters), Christopher Marlowe