Early Indian religions Ideas that would be recognized today as atheistic are documented in the
Vedic period and the
classical antiquity. Atheistic schools are found in early Indian thought and have existed from the times of the
historical Vedic religion. The thoroughly materialistic and anti-theistic philosophical
Chārvāka (or
Lokāyata) a school that originated in
India around the 6th century BCE is probably the most explicitly atheistic school of philosophy in India, similar to the Greek
Cyrenaic school. This branch of Indian philosophy is classified as
heterodox due to its rejection of the authority of
Vedas and hence is not considered part of the six orthodox schools of
Indian philosophy. It is noteworthy as evidence of a materialistic movement in ancient India. Satischandra Chatterjee and Dhirendramohan Datta explain in
An Introduction to Indian Philosophy that our understanding of Chārvāka philosophy is fragmentary, based largely on criticism of the ideas by other schools: "Though
materialism in some form or other, has always been present in India, and occasional references are found in the Vedas, the Buddhistic literature, the Epics, as well as in the later philosophical works we do not find any systematic work on materialism, nor any organized school of followers as the other philosophical schools possess. But almost every work of the other schools states, for refutation, the materialistic views. Our knowledge of Indian materialism is chiefly based on these." Other Indian philosophies generally regarded as atheistic include
Classical Samkhya and
Purva Mimamsa. The rejection of a personal creator, "God", is also seen in
Jainism and
Buddhism in India.
Classical antiquity pointing to the casus, the downward movement of the
atoms. In his work
De rerum natura, Lucretius stated that everything consists of material substance moving in infinity. Western atheism has its roots in
pre-Socratic Greek philosophy, but did not explicitly deny the gods' existence.
Anaxagoras, whom
Irenaeus calls "the atheist", was accused of impiety and condemned for stating that "the sun is a type of incandescent stone", an affirmation with which he tried to deny the divinity of the celestial bodies. In the late fifth century BCE, the Greek lyric poet
Diagoras of Melos was sentenced to death in
Athens under the charge of being a "godless person" (ἄθεος) after he made fun of the
Eleusinian Mysteries, but he fled the city to escape punishment. but in modern scholarship Marek Winiarczyk has defended the view that Diagoras was not an atheist in the modern sense, in a view that has proved influential.
A fragment from a lost Attic drama that featured
Sisyphus, which has been attributed to both
Critias and
Euripides, claims that a clever man invented "the fear of the gods" in order to frighten people into behaving morally. The Athenian public associated
Socrates () with the trends in pre-Socratic philosophy towards naturalistic inquiry and the rejection of divine explanations for phenomena. From a survey of these 5th-century BCE philosophers,
David Sedley has concluded that none of them openly defended radical atheism, but since Classical sources clearly attest to radical atheist ideas Athens probably had an "atheist underground". Religious skepticism continued into the
Hellenistic period, and from this period the most important Greek thinker in the development of atheism was the philosopher Epicurus (). Although Epicurus still maintained that the gods existed, Although not strictly an atheist, Euhemerus was later criticized by
Plutarch for having "spread atheism over the whole inhabited earth by obliterating the gods". In the 3rd century BCE, the
Hellenistic philosophers
Theodorus Cyrenaicus and
Strato of Lampsacus were also reputed to deny the existence of the gods. The
Pyrrhonist philosopher
Sextus Empiricus () compiled a large number of ancient arguments against the existence of gods, recommending that one should
suspend judgment regarding the matter. His relatively large volume of surviving works had a lasting influence on later philosophers. The meaning of "atheist" changed over the course of classical antiquity. During the
Roman Empire, Christians were executed for their rejection of the
Roman gods in general and the
Imperial cult of ancient Rome in particular. There was, however, a heavy struggle between Christians and pagans, in which each group accused the other of atheism, for not practicing the religion which they considered correct. When Christianity became the state religion of Rome under
Theodosius I in 381,
heresy became a punishable offense. as well as outspoken atheists such as
al-Maʿarri (973–1058). Al-Ma'arri wrote and taught that religion itself was a "fable invented by the ancients" and that humans were "of two sorts: those with brains, but no religion, and those with religion, but no brains". Despite the fact that these authors were relatively prolific writers, little of their work survives, mainly being preserved through quotations and excerpts in later works by Muslim
apologists attempting to refute them. In Europe, the espousal of atheistic views was rare during the Early Middle Ages and
Middle Ages (see
Medieval Inquisition). There were, however, movements within this period that furthered heterodox conceptions of the Christian god, including differing views of the nature, transcendence, and knowability of God.
William of Ockham inspired anti-metaphysical tendencies with his
nominalist limitation of human knowledge to singular objects, and asserted that the divine
essence could not be intuitively or rationally apprehended by human intellect. Sects deemed heretical such as the
Waldensians were also accused of being atheistic. The resulting division between
faith and reason influenced later radical and reformist theologians. The philosopher
Baruch Spinoza was "probably the first well known 'semi-atheist' to announce himself in a Christian land in the modern era", according to Blainey. Spinoza believed that natural laws explained the workings of the universe. In 1661, he published his
Short Treatise on God.
Criticism of Christianity became increasingly frequent in the 17th and 18th centuries, especially in France and England. Some Protestant thinkers, such as
Thomas Hobbes, espoused a materialist philosophy and skepticism toward supernatural occurrences. By the late 17th century, deism came to be openly espoused by intellectuals. The first known explicit atheist was the German critic of religion
Matthias Knutzen in his three writings of 1674. He was followed by two other explicit atheist writers, the Polish ex-Jesuit philosopher
Kazimierz Łyszczyński (who most likely authored the world's first treatise on the non-existence of God) and in the 1720s by the French priest
Jean Meslier. , atheist and editor of
Encyclopédie. In the course of the 18th century, other openly atheistic thinkers followed, such as
Baron d'Holbach,
Jacques-André Naigeon, and other
French materialists. Baron d'Holbach was a prominent figure in the
French Enlightenment who is best known for his atheism and for his voluminous writings against religion, the most famous of them being
The System of Nature (1770) but also
Christianity Unveiled. In Great Britain, William Hammon and physician Mathew Turner authored a pamphlet in response to
Joseph Priestley's
Letters to a Philosophical Unbeliever. Theirs was the first work in English to openly defend atheism, and implied that established sentiment of Christianity made speaking up in defense of atheism an act with a reasonable expectation of public punishment. Although Voltaire is widely considered to have strongly contributed to atheistic thinking during the Revolution, he also considered fear of God to have discouraged further disorder, having said "If God did not exist, it would be necessary to invent him." The philosopher David Hume developed a skeptical epistemology grounded in
empiricism, and
Immanuel Kant's philosophy has strongly questioned the very possibility of metaphysical knowledge. Both philosophers undermined the metaphysical basis of natural theology and criticized classical arguments for the existence of God. One goal of the
French Revolution was a restructuring and subordination of the clergy with respect to the state through the
Civil Constitution of the Clergy. Attempts to enforce it led to
anti-clerical violence and the expulsion of many clerics from France, lasting until the
Thermidorian Reaction. The radical
Jacobins seized power in 1793. The Jacobins were deists and introduced the
Cult of the Supreme Being as a new French state religion. In the latter half of the 19th century, atheism rose to prominence under the influence of
rationalistic and
freethinking philosophers. German philosopher Ludwig Feuerbach considered God to be a human invention and religious activities to be wish-fulfillment. He influenced philosophers such as Karl Marx and
Friedrich Nietzsche, who denied the existence of deities and were critical of religion. In 1842,
George Holyoake was the last person imprisoned in Great Britain due to atheist beliefs.
Stephen Law notes that he may have also been the first imprisoned on such a charge. Law states that Holyoake "first coined the term 'secularism'".
20th century Atheism advanced in many societies in the 20th century. Atheistic thought found recognition in a wide variety of other, broader philosophies, such as
Marxism,
logical positivism,
existentialism,
humanism and
feminism, and the general scientific movement. Proponents of
naturalism such as
Bertrand Russell and
John Dewey emphatically rejected belief in God.
Analytical philosophers such as
J.N. Findlay and
J.J.C. Smart argued against the existence of God. State atheism emerged in Eastern Europe and Asia, particularly in the Soviet Union under
Vladimir Lenin and
Joseph Stalin, and in
Communist China under
Mao Zedong. Atheist and anti-religious policies in the Soviet Union included
numerous legislative acts, the outlawing of religious instruction in the schools, and the emergence of the
League of Militant Atheists. Stalin softened his opposition to the Orthodox church in order to improve public acceptance of his regime during the second world war. In 1966,
Time magazine asked "Is God Dead?" in response to the
Death of God theological movement, citing the estimation that nearly half of all people in the world lived under an anti-religious power, and millions more in Africa, Asia, and South America seemed to lack knowledge of the Christian view of theology. Leaders like
Periyar E.V. Ramasamy, a prominent atheist leader of
India, fought against
Hinduism and
Brahmins for discriminating and dividing people in the name of
caste and religion. In the United States, atheist
Vashti McCollum was the plaintiff in a 1948
Supreme Court case that struck down religious education in US public schools.
Madalyn Murray O'Hair was one of the most influential American atheists; she brought forth the 1963 Supreme Court case
Murray v. Curlett which banned compulsory prayer in public schools. The
Freedom From Religion Foundation was co-founded by Anne Nicol Gaylor and her daughter,
Annie Laurie Gaylor, in 1976 in the United States. It promotes the
separation of church and state.
21st century ,
Lawrence Krauss and
Julia Galef in 2015 "New Atheism" is a movement among some early-21st-century atheist writers who have advocated the view that "religion should not be tolerated but should be countered, criticized, and exposed by rational argument wherever its influence arises". The movement is commonly associated with
Sam Harris,
Daniel Dennett, Richard Dawkins, Christopher Hitchens, and
Victor J. Stenger. The religiously motivated terrorist
events of 9/11 and the partially successful attempts to change the American science curriculum to include
creationist ideas, together with support for those ideas from the
religious right, have been cited by "new" atheists as evidence of a need to move toward a more secular society.
Melbourne hosted the first Global Atheist Convention in 2010 (branded as the largest event of its kind in the world), sponsored by the
Atheist Foundation of Australia and
Atheist Alliance International. It took place at the
Melbourne Convention & Exhibition Centre from 12 to 14 March that year. Over 2,000 delegates attended, with all available tickets selling out more than five weeks prior to the event. A second conference was held, also in Melbourne, from 13 to 15 April 2012. A third convention, planned for February 2018, was cancelled, apparently because of insufficient interest. == Demographics ==