- For information about the American band, see Atheist (band).
Atheism is the state either of being without theistic beliefs, or of actively disbelieving in the existence of deities. In antiquity, Epicureanism incorporated aspects of atheism, but it disappeared from the philosophy of the Greek and Roman traditions as Christianity gained influence. During the Age of Enlightenment, the concept of atheism re-emerged as an accusation against those who questioned the religious status quo, but by the late 18th century it had become the philosophical position of a growing minority. By the 20th century, atheism had become the most common position among scientists, rationalists, and humanists.
In early Ancient Greek, the adjective atheos (from privative a- + theos "god") meant "without God, godforsaken, abandoned by the gods". The word acquired an additional meaning in the 5th century BCE, expressing total lack of relations with the gods, that is, "denying the gods, godless, ungodly", with more actively atheistic connotations than asebēs "impious". Modern translations of classical texts sometimes translate atheos as "atheistic". As an abstract noun, there was also atheotēs: "atheism". Cicero transcribed atheos into Latin. The discussion of atheoi was pronounced in the debate between early Christians and pagans, who each attributed atheism to the other.
In English, the term atheism is the result of the adoption of the French athéisme around 1587. The French word is derived from athée "godless, atheist", which in turn is from Greek atheos. The words deist and theist entered English after atheism, being first attested in 1621 and 1662, respectively, followed by theism and deism in 1678 and 1682, respectively. Due to the influence of atheism, deism and theism exchanged meanings around 1700. Deism was originally used with a meaning comparable to today's theism, and vice-versa.
Types of atheism
There are two main forms of atheism:
Weak atheism, also known as implicit atheism and negative atheism, is the absence of belief in the existence of deities. A weak atheist may consider the nonexistence of deities likely, on the basis that there is insufficient evidence. An argument commonly associated with weak atheism is that of rationalism: one should believe only what one has reason to believe. Theists claim that a single deity and/or group of deities exist. Weak atheists do not assert the contrary; instead, they refrain from assenting to theistic claims. Because of a lack of consideration, or because the arguments and evidence provided by both sides are equally unpersuasive, some weak atheists are without opinion regarding the existence of deities. Having considered the evidence for and against the existence of deities, others may doubt the existence of deities while not asserting that deities do not exist. They may feel that it is impossible to prove a negative, or that the strong atheist has not been relieved of the burden of proof, which is also required of the theist, or that faith is required to assert or deny theism, making both theism and strong atheism untenable. Agnosticism is the epistemological position that the existence or nonexistence of deities is unknown and possibly unknowable. Agnostic theism regards understanding that the existence of deities is unprovable and continuing to hold theistic beliefs. Similarly, agnostic atheism concerns understanding that the existence of deities is unprovable while being without theistic beliefs. For a discussion of agnosticism and its variants, see: agnosticism, weak agnosticism, strong agnosticism, agnostic atheism.
Strong atheism, also known as explicit atheism and positive atheism, is the belief that no deities exist. This may be based on the view that there is insufficient evidence or grounds to justify belief in deities, on grounds such as the problem of evil, on arguments that the concept of a deity is self-contradictory and therefore impossible, or on the assertion that any belief in the supernatural is not rationally justifiable. It may also be based on an appreciation of the psychological characteristics of faith and belief (see True-believer syndrome, for example), and of a subsequent critical attitude towards any system that encourages faith, belief, and acceptance, rather than critical thinking, from its adherents.
Under the broader definition of atheism (that is, the "condition of being without theistic beliefs"), which is characteristic of "weak atheism", nonbelief, disbelief or doubt of the existence of deities are forms of atheism. However, many strong atheists, agnostics, and theists use a narrower definition of atheism, according to which it is the active "denial of the existence of God or gods". Adherents of this definition would not recognize mere absence of belief in deities (that is, "weak atheism") as a type of atheism at all, and would tend to use other terms, such as "skeptic" or "agnostic" for this position.
In English, believers usually refer to the monotheistic god as "God". In many philosophical and/or esoteric interpretations of monotheism or henotheism, God is not thought of as a supernatural being — as a deity or god; rather, God becomes a reified philosophical category: the All, the One, the Ultimate, the Absolute Infinite, the Transcendent, the Divine Ground, Being or Existence itself, etc. For example, such views are typical of pantheism, panentheism, and religious monism. Attributing anthropomorphic characteristics to God may be regarded as idolatry, blasphemy, or symbolism. Some theists may not believe in, or may even deny, the existence of deities as supernatural beings, while maintaining a belief in god as so conceived. For example, the Protestant theologian Paul Tillich described God as the 'ground of Being', the 'power of Being', or as 'Being itself', and caused controversy by making the statement "God does not exist", resulting in him occasionally being labelled an atheist. Nevertheless, for Tillich, God is not 'a' being that exists among other beings, but is Being itself. For him, God does not 'exist'; God is the basis of Being, the metaphysical power by which Being triumphs over non-Being. Most (though not necessarily all) atheists who deny the existence of deities as supernatural beings would also deny this and similar conceptions of God, or consider them incomprehensible.
Philosophies that involve living without theistic beliefs can be found in many cultures. In the East, living a contemplative life without gods began with Lao Zi who wrote of the Tao (the Way), and Siddhartha Gautama, the Buddha in the 6th century BCE, founder of Buddhism. These worldviews are considered major religions, however, the original doctrinal texts do not advocate or describe deities, or related deity-worship. While later enthusiasts introduced deities and deity-worship, the practical application of these worldviews to religious thought remains atheistic. In the West, theism was the fundamental belief that supported the divine right of the State. Historically, any person who did not believe in any deity supported by the State was fair game to accusations of atheism, a capital crime. For political reasons, Socrates in Athens (399 BCE) was accused of being 'atheos' ("refusing to acknowledge the gods recognized by the state"). Despite the charges, he claimed inspiration from a divine voice and on his deathbed he asked that a rooster be sacrificed to the god Asclepius. Christians in Rome were also considered subversive to the state religion and prosecuted as atheists. Thus, charges of atheism, meaning the subversion of religion, were often used similarly to charges of heresy and impiety — as a political tool to eliminate diversity in religion.
The oldest known expressions of atheism as we now understand it are attributed to Epicurus around 300 BCE. The aim of the Epicureans was mainly to attain peace of mind by exposing fear of divine wrath as irrational. One of the most eloquent expression of Epicurean thought is Lucretius' On the Nature of Things (1st century BC). (It should be noted that Lucretius was not exactly an atheist as he did accept the existence of gods, and Epicurus was ambiguous on this topic too. However both of them certainly thought that if gods existed they were uninterested in human existence. Both of them also denied the existence of an afterlife. Perhaps they are better described as materialists than atheists.) Epicureans were not persecuted, but their teachings were controversial, and were harshly attacked by the mainstream schools of Stoicism and Neoplatonism. The movement remained marginal, and gradually died out at the end of the Roman Empire, until it was revived by Pierre Gassendi in the 17th century. During the late Roman Empire, atheism — a capital crime — was a common legal prosecution against Christians by henotheists. Christians rejected all gods but Jesus, and henotheists rejected the exclusivity of Christian monotheism.
In the European Middle Ages people were persecuted for heresy, especially in countries where the Inquisition was active. Medieval impiety and godlessness were closer to weak atheism than avowed strong atheism (see below), and hardly any expression of strong atheism is known from this period. The term 'Epicurean' was essentially a slur and had no active proponents. Saint Anselm's ontological argument at least seems to acknowledge the validity of the question about god's existence. Medieval beliefs that most closely approach strong atheism were probably held by some members of the pantheistic Brethren of the Free Spirit. A man called Löffler, who was burned in Bern in 1375 for confessing adherence to this movement, is reported to have taunted his executioners that they would not have enough wood to burn "Chance, which rules the world". Contemporaneously, in India the Carvaka school of philosophy, which continued until the fourteenth century, was openly atheistical and empirical.
During the time of the Renaissance and the Reformation, criticism of the religious establishment started to become more frequent, but did not amount to actual atheism. The dissidents also turned against each other: John Calvin narrowly escaped being burned by Lutherans in 1532, and himself approved of the burning of the Unitarian Christian Michael Servetus in 1553.
The term atheisme itself was coined in France in the 16th century, and was initially used as an accusation against critics of religion, scientists, materialistic philosophers, deists, and others who seemed to represent a threat to established beliefs. The charge was almost invariably denied. Thus, the concept of atheism re-emerged initially as a reaction to the intellectual and religious turmoil of the Age of Enlightenment and the Reformation — as a charge used by those who saw the denial of god and godlessness in the controversial positions being put forward by others. How dangerous it was to be accused of being an atheist at this time is illustrated by the fact that in 1766, the French nobleman Jean-François de la Barre, was tortured, beheaded, and his body burned for alleged vandalism of a crucifix, a case that became celebrated because Voltaire tried unsuccessfully to have the sentence reversed.
Among those accused of atheism was Denis Diderot (1713–1784), one of the Enlightenment's most prominent philosophes, and editor-in-chief of the Encyclopédie, which sought to challenge religious, particularly Catholic, dogma: "Reason is to the estimation of the philosophe what grace is to the Christian," he wrote. "Grace determines the Christian's action; reason the philosophe's".  Diderot was briefly imprisoned for his writing, some of which was banned and burned.
The English materialist philosopher Thomas Hobbes (1588–1679) was also accused of atheism, but he denied it. His theism was unusual, in that he held god to be material. Even earlier, the British playwright and poet, Christopher Marlowe (1563–1593), was accused of atheism when a tract denying the divinity of Christ was found in his home. Before he could finish defending himself against the charge, Marlowe was murdered, although this was not related to the religious issue.
By the 1770s, atheism was ceasing to be a dangerous accusation that required denial, and was evolving into a position openly avowed by some. The first open denial of the existence of god and avowal of atheism since classical times may be that of Paul Baron d'Holbach (1723–1789) in his 1770 work, The System of Nature. D'Holbach was a Parisian social figure who conducted a famous salon widely attended by many intellectual notables of the day, including Diderot, Jean Jacques Rousseau, David Hume, Adam Smith, and Benjamin Franklin. Nevertheless, his book was published under a pseudonym, and was banned and publicly burned by the Executioner. Matthew Turner (d. 1788?), a Liverpool physician who wrote (or perhaps co-wrote) the atheistic pamphlet Answer to Dr Priestley's Letters to a Philosophical Unbeliever in 1782, is considered the first British atheist openly to declare himself, although the pamphlet was in fact issued by a pseudonymous editor and attributed to an anonymous author.
Afterward, the French Revolution of 1789 catapulted atheistic thought into political notability, and opened the way for the 19th century movements of Rationalism, Freethought, and Liberalism. An early atheistic influence in Germany was The Essence of Christianity by Ludwig Feuerbach (1804–1872). Other German 19th century atheistic thinkers were Arthur Schopenhauer (1788–1860) and Friedrich Nietzsche (1844–1900). The freethinker Charles Bradlaugh (1833–1891) was repeatedly elected to the British Parliament, but was not allowed to take his seat after his request to affirm rather than take the religious oath was turned down (he offered to take the oath, but this too was denied him). After Bradlaugh was re-elected for the fourth time, Parliament did relent , however, and he became the first avowed atheist to sit in Parliament, where he participated in amending the Oaths Act . In many countries, denying god was included as a crime of blasphemy. In several countries, such as Germany, Spain, and the United Kingdom, these laws remain. Likewise, some American states, such as Massachusetts, retain such laws; however, these laws are rarely enforced, if at all.
In 1884, Karl Marx (1818–1883), an atheistic political economist, wrote in his Contribution to the Critique of Hegel's Philosophy of Right:
"Religious suffering is, at one and the same time, the expression of real suffering and a protest against real suffering. Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people. 
Marx believed that people turn to religion in order to dull the pain caused by the reality of social situations; that is, Marx suggests religion is an attempt at transcending the material state of affairs in a society — the pain of class oppression — by effectively creating a dream world, rendering the religious believer amenable to social control and exploitation in this world while they hope for relief and justice in life after death. In the same essay, Marx states, "...[m]an creates religion, religion does not create man..."
Friedrich Nietzsche, a prominent 19th century atheist, coined the aphorism "God is dead". Nietzsche argued that the Western belief system was a metaphysical system based on theological (Christian) foundations. With the death of God (i.e., the collapse of Christianity as a serious belief system), the whole system of Western thought crumbled, hence Nietzsche's call for a re-evaluation of all values.
State support of "atheism" and opposition to organized religion was made policy in most communist countries, including the People's Republic of China  and the former Soviet Union. In theory, these states were secular. Some churches were tolerated, but were subject to strict control. Consequently, religious organizations, such as the Catholic Church, were among the staunchest opponents of communist regimes.
During the Cold War, the communist adversaries of the United States were officially "atheists" ("Godless Communists") which tended to reinforce the view that atheists were unreliable and unpatriotic (an example of the fallacy known as affirming the consequent). In the 1988 U.S. presidential campaign, Republican presidential candidate George H. W. Bush said, "I don't know that atheists should be regarded as citizens, nor should they be regarded as patriotic. This is one nation under God." 
Atheism is common in Western Europe, in former or present communist states, and in the United States and Canada. It is particularly prevalent among scientists, a tendency already quite marked at the beginning of the twentieth century, developing into a dominant one during the course of the century. In 1914, James H. Leuba found that 58% of 1,000 randomly selected U.S. natural scientists expressed "disbelief or doubt in the existence of God". The same study, repeated in 1996, resulted in 93% expressing such disbelief or doubt. Expressions of positive disbelief rose from 52% to 72%.  (See also The relationship between religion and science).
In the United States, there is widespread disapproval of atheists. For example, according to motherjones.com, 52% of Americans claim they would not vote for a well-qualified atheist for president.  Notwithstanding such attitudes, atheists are legally protected from discrimination in the United States. They have been among the strongest advocates of the legal separation of church and state. American courts have regularly, if controversially, interpreted the constitutional requirement for separation of church and state as protecting the freedoms of non-believers, as well as prohibiting the establishment of any state religion. Atheists often sum up the legal situation with the phrase: "Freedom of religion also means freedom from religion." 
In the Board of Education of Kiryas Joel Village School District v. Grumet , Justice Souter ruled: "government should not prefer one religion to another, or religion to irreligion."  Everson v. Board of Education established that "neither a state nor the Federal Government can... pass laws which aid one religion, aid all religions, or prefer one religion over another". This applies the Establishment Clause to the states as well as the federal government.  However, several state constitutions make the protection of persons from religious discrimination conditional on their acknowledgement of the existence of a deity, apparently making freedom of religion in those states inapplicable to atheists. These state constitutional clauses have not been tested. Civil rights cases are typically brought in federal courts; so such state provisions are mainly of symbolic importance.
In the Newdow case, after a father challenged the phrase "under God" in the United States Pledge of Allegiance, the Ninth Circuit Court of Appeals found the phrase unconstitutional. Although the decision was stayed pending the outcome of an appeal, there was the prospect that the pledge would cease to be legally usable without modification in schools in the western United States, over which the Ninth Circuit has jurisdiction. This resulted in political furor, and both houses of Congress passed resolutions condemning the decision, nearly unanimously. A very large group consisting of almost the entire Senate and House was televised standing on the steps of Congress, hands over hearts, swearing the pledge and shouting out "under God". The Supreme Court subsequently reversed the decision, ruling that Michael Newdow did not have standing to bring his case, thus disposing of the case without ruling on the constitutionality of the pledge.
In early 2004, it was announced that atheism would be taught during religious education classes in Britain.  A spokesman for the 'Qualifications and Curriculum Authority' stated the following about the decision: "There are many children in England who have no religious affiliation and their beliefs and ideas, whatever they are, should be taken very seriously." There is also considerable debate in the U.K. on the status of faith-based schools, which use religious as well as academic selection criteria. 
As some governments have strongly promoted atheism, whilst others have strongly condemned it, atheism may be either over reported or underreported for different countries. There is a great deal of room for debate as to the accuracy of any method of measurement, as the opportunity for misreporting (intentionally or not) a belief system without an organized structure is high. Also, many surveys on religious identification ask people to identify themselves as "agnostics" or "atheists", which is potentially confusing, since these terms are not uniformly interpreted, with many people identifying themselves as both.
The following surveys are in chronological order, but as they are different studies with different methodologies it would be inaccurate to infer trends on the prevalence of atheism from them:
A 1995 survey  attributed to the Encyclopedia Britannica indicates that non-religious are about 14.7% of the world's population, and atheists around 3.8%.
In the 2001 Australian Census  15.5% of respondents ticked 'no religion' and a further 11.7% either did not state their religion or were deemed to have described it inadequately (there was a popular and successful campaign at the time to have people describe themselves as Jedi).
A 2002 survey by Adherents.com  estimates the proportion of the world's people who are "secular, non-religious, agnostics and atheists" as about 14%.
In a 2003 poll in France, 54% of those polled identified themselves as "faithful", 33% as atheist, 14% as agnostic, and 26% as "indifferent". 
A 2004 survey by the BBC  in 10 countries showed the proportion of the population "who don't believe in God nor in a higher power" varying between 0% and 30%, with an average close to 10% in the countries surveyed. About 8% of the respondents stated specifically that they consider themselves to be atheists.
A 2004 survey by the CIA in the World Factbook  estimates about 12.5% of the world's population is non-religious, and about 2.4% are atheists.
A 2004 survey by the Pew Research Center  showed that in the United States, 12% of people under 30 and 6% of people over 30 could be characterized as non-religious.
The country with the highest percentage of self-described atheists (59%) is probably the Czech Republic.
Views of atheism
In general, formulations of Jewish principles of faith require a belief in God (represented by Judaism's paramount prayer, the Shema). In many modern movements in Judaism, rabbis have generally considered the behavior of a Jew to be the determining factor in whether or not one is considered an adherent of Judaism. Within these movements it is often recognized that it is possible for a Jew to strictly practise Judaism as a faith, while at the same time being an agnostic or atheist, giving rise to the riddle: "Q: What do you call a Jew who doesn't believe in God? A: A Jew." It is also worth noting that Reconstructionism does not require any belief in a deity, and that certain popular Reform prayer books such as Gates of Prayer offer some services without mention of God.
Rabbi Abraham Isaac Kook , first Chief Rabbi of the Jewish community in pre-state Israel, held that atheists were not actually denying God: rather, they were denying one of man's many images of God. Since any man-made image of God can be considered an idol, Kook held that, in practice, one could consider atheists as helping true religion burn away false images of god, thus in the end serving the purpose of true monotheism.
In Islam, those who deny the existence of god are categorized as kafirun, a term that is also used to describe polytheists, and that translates roughly as "denier" or "concealer." The noun kafir carries connotations of blasphemy and disconnection from the Islamic community. Monotheists such as Christians and Jews are sometimes erroneously called kafirun by Muslims, although the Qur'an makes clear that these groups have special status as People of the Book both inside and outside Islamic communities. The Arabic translation of 'atheism' is ilhad (إلحاد).
Hinduism, Buddhism, and Chinese traditional religion
It is difficult to categorize the Eastern thought systems in distinct terms of theism or atheism. Therefore, it should be noted that even the thoughts that would be characterized as atheistic in the western sense, often have some theistic tendencies, and vice versa.
Carvaka (also Charvaka) was a materialist and atheist school of thought in India, which is now known principally from fragments cited by its Hindu and Buddhist opponents. The proper aim of a Carvakan, according to these sources, was to live a prosperous, happy, productive life in this world (cf Epicureanism). There is some evidence that the school persisted until at least 1578. Buddhism itself may be considered as originally atheistic, since it opposed the gods and rituals of Vedic religion, and early Buddhism included no notion of a creator deity. It is the later expressions of Buddhism, especially the Mahayana schools, that display many theistic characteristics in their descriptions of the cosmic Buddha, and reality (for lack of a better term).
Confucianism and Taoism are arguably atheistic in the sense that they do not explicitly affirm, or are founded upon a faith in, a higher being or beings. However, Confucian writings do have numerous references to 'Heaven,' which denotes a transcendent power, with a personal connotation. Neo-Confucian writings, such as that of Chu Hsi, are vague on whether their conception of the Great Ultimate is like a personal deity or not. Also, although the Western translation of the Tao as 'god' in some editions of the Tao te Ching is highly misleading, it is still a matter of debate whether the actual descriptions of the Tao by Lao Zi has theistic or atheistic undertones.
Atheism, morality, and religion
Many world religions teach that morality is derived from, for example, the commandments of a particular deity, and, further, that fear of the gods is a major factor in motivating people towards moral behavior. Consequently, atheists have frequently been accused of being amoral or immoral. For example, for many years in the United States, atheists were not allowed to testify in court because it was believed that an atheist would have no reason to tell the truth.
Atheists reject this view and often assert that they are as motivated towards moral behavior as anyone — if only by their upbringing, a human concern for others, society's laws, a desire for a good reputation, and self-esteem. Francis Bacon writes: "Atheism leaves a man to sense, to philosophy, to natural piety, to laws, to reputation; all of which may be guides to an outward moral virtue, even if religion vanished; but religious superstition dismounts all these and erects an absolute monarchy in the minds of men."  In addition, while atheism, as a negative position, does not entail any particular moral philosophy, many atheists are drawn towards views like Secular Humanism, which provide a moral framework that is not founded on faith in deities.
Similarly, atheism is not synonymous with irreligion. There are religious belief systems, including much of Buddhism, Taoism, and Unitarian Universalism, which do not require theistic belief. A number of atheistic churches have been established, such as the Naturalistic Pantheists, Brianism, and the Fellowship of Reason.
- Baggini, J. (2003). Atheism: A very short introduction. Oxford: Oxford University Press.
- Buckley, M. J. (1987). At the origins of modern atheism. New Haven, CT: Yale University Press.
- Cudworth, Ralph, The True Intellectual System of the Universe: the first part, wherein all the reason and philosophy of atheism is confuted and its impossibility demonstrated (1678).
- d'Holbach, P. H. T. (1770). The system of nature. Electronic versions:
- de Mornay, Phillipe, A woorke concerning the Trewnesse of the Christian Religion, written in French; Against Atheists, Epicures, Paynims, Iewes, Mahumetists in London, 1587.
Evolution and Religion Can Coexist, Scientists Say
- Flew, Anthony. (1984). The Presumption of Atheism. New York: Prometheus.
- Hitchens, Christopher (2001). Letters to a Young Contrarian. New York: Basic Books.
- Krueger, D. E. (1998). What is atheism?: A short introduction. New York: Prometheus.
- LePoidevin, R. (1996). Arguing for atheism: An introduction to the philosophy of religion. London: Routledge.
- Mackie, J. L. (1982). The miracle of theism: Arguments for and against the existence of God. Oxford: Oxford University Press.
- Martin, M. (1990). Atheism: A philosophical justification. Philadelphia, PA: Temple University Press.
- Martin, M., & Monnier, R. (Eds.). (2003). The impossibility of God. New York: Prometheus.
- Nielsen, K. (2001). Naturalism and religion. New York: Prometheus.
- Smith, G. H. (1979). Atheism: The Case Against God. New York: Prometheus.
- Smith, G. H. (1990). Atheism, Ayn Rand, and Other Heresies. New York: Prometheus.
- Stein, G. (Ed.). (1985). The encyclopaedia of unbelief (Vols. 1-2). New York: Prometheus.