Here's a very brief history of atheism, from the cooling of the earth's core to recent centuries, to the present moment.

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Where should we start a history of atheism?

Shall we start at the cooling of the Earth’s core a few billion years ago? Earlier? Shall we begin at the Big Bang? The point here is that it takes humans to believe or disbelieve in Gods, and billions of years passed before any humans appeared on the scene.

And when humanoids did appear on the scene, atheism existed before theism. Atheism was the original state of humanity. It would take millions of years of evolution of a humanoid brain in order for a human mind to evolve to the point of believing in Gods. God belief required a certain sophistication of brain matter.

Belief in numerous (and maybe innumerable) invisible entities was a prehistoric reality, as attested to by isolated aboriginal tribes discovered by numerous outsider travelers over hundreds of years. (Aboriginal tribes provide a window into prehistory.) ‘Animism’— the belief that conscious spirits animate everything and everything can be worshipped—reigned for thousands of years among tribes all over the planet. Those spirits became the polytheistic gods of various world pantheons.

At the dawn of history (history = the birth of writing) some 6000 years ago or so, we find polytheism everywhere.

Monotheism arrived late to the world stage only 3000 years ago.

Documented atheism (skepticism put in writing) arrived 2600 years ago or so—in India with the Buddha, in India perhaps with Mahavira, in China with Lao Tzu, in China perhaps with Confucius, in Greece with numerous thinkers, and in Rome about 2000+ years ago with several writers. It is the ancient Greeks and Romans who influenced Western atheism.

Ancient Greek and Roman skeptics offered what would become recurring themes in the atheist’s playbook:

Natural explanations for nature’s phenomena, not supernatural explanations. (Stars are gaseous orbs, not sparkling gods).

Natural explanations for the origin of religion, such as:

  • Religions arose as a result of an ignorance of natural causes for things and thinking there were supernatural causes for things. (A God in a chariot pulls the sun across the sky).
  • Religion arose as a means of social control: obey these rules because they are divine.
  • Religion arose as the deification of long-past, deceased human heroes.
  • Religion arose by divinizing nature: water, fire, air, sky (Poseidon, Hephaestus, Hera, Zeus).
  • Religion arose by divinizing human goods and then the creator of those goods (wine, Dionysus).
  • Religion arose from fear of nature and a desire to control nature by appeals to supposed invisible powers.

Specific arguments and tactics, such as:

  • Anthropomorphic Gods—human-like Gods— are unbelievable. (Does God have a hairy chest?).
  • The ‘Problem of Evil’ (where ‘evil’ = animal and human suffering). A high degree of suffering on our planet suggests no good and powerful God exists:  “If God wants to prevent evil, but cannot, then God is not all powerful. If God can prevent evil, but does not want to, then God is not all good.” (Epicurus, circa 300 BCE).
  • Critiques of theists being no more moral than anyone else, and sometime less moral.
  • Plausible denial of a charge of atheism by saying a character you created in a play or a work of fiction is atheist, but you, the playwright and author, are a believer.
  • Satire towards, and the mocking of theists, when the skeptical minority thinks the theistic majority is wrong.

With the rise of Christianity, Greek and Roman skeptical writings were suppressed. Three hundred years after Christ, with Christian Emperor Theodosius I, Christianity became the official religion of the Empire. Four hundred years after Christ, with Christian Emperor Theodosius II, laws were enacted against heresy (wrong religious beliefs), against apostasy (leaving the true religion Christianity), and against public debate on religion. Theodosius II destroyed ancient Greek and Roman temples, and skeptical Greek and Roman writings were suppressed and taken out of circulation for the reading public. (Interestingly, in Christian monasteries that became scriptoriums, monks copied some of the ancient skeptical documents from the Greeks and Romans. That’s how we have these documents today).

For almost 1000 years, there was no skeptical reading or writing in Europe. That does not mean there were no skeptics. It means that it was not safe to profess or publish disbelief since disbelief was criminalized and punishable by death in some cases.

But religious skepticism returned to Europe … by degrees:      

1300s: ‘Education by disputation’ in universities (universities were in Europe since 1100s) allows professors and students to dispute every claim to knowledge, even belief in God.

1400s: The Renaissance, or ‘rebirth,’ of Greek and Roman art, architecture, and literature means that intellectuals get their hands on ancient Greek and Roman skeptical literature.

1500s: Italian and French thinkers publish skeptical works based on Greek and Roman authors. The Protestant Reformation creates space for religious dissent, which eventually means space for religious skepticism and the softening of laws against unbelief.

1600s: Books opposed to atheism arise, obsessing about atheism (suggesting that atheism exists even in the absence of atheistic writings). Deistic writings arise to oppose every syllable of Christianity. (Deism is the belief in God but not in a God who reveals information to humanity via a religion or sacred text). Scientists Galileo and Newton, both theists, inadvertently start scientific skepticism toward religion.

1700s: Openly avowed atheism returns to the West, by these steps: Anonymity: skeptical books by no-named authors; pseudonymity: skeptical books by fake-named authors; skeptical authors write between the lines: hinting at religious skepticism; skeptical authors offer escape clauses to show they are really believers (when they are not):  “If I wasn’t a Christian I would say that the Holy Spirit’s conception of Jesus in Mary is completely incredible just as many Greco-Roman heroes had human mothers impregnated by a God.” And so, the reader gets exposed to the skeptical idea while the author claims not to hold that idea; skeptical authors offer literature in ‘Dialogues,’ conversations between characters, one of whom is skeptical (and usually the most potent speaker); skeptical authors offer ‘feeble defenses’ of theism (suggesting their true sympathies are with the atheists, though they pose as theists); deistic writings from famous authors like Thomas Paine of America and Voltaire of France offer powerful critiques of Christianity; then, finally, publicly avowed atheism re-appears in France and in England; and then elsewhere in Europe; Freethought literature emerges after this (‘free’ from religious oppression and censorship); scores of books arrive critiquing Christianity.

1800s: Growing skeptical literature, books, and magazines appear. Skeptical organizations like ‘Secular Societies” and ‘Ethical Societies,’ and ‘Freethought Societies’ arise. The process of secularization starts setting in, minimizing the importance of religion in Western European societies. The science of Darwin is used to argue against theism (though Darwin himself was not an anti-religion polemicist). The new word ‘agnostic’ is coined for those claiming not to know if God exists or not. (The term agnostic was meant to be softer than ‘atheist,’ but the agnostic is not any kind of believer in God).

1900s: Greater secularization in the West occurs and a vast falling away from religion happens in Europe by the end of the 1960s. The majority of the intellectual class becomes irreligious, 60% or higher. (For a thousand years prior, almost 100% of intellectuals believed in God.)  University disciplines ramp up the of study religion like any other social phenomenon. Communist countries suppress religion by law. (When Communism fell, some of those countries remained atheistic, but not all.)

2000s: More falling away from religion in Europe, and now in the USA. Several ‘new atheist’ authors Sam Harris, Richard Dawkins, and Christopher Hitchens produce best-selling books, but these authors did not create their skeptical readership: the people buying those books were already religious skeptics. Religious indifference replaces active opposition to religion in many non-believers. Some atheists say they don’t rise to the level of calling themselves ‘atheist’ because they are completely indifferent to religion and the term ‘atheist’ suggests a person is still in the religion game.

And that is the very short history of atheism in the West, from the cooling of the earth’s core to the present moment.

The literature of religious skepticism over the last 2600 years is huge, and most of it is high-quality writing, with many famous authors contributing. But none of us got exposed to this literature during our years of formal education. From kindergarten to the Ph.D., virtually no one reads the vast literature of unbelief.

To correct that, you might consult a few of the collections of primary sources below, which, as good as they are, only provide a tiny sampling of this very large literature:

‘Varieties of Unbelief’ by Gaskin

‘Anthology of Atheism and Rationalism’ in two volumes by Stein.

‘Atheism: A Reader’ by Joshi

‘The Portable Atheist’ by Hitchens

‘Women Without Superstition’ by Gaylor

‘A Short History of Freethought’ 2 vols. by Robertson

‘A History of Freethought in the Nineteenth Century’ 2 vols. by Robertson

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J. H. McKenna (Ph.D.) has taught the history of religius ideas since 1992 at various colleges and since 1999 at the University of California, where he has won teaching awards. He has published in academic...