What Is Atheism?

What Is the Question?

The word "atheism" comes from the Greek a-theos, meaning "without God." But that etymology only begins the work, because the question of what atheism is has been contested for centuries. Is atheism a denial that God exists, or merely the absence of belief? Is it a claim that requires argument, or a default position that needs no defense? Is it a worldview, a movement, or simply a stance on one philosophical question? Getting the definition right matters, because the wrong framing makes the debate look more aggressive, or more timid, than it actually is.

The answer offered here follows the dominant philosophical usage. Atheism, in its broadest sense, is the absence of belief in God or gods. Within that broad category we can distinguish negative atheism (withholding belief) from positive atheism (asserting that no God exists). The distinction is not a verbal trick; it tracks a real difference in what a person is claiming and what they owe by way of argument. See the companion entry on agnosticism for the closely related position that the question cannot be settled.

Historical Background

Atheism is older than the modern world. The Greek poet Diagoras of Melos was known as the "first atheist" in the fifth century BCE. The Atomists, Democritus and later Epicurus, explained the world without reference to the gods, and the Roman poet Lucretius argued in De Rerum Natura that fear of the gods was the source of human misery. In the ancient world, "atheist" was often an insult hurled at anyone who denied the local gods; Christians were called atheists because they refused to worship the Roman pantheon.

The IEP article on atheism notes that the modern sense of the term, as a principled rejection of all gods, took shape during the Enlightenment. David Hume did not call himself an atheist, but his critique of miracles and his skepticism about natural theology cleared the ground. The French philosophes such as Diderot and Holbach were more openly atheist. In the nineteenth century, Feuerbach argued that God is a projection of human nature, Marx called religion the opium of the people, and Nietzsche announced the death of God, meaning that the cultural authority of theism had collapsed. The twentieth century added logical positivism's dismissal of metaphysical claims as cognitively meaningless, and the mid-century problem of evil, sharpened by J. L. Mackie, put theistic belief on the defensive analytically.

Key Varieties

The most useful distinction is between negative and positive atheism, drawn carefully by Antony Flew and now standard in the literature. Negative atheism is the absence of belief in God; it includes the person who has never considered the question and the person who has considered it and remains unconvinced. Positive atheism is the stronger claim that God does not exist, that the divine hypothesis is false. Positive atheism requires an argument, because it makes a claim about reality; negative atheism may require no argument at all, because it makes no claim but simply withholds one.

A second useful distinction concerns the scope of what is denied. A theist typically believes in a personal, omniscient, omnipotent, perfectly good creator, what the tradition calls "classical theism." But there are thinner conceptions of the divine: the God of the deist, who creates and then leaves the world alone; the God of Spinoza, which is identical with nature; the pantheist's God, in which all things participate. A person can be an atheist about classical theism while being a pantheist, or a deist, or an agnostic about a thin divine reality. The IEP entry is careful to flag that the question "do you believe in God?" is ambiguous until we know which God is on the table.

A third distinction is practical. Some atheists treat their atheism as a private stance, a matter of intellectual conscience. Others treat it as a public commitment, joined to a critique of religion's social power. The latter group overlaps with antitheism and with New Atheism, and it is important not to confuse the philosophical position with the political posture.

The Main Arguments

The most influential argument for positive atheism is the problem of evil. Mackie's version asks how God, if perfectly good and omnipotent, could permit the quantity and quality of suffering we observe. The free will defense, developed most fully by Alvin Plantinga, replies that genuine freedom requires the possibility of evil, and that God's goods may outweigh the evils we see. But the debate is live; the existence of horrific natural evils and of animal suffering before humans existed remains a sharp challenge.

The second argument is divine hiddenness. If a loving God exists, why is God not more plainly visible? The argument, developed by J. L. Schellenberg, holds that a perfectly loving God would ensure that any person capable of relationship with God would be in a position to enter that relationship, and so the existence of reasonable nonbelief counts against theism. The theist may reply that hiddenness serves some greater good, but the hiddenness literature is now a serious player in the debate.

The third family of arguments is undercutting. Atheists such as the New Atheists argue that theistic belief is best explained by psychology and sociology, not by contact with a real divine being. If the prevalence of religion can be explained by evolutionary psychology and cultural inheritance, the explanatory role of God shrinks. Theists reply that the explanation of why people believe need not settle whether the belief is true, and that naturalism itself may lack the resources to explain consciousness, morality, or the fine-tuning of the universe.

Atheism and the Burden of Proof

A central debate is who bears the burden of proof. The theist says the atheist, because atheism is a claim that reality contains no divine being, and claims require evidence. The atheist says the theist, because theism adds a substantive entity and so must earn its place. Flew's parable of the invisible gardener is the classic statement: a claim that becomes unfalsifiable through endless qualifications has been eroded without contradiction, and the burden remains with whoever proposes the entity.

Contemporary atheists such as Richard Dawkins, in The God Delusion, argue that theism is not just unsupported but probably false, on the grounds that any God complex enough to design the universe would itself need an explanation, and that naturalistic explanations of biological complexity are available. The philosophical mainstream is more cautious: most analytic atheists defend negative atheism and decline to claim that the nonexistence of God has been proved, holding instead that theism has not met its burden.

Atheism and Ethics

A common objection, raised from Pascal and Kierkegaard through contemporary apologists, is that atheism cannot ground morality. If there is no God, so the worry runs, then anything is permitted. The philosophical atheist has several replies. One is that moral realism does not require God: moral truths may be necessary truths, like mathematical ones, and need no author. Another is that virtue ethics, rooted in human flourishing, can stand on its own feet, as Aristotle showed centuries before Christ. A third is that even if atheism complicates morality, the truth of atheism, if it is true, cannot be avoided for the sake of convenience.

The more interesting question is whether atheism can carry the weight of meaning, hope, and reverence that religion has carried. Atheists such as Camus, Sartre, and the later existentialists argued yes, through defiant honesty in the face of the absurd. The IEP entry on atheism treats the existential question as serious but separable: atheism is a claim about metaphysics, and what we do with that claim is a separate, harder question.

Contemporary Relevance

Atheism has grown more visible in the last two decades. The New Atheism of Dawkins, Harris, Hitchens, and Dennett made atheist books bestsellers, and the rise of the "nones," people with no religious affiliation, in Western societies has made atheism a mainstream option. But the visibility has also produced confusion. Some New Atheist rhetoric treats all religion as irrational and harmful, which philosophers such as William James would have found naive, given the evidence that religious belief can carry genuine moral and psychological goods.

The deeper contemporary issue is whether atheism, once it is no longer a forbidden stance, can supply what religion supplied: communities of memory, rituals of passage, practices of attention, and a story large enough to live in. The philosophical atheist's answer is that atheism is not supposed to supply those things; it is a position on a question, and the rest is the work of culture, philosophy, art, and relationships. Whether that division of labor is stable is one of the live questions of our time.

Sources

• Internet Encyclopedia of Philosophy, "Atheism" — https://iep.utm.edu/atheism/
• Stanford Encyclopedia of Philosophy, "Philosophy of Religion" — https://plato.stanford.edu/entries/philosophy-religion/
• Stanford Encyclopedia of Philosophy, "The Problem of Evil" — https://plato.stanford.edu/entries/evil/
• Stanford Encyclopedia of Philosophy, "Divine Hiddenness" — https://plato.stanford.edu/entries/divine-hiddenness/

Related Topics

• What Is Agnosticism? — the position that the question cannot be settled.
• What Is New Atheism? — the popular movement.
• What Is Antitheism? — opposition to religion as harmful.
• Who Bears the Burden of Proof for God? — the procedural question.
• Does God Exist? — the central question.
• Philosophy of God — the wider domain.