Author: Nathan Nobis
Category: Philosophy of Religion, Ethics, Epistemology, Metaphysics
Word count: 1000
Atheists believe God does not exist.[1] Atheists reject theism, the view that God—an all-powerful, knowing, and good being—exists.[2] Atheists are not agnostics, who suspend judgment on the matter and so neither believe nor disbelieve there’s a God.[3]
This essay introduces some of the core philosophical issues about atheism: what it is, how and why people accept atheism, and the relationships between atheism and meaning in life and ethics.[4]
1. Defining Atheism
Atheists are sometimes defined as people who do not believe there is a God.[5] But such people are better characterized as non-theists or not theists. This is because believing that some claim is not the case and not believing that claim are different: thinking this medicine is ineffective is different from not thinking this medicine is effective when, say, you have never heard of it or have no view on its efficacy.[6] Atheists affirm the claim “God does not exist” as true; they do not merely lack the belief that God exists.
Non-theists include agnostics—since they don’t believe there’s a God—but agnostics aren’t atheists since they don’t disbelieve there’s a God: they suspend judgment. Non-theists also include people who have never even considered God’s existence, perhaps because the concept is not part of their culture: indeed, some of them might immediately affirm God’s existence if the concept of God were introduced to them. And things that can’t have beliefs about God, like babies, and things that don’t have beliefs at all are not theists either.
2. Confidence, Knowledge, and Rationality
Like theists, atheists vary in their confidence in their beliefs. Some atheists are very confident—they feel certain—thinking atheism has been “proven.” Other atheists believe that God probably doesn’t exist, with varying levels of confidence.[7] But confidence does not entail truth or rationality: people can confidently hold false or irrational beliefs.[8] And people can have true beliefs, yet lack confidence in them.
Some atheists think they know that God doesn’t exist.[9] Others think they have strong evidence for atheism, but not knowledge. Some atheists could think their evidence for atheism is weak but they disbelieve nevertheless.[10] Some atheists insist that only atheism is rational; others hold that, since different people have different evidence, different views on God’s existence can potentially be rational for different people.[11] What anyone really knows or reasonably believes here depends on what knowledge is and what’s required for rationality or justification.[12]
3. Arguments and Atheism
Atheists usually believe the overall evidence to believe there is not a God is stronger than the evidence to believe there is a God.[13] So, they might think the evidence for theism is weak, and the evidence for atheism is strong; or they might think the evidence for theism is strong, but the evidence for atheism is stronger.[14]
Atheists often critique the arguments for theism. They also often argue that what theists try to explain by appealing to God can be explained just as well—or better—without appealing to God.[15] They also sometimes argue that the concept of God itself is incoherent: e.g., that there couldn’t be an immaterial being.[16]
Concerning arguments against God’s existence, probably the most important are versions of the “argument from evil”:
if there were a God, then there probably would not be as much truly horrendous suffering and evil in our world; yet there is such evil, so probably there isn’t a God.[17]
And arguments from “divine hiddenness”:
if God existed, God’s existence would be more obvious to everyone; since it isn’t, probably there isn’t a God.[18]
And an argument applying a principle like this to a person’s total evidence:
if there’s insufficient reason to believe that some being exists, and some good reason to believe it doesn’t exist, then people are justified in believing that being does not exist.
4. The “Presumption of Atheism”
Some argue that atheists don’t need to provide arguments that there’s not a God in order for their disbelief to be rational. They argue that we don’t need arguments that unfamiliar things do not exist to reasonably believe they don’t.
This view is that there is a “presumption of atheism”: the starting point is not believing there’s a God and the “burden of proof” lies with theists to provide strong arguments for God’s existence.[19] Until they do so, non-theists are justified in withholding belief, even without positive arguments for their non-theisms.
Whatever the merits of any such presumption, it doesn’t end the discussion: atheists who accept it still must engage arguments for theism to evaluate their strength. And it is often a moot point since most atheists have some positive reasons for their views: they usually don’t just find arguments for theism inadequate.
5. Values
Some people seem to think that atheists can’t have meaningful lives. Whether this is true or not depends on what makes lives meaningful. If what makes lives more meaningful are things like positive relationships with friends and family, a rewarding job, service to others, and having some fun, then atheists surely can, and often do, have meaningful lives.[20]
Atheists usually reject claims that a meaningful life requires belief in God or belief in an eternal existence, finding no good reason to believe that.[21]
About ethics, some think atheists are inclined to be immoral, or wouldn’t understand the difference between right and wrong, or won’t care, but this stereotype is unfounded.[22]
Like most people, atheists usually believe that some actions are wrong and others are right. They might explain that many wrong actions are wrong because they tend to cause more harm than benefit, or because they disrespectfully “use” people without consent, or because they violate rules that people wouldn’t consistently apply to themselves.[23] Right actions tend to be those that are beneficial, respectful, and fair.
They also might observe that these moral explanations have nothing immediately to do with God’s existence, so ethics doesn’t depend on God or anything religious.[24]
6. Conclusion
All atheists believe there’s not a God. Exactly why each atheist believes this, and what else they believe because of it, varies. What is this? Ask them!
Notes
[1] This is a traditional, classic understanding of the concept of God, but there are other definitions and understandings of the concept of God. For more on definitions of theism, see The Concept of God: Divine Attributes by Bailie Peterson. Atheists also usually deny the existence of any proposed God who is less than all-powerful, knowing, or good.
[2] For introductions to many arguments for and against theism and theistic belief, see the essays in the Philosophy of Religion category of 1000-Word Philosophy.
[3] For more on agnosticism, see Agnosticism about God’s Existence by Sylwia Wilczewska.
A view related to agnosticism is apatheism: apatheists have considered the question of whether God exists, but do not even suspend judgment on the issue, since they are apathetic about the issue: they just don’t care either way; they think having views whether God exists or whether anyone should or shouldn’t believe there’s a God is unimportant or uninteresting. For an introduction to apatheism, see Hedberg and Huzarevich (2017).
[4] It is noteworthy that the 2020 PhilPapers survey of professional philosophers found that 66.95% report that they “accept or lean toward” atheism. 7.18% reported that they are agnostic or undecided. 18.93% reported that they accept or lean towards theism. See PhilPapers (2020).
[5] For example, the organization American Atheists writes this on their “What is Atheism?” webpage:
Atheism is one thing: A lack of belief in gods. Atheism is not an affirmative belief that there is no god [or “there are no gods”] . . To be clear: Atheism is not a disbelief in gods or a denial of gods; it is a lack of belief in gods.
While people are free to define “atheism” in different ways—or use the term “atheism” to label whatever grouping they like—there are often better and worse ways to categorize. So putting (a) people who have carefully thought about whether there’s a God and have concluded there (probably) isn’t a God and (b) people who have never considered any idea of God at all—perhaps because their culture just doesn’t have any such concept—is not ideal since the broader category of non-theists or not-theists better describes the category: e.g., having to respond to a question, “What do atheists think about God?” with “Some atheists have never even considered the idea of God,” is not ideal for many purposes. Furthermore, the non-theists or not theists versus atheists (and agnostics) distinction is also readily understood.
A further error, however, with a “lack of belief” definition of atheism as it is sometimes stated is that physical objects (rocks, plants, electrons, etc.) have a “lack of belief in gods,” since they lack beliefs, period. Babies and animals also lack belief in Gods. But, presumably, nobody would want to consider a rock (or any other entity that lacks any beliefs) or a baby or an animal an atheist, or want to group rocks and thoughtful people who believe there is not a God into the same category for purposes related to philosophy of religion, politics, or any social scientific investigation. So, at least, such a definition of “atheist” should at least be stated in terms of a person, or a being who could have belief about Gods, lacking beliefs about gods.
[6] The general theme here is this: for any claim C, believing not-C and not believing C are not the same: they are importantly different.
[7] People can believe that something probably does not exist with varying degrees of confidence. For more on how this probability can be understood, see Interpretations of Probability by Thomas Metcalf.
Some people seem to understand atheism in terms of the belief that God does not exist combined with some claim about the particular confidence level for that belief—e.g., that atheists are certain that God doesn’t exist, or that atheists are very confident that God doesn’t exist, etc. But these issues of what is believed and any believer’s confidence are separable: different people believe that God does not exist and their beliefs can be, and are, held with different levels of confidence.
[8] For example, “conspiracy theories” are often false and contrary to the best evidence, yet are confidently accepted and mistakenly believed to be well-justified and even known by their adherents. For discussion see Conspiracy Theories by Jared Millson.
[9] Some people seem to define atheism in terms of the belief that God does not exist combined with some claim about a particular the “epistemic status” of that belief (epistemic concerns knowledge and justification): e.g., that atheists always believe God does not exist and think they know that God doesn’t exist, or that atheists always think they are strongly justified in believing that God doesn’t exist, or that atheists are never justified in believing that God doesn’t exist, etc. But the issues of what is believed and that belief’s epistemic status are separable: different people believe that God does not exist and their beliefs are often held in with different at least perceived epistemic statuses.
[10] There are various versions of theistic “fideism,” views that that theistic belief is or should be held without reason or even contrary to reason (which may or may not be described in terms of an appeal to “faith”): see Clark (n.d.). So, it is possible that there could be forms of atheistic fideism. Also, someone could accept atheism “just because” they were raised that way, or they find it emotionally or personally satisfying in some way, see this as not having much in the way of good reasons for their atheism, and either think that’s a problem or not.
[11] The latter position here refers to a distinction between “friendly” and “unfriendly” atheists (and theists, and agnostics). “Friendly” outlooks recognize that whether someone’s beliefs are justified for them depends on their evidence, and since different people have different evidence, different beliefs can be justified for different people: so atheism might be justified for some people and theism might be justified for different people. “Unfriendly” thinkers deny this: e.g., a theist thinking that ‘all atheists are unjustified in believing there is not a God’ would be an “unfriendly” theist, and an atheist thinking that ‘all theists are unjustified in believing there is a God’ would be an unfriendly atheist. For a discussion of this distinction, see Rowe (1979) and (2006).
[12] A common, initial view is that knowledge is beliefs that are true and rational or justified. For introductions to these general issues see, Epistemology, or Theory of Knowledge by Thomas Metcalf, The Gettier Problem & the Definition of Knowledge by Andrew Chapman, and Epistemic Justification: What is Rational Belief? by Todd R. Long. On the importance of knowledge and justified belief, see “The Ethics of Belief”: Is it Wrong to Believe Without Sufficient Evidence? by Spencer Case.
[13] Some people insist there is “no evidence” for theism, and others insist there is “no evidence” for atheism. According to most views of what “evidence” is, claims like these are mistaken: evidence provides some reason to believe something, not all evidence is strong evidence (and certainly not all evidence is “proof”): indeed, some evidence is weak; and (weak) evidence can be overridden or undercut by stronger evidence for a contrary claim. For more on what evidence is, see Epistemic Justification: What is Rational Belief? by Todd R. Long. On the importance of knowledge and justified belief, see “The Ethics of Belief”: Is it Wrong to Believe Without Sufficient Evidence? by Spencer Case.
[14] In contrast, agnostics tend to think the evidence is roughly equal in strength.
[15] On what arguments are and how they are evaluated, see Arguments: Why Do You Believe What You Believe? by Thomas Metcalf and Critical Thinking: What is it to be a Critical Thinker? by Carolina Flores.
For introductions to many arguments for theism, see the essays in the Philosophy of Religion category of 1000-Word Philosophy.
While many people think that beliefs about God’s existence will be rational only if they are based on arguments or explicit reasoning, there are arguments against this view for both theism and, potentially, atheism. See “Properly Basic” Belief in God: Believing in God Without An Argument by Jamie B. Turner.
[16] It is commonly thought that minds or mental characteristics depend on a physical basis, such as a brain or, perhaps eventually, a very sophisticated computer system. If this is always the case, then it is unclear how a non-physical, minded being—as the concept of God is often understood—could exist. For relevant discussion of what minds are, see The Mind-Body Problem: What Are Minds? by Jacob Berger.
[17] For an introduction to the various arguments from evil, see The Problem of Evil: Is Suffering Evidence That There Is Not a God? by Thomas Metcalf.
[18] For an introduction to this type of argument, see Divine Hiddenness: Do Some People Not Find God Because God Doesn’t Exist? by David Bayless.
[19] The “Presumption of Atheism” originates in Antony Flew’s (1923–2010) writings on the issue: see Flew (1972) and (1976). However, this original terminology is unfortunately misleading since what Flew means by “atheism” is the broader view “not-theism,” which includes many ways of not believing there’s a God: atheism, agnosticism, and other forms of non-theism. Both atheists and agnostics might both accept something like Flew’s presumption, but disagree on the appropriate response to their finding arguments for theism to be inadequate, and so it’s unclear whether there should be a presumption of atheism or a presumption of agnosticism. It’s perhaps interesting that Flew was an atheist for much of his life, but later rejected atheism: see Flew and Varghese (2007).
For further interesting discussion of issues related to presumptions of atheism, see “The Agnostic’s Dilemma” and “What I Don’t Believe” in Hanson (2020 [1971]).
[20] For an introduction to theories on what makes life meaningful, see Meaning in Life: What Makes Our Lives Meaningful? and The Meaning of Life: What’s the Point? by Matthew Pianalto.
[21] Indeed, some argue that an eternal life would get boring and lose meaning. For discussion, see Is Immortality Desirable? by Felipe Pereira.
[22] For example, many atheists are involved in the “effective altruism” movement, which is motivated by ethical concerns to address the world’s most pressing problems, such as starvation and poverty: see Ethics and Absolute Poverty: Peter Singer and Effective Altruism by Brandon Boesch.
[23] These are brief statements of some of the most influential ethical theories or explanations of what makes wrong actions wrong and right actions right. For introductions to these theories, see Consequentialism and Utilitarianism by Shane Gronholz, Kantian Deontology: Immanuel Kant’s Ethics by Andrew Chapman, John Rawls’ ‘A Theory of Justice’ by Ben Davies, as well as “pluralistic” approaches that attempt to integrate these ethical foundations, such as W.D. Ross’s Ethics of “Prima Facie” Duties by Matthew Pianalto and Principlism in Biomedical Ethics: Respect for Autonomy, Non-Maleficence, Beneficence, and Justice by G. M. Trujillo, Jr.
There are a number of options for what “meta-ethical” theory—concerning the philosophical foundations of ethics—atheists might accept, such as ethical naturalism, ethical non-naturalism, and various forms of ethical irrealism. For discussion, see Ethical Realism, or Moral Realism by Thomas Metcalf.
[24] Some argue that if God existed, God would understand that these types of factors are what makes actions right and wrong. Such is a lesson of Socrates’ “Euthyphro dilemma”: e.g., either there would be a reason why God would command us to do some action, or not. If not, the command would be arbitrary, and so God could have commanded a contrary action. But if there is a reason why God would command an action, then that reason would be what would make the action wrong. Furthermore, there would either be a reason why God would have the character he does not or not; there would be a reason why God’s character would oppose various actions (e.g., being a school shooter, physically abusing the elderly in a nursing home, etc.) or not. For discussion of these issues, see Because God Says So: On Divine Command Theory by Spencer Case and Ethics and God: the Divine Command Theory and the Euthyphro Dilemma by Nathan Nobis.
References
American Atheists. “What is Atheism?” Accessed July 7, 2025.
Clark, Kelly. (n.d.). Religious Epistemology. The Internet Encyclopedia of Philosophy.
Flew, Antony. (1972). “The Presumption of Atheism.” Canadian Journal of Philosophy, 2(1): 29-46.
Flew, Antony. (1976). The Presumption of Atheism and Other Philosophical Essays on God, Freedom, and Immortality. Elek/Pemberton.
Flew, Antony, and Varghese, Roy Abraham. (2007). There is a God: How the World’s Most Notorious Atheist Changed His Mind. HarperOne.
Hanson, Norwood Russell (2020 [1971]). The Agnostic’s Dilemma in What I Do Not Believe, and Other Essays. Springer Dordrecht: 305-309.
Hanson, Norwood Russell (2020 [1971]). What I Do Not Believe in What I Do Not Believe, and Other Essays. Springer Dordrecht: 311-327.
Hedberg, Trevor & Huzarevich, Jordan. (2017). Appraising Objections to Practical Apatheism. Philosophia, 45, 1: 257-276.
PhilPapers. (2020). PhilPapers Survey. Survey Results: God: Theism or Atheism?
Rowe, William L. (1979). The Problem of Evil and Some Varieties of Atheism. American Philosophical Quarterly, 16 (4): 335-341.
Rowe, William. (2006). Friendly Atheism, Skeptical Theism, and the Problem of Evil. International Journal for Philosophy of Religion, 59, 2: 79–92.
For Further Reading
Draper, Paul. (2002). Atheism and Agnosticism. Stanford Encyclopedia of Philosophy (Summer 2022 Edition), Edward N. Zalta (ed.).
McCormick, Matt. (n.d.) Atheism. Internet Encyclopedia of Philosophy.
Related Essays
The Concept of God: Divine Attributes by Bailie Peterson
Agnosticism about God’s Existence by Sylwia Wilczewska
Theism and Atheism: Reasons for Belief and Disbelief by Tom Metcalf
Interpretations of Probability by Thomas Metcalf
Conspiracy Theories by Jared Millson
Epistemology, or Theory of Knowledge by Thomas Metcalf
The Gettier Problem & the Definition of Knowledge by Andrew Chapman
Epistemic Justification: What is Rational Belief? by Todd R. Long
“The Ethics of Belief”: Is it Wrong to Believe Without Sufficient Evidence? by Spencer Case
Arguments: Why Do You Believe What You Believe? by Thomas Metcalf
Critical Thinking: What is it to be a Critical Thinker? by Carolina Flores
“Properly Basic” Belief in God: Believing in God Without An Argument by Jamie B. Turner
The Mind-Body Problem: What Are Minds? by Jacob Berger
Design Arguments for the Existence of God by Thomas Metcalf
The Fine-Tuning Argument for the Existence of God by Thomas Metcalf
Cosmological Arguments for the Existence of God by Thomas Metcalf
Pascal’s Wager: A Pragmatic Argument for Belief in God by Liz Jackson
The Problem of Evil: Is Suffering Evidence That There Is Not a God? by Thomas Metcalf
Divine Hiddenness: Do Some People Not Find God Because God Doesn’t Exist? by David Bayless
Meaning in Life: What Makes Our Lives Meaningful? by Matthew Pianalto
The Meaning of Life: What’s the Point? by Matthew Pianalto
Is Immortality Desirable? by Felipe Pereira
Ethics and Absolute Poverty: Peter Singer and Effective Altruism by Brandon Boesch
Consequentialism and Utilitarianism by Shane Gronholz
Kantian Deontology: Immanuel Kant’s Ethics by Andrew Chapman
John Rawls’ ‘A Theory of Justice’ by Ben Davies
W.D. Ross’s Ethics of “Prima Facie” Duties by Matthew Pianalto
Principlism in Biomedical Ethics: Respect for Autonomy, Non-Maleficence, Beneficence, and Justice by G. M. Trujillo, Jr.
Ethical Realism, or Moral Realism by Thomas Metcalf
Because God Says So: On Divine Command Theory by Spencer Case
Ethics and God: the Divine Command Theory and the Euthyphro Dilemma by Nathan Nobis
PDF Download
Download this essay in PDF.
About the Author
Nathan Nobis is a Professor of Philosophy at Morehouse College, Atlanta, GA. He is co-author of Thinking Critically About Abortion, author of Animals & Ethics 101, and the author and co-author of many other writings and materials in philosophy and ethics. NathanNobis.com
Follow 1000-Word Philosophy on Facebook, Bluesky, Instagram, Twitter / X, Threads, and LinkedIn, and subscribe to receive email notifications of new essays at 1000WordPhilosophy.com.
Discover more from 1000-Word Philosophy: An Introductory Anthology
Subscribe to get the latest posts sent to your email.
11 thoughts on “Atheism: Believing God Does Not Exist”
Comments are closed.