--- title: "Circular Reasoning" description: "Circular reasoning assumes the conclusion it is supposed to prove, so the argument's support depends on the very claim in question. The reasoning may be perfectly valid in form and still establish nothing, because anyone who doubts the conclusion has equal reason to doubt the premise offered for it." last_updated: "2026-08-02" --- # Circular Reasoning *Also known as: begging the question* Circular reasoning assumes the conclusion it is supposed to prove, so the argument's support depends on the very claim in question. The reasoning may be perfectly valid in form and still establish nothing, because anyone who doubts the conclusion has equal reason to doubt the premise offered for it. An argument in which the conclusion is assumed within its own premises, so it proves nothing beyond what it presupposes. *Example: "This book is trustworthy because it says so right here on the cover."* ## What it looks like **In a discussion about a text's authority** > This book is trustworthy because it says so itself, and what it says is true. *Why it fails:* The book's reliability is both the premise and the conclusion. Anyone who doubts it has exactly as much reason to doubt its self-endorsement, so nothing has been added. **In a workplace debate** > He's the best candidate because he's more qualified than anyone else — and you can tell he's more qualified because he's the best candidate. *Why it fails:* Each claim leans on the other and neither touches outside evidence. The pair can be repeated indefinitely without ever contacting a fact about his qualifications. **In a product argument** > Our approach is the industry standard because everyone serious uses it, and the serious teams are the ones using our approach. *Why it fails:* "Serious" is defined by using the approach, so the claim cannot fail. A statement that no evidence could contradict is not being supported by evidence. ## Practice ### Question 1 Which of these is circular reasoning? A. "The policy reduced crime, because crime fell by 12% in the two years after it took effect." B. "Lying is wrong because it is immoral to tell untruths." C. "The bridge is unsafe, because the inspection found corrosion in three support columns." D. "She is qualified, because she has ten years in the role and two relevant certifications." **Answer: B.** Option B restates the conclusion in different words: "wrong" and "immoral to tell untruths" are the same claim, so no support has been offered to someone who disagrees. The other three cite something independent of the conclusion — a crime statistic, an inspection finding, a work history — which is precisely what circular arguments lack. Note that option A may have other problems, such as confusing correlation with causation, but circularity is not among them. ### Question 2 Why is circular reasoning a problem even though the argument is logically valid? A. It is not actually valid; the logic is broken B. Validity only guarantees the conclusion follows if the premises are true — and here believing the premise already requires believing the conclusion, so the argument persuades nobody who does not already agree C. Because it uses the same words twice D. Because valid arguments are always fallacious **Answer: B.** This is the subtle point: circular arguments are technically valid, since the conclusion does follow from a premise that contains it. What they lack is any power to convince, because they give no independent reason to accept the premise. Validity and persuasiveness come apart here, which is exactly why the fallacy is hard to spot in long-form writing where the circle spans several paragraphs. ### Question 3 What is question-begging, and how does it relate to circular reasoning? A. It means raising an obvious follow-up question B. It means assuming the point at issue within a premise — essentially the same failure as circular reasoning, though often hidden in a single loaded word or phrase C. It is the opposite of circular reasoning D. It applies only to formal logic, not everyday argument **Answer: B.** "Begging the question" means assuming what you set out to prove, so it names the same defect. It often hides inside a single word: calling a policy "the sensible reform" while arguing that it is sensible packs the conclusion into the description. Note that popular usage has drifted toward option A, meaning "raises the question" — but the logical term means something else. ### Question 4 A team argues: "We know the model is accurate because it agrees with our forecasts, and our forecasts are reliable because the model supports them." What is the practical danger here? A. There is no danger; mutual support strengthens both claims B. The two claims validate each other without either being checked against reality, so both could be wrong together and nothing in the system would reveal it C. The model should have been built by a different team D. Forecasts should never be compared to models **Answer: B.** This is a wider circle — sometimes called circular support — and it is more dangerous than the one-sentence version precisely because it looks like corroboration. Two things agreeing means little if each is calibrated to the other. The fix is an external check: compare both against outcomes neither was tuned on. ### Question 5 How can you test whether an argument is circular? A. Check whether it is longer than three sentences B. Ask whether someone who does not already accept the conclusion would have any reason to accept the premise C. Check whether the speaker is an expert D. Count how many times the key term appears **Answer: B.** This test cuts straight to what circularity actually breaks: the ability to move someone from doubt to belief. If the premise only looks true to people who already hold the conclusion, the argument cannot do that work. Length is irrelevant — long arguments hide circles better, but a circle spanning ten paragraphs is still a circle. ## Frequently asked ### Is circular reasoning the same as begging the question? They name the same failure — assuming what you are trying to prove. "Begging the question" is the traditional term and often refers to a premise that quietly packs in the conclusion, while "circular reasoning" usually describes a more visible loop. In practice the two are used interchangeably. ### Can a circular argument have a true conclusion? Yes. Circularity is a defect in the support, not in the claim. The conclusion may well be true — the argument simply gives no reason to believe it. This is why identifying circularity means the question is still open, not that the answer is no. ### Why is circular reasoning hard to spot? Because the circle is usually spread across enough text that you do not see both ends at once, and because the repeated claim is often reworded rather than repeated. Paraphrasing an argument down to its bare premises and conclusion is the reliable way to make a hidden loop visible. ## Related - [Premise](https://www.criticalthinkingexercise.org/pages/glossary/premise.md) - [Argument](https://www.criticalthinkingexercise.org/pages/glossary/argument.md) - [Validity](https://www.criticalthinkingexercise.org/pages/glossary/validity.md) - [Identifying Logical Fallacies](https://www.criticalthinkingexercise.org/pages/exercises/identifying-fallacies.md) - [Identifying Hidden Assumptions](https://www.criticalthinkingexercise.org/pages/exercises/hidden-assumptions.md) - [Lesson: traps-and-pitfalls/logical-fallacies-presumption-ambiguity-causal](https://www.criticalthinkingexercise.org/pages/learn/traps-and-pitfalls/logical-fallacies-presumption-ambiguity-causal.md) ## Sitemap See the full [sitemap](https://www.criticalthinkingexercise.org/sitemap.md) for all pages.