Circular Reasoning Definition and Examples

In informal logic, circular reasoning is an argument that commits the logical fallacy of assuming what it is attempting to prove. Fallacies closely related to circular reasoning include begging the question and petitio principii.

"The fallacy of the petitio principii," says Madsen Pirie, "lies in its dependence on the unestablished conclusion. Its conclusion is used, albeit often in a disguised form, in the premises which support it" (How to Win Every Argument: The Use and Abuse of Logic, 2015).

Examples and Observations

• "The circular argument uses its own conclusion as one of its stated or unstated premises. Instead of offering proof, it simply asserts the conclusion in another form, thereby inviting the listener to accept it as settled when, in fact, it has not been settled. Because the premise is no different from and therefore as questionable as its conclusion, a circular argument violates the criterion of acceptability." (T. Edward Damer, Attacking Faulty Reasoning. Wadsworth, 2001)
• "Circular argument: A sentence or argument that restates rather than proves. Thus, it goes in a circle: 'President Reagan was a great communicator because he had the knack of talking effectively to the people.' The terms in the beginning of the sentence (great communicator) and the end of the sentence (talking effectively) are interchangeable." (Stephen Reid, The Prentice Hall Guide for College Writers, 5th ed., 2000)

Mental Illness and Violent Crimes

• "The assumption that people with mental health issues are violent is deeply entrenched (cleaver-wielding 'lunatic' costumes, anyone?). It often leads to circular reasoning. How often have you heard people claim that committing a violent crime is proof of mental illness? 'Only a mentally ill person would kill someone, so anyone who kills someone is automatically mentally ill.' Leaving aside the vast majority of homicides which aren’t committed by people with mental problems, this isn’t evidence based." (Dean Burnett, "Stop Blaming Mental Illness for Violent Crimes." The Guardian [UK], June 21, 2016)

Circular Reasoning in Politics

• "Senator Kent Conrad of North Dakota offers a perfectly circular argument: we can't have the public option, because if we do, health care reform won't get the votes of senators like him. 'In a 60-vote environment," he says . . ., 'you've got to attract some Republicans as well as holding virtually all the Democrats together, and that, I don't believe, is possible with a pure public option.'" (Paul Krugman, "Health Care Showdown." The New York Times, June 22, 2009)
• "Ralph Nader and Pat Buchanan are banging at the doors, and the political establishment, consisting of both politicians and the media, seems determined not to let them in on the grounds that they have no public support. This is a circular argument; one of the reasons they have so little support is that they are generally ignored by the press and will most likely be barred from the presidential debates, which require a base support of 15 percent of the electorate." (Lars-Erik Nelson, "Party Going." The New York Review of Books, August 10, 2000)

Going in Circles

• "Circular reasoning can be used fallaciously . . . in arguments which require the use of premises that can be shown to be better established than the conclusion to be proved. The requirement here is one of evidential priority . . .. Arguing in a circle becomes a fallacy of petitio principii or begging the question where an attempt is made to evade the burden of proving one of the premises of an argument by basing it on the prior acceptance of the conclusion to be proved. . . . So the fallacy of begging the question is a systematic tactic to evade fulfillment of a legitimate burden of proof . . . by the proponent of an argument in dialogue by using a circular structure of argument to block the further progress of dialogue, and, in particular, to undermine the capability of the respondent, to whom the argument was directed, to ask legitimate critical questions in reply." (Douglas N. Walton, "Circular Reasoning." A Companion to Epistemology, 2nd ed., edited by Jonathan Dancy et al. Wiley-Blackwell, 2010)