Begging the Question




Also Known as: Circular Reasoning, Reasoning in a Circle, Petitio Principii


Begging the Question is a fallacy in which the premises include the claim that the conclusion is true or (directly or indirectly) assume the conclusion is true. This sort of “reasoning” typically has the following form.


Premises: Premises in which the truth of the conclusion is claimed, or the truth of the conclusion is assumed (either directly or indirectly).

Conclusion: Claim C, the conclusion, is true.


This is fallacious because assuming the conclusion is true (directly or indirectly) is not evidence for that conclusion. Simply assuming a claim is true does not serve as evidence for that claim. This is especially clear in particularly blatant cases: “X is true. The evidence for this claim is that X is true.”

Some cases of question begging are blatant, while others can be extremely subtle. While it might seem odd, a case of circular reasoning can be valid deductive argument. For example, this obviously circular reasoning is also valid:


Premise: P

Conclusion: P


It is valid because validity means that if the premises of an argument are all true, then the conclusion must be true. If P is true, then it follows that P is true. That is indeed hard to dispute. But assuming P is true does not give you a reason to accept that P is true and that is why circular reasoning is fallacious.


Defense: The defense is to consider whether the premises simply assume the conclusion is true. If they do, this fallacy is committed.


Example #1:

Bill: “God must exist.”

Jill: “How do you know.”

Bill: “Because the Bible says so.”

Jill: “Why should I believe the Bible?”

Bill: “Because the Bible was written by God.”


Example #2:

“If such actions were not illegal, then they would not be prohibited by the law.”


Example #3:

“The belief in God is universal. After all, everyone believes in God.”


Example #4:

Interviewer: “Your resume looks impressive, but I need another reference.”

Bill: “Jill can give me a good reference.”

Interviewer: “Good. But how do I know that Jill is trustworthy?”

Bill: “Certainly. I can vouch for her.”

Originally appeared on A Philosopher’s Blog Read More