To beg the question is to assume what we are trying to prove. That is, the conclusion is stated or assumed in the premises.
1) God exists because the Bible says so, and the Bible is true because it is the word of God.
2) I should knock you on the head because it is right and good to knock persons like yourself on the head.
3) Consciousness is physical because consciousness just is the brain.
4) You can trust John because Sue told me he is trustworthy, and Sue believes it because Bob told her, and Bob believes it because John told him.
5) Of course smoking pot should be illegal! After all, it's against the law!
6) All knowledge is scientific because all nonscientific claims are not really knowledge.
7) Of course the future will be like that past… and scientific laws will continue to operate in the future! After all, past futures have been like past pasts, so future futures will be like the past futures.
An argument that begs the question is a valid argument, but it is trivial. For example, if I argue "everyone is selfish because all people are always selfish" then the conclusion validly follows from the premise, but only because the conclusion is simply a rewording of the premise. I’ve assumed in the premises what I supposedly proved in the conclusion.
The bottom line is you cannot assume what you are trying to prove.
This may seem like a simple fallacy, but very intelligent people fall for complex versions of it. For example, consider number 7 in the exercises above.
People may use the phrase “Begging the question” is different ways. For example, some people mean a premise has been omitted. Sometimes people say “it begs the question” when there is a question that should be part of discussion. For example, in discussing prayer in school, a debater might say, “It begs the question as to what the First Amendment says.” But in the field of Logic and Philosophy, begging the question means arguing in a circle or assuming what you are trying to prove.
How to avoid
Make sure your conclusion is not a mere rewording of your premises. Do not argue in a circle.
- If you could prove Muhammad was a trustworthy man who never lies, would citing the Koran to prove God's existence still be a case of begging the question?
- Try to construct an argument proving you have free free will (that you could have acted otherwise) without begging the question.
- Try to prove the external world exists without begging the question. Note: the external world is the world of people, tables, trees, cars, and other things that you believe exist “outside” of your mind.
- Answers will vary. Some will argue that “extraordinary claims require extraordinary evidence” and even if he was trustworthy, he may be experiencing some sort of hallucination. So, his claims are probably false. It is interesting to think about when we should and should not trust testimony.
- Philosophers have presented some interesting arguments. However, most people present circular arguments. For example, “I’m free because, look, I just freely raised my hand,” or “I’m free because I could have skipped class today.”Some also confuse the different meanings of “free,” which leads to the next fallacy (equivocation).
- Many beg the question because they argue or assume that our senses can be trusted without giving a good reason why.