Begging the Question (Petitio Principii)

Fallacies of Presumption

Fallacy Name:
Begging the Question

Alternative Names:
Petitio Principii
Circular Argument
Circulus in Probando
Circulus in Demonstrando
Vicious Circle

Fallacy of Weak Induction > Fallacy of Presumption

This is the most basic and classic example of a Fallacy of Presumption, because it directly presumes the conclusion which is at question in the first place. This can also be known as a "Circular Argument" - because the conclusion essentially appears both at the beginning and the end of the argument, it creates an endless circle, never accomplishing anything of substance.

A good argument in support of a claim will offer independent evidence or reasons to believe that claim. However, if you are assuming the truth of some portion of your conclusion, then your reasons are no longer independent: your reasons have become dependent upon the very point which is contested. The basic structure looks like this:

1. A is true because A is true.

Examples and Discussion

Here is an example of this most simple form of begging the question:

2. You should drive on the right side of the road because that is what the law says, and the law is the law.

Obviously driving on the right side of the road is mandated by law (in some countries, that is) - so when someone questions why we should do that, they are questioning the law. But if I am offering reasons to follow this law and I simply say "because that is the law," I am begging the question. I am assuming the validity of what the other person was questioning in the first place.

3. Affirmative Action can never be fair or just. You cannot remedy one injustice by committing another. (quoted from the forum)

This is a classic example of a circular argument - the conclusion is that affirmative action cannot be fair or just, and the premise is that injustice cannot be remedied by something that is unjust (like affirmative action).

But we cannot assume the unjust-ness of affirmative action when arguing that it is unjust.

However, it is not usual for the matter to be so obvious. Instead, the chains are a bit longer:

4. A is true because B is true, and B is true because A is true.
5. A is true because B is true, and B is true because C is true, and C is true because A is true.

More Examples and Discussion:

« Logical Fallacies | Begging the Question: Religious Arguments »

It's not uncommon to find religious arguments that commit the "Begging the Question" fallacy. This may be because the believers using these arguments are simply unfamiliar with basic logical fallacies, but an even more common reason may be that a person's commitment to the truth of their religious doctrines may prevent them from seeing that they are assuming the truth of what they are attempting to prove.

Here is an oft repeated example of a chain like we saw in example #4 above:

6. It says in the Bible that God exists. Since the Bible is God's word, and God never speaks falsely, then everything in the Bible must be true. So, God must exist.

Obviously, if the Bible is God's word, then God exists (or at least did exist at one time). However, because the speaker is also claiming that the Bible is God's word, the assumption is made that God exists in order to demonstrate that God exists. The example can be simplified to:

7. The Bible is true because God exists, and God exists because the Bible says so.

This is what is known as circular reasoning - the circle is also sometimes called "vicious" because of how it works.

Other examples, however, aren't quite so easy to spot because instead of assuming the conclusion, they are assuming a related but equally controversial premise to prove what is at question.

For example:

8. The universe has a beginning. Every thing that has a beginning has a cause. Therefore, the universe has a cause called God.
9. We know God exists because we can see the perfect order of His Creation, an order which demonstrates supernatural intelligence in its design.
10. After years of ignoring God, people have a hard time realizing what is right and what is wrong, what is good and what is bad.

Example #8 assumes (begs the question) two things: first, that the universe does indeed have a beginning and second, that all things that have a beginning have a cause. Both of these assumptions are at least as questionable as the point at hand: whether or not there is a god.

Example #9 is a common religious argument which begs the question in a slightly more subtle way. The conclusion, God exists, is based upon the premise that we can see intelligent design in the universe. But the existence of intelligent design itself assumes the existence of a designer - that is to say, a god. A person making such an argument must defend this premise before the argument can have any force.

Example #10 comes from our forum. In arguing that nonbelievers are not as moral as believers, it is assumed that a god exists and, more importantly, that a god is necessary for, or even relevant to, the establishment of norms of right and wrong. Because these assumptions are critical to the discussion at hand, the arguer is begging the question.

« Begging the Question: Overview & Explanation | Begging the Question: Political Arguments »

It's not uncommon to find political arguments that commit the "Begging the Question" fallacy. This may be because so many people are simply unfamiliar with basic logical fallacies, but an even more common reason may be that a person's commitment to the truth of their political ideology may prevent them from seeing that they are assuming the truth of what they are attempting to prove.

Here are some examples of this fallacy in political discussions:

11. Murder is morally wrong. Therefore, abortion is morally wrong. (from Hurley, p. 143)
12. In arguing that abortion is not really a private moral matter, Fr. Frank A. Pavone, National Director Priests for Life, has written that "Abortion is our problem, and the problem of every human being. We are one human family. Nobody can be neutral on abortion. It involves the destruction of an entire group of human beings!"
13. Executions are moral because we must have a death penalty to discourage violent crime.
14. You would think that taxes should be lowered because you are a Republican [and therefore your argument about taxes should be rejected].
15. Free trade will be good for this country. The reason is patently clear. Isn't it obvious that unrestricted commercial relations will bestow on all sections of this nation the benefits which result when there is an unimpeded flow of goods between countries? (Quoted from With Good Reason, by S. Morris Engel)

The argument in #11 presumes the truth of a premise that isn't stated: that abortion is murder. As this premise is far from obvious, is closely related to the point in question (is abortion immoral?), and the arguer doesn't bother mention it (much less support it), the argument begs the question.

Another abortion argument occurs in #12 and has a similar problem, but the example is provided here because the problem is a bit more subtle.

The question being begged is whether or not another "human being" is being destroyed - but that is exactly the point being disputed in abortion debates. By assuming it, the argument being made is that it is not a private matter between a woman and her doctor, but a public matter appropriate for the execution of laws.

Example #13 has a similar problem, but with a different issue. Here, the arguer is assuming that capital punishment serves as any sort of deterrent in the first place. This may be true, but it is at least as questionable as the idea that it is even moral. Because the assumption is unstated and debatable, this argument also begs the question.

Example #14 might normally be considered an example of a Genetic Fallacy - an ad hominem fallacy which involves the rejection of an idea or argument because of the nature of the person presenting it. And indeed, this is an example of that fallacy, but it is also more.

It is essentially circular to assume the falsehood of the Republican political philosophy and thereby conclude that some essential element of that philosophy (like lowering taxes) is wrong. Maybe it is wrong, but what is being offered here is not an independent reason why taxes should not be lowered.

The argument presented in example #15 is a little bit more like the way the fallacy normally appears in reality, because most people are smart enough to avoid stating their premises and conclusions in exactly the same manner. In this case, "unrestricted commercial relations" is simply a long way of stating "free trade" and the rest of what follows that phrase is an even longer way of saying "good for this country."

This particular fallacy makes it clear why it is important to know how to take apart an argument and examine its constituent parts. By moving beyond the wordiness, it is possible to look at each piece individually and see that we just have the same ideas being presented more than once.

The U.S. government's actions in the War on Terrorism also provide good examples of the Begging the Question fallacy.

Here is a quote (adapted from the forum) made in reference to the incarceration of Abdullah al Muhajir, accused of plotting to construct and detonate a 'dirty bomb':

16. What I do know is that if a dirty bomb goes off on Wall Street and the winds are blowing this way, then I and much of this part of Brooklyn are possibly toast. Is that worth possible violations of the rights of some psycho-violent street thug? To me it is.

Al Muhajir was declared an "enemy combatant," which meant that the government could remove him from civil judicial oversight and no longer had to prove in an impartial court that he was a threat. Of course, incarcerating a person is only a valid means of protecting citizens if that person is, in fact, a threat to people's safety. Thus, the above statement commits the fallacy of Begging the Question because it assumes that al Muhajir is a threat, exactly the question which is at issue and exactly the question which the government took steps to ensure was not answered.

« Begging the Question: Religious Arguments | Begging the Question: Non-Fallacy »

Sometimes you will see the phrase "begging the question" being used in a very different sense, indicating some issue which has been raised or brought to everyone's attention. This isn't a description of a fallacy at all and while it's not an entirely illegitimate use of the label, it can be confusing.

For example, consider the following:

17. This begs the question: Is it really necessary for people to be talking while on the road?
18. Change of plans or a lie? Stadium begs the question.
19. This situation begs the question: are we all in fact guided by the same universal principles and values?

The second is a news headline, the first and third are sentences from news stories. In each case, the phrase "begs the question" is used to say "an important question is now just begging to be answered." This should probably be considered an inappropriate use of the phrase, but it is so common by this point that it cannot be ignored. Nevertheless, it would probably be a good idea to avoid using it this way yourself and instead say "raises the question."

« Begging the Question: Political Arguments | Logical Fallacies »