Begging the question

This is from an article about 'begging the question', from a fascinating site or blog called Words at Play, the run by Webster's Dictionary, and the people who hate its 'misuse'. 

(I am with the haters, though I had to check I remembered the correct meaning. Although I am so passionate a believer in freedom that I have been accused of being a libertarian, it clearly shows my basically authoritarian tendencies. I believe in freedom but I want society to police itself somewhat rigorously, and very rigorously when it comes to grammar.)

There is a segment of the population that would be enormously relieved if phrases like a question that begs an answer replaced the usual begs the question uses. These are people who think using beg the question to mean "to cause someone to ask a specified question as a reaction or response" is completely and thoroughly wrong. There are probably more of these people than you think, and they are judging the rest of us.

For these people, the only "correct" way to use the phrase beg the question is with the meaning "to ignore a question or issue by assuming it has been answered or settled."...

But the notion of a homunculus—a "little man"—inside the brain who watches the world on something like a little television set is hardly an explanation, because it begs the question of how the little man himself is able to perceive things. Concealed in him must be an even smaller man who watches an itsy-bitsier TV, and so on ad infinitum, like nested Chinese boxes.

— Paul Hoffman, Discover, September 1987

The problem is that beg the question is only very rarely used this way, as language blogger Stan Carey explains here. In our dictionary the sense bears the label "formal."

The formal meaning does, though, help us get to the origin of the phrase itself.

Origin of Beg the Question

Beg the question is a phrase from formal logic. We have Aristotle to thank for it—or, actually, an anonymous 16th century translator who took Aristotle's phrase petitio principii and rendered it in English as "beg the question." A better translation would have been "assume the conclusion," as linguist Mark Liberman at Language Log explains; petitio principii is used to name the logical fallacy in which an argument assumes the very thing it's trying to prove. Here's an example:

If left to themselves, children will naturally do the right thing because people are intrinsically good.

This statement tries to prove that children will naturally do the right thing by using the unproven assertion that people are intrinsically good. That assertion is problematic because it is little more than a broader version of the thing that is being proven.

So that's where beg the question comes from, but all this, ahem, begs the question of what you should do with all this knowledge about the phrase. Liberman recommends that people avoid it altogether (but also "cultivate an attitude of serene detachment in the face of its use by others").