How do I understand "Begging the question" in philosophical context?

Question

I understand the fallacy of begging the question's definition. but I can't see why this fallacy's name should be "begging the question."

According to the Macmillan's English dictionary, "to beg the question" means to make you want to know the answer to a particular question.

In philosophical context, does the phrase "to beg the question" have same usage as well as in usual English? If so, the reason why this fallacy's name is "begging the question" is to raise a question to a premise which is not proved?

Answer 1

"Begging the question" in a philosophical context means assuming what one is trying to prove. Typically it is a matter of having a premise that is very similar to one's conclusion. It does not make an argument deductively invalid, but means that the argument can be only trivially valid. For example:

• Someone asks, "You really claim to be the tennis player in the world?" I argue, "Sure, I'm the best player in the world at EVERY sport, so of course I'm the best at tennis."

This is actually a valid deductive argument, but the premise assumes the conclusion, and yet is itself controversial. Anyone who doesn't believe that I'm not the best at tennis is really not going to believe that I'm the best at every sport including tennis.

It is related to the ordinary usage because it offers a premise which invites or requires or begs an interlocutor to ask a further question: "but how do you know THAT?" or "why should I believe THAT?" Deductive arguments are practically good when they not only are deductively valid and have true premises but also are useful for persuading someone of something. An argument that begs the question is not generally going to persuade anyone of anything they don't already believe. It could only do so in very specific and unsual contexts (like if you didn't understand that tennis is a sport).

Mozibur Ullah's answer is very close. It's right that it's a matter of there being a premise that is neither self-evident nor argued for, and which therefore requires a further argument. But it's worth pointing out that begging the question is not a formal fallacy, meaning that it does not make arguments invalid (and it isn't typical to describe sentences like conclusions as valid or invalid).

Answer 2

Begging the question in ordinary English usage means simply to raise, evade or even ignore the question. For example:

The football world cup is going to be played in Qatar in the height of summer, which begs [raises] the question - how are we going to play in that heat?!

But in philosophy, there is a technical sense which was first elaborated in Aristotle's Prior Analytics. In Latin this fallacy was called petitio principii, literally meaning 'assuming the initial point'. That is, the conclusion of the argument is invalid, because a premise used as the conclusion is not self-evident or has not been previously argued for and so requires an argument or a proof.

This term was first translated in the 16th Century from Latin into English. At some point this expression became 'begging the question', as in the following excerpt from the relevant section in Aristotle's Prior Analytics:

Begging or assuming the point at issue consists (to take the expression in its widest sense) [of] failing to demonstrate the required proposition...[B]egging the question is proving what is not self-evident by means of itself...

Aristotle, Hugh Tredennick (trans.) Prior Analytics