1
general::
Take for granted or assume the truth of the very thing being questioned. For example, Shopping now for a dress to wear to the ceremony is really begging the question? she hasn't been invited yet. This phrase, whose roots are in Aristotle's writings on logic, came into English in the late 1500s. In the 1990s, however, people sometimes used the phrase as a synonym of "ask the question" (as in The article begs the question: "What are we afraid of?").
American Heritage Idioms
2
general::
Phrase(s): beg the question
1. to carry on a false argument where one assumes as proved the very point that is being argued, or more loosely, to evade the issue at hand. (Essentially a criticism of someone’s line of argument.) • Stop arguing in circles. You’re begging the question. • A: Why do two lines that are equidistant from one another never meet? B: Because they are parallel. A: You are begging the question. 2. to invite the (following) question. (This reinterpretation of beg the question is incorrect but is currently in widespread use.) • His complaints beg the question: Didn’t he cause all of his problems himself ?
McGrawhill's American Idioms And Phrasal Verbs