Almost exclusively, she points out, younger people use this expression in quite different ways now, as meaning either to invite the question or to raise an obvious one.
When my parents argued, as they often did, from incommensurate premises, Dad would reproach Mom, "You beg the question." She frustrated him with her tendency to assume she was right, rather than logically examining her beliefs, as he felt she should.
In contemporary usage, any expression containing the word beg is automatically unfashionable--I beg your pardon is another case in point. But this this begs the question of accuracy. Are the new usages more or less accurate than the old? Neither, I think. Language moves on, and though most try, no generation can rein it in.
Recently, I was delighted to hear the expression to beg the question used in the original way by none other than Alexander McCall Smith’s fictional philosopher Isabel Dalhousie, in The Careful Use of Compliments (2007). I was listening to it in the car, as an audio book beautifully narrated by Davina Porter.
There’s a certain level of linguistic—what is it? muscle, perhaps—that develops with long years of faithful and attentive reading and writing. McCall Smith has that in spades, and it enables him to bring forward, not only the fading lore of W.H. Auden, Isabel Dalhousie's favourite poet, but many delectable linguistic constructions of earlier generations. To beg the question was definitely used in what Isabel calls "old Edinburgh."