Petitio Principii

Comfortably lounging in my glass house, in my last post, I tossed a stone or two in the direction of those who use the phrase "begs the question" to mean "invites the obvious question." In my post (since edited), I presented what I believed was the correct usage--"avoids answering the question." While this is one usage of the phrase, according to alt-english-usage.org, the oldest usage is in logic, where begging the question implies a circular argument. Here are excerpts from the explanation by Mark Israel, at alt-english-usage.org:

Fowler defines "begging the question" as the "fallacy of founding a conclusion on a basis that as much needs to be proved as the conclusion itself."

and

Many people unaware of the technical meaning of "to beg the question" in logic use it in one of two looser senses. The first of these, "to evade the question, to duck the issue", is attested since 1860 (WDEU). The second, "to invite the obvious question, (with an inanimate subject) to raise the question", is now the most commonly heard use of the phrase, although we have found no mention of it prior to The Oxford Guide to English Usage, 1st edition (1983), and it is not yet in most dictionaries. The meaning of the adjective "question-begging" does not seem to have suffered a similar broadening.

I also learned that the Latin for this fallacy is petitio principii. Thank goodness I corrected myself before one of my dozens of potential readers caught my error.