Begging the question

A quick note on logic: "begging the question" does not mean "making somebody want to ask this question really badly." It's a technical logical term for a particular dirty trick. You pretend to be proving something, but you sneak the thing you're trying to prove into the "facts" you try to get the naive listener to accept up front. Then from those facts you "prove" your conclusion. (The traditional names for this fallacy are petitio principii and petitio elenchi.)

Example: The Catholic Church is infallible, and we know she is, because if you look back throughout the Church's history, every time people have disagreed with the Catholic Church, they've turned out to be heretics.