Rhetorical questions are an interesting phenomenon; we ask questions so as indirectly to make assertions. It's usually said that rhetorical questions do this by way of expected answer, but I don't think this is quite right, because in many cases the point the rhetorical question is making is not a direct answer to the question. For instance, suppose I were to read a paper you'd written and said drily, "Do you think it is really wise to call your opponent an idiot?" This is a rhetorical question. Were you to answer the question directly, however, you would say, "Yes, I think it is really wise to call my opponent an idiot," or "No, I don't think it is really wise to call my opponent an idiot." But in doing so you would have missed the point of the question entirely, which, despite the words, is not about what you think at all: the point of the question is simply that it is, at least prima facie, not wise to call your opponent an idiot. If you ask me, "Do you like Maria?" and I say, "Is the Pope Catholic?" I'm giving an affirmative answer, but the affirmative answer I am giving is to your question, not the answer to the question, "Is the Pope Catholic?" I'm merely playing on the fact that in English you can abbreviate affirmative responses to questions with 'Yes' if the question is clear; but that's all 'Yes' does: it indicates an affirmation, but on its own doesn't tell you what is being affirmed. They don't actually have the same answer, just the same type of answer.
The title of this post is sometimes used as the name of a punctuation mark that fell out of use: a backwards question mark, which indicated that the statement was a rhetorical question ('percontation' in the broad simply means 'question'). In some ways it would actually be nice to have a written mark to indicate rhetorical questions specifically; one of the difficult things with reading questions, as opposed (usually) to hearing them, is that it can be very difficult to tell which questions are supposed to be genuinely interrogative and which are supposed to be rhetorical. And it takes only a little skill for a writer to learn how to play on the equivocation this permits. Or am I not right?