A rhetorical question is a question asked in order to guide an argument, sway a listener, or otherwise have a rhetorical effect. The person who asks a rhetorical question does not expect, nor even desire, a verbal response from the receiver of the rhetorical question. One merely wants the listener/reader's brain to react in a way that disposes him toward the speaker, sets up a logical chain for her to follow, or the like.
For example:
Why does the word "rhetoric" nowadays seem to have a negative connotation? (Trying to grab attention, perhaps subtly suggest that people don't know what "rhetoric" means, which will rile those that don't, and will make those that do think I'm brilliant.)
So what is, rhetoric, anyway? (bring audience back to issue) It's the art of speaking, making arguments, changing the audience's minds, etc.
A rhetorical question is a question asked in order to guide an argument, sway a listener, or otherwise have a rhetorical effect. Does the speaker/writer want the reader/listener to answer the question? (guiding argument)
No! S/he merely wants the listener/reader's brain to react in a way that disposes him toward the speaker, sets up a logical chain for her to follow, or the like.
A RhetoricalQuestion is not to be confused with a LeadingQuestion? like "Do you still beat your wife?"
Where would we be without rhetorical questions?