A question asked without expecting an answer, because the answer is already implied, or because what matters is the doubt it exposes.
In Notes from Underground
Why was I made with these desires? Was I made only to reach the conclusion that my whole constitution is a sham? Is that the whole aim? I don't believe it.
The three questions in a row do not ask for an answer from the reader: the answer is his own, and it comes right after, in «I don't believe it», which closes the series.