Do you write to teach or to entertain

When writers discuss why they write, most of them don't claim to have an agenda that extends beyond storytelling. Some of us say we write because we have to or we feel called to do it or that our muses won't give us a break if we try to ignore them.

Maybe admitting to an agenda sounds presumptuous or, possibly nasty. Who are we that we might also teach or promote certain themes and ideas? Worse yet, who are we that we should do such things covertly via fiction rather than treatises and other n...