Literature deals with morality but does not necessarily, does not, qua literature, help you to be more moral, either by precept or example. It makes you more aware. Which is to say that it makes you more human by making life more, not less, difficult. When you become more aware, the area of moral choice is widened. You can be a better man; you can also be a worse. Literature will not determine which. It is the equivalent of neither grace nor good works.
