Pierre Choderlos De Laclos 
Dangerous Connections 

What is a novel? A correct picture of morals put in motion.-What should be the aim of a novel? To blend instruction with amusement.-When the morals of the actors are corrupt, is it allowable, with deference to decency, to draw them in their proper shades and colours? Undoubtedly it is; but with the greatest caution, lest by giving vice, whose contagion must be dreaded, its true, though seducing and agreeable aspect, without resisting, diminishing, or rendering useless, the effect it may produce by the contrast of gentleness, peace, and happiness, which virtue secures.