Nobody who admits that the business of fiction is to exhibit human
life, can deny that scenes of misery and crime must of necessity,
while human nature remains what it is, form part of that exhibition.
Nobody can assert that such scenes are unproductive of useful results,
when they are turned to a plainly and purely moral purpose. If I am
asked why I have written certain scenes in this book, my answer is to
be found in the universally-accepted truth which the preceding words
express. I have a right to appeal to that truth; for I guided myself
by it throughout. In deriving the lesson which the following pages
contain, from those examples of error and crime which would most
strikingly and naturally teach it, I determined to do justice to the
honesty of my object by speaking out. In drawing the two characters,
whose actions bring about the darker scenes of my story, I did not
forget that it was my duty, while striving to portray them naturally,
to put them to a good moral use; and at some sacrifice, in certain
places, of dramatic effect (though I trust with no sacrifice of truth
to Nature), I have shown the conduct of the vile, as always, in a
greater or less degree, associated with something that is selfish,
contemptible, or cruel in motive. Whether any of my better characters
may succeed in endearing themselves to the reader, I know not: but
this I do certainly know:--that I shall in no instance cheat him out
of his sympathies in favour of the bad.

To those persons who dissent from the broad principles here adverted
to; who deny that it is the novelist's vocation to do more than merely
amuse them; who shrink from all honest and serious reference, in
books, to subjects which they think of in private and talk of in
public everywhere; who see covert implications where nothing is
implied, and improper allusions where nothing improper is alluded to;