What would be a good thesis statement for the book Oliver Twist?

If you have read any of Dickens's other works or
researched this author, you may, then, be familiar with a prevailing social concern of
his:  the dehumanizing effects of crime.  Certainly these effects are evinced in the
characters of Oliver Twist.  Now, if you wish to compose a thesis
on this topic, you may wish to limit your examination to one character if your
assignment is an essay.  However, if your assignment is a paper, then you will want to
analyze several characters.

Oliver Twist
is a narrative in which the most depraved villains preside, with the heinous
Fagin controlling the others.  That he loses all humanity is apparent throughout the
novel, most strikingly at the end when, incarcerated and alone in his depravity, Fagin
loses his mind. As a metaphor of this transformation, the turnkey asks
him,

"Fagin,
Fagin! Are you a man?"

"I shan't be one long," he replied,
looking up with a face retaining no human expression but rage and
terror....

Another character,
the murderous bully Sikes, evolves throughout the novel into an absolute monster.  Under
his control, poor Nancy struggles to retain her humanity, regaining it in her solicitous
acts on behalf of Oliver, but falling victim to the band of criminals who will not
release her.  In contrast to Oliver, his half brother degenerates spiritually until his
final end. For a time, Oliver even suffers some dehumanization and he worries that he
will never be believed or treated fairly even if he escapes the evil band of thieves who
have captured him.