What is the main theme that is developed in Oliver Twist?was the aim of the author to describe his challenging childhood?

Charles Dickens used his pen not only to entertain but
also to shine a light on the ills in Victorian
society.

Nineteenth century England was a time of
contradictions.  It was a time of extreme wealth and extreme poverty.  The Industrial
Revolution had changed England from an agrarian society to and industrial one.  Labor
was needed for this, the cheaper, the better.  The cheapest laborers were children and
they were expendable.  Children were forced to work long hours under brutal conditions. 
Due to extreme poverty, children were often sold when there was not enough money to feed
the many hungry mouths.

Orphanages were warehouses for
unlucky children and fair game for those who exploited
children.

Men like Bill Sikes and Fagen lurked along the
wharfs south of the river to prey on the
unsuspecting.

Children like the Artful Dodger did what they
had to do to survive on the streets of London.

Children
like Oliver were exploited by those in positions of
power.

In writing Oliver Twist,
Dickens sought to expose the seamier sides of life in Victorian London.  He hoped to
change the conditions that caused children to be
exploited.

Eventually laws were enacted to protect children
thanks to writers like Charles Dickens.