There was no need of lock, of door, of wall: this was a prison whose bars were ten thousand miles of water.
-- Narrator (Strangers paragraph 1)

Importance: Although Thornhill was still considered to be a prisoner, the prison to which he had been transported in Australia had no bars or locks. Australia was an entire land used as a prison by the English government.

They were all thieves, any time they got the chance. The dainty parson could shrill all he liked about sin, but there could be no sin in thieving if it meant a full belly.
-- Narrator (Part One: London paragraph 35)

Importance: For people in conditions like that faced by Thornhill, they felt that their actions could not be considered sinful if they were stealing so that they and their families could eat.

It was not just the generous slab of bread, spread with good tasty dripping: it was the feeling of having a place. Swan Lane and the...
-- Narrator (Part One: London paragraph 42)