The cruelty that is practised by day and night on children in English prisons is incredible except to those that have witnessed it and are aware of the brutality of the system.
"People nowadays do not understand what cruelty is....

Ordinary cruelty is simply stupidity.
"The prison treatment of children is terrible, primarily from people not understanding the peculiar psychology of the child's nature.

A child can understand a punishment inflicted by an individual, such as a parent, or guardian, and bear it with a certain amount of acquiescence.

What it cannot understand is a punishment inflicted by society.

It cannot realise what society is....
"The terror of a child in prison is quite limitless.