The pessimist could see no good in them.
"'But you are wrong,' argued the dominie.

'There's good in the worst among them all.

Stay; I'll prove it.' Then, turning to the guard: 'Sir, please bring us to the very worst character who is prisoner here.' On their way to the abandoned one, the dominie observed to the pessimist: 'I'll guarantee, by a few adroit questions, to so develop the good side of this fallen creature that you will be driven to confess its existence.' "They traveled the corridors, and finally the guard threw open a cell wherein was a man whose face was so utterly brutal that its softest expression was a breach of the peace.

The man, who was in for life, had committed an atrocious murder.
"The only thing in the cell besides the man was a rat, which--wheel within wheel--was confined in a little cage.

This rat was the prisoner's darling; the guard said that he would draw blood from his arm to feed it.