The lawyer's change of character has to be the result of spending fifteen years in solitary confinement. In order to pass the time, and in order to keep from going "stir crazy," the lawyer has devoted much of his time to the study of great works of literature.
In the second half of the sixth year the prisoner began zealously studying languages, philosophy, and history. . . . It was during this period that the banker received the following letter from his prisoner:
"My dear Jailer, I write you these lines in six languages. Show them to people who know the languages. Let them read them. If they find not one mistake I implore you to fire a shot in the garden. That shot will show me that my efforts have not been thrown away. The geniuses of all ages and of all lands speak different languages, but the same flame burns in them all. Oh, if you only knew what unearthly happiness my soul feels now from being able to understand them!"
The prisoner's exposure to the thoughts of so many great geniuses--unmixed with any petty small talk with people in the outside world--have changed him into a deep thinker.
Then after the tenth year, the prisoner sat immovably at the table and read nothing but the Gospel.
The Gospel is full of advice about preferring spiritual wealth to material wealth. For example, here are two famous passages from Matthew in the King James Version:
Lay not up for yourselves treasures upon earth, where moth and rust doth corrupt, and where thieves break through and steal: but lay up for yourselves treasures in heaven, where neither moth nor rust doth corrupt, and where thieves do not break through nor steal: for where your treasure is, there will your heart be also.
No man can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other. Ye cannot serve God and mammon.
When the banker enters the prisoner's room with the intention of killing him in order to avoid having to pay him two million rubles, he finds a note in which the prisoner explains how he has changed after fifteen years of solitary study and meditation. He seems to have undergone a religious conversion. He writes:
"Your books have given me wisdom. All that the unresting thought of man has created in the ages is compressed into a small compass in my brain. I know that I am wiser than all of you."
The prisoner's note makes the banker ashamed of himself. He has been thinking about nothing but acquiring money for these fifteen years--and where has it gotten him? He is unhappy, depressed, dreadfully anxious. He has been "serving mammon" all these years, while his prisoner has been "serving God." The banker has sunk so low in his character that he is actually considering committing an outrageous murder in order to default on his bet. Not only that, but he toys with the idea of framing an innocent man.
"If I had the pluck to carry out my intention," thought the old man, "suspicion would fall first upon the watchman."
The original bet was inspired by an argument as to whether the death penalty or life imprisonment is more humane. The prisoner seems to have won the argument as well as the bet, because he advocated life imprisonment. His own incarceration has led him to happiness and self-realization. His ordeal suggests that life imprisonment is more humane because it gives the criminal a chance to study, meditate, repent, achieve spiritual enlightenment, transform his character, and save his soul.