Who is the more humane executioner, one who kills you in a few seconds or one who draws the life out of you incessantly, for years?
The initial premise of the bet is based on this supposition by the banker in the beginning of the story. At a party he's hosting, conversation traverses the innate sufferings of capital punishment compared to life imprisonment. This comment is actually ironic by the story's end. Although the lawyer chooses a self-imposed imprisonment, he seems to lose his relationship with humanity in the process, instead adopting an ascetic and cynical view of the world and disdaining the wealth he once sought.
"If you mean it seriously," replied the lawyer, "then I bet I'll stay not five but fifteen."
The lawyer proves himself arrogant and impulsive in his youth. While the initial bet is to stay five years (a lengthy confinement to volunteer oneself for), the lawyer raises the terms of the bet to three times its original length and for no further monetary gain. His conviction and desire for wealth lead him to relinquish his entire youth in order to acquire the money and be proven intellectually superior.
In the second half of the sixth year, the prisoner began zealously to study languages, philosophy, and history. He fell on these subjects so hungrily that the banker hardly had time to get books enough for him. In the space of four years about six hundred volumes were bought at his request.
In the initial years, the lawyer asks only for light reading, but as time wears on, he begins to consume deep literature with lasting significance. He begins to connect himself with cultures across time periods, wanting to know the passions that span place and time. He becomes fluent in six different languages so that he can decipher books in various disciplines for himself. And, contrary to the confinement, he initially finds that these insights bring him great pleasure, as evidenced in his letter to the banker:
Oh, if you knew my heavenly happiness now that I can understand them!
The lawyer undergoes another transformation after about a decade:
Later on, after the tenth year, the lawyer sat immovable before his table and read only the New Testament. The banker found it strange that a man who in four years had mastered six hundred erudite volumes, should have spent nearly a year in reading one book, easy to understand and by no means thick.
The lawyer's thoughts turn inward as he considers his faith in the midst of trial. While the banker easily dismisses the New Testament as "easy to understand," the principles it contains are exceedingly difficult to live out. It is likely at this point that the lawyer begins to see the futility of living for things of the world, as evidenced by some key verses in the New Testament:
For everything in the world—the lust of the flesh, the lust of the eyes, and the pride of life—comes not from the Father but from the world. (1 John 2:15, NIV)
Keep your lives free from the love of money and be content with what you have, because God has said, “Never will I leave you; never will I forsake you.” (Hebrews 13:15, NIV)Then he said to them, “Watch out! Be on your guard against all kinds of greed; life does not consist in an abundance of possessions.” (Luke 12:15, NIV)But godliness with contentment is great gain. For we brought nothing into the world, and we can take nothing out of it. But if we have food and clothing, we will be content with that. Those who want to get rich fall into temptation and a trap and into many foolish and harmful desires that plunge people into ruin and destruction. For the love of money is a root of all kinds of evil. Some people, eager for money, have wandered from the faith and pierced themselves with many griefs. (1 Timothy 6:6-10, NIV)
(The entire section is 1,032 words.)