"What can change the nature of a man?" is a philosophical question that has been explored in various contexts, including the video game Planescape: Torment. While there is no single correct answer, the game offers several possibilities:

• Belief: One character in the game suggests that belief can change the nature of a man. "Whether regret, or love, or revenge or fear - whatever you believe can change the nature of a man, can. I’ve seen belief move cities, make men stave off death, and turn an evil hags heart half-circle. This entire Fortress has been constructed from belief".

• Regret: Another character suggests that regret can change the nature of a man. "Regret, my dear sir, is the very springboard of life. He who has none... well, he ceases to be human".

• Wisdom: According to the games creator, Chris Avellone, the high Wisdom response at the end of the game is the "true" answer to the question.

Ultimately, the question is left open to interpretation, and the answer that is capable of changing the Nameless One, the games protagonist, is the one that he chooses.