If you strike at, imprison, or kill us, out of our prisons or graves we will still evoke a spirit that will thwart you, and perhaps, raise a force that will destroy you! We defy you! Do your worst!
Whatever you think of de Sade, he was a complex figure and we should not look for easy answers with him. He was, strangely perhaps, against the death penalty, and he was never put in prison for murders or anything like that.
Why would anyone expect him to come out smarter? He went to prison for three years, not Princeton.