I don't know. It seems somewhat strange
to me that someone of Sade's obvious standing
in society and intellectual gifts
should turn his hand to disgusting
those around him in so blatant a manner. I find the idea that someone who could write 120 days of Sodom
would have a hard time killing people difficult to swallow.
I think it wasn't so much the idea of death that he was at, as perversity. The idea that as a human being you are free to twist and distort the core values of others as an expression of yourself seems to be central to Sade's exposition in many of his works, notably Sodom. The book wasn't written in a vacuum, as a detached clinical experiment on humanity, it's purpose is (as K9 suggests) to warp the viewer, and to question the morality of the universe that Sade was born into. The people that he was torturing didn't exist, at least we hope not. The images in our minds, did however and Sade is responsible for violating the identification we have with their humanity by slowly stripping them of all human virtue and dignity. It is in this arena of amoral gratification that he seeks to 'liberate' us from our strict adherence to conventionality.
There are so many mistakes there that it is hard to count. Firstly, the attacks on others in this way seems to be an externalisation of his primary insecurities about the nature of power, and peoples own identities. Why would he do this if he was comfortable in and of himself? He seemed to have no deep personal attachments to anyone throughout his life. For a man of such stature could it have been that he was unable to achieve true love from others, and thus feared that any such thing was an illusion? If he sincerely believed in what he wrote, his actions would have borne themselves out through some pattern of consistency, but this is not the case. He was never as evil as he made himself out to be, nor was he as contrite as he appeared to be in those moments when he was caught. I believe Sade lived a life of illusions and simple imagery. He semi-believed the lies of others, and the lies he told himself, and when he grew to realise just how empty and transparent they all were, he railed against the universe which bore him.