Aside from reference to Sade's pornographic/philosophical works, I've not been able to find out much about the ideas of sadistic philosophy. Does anyone know of any resources that explain the field without muddying the waters with pornography too much? I'm more interested in sadism as it relates to libertinism and existentialism than as a form of perversion.
I suspect you will have a difficult time finding resources that don't incorporate the erotic aspects. The closest you are likely to come to a balanced view is discussions of BDSM by abuse survivors using the dynamics to work through their abuse issues. But even there you will see a lot of exploitation and rationalization.
It is fairly easy just tweak your search parameters, there are loads of books relating to the use of torture and war crimes through history - these don't often deal with the sexual aspect except when rape is used as a a form of torture. Japan's Gestapo, Murder, Mayhem and Torture in Wartime Asia is good can't remember the author. Katy Reichs wrote a book think it is called Monday Mourning might be interesting. Torture and Democracy is another that is really interesting Humans have always been very interested in the more gruesome side of their potential. Julian Boon is a forensic psyhiatrist his books may hold some interest and give you information.
being a practicing philosopher and a moralist, i consider sadism as more a criminal perversion, than a 'philosophy'...
ISBN 1406791032 War, Sadism and Pacifism by Edward Glover I'm sure there are more out there, but sadism is all about the causing of pain and suffering for self gratification. Some people take this to the sex level, maybe look up stuff relating to torture as well.