It depends on what you mean by Satanism. Theres different kinds of demonology and demon worship, but thats not the "religion" of The Church of Satan. Satanism was created in 1966 by Anton LaVey. There is no demon or devil worship, you basically worship yourself as a god. He chose the name Satanism and used traditional satanic images to show that it was the antithesis of Christianity in every way shape and form (Satanists are essentially atheists and don't believe in "the devil" or "god"). Philosophically, without going into a shit ton of detail, its essentially Neitzscheism, and then they do rituals. There are many admirable tenants of its philosophy, and I was considering becoming a Satanist for a time, but the bad outweigh the good IMO (theres a big emphasis on domination of the weak by the strong, those who can be used and manipulated should be, and deserve to be). Basically like a twisted and corrupted version of the Randian Objectivism I currently study. Still, I feel more in tune with Satanic morals than Christian ones.