That and the Light siders consider the Dark Side to be a corruption of the Force, of nature itself. A corruption that needs to be removed in order to restore balance to the Force. Others hold that the two have to be in balance for the universe to function. There is not definite answer to the ideology, as it seems to depend greatly on one's point of view. Those that study the Dark Side likely have their own ideas about what the universe is like, or what the Force is and what it is for. We get some of that via Palpatine and some of the other Sith Lords.