star wars - Can there really be Sith motivated by happiness or "joie de vivre"?

A friend of mine said that Sith aren't necessarily motivated by hate and anger, but rather that they draw their power from volatile emotions in general, while the Jedi focus on a zen-like inner calm. He mentioned the possibility of a Sith warrior motivated by more positive emotions, like passion or lust for life, enjoying his grand adventure as he fights against the stick-in-the-mud Jedi.

Is that a thing? In the movies it seems like the Sith are straight-up evil, start to finish. Are there members of the Sith who are motivated by something other than hatred?

Note that I'm not asking about the possibility of a good Sith, I'm talking about the midset of a Sith warrior, good or evil. I'm asking, whether the Jedi/Sith split is one of emotionlessness vs emotion, or whether the Sith specifically work with negative emotions only.

Answer

While not addressing the notion of "volatile" emotions, or even hatred specifically, the EU (Legends) novel Shadows of the Empire DID establish that feeling joy or happiness weakens a Sith's connection to the Dark Side of the Force.

In the novel, Vader is shown - from his own POV - attempting to breathe without his helmet while inside his hyperbaric chamber (the spherical 'throne' seen in Episode V). Unfortunately, every time he managed to heal his lungs somewhat using the Dark Side, he would then feel elation at being able to breathe on his own. The joy he feels at his success would immediately cause him to "lose" his grip on the Dark Side, and puts him back at square one. Here is the relevant part:

He concentrated on the injustice of his condition, on his hatred of Obi-Wan, who had made him so. With the anger and hatred, the Dark Side of the Force permeated Vader.

For a moment, his ruined tissues altered, his scarred lungs and dead alveoli and constricted passages smoothed out and became whole. For a moment, he could breathe as normal beings breathed.

His sense of relief, his triumph, his joy at being able to do so drove the Dark Side from him as surely as a light chases away shadow. The Dark Side eagerly consumed anger, but it was poisoned by happiness. It left him, and when it did he could breathe no longer.

Also, in one of the many stories featured in Star Wars: Tales, a Sith master explains to his apprentice that "good" feelings, such as love or joy, are useless to a Sith. In the story "The Apprentice", the current Sith Master explicitly refers to compassion as a Jedi trait.

EDIT: I felt I should add that your friend is partially right, however. Unlike a Jedi - who attempts to tightly control both what they feel AND the motivations behind those feelings - a Sith embraces emotion. Therefore a Sith would not shy away from lust or passion, and in fact many Sith took lovers to sate those emotions. In short, a Sith does whatever the heck they want when they want.