. . . Evil for evil's sake is usually, but not always, fairly weak as far as motivations go. . . .
I agree entirely, it's a point that I've felt no little irritation toward for a good while. There are always some stories that make good use of a standard Evil Is Evil Because It's Evil standpoint while Good Is Good Because It's Good to oppose it, but it's all very two dimensional. There aren't any greater motives than that. Evil must be eliminated and Good must triumph.
With the way our own understandings of human minds and desires have expanded, the expectation of depictions of those minds and desires have grown as well. We want something believable. Yes, there are spells flying left and right, and a mystical talking turtle that is actually an ancient Wizard who has been trapped in this form for centuries to prevent him from saving the world, but we can allow ourselves to believe all of that if the motivations and the people around these items are realistic enough.
Valid points.
I guess I try to imagine it from a logical perspective. Which, in the case of evil (and fantasy), logic is not always neccessary.
I will agree that it's not -always- necessary since we are indeed talking about fantasy here, I think that with the same token, your fantasy world will be far more believable if you use that logic when building it and its people. I have my own fantasy world, and as any of us could have, I could have filled it with any number of random magical things and said "Done!" whether they followed any form of logic or not, but I've gotten quite a bit of positive feedback regarding my decision to use as much of our own world's physics in how I built the magic system. I don't intend to break that down for the readers, but what it gives you is a system with internal integrity that (hopefully) prevents the reader from being shocked out of the narrative by something that doesn't jive quite right.
What motivates people to do bad deeds are strong emotions: anger, fear, vengeance. Also, some people get a rush by manipulating people; they "win" at a game only they can see. Serial killers get a rush by having total control over their victims.
But probably the biggest motivator is righteousness. More people have been murdered in the name of religion than any other cause. Hitler murdered jews because he thought the final solution was what god wanted. He had a deep emotional belief he was Right and anything he did to promote god's plan was justified.
I think that's a good assessment of what drives many, but I also see our breed as being like profilers. It's up to us to understand how the human mind works, whether we're talking about people doing good works, or bad.
Sociopaths, for example, lack the ability to feel guilt or sympathy. I suppose you could say that they're freer individuals in that they can act without fearing the consequences. If it's a scientific experiment, they can do things to people without feeling pangs of guilt over what suffering they go through, or ultimately if they even die. There are several things which typify most sociopaths, though, beginning with childhood. I recommend watching shows like Most Evil on the ID (Investigation Discovery) channel. Highly enlightening.
Teresa had an excellent point and observation with vanity. Many killers, serial killers, can be very narcissistic and arrogant. They think that they'll never get caught, that no one is smart enough to follow their trail, that if someone found out then they could easily outsmart the pursuer, that no one could possibly understand the reasons -why- they're doing what they're doing.
So I think the more you understand what has driven people to do things you'd consider evil in the past, the better able you'll be to both figure out and portray it in your characters.
>_> Hope that wasn't too long . . .