"I know, Ruth; but just now & again one comes across an inexplicably bad person [I saw it in my years of teaching, e.g.] where one just has to fall back on the concept."

See, i find that very hard to reconcile with. There are so many factors that will determine behaviour: social, psychological, brain chemistry. These things all have determinate roots and causes.

"Evil" points to something intangible and without cause; something spiritual. To believe in evil, you have to have a spirituality. I can't make myself believe in anything spiritual, so consequently can't believe that there is a "badness" in the world, and that some people are born with it and some aren't. It's all chemicals and conditioning, in my opinion. If you factor "evil" into the eqiuation, it's too easy for society to write off certain members as irredeemable, because they are fundamentally "bad".