does evil exist?

[The Grand Nudger]

This is correct, suffering is not necessary at all, no matter how many stupid people will claim suffering is necessary.

Yes, but with a caveat.

Necessity implies a goal.  If you want not to burn off your hand, suffering when you put your hand on a hot stove will cause you to remove it, thereby saving your hand.  In that sense, it's necessary to suffer.

Is it necessary that humans keep their hands intact, or survive, or live in comfort, or exist on any level?  No.

The same goes for "evil" itself.  Can the devil be evil?  Can a mass murderer be evil?  No-- it's all just a change of material state, accompanied by suffering perhaps.  What makes it evil?

Buddhists play with this-- see the emptiness in horror, in grief, etc. and analyze it all philosophically.  Some of them get very good at disengaging from suffering.  In that sense, I'd argue that to an enlightened Buddhist, nothing can really be evil.

Necessity doesn't imply any goals.  If you step off a buildings ledge you will necessarily fall.  The building isn't looking to kill you, or make you fall.  Gravity, also not looking to kill you, or make you fall.  All necessity means is that there is no other logical alternative.

A necessary evil, therefore, is some thing which is evil, but for which there is no logical alternative. So, for example, when heterotrophs eat - this may be evil, depending on your definition of evil - and if so it is a necessary evil - because heterotroph. It's not logically possible for you to be a heterotroph without engaging in evil under such an understanding of evil.

Sometimes we see people split that baby, and say that..sure, killing things to eat is of moral import, but only killing things of a certain kind is of the moral import which concerns us most. Is evil. This, conveniently, is the conceptual difference between bad and evil, where vegan heterotrophy is considered..perhaps not exactly good, but not as bad, as omnivorous heterotrophy, which is the Bad Bad.