I recently was involved in a twitter discussion in which I concluded that a rational and natural evil was nonsensical. The path to there is a little convoluted, but it hinges on motivation: what is the objective of evil? Most rational objectives I can think of are pretty bad but not really what we think of as Evil. Maybe evil but not Evil if you follow.
Say, for example, orcs really hate humans. They kill all humans and destroy all human things. But if they are natural and rational, then they have an end-game, a perfect world. They have an agenda that is not just external to them (kill everything) but internal: something they want and strive for. Clearly this is just a world without humans but otherwise kind of nice — everyone rational wants things to be kind of nice, at least for them. This is extreme and aggressive but, depending on the backstory for their hatred, not necessarily evil and not innate so certainly not Evil. Maybe their human-free world is awesome. Too bad for us but more power to them.
But if evil is rational and supernatural we can kind of get our teeth into something meaty. Perhaps our Evil is a deity that despises this reality and wants to destroy it to replace it with their own (whatever that looks like doesn’t matter since it doesn’t have us in it). A kind of failed god like Morgoth in The Silmarillion — they hate the existing reality and are jealous of the power of creation. Their dedication to the destruction of everything is rational but supernatural: they want their own vision realised. That’s their rational end game.

Or perhaps it’s supernatural but irrational — it’s just a kind of hate elemental, a realization of pure nihilism that only destroys. Maybe that’s not even Evil but it’s a neighbour. It is interesting however simple its agenda is. It will be content in its end-game to rule over ashes. But it has to be irrational: there is no constructive agenda, no genuine plan for the future. Just wreckage and horror.
But where do orcs go? It seems to me there are few places for orcs and evil. One is that they are an autonomous species with their own culture and a complex agenda (not Evil intrinsically) but they are unwillingly or unwittingly under the command of our hate elemental or jealous near-deity. They will ultimately be consumed as well. These orcs have a complex relationship with the world and are, to my mind, very interesting now. They can be saved or, much better, save themselves. They don’t really need a variation in shape, though — they could as easily be humans. Again, their evil is situational and not innate. They can and would likely prefer to find a different path.
Another way to read them would be as beings that do not have a culture, that do not exist as normal biological organisms do. That is, they bear no children and have no relationships but are fabricated by our Evil entity with only enough autonomy to serve as soldiers. Not even that, but really as just appendages of this Evil entity. These orcs cannot be saved because they are just semi-detached tentacles of the Evil. They are not “like” people beyond the fact that they sort of look like people. They are the best our hateful and destructive demigod of the ashes can do as far as creation goes and they will be expended in the end. Since they are basically automatons they can’t really be Evil themselves — they are an expression of our hate monster’s evil.
But I don’t see a way that rational, natural beings can be intrinsically evil (or Evil really) because there’s no end game to a philosophy of pure hate and destruction. They have no agenda that makes any sense. Anything you try to make them want requires either supernatural power (re-create the world as something functional for them), lack of rationality (a pure hate for everything), or not being actually evil (a complex and destructive relationship with the status quo).
Thanks Levi, I didn’t need to sleep anyway.