Sauron grew up in a typical Ainur family. Some say he was radicalized during his years as a soldier during WW1, but the truth is, Sauron harbored a disease of the soul which has its roots deep in the the story of creation.

Sauron thinks he's totally isolated from the rest of the world, so the world looms in his imagination as a potential threat. Put simply, he wants to control the world to protect himself. He is not able to trust anyone. At times, he just wants to give up and destroy the world instead of trying to control it.

This is why it's not as evil as it looks to work with Sauron. We don't want to leave him desperate.

What was Sauron's aim? — baker

Enslave, or destroy, all Eldar and Edain.

What motivated him?

Perhaps 'the lost cause' – Morgoth's Wrath.

Okay, he wanted to rule the world. But why exactly?

WWMD. :death:

And why with the help of those filthy orcs?

"You go to war with the army you have, not the army you might want or wish to have at a later time." ~Donald Rumsfeld

How much of Tolkien's narrative about good and evil, is, basically, just Tolkien's Christian background talking, and how much of it is relevant outside of that context?

All of it. Manichaen duality, taijitu yinyang, Hegelian dialectic (Chaoskampf), harmony-dissonance (re: Ainulindalë), etc ...

I remember thinking who would want to rule a world of orcs?

basically, just Tolkien's Christian background talking, and how much of it is relevant outside of that context? — baker

How much of this OP is just baker's atheist background talking, and how much of it is relevant outside of that context. OH. All of it. :lol:

Uh, Sauron's aim is pretty clear in the books.

How much of Tolkien's narrative about good and evil, is, basically, just Tolkien's Christian background talking, and how much of it is relevant outside of that context? — baker

So if you want to talk about this, that would be a separate discussion.

What I'm slowly getting at is that the narrative of the struggle between good and evil might not be universal, might not be a given, and that it might be possible to conceive of life and morality in very different terms than in the terms of said narrative.