[HerenIstarion]

Thanks, lmp

But you didn't really distinguish between Evil and Pure Evil-sense one

Redeemable evil - evil
Irredeemable evil - 'pure' evil (where sense 2 is concerned, let pure stand in quotation marks)

I.e - Gollum is evil up to a point - there is a chance of him turning around, and that is what Frodo is trying - to actually redeem him. After Sam's rebuke, Gollum goes over to 'pure' evil state - there is no chance of his coming back. Mark the sign of the transfer a little before - Gollum the Great, Lord Smeagol etc he starts to call himself, though there are yet signs the transfer is not total - he wishes for fish in between. In the beginning he is after knowledge - he wishes to learn 'secrets under the mountains' at the early stage of being in possession of the ring.

Sauron likewise - by the end of First Age he's evil, but able to repent. Mark the sign of the transfer to 'pure' evil - self proclaim of being the god in Numenor and open self-worship

Roughly - evil is when self pursues some good but does so in crooked way. (Saruman - order and knowledge he's after are good, but the way he seeks them is bad. But pure evil seeks nothing that is good, but only worships its own self - once he switches from order as the final goal to the Saruman the Lord as the final goal, here is transition)

Mark how 'do not judge' principle is woven into the story - Gandalf does not give up trying to bring Saruman back. He is not trying to make Sauron repent not only because it is obvious Sauron is beond recall, but also as Sauron is the mentally stronger, and essey is more likely to pull Gandalf to the 'dark side' rather (personally, I sometimes wonder if Tolkien could write in Gandalf/Sauron stand-up by Palantir with Gandalf trying to make Sauron repent)

That's why the most 'purely' evil beings are orks - there was not a state from where they 'slipped' into evil ways, but they were so originally (at least, most of them, leaving aside elven theory and inbreeding of men). Self worship here is expressed in their urge to indulge they every wish. (hungry - bite at the one nearest, feel like tearing something apart - tear whatever you find 'tearable' etc)

Did I just repeat myself? Well, I suppose yes, but with samples this time

Here, I've found a good illustration:

In all the deeds of Melkor the Morgoth upon Arda, in his vast works and in the deceits of his cunning, Sauron had a part, and was only less evil than his master in that for long he served another and not himself. But in after years he rose like a shadow of Morgoth and a ghost of his malice, and walked behind him on the same ruinous path down into the Void.

The 'walking to the Void' starts as Sauron turns to self-service