A few years ago on HPFGU, before OotP, there was a discussion as to what was so bad with the Aurors being given the authority to use the Avada Kevadra curse. And when it came to that, why call the curse Unforgivable? To some listies, including me, an initial reading seemed to equate the AK curse with lethal force, as used by the police. Certainly, the question of when/whether the police should use lethal force is a tricky one, but unforgivable?
skelkins outlined one possible answer among others. One that later canon seems to affirm. Yes, what are the Dark Arts? Are there forms of magic that are intrinsically 'Dark'—that are, for example, spiritually corrupting by their very nature? Or is Darkness merely a matter of application, the tool of magic used for evil ends? Or is the term used loosely, to refer both to a particular brand of magic and to criminally wicked wizarding behavior?
Take the Unforgivables, for example. Their "Unforgivable" status is described in "Moody's" class as a matter of legal distinction: they are the spells the use of which is most severely punishable under Wizarding Law. But are they also Dark in some metaphysical or spiritual sense? Does one learn about them in a DADA class because only a "Dark" (ie, criminal) Wizard would be casting an illegal spell in the first place, making defending oneself against them DADA by default? Or is there something intrinsically Dark about them apart from their nasty effects?
Before Crouch authorized his Aurors to use the Unforgivables, were they allowed to kill in self-defense? And if so, then were there non-'Dark' lethal magics that they would have used, rather than the dread AK? (Light and fluffy lethal magics, perhaps?) Or would all magics designed to kill be designated 'dark' by default?
I've seen others speculate that the Unforgivables may be Dark because they require a certain purity of intent: that to cast Cruciatus, for example, would require a focused and sincere desire to cause pain, to cast Imperius the desire to dominate, to cast AK the desire to kill. This would certainly seem to make them Dark by nature.
As I said, this is borne out by later canon. In OotP, Bellatrix certainly endorses this theory.
`Never used an Unforgivable Curse before, have you, boy?' she yelled. She had abandoned her baby voice now. `You need to mean them, Potter! You need to really want to cause pain - to enjoy it - righteous anger won't hurt me for long - I'll show you how it is done, shall I? I'll give you a lesson -' - Chapter 28, OotP
The implications of this for "The Big Death" are immensely interesting. I do incline to the school of thought that Dumbledore was on board with his death, whether he actually planned it or not. There seems to be a good deal of evidence to that effect.
However, if 'Avada Kedavra' requires hatred, and I think the text indicates it does, Snape's relationship with Dumbledore would seem to be a little more complex than one of love and absolute trust, even *if* Snape is indeed Dumbledore's man and on the side of the light.
Killing Dumbledore was not just a matter of necessity, not only a sacrifice. Killing Dumbledore with an Unforgivable Curse is not the equivalent of killing a person with a gun.
To do what he did, Snape had to hate Dumbledore.
I don't find this very odd, actually. There has always seemed to be a huge undercurrent of resentment in Snape's relationship with the headmaster. Of disgust at the way Dumbledore runs things, his favouritism of students like Harry and Sirius. I think Snape loved Dumbledore. I think he hated him also.
It was of erotic love that the Roman poet said, "I love and hate," but other kinds of love admit the same mixture. - C.S. Lewis, the Four Loves
There is a character who always reminds me of Snape in G.K. Chesterton's The Man Who Was Thursday. He was at odds with someone a little greater than Dumbledore. God, in fact.
There was complete silence in the starlit garden, and then the black-browed Secretary, implacable, turned in his chair towards Sunday, and said in a harsh voice--
"Who and what are you?"
"I am the Sabbath," said the other without moving. "I am the peace of God."
The Secretary started up, and stood crushing his costly robe in his hand.
"I know what you mean," he cried, "and it is exactly that that I cannot forgive you. I know you are contentment, optimism, what do they call the thing, an ultimate reconciliation. Well, I am not reconciled. If you were the man in the dark room, why were you also Sunday, an offense to the sunlight? If you were from the first our father and our friend, why were you also our greatest enemy? We wept, we fled in terror; the iron entered into our souls--and you are the peace of God! Oh, I can forgive God His anger, though it destroyed nations; but I cannot forgive Him His peace."
I think there's something of that sort of relationship between Snape and Dumbledore, that the moment of truth was one of both love and hate.
And if I've suggested that Dumbledore has some parallels with God, I'll beg you not to press me on that, as I promise to touch on those in another longer essay on Dumbledore, which is mostly written already.
NM