“One of the dark truths of the Killing Curse, son, is that once you’ve cast it the first time, it doesn’t take much hate to do it again.”
“It damages the mind?”
Again Moody shook his head. “No. It’s the killing that does that. Murder tears the soul—but that’s just the same if it’s a Cutting Hex. The Killing Curse doesn’t crack your soul. It just takes a cracked soul to cast.” If there was a sad expression on the scarred face, it could not be read. “But that doesn’t tell us much about Monroe. The ones like Dumbledore who’ll never be able to cast the Curse all their lives, because they never crack no matter what—they’re the rare ones, very rare. It only takes a little cracking.”
I took this passage as saying that you don’t have to be especially pathological to cast the killing curse a second time—Moody explicitly says it “doesn’t tell us much”. So if we trust him, it doesn’t tell us much.
“It takes a cracked soul to cast.” and “Murder tears the soul.” just says that if you’ve gotten to the point where you could cast it once, that particular pre-requisite is already accomplished, so the work to crack your soul is already put in. It doesn’t say anything about removing the requirement of wanting someone dead.
Though, so long as we’re looking at evidence, if we take Quirrell at his word, then his ability to cast the spell despite not wanting his opponent dead is pretty strong evidence that the requirement is in fact removed. In fact, we already know that some “requirements” to cast spells are not set in stone: from that same scene, Harry cast the true patronus without the carefully practiced stance and wand twitches, instead merely “one desperate wish that an innocent man should not die—”—but the constant requirement in this case seems to be the thought that accompanies the casting of the spell, which is why I’m hesitant to believe the wish of death is removed from AK’s casting requirement.
Though, so long as we’re looking at evidence, if we take Quirrell at his word, then his ability to cast the spell despite not wanting his opponent dead is pretty strong evidence that the requirement is in fact removed.
Just because he didn’t intend to kill him doesn’t mean he didn’t want him dead. As Moody said, you have to want it, not just for the greater good, but as an end unto itself. Quirrell might have wanted to kill Bahry as an end unto itself, whereas for matters of convenience it was better to leave him alive.
I took this passage as saying that you don’t have to be especially pathological to cast the killing curse a second time—Moody explicitly says it “doesn’t tell us much”. So if we trust him, it doesn’t tell us much.
“It takes a cracked soul to cast.” and “Murder tears the soul.” just says that if you’ve gotten to the point where you could cast it once, that particular pre-requisite is already accomplished, so the work to crack your soul is already put in. It doesn’t say anything about removing the requirement of wanting someone dead.
Though, so long as we’re looking at evidence, if we take Quirrell at his word, then his ability to cast the spell despite not wanting his opponent dead is pretty strong evidence that the requirement is in fact removed. In fact, we already know that some “requirements” to cast spells are not set in stone: from that same scene, Harry cast the true patronus without the carefully practiced stance and wand twitches, instead merely “one desperate wish that an innocent man should not die—”—but the constant requirement in this case seems to be the thought that accompanies the casting of the spell, which is why I’m hesitant to believe the wish of death is removed from AK’s casting requirement.
Harry didn’t cast the patronus then, it was already active, he just moved it.
Fair point, though that also removes the point of evidence that casting requirements are removed with practice.
Just because he didn’t intend to kill him doesn’t mean he didn’t want him dead. As Moody said, you have to want it, not just for the greater good, but as an end unto itself. Quirrell might have wanted to kill Bahry as an end unto itself, whereas for matters of convenience it was better to leave him alive.