Dork dork dork.

I re-read Harry Potter and The Half Blood Prince this weekend (if you haven't read the book yet, just skip the rest of this post). I'm a big dork you see, and I like Harry Potter books, and I figured this one, which sort of settled into the spot of my favourite one pretty quickly deserved some close reading attention. I forced myself to slow down and pay attention to little details. I was also armed with the inside knowledge that the barman at the Hog's Head is actually Aberforth Dumbledore, the headmaster's brother. It makes the parts where he's mentioned more interesting.

Anyhoo, I had a genuine point to bring up about the climax of this novel. As you all know (since only people who have read the book are bothering to read this) at the end of the story, Severus Snape murders Albus Dumbledore, completing the job that Draco Malfoy had been given by Lord Voldemort. Snape made an unbreakable vow with narcissia malfoy - saying he would help her son accomplish his task of killing dumbledore. If snape did not do so, he would die.
As we all know, many people in the Order of the Pheonix and many students at Hogwarts did not trust snape. Dumbledore never explained why. The reasoning seems to be, however, that Snape felt genuine remorse for being the one who told Lord Voldemort of the prophecy that would cause harry to be marked as the dark lord's equal. Whether this is the actual reason or not remains to be seen.
The point I am arriving at, however, is that all of the charactes believe Snape a betrayer of the Order of the pheonix because he murdered Dumbledore. I belive the opposite. I belive for Snape to continue doing his job (mainly: telling the order of the dark lord's plans) it was necessary for him to kill dumbledore.
The first and most obvious argument against my idea is that snape, having apparently betrayed the order, would have no way to communicate with them anymore. I'll confess this is a strong argument - however, I expect that there could easily be some sort of anonnymous communication put into place. This is a moot point and entierly speculative - you'll just have to trust that the rest of the evidence seems to point towards my theory.
There is another outstanding antithesis that could be posed. Hagrid overhears dumbledore and snape arguing and reportedly hears snape saying that he does not wish to continue doing something. It is never specified what that is - I believe that this point is inserted to make the reader sympathise with harry potter's views. That is to say, Rowling is setting up an interesting twist - all through six novels, snape has been suspected of being evil. Then, in the sixth, it seems that this is proved as true. It must be remebered, however, that except for the first chapter of Harry Potter and the Philosopher's Stone, the first chapter of the Harry Potter and the Goblet of Fire and the first two chapters of Harry Potter and the Half-Blood Prince, the entier narrative is focalised through Harry Potter's eyes. This means we are always subject to Harry's bias, even when his friends disagree with him. All evidence seems to point towards Snape's guilt in betraying the order, but we are not aware of what Snape and Dumbledore actually knew, nor are we likely to know until the next book comes out.
There is no doubt in my mind that Snape has killed Dumbledore. I belive that this action was necessary in the structure of the narrative to make Harry accept his fate of having to face Voldemort. Some believe that Dumbledore isn't really dead (I heard an interesting - albeit flawed - theory about a horcrux) - I'm not here to dispute that point - I will withhold judgement until the end of the series. Let us assume, however, the there is no way that dumbledore will come back to life (as much as we might want him to).
Dumbledore was aware of Malfoy's attempts to kill him. How would dumbledore have have known of this plan? The book seems to suggest that the only people aware of the plan are bellatrix lestrange, narcissa and draco malfoy, severus snape and lord voldemort himself. More death eaters become aware of the plan when they invade hogwarts, obviously, but there is no textual evidence to show that they were aware of the plan at the beginning of the novel. The most logical conclusion is that Snape himself told dumbledore of the plan. Upon taking the unbreakable vow, snape made a decision that allowed him to remain in proper service of dumbledore's cause. Snape, perhaps, is one of the most intellegent and accomplished wizards in the series besides Voldemort and Dumbledore themselves. It is because of this, perhaps, that dumbledore trusted him to make this sort of decision. In fact, this is of course pure conjucture, but I would reason to guess that Dumbledore knew some way of saving snape from the unbreakable vow. Alas Snape kills dumbledore. It is important to note that snape was infront of five death eaters when this happened. He could not back down from the job, he needed to maintain his position as a double agent, working for the order (not against it).
Dumbledore pleads with snape not to kill him. Or so it seems... He never says "don't kill me." Need I note that Dumbledore himself says of Nicholas Flammel in Harry Potter and the Philosopher's Stone that "death, to a well organised mind, is nothing but the next great adventure" (or something to that effect). Does Dumbledore, then fear death at all? Was he pleading for his life? It seems unlikely, since he just consumed a potion that might have killed him eventually anyway. Furthermore, he risked death before the narrative when he destroyed the horcrux that was the ring. Dumbledore was no stranger to the danger of death, so why would he plead for his life? Perhaps the answer is that he is only human, but something doesn't quite sit right still.
Furthermore, consider, if you will, how dumbledore puts himself at draco malfoy's mercy. It is evident that Dumbledore does not need a wand to preform magic, much as young wizards, in times of distress, do not. Why then could he not disarm Malfoy? The answer, of course, is that he did not want to. With just Dumbledore, Malfoy and Harry up on the tower, Malfoy could have been stopped. If malfoy had be stopped, then so could have the death eaters and Snape.
Let us turn to Snape's escape. Throughout the entier time snape does not bother to touch one memeber of the order of the pheonix and only (apparently) puts an impediment jinx on professr flitwick. Why would he so brazenly avoid hurting anybody (hagrid and harry in particular, as he must get past them both to escape from the school and he likes neither of them) Harry potter accuses snape of being a coward for killing dumbledore and running. Snape does not take well to this. He shouts "Do not call me a coward" when his face is contorted in rage instead of the smirk that harry expects. Why is snape so mad at harry? well, first off, harry is hated by snape, but also, snape has just done something very brave - he has killed the leader of the order of the penix, turning the same against himself, so he can continue to operate against the dark lord. he is now in danger of being found out by voldemort and being killed there, and in danger of being found by the order and killed there. That is why he does not want to be called a coward - because it is not true.
Historically, as well, snape has been proven to be not evil. Let's take this evidence as precident.
Do you see where I'm going with this argument? Snape, not evil.

Damn it! I overthought Harry Potter. AGAIN!