What turned Snape (Was: JKR site update SPOILERS)

[justcarol67]

No: HPFGUIDX 159067

Carol earlier:
> > But Snape "returned to our side" before Godric's Hollow and was
spying for Dumbledore "at great personal risk" before he was hired as
Potions Master several months before the Potters died (probably in
July or August of that year; he would have begun teaching September
1.) So the life debt doesn't explain why he turned against Voldemort
or why Dumbledore trusts him. All it explains is why he would regret
James's death and try to save Harry in Book 1. 
> 
> Neri:
> This sounds strange. Dumbledore says that Snape's debt to James is
> what made Snape try saving Harry in SS/PS. So you think his debt to
> James would make Snape try to save Harry but *not* James? I don't
get your logic here.  <snip>
> 
Carol:
Huh? I must have been extremely unclear or assumed something that I
left unstated. Of course I think that snape tried to protect James. He
told Dumbledore about Voldemort's interpretation of the Prophecy and
that LV was going after the Potters (and possibly the Longbottoms).
Since Snape resents James's "arrogance" in refusing to believe that
Sirius Black was the spy, he either tried to warn James himself and
was rejected or he knows that James rejected Dumbledore's SK offer.
Since I believe that neither he nor Dumbledore were told the Secret (I
think they knew it earlier because DD owned the cottage at Godric's
Hollow but magically "forgot" it after Peter became SK), that was all
he could do until, IMO, he woke up with his Dark Mark burning him and
then disappearing. He may also have woken up knowing the secret, as I
think DD also did, and I think he was in on the plans for saving
Harry, having failed to save James. But I don't think that James was
his sole concern. I think he also wanted to protect James's innocent
wife and child--and failed to do so. Hence, the life debt to James is
only partial motivation. Whether it was paid off in SS/PS or not, I
don't know. It may simply have been one of the half truths that DD is
always telling, a true but incomplete explanation of Snape's
motivation in attempting to save Harry, one that Harry would
understand and that would not violate Snape's confidence.

My point is that the life debt cannot fully account for Snape's
becoming Dumbledore's Man and spying for him "at great personal risk"
before Godric's Hollow. I think he felt troubled and guilty over his
failure to save Lily and remorse for orphaning Harry and Snapelike
anger at James for daring to die when he had not yet repaid his life
debt. I think that his sense of honor (yes, he has one) caused him to
transfer the life debt over to Harry. But once he's saved Harry's life
in SS/PS, why does he keep on saving or trying to save it (in PoA and
OoP, at least) and keep on risking his life (from the end of GoF
onward) if the life debt is his only motivation?

At any rate, I think that James was only one factor in Snape's
decision to "return to our side" and not necessarily the primary one,
which may have been the desire to protect an innocent child from death
or revulsion at Voldemort's true goals and methods (e.g., the murder
of Regulus Black, who may have been a friend of Severus's).

I'm snipping the rest of your post as I still believe that Snape is
DDM, though I concede that JKR has made it look otherwise (unless we
read carefully) in HBP. And even though Dumbledore wants people (Snape
and Harry before the cave episode) to keep their promises, he won't
compel them to act until they've given their word. And IMO, he would
never resort to magical compulsion (Imperio, Unbreakable Vow, etc.)
and he would never *trust* someone *completely* based on such magical
compulsion.

No, I think there's some understanding between Snape and Dumbledore
related to the glance they exchanged on the tower and to the reasons
for trusting Snape that DD concealed from Harry.

As someone else has mentioned, Dumbledore has already told Harry that
James saved Severus's life when they were both sixteen; Harry knows
about the life debt concept because of Wormtail. If that's all there
is to it, why did Dumbledore remain silent about his *reasons* and
merely state that he trusts Snape completely?

Carol, hoping that her position is clearer now