The best reason for Dumbledore to trust Snape (Lily?)

[lagattalucianese]

No: HPFGUIDX 137861

Valky:
> 
> ...All the while Hagrid remained his flawed self, breeding 
> creatures and almost losing everything over his love of Buckbeak 
> and Norbert...
> 
Gatta:

I think you just stumbled over something very important here, kind of
by accident and kind of in passing, but important nevertheless.
(Apologies if someone has already pointed this out; I'm a new kid in
town, and there are an awful lot of archives to poke through.)

The thing that stands out about Voldemort is that he can't tolerate
love, and as we find out in HBP13, has never experienced it. (Merope
dies at his birth, and nobody else has ever really cared about him,
especially after the evil nature of his character begins to assert
itself.) Whereas the point is made repeatedly that Harry survived
Voldemort's attack on him as a baby and Harry has the power to destroy
Voldemort's followers (and one assumes eventually Voldemort himself)
because of the strength with which Lily's love has imbued him. In this
respect Harry and Hagrid (who had a father's love) are very much
alike; most of the "mistakes" Harry makes (rescuing Ginny from the
Chamber of Secrets, helping Sirius to escape) are the result of love
and the desire to do the right thing.

Now which the two, Voldemort and Harry, is Snape more like? I think I
would have to come down on the side of Harry; Snape has known a
mother's devoted love, just as Harry has, and while his years at
Hogwarts are not without conflict and incident--unlike Harry's, of
course ;)--we don't see him actually doing anything overtly evil
(well, O.K., his educational methods leave a bit to be desired, but
the kids seem to survive him without losing too much skin; we have to
remember that the model for Hogwarts is the English "public" school
system, which treats children a good deal less gently than the
American school system does) until the moment when he kills Dumbledore. 

Which leaves me wondering if that act is one of those apparent
"mistakes" like Harry's (for example, killing Professor Quirrel,
surely something a student would not normally get away with), for
which there is after all an underlying explanation that we we don't
know about, but Dumbledore (and JKR) do.

Until I know better, I'm giving Severus Snape the benefit of the doubt.