Dumbledore's trust for Severus Snape.

[finwitch]

No: HPFGUIDX 138371

"colebiancardi":
> 
> Nope, I cannot buy that reason.  This is an Ex-Death Eater and now 
> turned spy for Dumbledore.  Do you really think he would just 
accept 
> him with open arms and not make sure Snape's story checked out?  
That 
> there HAD to be some proof of Snape's turn to good(i.e. I'm still 
> sticking with my Regulus Theory)....
> 
> Dumbledore is trusting, but he isn't a fool.  He didn't trust 
Riddle, 
> he didn't give Riddle a chance when Riddle came to apply for the 
DADA 
> job.

Finwitch:

Dumbledore would, however, require a reason NOT to trust someone 
rather than a reason to trust. Tom Riddle has given him that reason 
one way or other. If only his bullying before he came to the school; 
maybe Tom even tried to use some sort of Legilimency Charm he had 
successfully used on other teachers on Dumbledore, who of course 
wasn't tricked by it?

As for that, Dumbledore does use Legilimency when he doubts - Harry's 
experienced this often enough.

As for Snape - well, he's an Occlumens and he hasn't given Dumbledore 
a reason not to trust him. And don't forget that Crouch Jr. managed 
to fool Dumbledore to think he was Alastor Moody for a while... I 
think it possible that Snape could use the same sort of trick as Tom 
did with Harry: showing him memories that made it seem that Hagrid 
had been the guilty one.

Finwitch