Dumbledore's Trusting Nature

[carodave92]

No: HPFGUIDX 146632

In re-reading HBP (US edition), I noticed a comment regarding 
Dumbledore's trusting nature.  Unfortunately, now that it is time to 
post my question, I can no longer find the quote, but as I remember 
it, someone remarked that Dumbledore's weakness is that he  HAS to see 
the best in people.  Not that he looks for the best, or would like to 
believe the best, but that he HAS to, which implies lack of choice in 
the matter.  Of course, I could be reading into this based upon his 
continued trust of Snape and Malfoy in the face of all evidence, but 
it struck me as an odd choice of wording.

Did anyone else notice this, and do you think it has any meaning?  Is 
there already a thread on this topic?  (If so, please point me to it.)

Carodave