Harry, Snape and Dementors WAS: Re: CHAPTER Chamber of Secrets Chapter 18:

[pippin_999]

No: HPFGUIDX 189374

 
> Alla:
. I can totally see Snape NOT ever bring up any OTHER methods and call his the BEST one and expect his students to take it on faith. Simply because his arrogant highness deemed his method the best in my opinion.
> 

Pippin:
I agree that Snape would  not allow Harry (or any other student) to disagree with him in class. But you do understand that if he called it the best, he acknowledged there were other methods even if he refused to discuss them? JKR  makes a joke about this feature of English in CoS. 

"Professor Dumbledore obviously thought he was the best man for the job--"
"He was the *on'y* man for the job," said Hagrid, offering them a plate of treacle fudge, while Ron coughed squelchily into his basin. "An' I mean the *on'y* one."

Harry himself has doubts about the usefulness of learning the patronus charm in a classroom setting, "as Harry kept reminding them, producing a Patronus in the middle of a brightly lit classroom when they were not under threat was very different to producing it when confronted by something like a dementor." --OOP ch27

I do not think Snape's reluctance to teach the charm has anything to do with his ego or his need to conceal his own patronus. Lupin taught it to Harry without revealing what his own patronus was. But Lupin's lessons only got Harry as far as producing the incomplete patronus. Since that only holds the dementor at bay while draining the wizard of his power, it is in the end no better than a trap, unless other help arrives.
 
If Lupin had thought there was any chance of Harry encountering dementors on his own, away from the protection of other wizards, I wonder if even  he would have suggested the patronus charm? As it is, he's constantly wondering if it's too advanced.

Pippin