Prophecy Pub/Less Than The Meanest Ghost/Black Family Tree

[pippin_999]

 > > Pippin:
> 
> > The Hat contains the brains of the younger Slytherin, the one who
> > who helped found a school where Muggleborns could study 
> > magic. He must have been more flexible and tolerant than the
> > person who left the basilisk in the Chamber.

Nora:
> Ummm, could you cite me canon for the time of the creation of the Hat, 
> and that this necessarily involved a younger Slytherin, and a younger 
> Slytherin was genuinely more tolerant? 

Pippin:
The Hat was created at a time when the House system was working well
enough that the Founders desired to perpetuate it. 


"While still alive/They did divide/Their favorites from the throng,/
Yet how to pick the worthy ones/When they were dead and gone?" 
--Hat Song, GoF

The Hat says it was Gryffindor's idea  and all the founders 
put brains in the Hat:"The founders put some brains in me
so I could choose instead." -- Hat Song, GoF

The  Slytherin who contributed his brains to the Hat was
necessarily younger than the one who quarrelled with the other
Founders, unless, like TH White's Merlin, he aged backwards. <g>

Slytherin  was tolerant enough to be satisfied with the House system
and his friends' selections: "Thus the Houses and their founders/
Retained friendships firm and true." --Hat Song, OOP

The hat tells us that it saw dissension grow "So how could it have gone
so wrong?/How could such friendships fail?/Why I was there and
so can tell/The whole sad sorry tale." -- Hat Song, OOP

Since the Hat is sincere, we can't posit eeevil Slytherin who was
always planning to betray his pal Godric.

Nora:
 I suppose it's possible that he  was 'more tolerant' at one time.  
He was a Founder of the school  wherein the other three took 
Muggleborns, but he certainly could have  always had his beliefs 
(and just not expressed them as strongly).  
Meets at least one definition of tolerance, but isn't too impressive.


Pippin:
I'm not sure what you mean here. He preferred to teach pure-blood
wizards from the beginning, yes. That he did so fanatically is 
not supported by canon.  Indeed, the one year the Hat does not mention
blood is the year there is well-known halfblood student whom it seeks to
recruit for Slytherin.

I'm not saying younger Slytherin was an impressive example of tolerance,
just that he was willing to cooperate with the other Houses. That
he had no objection to bending rules when it was in his interest shows
a certain flexibility. That he was prone to see less virtue in Muggleborn 
students does not argue that he could see no virtue in them at all.

The Hat took Tom Riddle for Slytherin without any deliberation at
all, despite his belief that he was halfblood.   Rowling says that there
are not really any purebloods, just people who are selective about
acknowledging their ancestry.  

http://www.jkrowling.com/textonly/en/faq_view.cfm?id=100

Are all the pure-blood families going to die out? (We've lost the 
Blacks and the Crouches during the series)

Don't forget that, as Sirius revealed in 'Order of the Phoenix', 
none of these families is really 'pure' – in other words, they 
merely cross Muggles and Squibs off the family tree and pretend that 
they didn't exist. But yes, the number of families claiming to be pure 
is diminishing. By refusing to marry Muggles or Muggle-borns, they 
are finding it increasingly difficult to perpetuate themselves. This 
subject is touched upon in 'Half-Blood Prince'.
---
If there was some detectable difference between those who
have no wizarding blood and those who do, the so-called purebloods
would hardly be able to perpetuate this charade.

Pippin