Called to task.
- The Last Wish:
Kaer Morhen... There were produced ones like me. It's not being
done anymore.
- Blood of Elves:
Verily, there is nothing so hideous as the monsters, so contrary to nature, known as witchers for they are the offspring of foul sorcery
and devilry. They are rogues without virtue, conscience or scruple,
true diabolic creations, fit only for killing. There is no place
amidst honest men for such as they. And Kaer Morhen, where these
infamous beings nestle, where they perform their foul practices, must
be wiped from the surface of this earth, and all trace of it strewn
with salt and saltpetre. - Monstrum, or Description of the Witcher
- Blood of Elves:
The gelding snorted and jerked its head, crossing what remained of the
bridge over the moat. Triss tugged at the reins. The decaying skulls
and skeletons strewn across the river bed made no impression on her.
She had seen them before.
“I don’t like this,” the girl suddenly remarked. “It’s not as it
should be. The dead should to be buried in the ground. Under a barrow.
Shouldn’t they?”
“They should,” the magician agreed calmly. “I think so, too. But the
witchers treat this graveyard as a… reminder.”
“Reminder of what?”
“Kaer Morhen,” Triss said as she guided the horse towards the
shattered arcades, “was assaulted. There was a bloody battle here in
which almost all the witchers died. Only those who weren’t in the keep
at the time survived.”
“Who attacked them? And why?”
“I don’t know,” she lied. “It was a terribly long time ago, Ciri. Ask
the witchers about it.”
“I have,” grunted the girl. “But they didn’t want to tell me.”
I can understand that, thought the magician. A child trained to be a
witcher, a girl, at that, who has not undergone the mutations, should
not be told such things. A child like that should not hear about the
massacre. A child like that should not be terrified by the prospect
that they too may one day hear words describing it like those which
were screamed by the fanatics who marched on Kaer Morhen long ago.
Mutant. Monster. Freak. Damned by the gods, a creature contrary to
nature. No, I do not blame the witchers for not telling you about it,
little Ciri. And I shan’t tell you either. I have even more reason to
be silent. Because I am a wizard, and without the aid of wizards those
fanatics would never have conquered the castle. And that hideous
lampoon, that widely distributed Monstrum which stirred the fanatics
up and drove them to such wickedness was also, apparently, some
wizard’s anonymous work. But I, little Ciri, do not recognise
collective responsibility, I do not feel the need to expiate the
events which took place half a century before my birth. And the
skeletons which are meant to serve as an eternal reminder will
ultimately rot away completely, disintegrate into dust and be
forgotten, will disappear with the wind which constantly whips the
mountainside…
- Season of Storms
"Winter will come," said with the effort Brehen. "And I, unlike some, have no place to wait it over. Cozy and warm Kaer Morhen not for me."
EDIT:
The conclusion of all those excerpts is that nowhere - up until Season of Storm - it's mentioned that there are multiple Schools. We have only faintest hints in form of witchers' medallions in different shapes, but that's that. Also, every time when Kaer Morhen is mentioned, every person knows it was the home and source of witchers, including magi who knows best (again, as mentioned in Season of Storms), as opposed to a home.
In short: multiple Schools as we know them are the game concept only - books mentions only one, in connection with just one other witcher, and there's actually not much more than that. In contrast, the information on the uniqueness of Kaer Morhen is as follows:
- Monstrum says that in order to get rid of witchers Kaer Morhen must
be destroyed
- The battle that ensued after wide distribution of the Monstrum wiped nearly all witchers. It would not be possible if there were more Kaer Morhens elsewhere
- Even when we get to part where other
Schools witchers are mentioned Kaer Morhen is the only place of relative safety for witchers. What's more - those witchers, calling themselves Cats, are known to be failed mutations, defective both from the point of the Trials and in the meaning of true witcher (defender of humanity against the monsters)
- Indirect mentions of the Keep also are in the context of it being the only source
- From the bit where Triss contemplates the witchers training and diet of Ciri one can also infer (but this is by no means anything more) that Kaer Morhen area is the place of prevalence of organisms not seen elsewhere, and which are crucial in the forming of the witcher.
EDIT 2:
And I have to retract the statement made elsewhere that Season of Storms says that Kaer Morhen is the source. Book states who made witchers, not where. Damn and blast the fragilis of my memoriam... So I'm clearing that up.
