Why are most mages sterile?

[dragonbird]

Brilliantly put. How do you people come up with these?

Listening to tone-deaf karaoke singers.

 

[Vermeer]

Yeah, I agree with dragonbird. You have to posess magical talent in some degree in order to become a sorcerer (Yennefer tested Ciri for it; she knew Ciri could learn magic because she felt energy in Yen's necklace or something like that), but it seems this trait is not uncommon, just commonly unexploited. The same way many people could potentially become musicians, mathemathics, painters and such, I think. You need talent + studies + practice. Sorcerer as a profession has a bad name though, but still allows you to earn huge amounts of money, so upper-class people send their malformed, un-marriable children into sorcery school.

I suppose there are people overwhelmed by their magical talent too. Like, possesing a great amount of power but little intelligence, will to tame it, or just lacking the opportunity of someone to teach them, thus becoming crazy, catatonic, etc, like Tissaia wrote. I think Cedric may be an example of this. I doubt they actually forced sterilization in the young adepts. Most of them were going to end up sterile anyway.

 

[idreim]

I dont remember any suggestion that Tissaia's proposition has been put into force. I think, it is just supposed to show, that there is an ongoing discourse on the subject.

Personally, what I took from that excerpt was that Tissaia actually forced the sterilization upon the girls when she was the headmistress, and that was the origin of Yennefer's sterility (she was a novice back then if I don't misremember).
But it's more a feeling than anything else.