[quote=TheSovereignGrave]
I'm not really familiar with The Witcher, so I'm not entirely certain what it is you mean.
[/quote]

I may have to do a bit of game-lore then.

In brief: Yeavinn and Iorveth are both leaders of units of non-human commando units known broadly as the Scoae'tel, known popularly as The Squirrels. They both have varying degrees of passionate hatred for humans, or at least to the "Northern Kingdoms".

In a fuller respect: The Witcher as video game takes place something like five years after the start of a war between the four Northern Kingdoms and the southern human Empire of Nilfgard. Nilfgard made heavy use of light-commando units of Elven and Dwarven composition to harass the Northern Kingdoms and disrupt their war effort. This however fails and Nilfgard is forced to sign a peace which calls for the disarming of the elven commando units and other concessions. In protest however, the elves and dwarven commandos refuse to disarm and continue to fight The North, intensifying persecution against Nonhumans by humans and persecution of humans by nonhumans (or really just swelling their ranks with pissed-off nonhumans).

The first game in the series introduces Geralt - the player - to a elven commander named Yeavinn. As an effect of the shoddy treaty (or as he perceives it) he must keep fighting the humans. There's some other philosophy but it's really broad, and strange, and abstract. I imagine it's hum trying to make himself feel good or look good by talking all metaphorically about his mission. In short: he's a huge dick.

Witcher 2 brings in a new Scoia'tel leader by the name of Iorveth, himself a veteran and well respected commander (Yeavinn is mentioned in the second game a few times, but because the series' themes concerns itself with moral relativity it's done in such a way he could have died or lived after the first game, depending on what you think). Iorveth, though still racist, is more shrouded in relativity than Yeavinn who I think just wants to kill everything with rounded ears.

[url=http://youtu.be/hCcC6aQIsMM?t=43s]At introduction I think Iorveth does a better job than Yeavinn could have dreamed.[/url]

It's probably because I played Witcher 1 associated with the humans. But playing Witcher 2 sided with the elves makes Iorveth out to have a better developed philosophy and reason for fighting then Yeavinn blabbering about trees and shit.