Originally Posted by Child-of-the-Emperor
But just to clarify; the Tau are not immune to Chaos, and I would struggle to find how they could become a useful ally for the Eldar against the insidious nature of Chaos.
I'll give you that the Tau are not "Chaos-Proof," but they do have some advantages over other races when it comes to dealing with the beasts in the void:
1) Their limited warp signature means that the Dark Gods pay little attention to them.
2) Given the Ethereal's control over the other castes, and looking at Tau culture as a whole (where your rank and place in society are more important than you as an individual), they benefit from a lack of the more base emotions and impulses that fuel so many of the actions of other races. Compare them to the human race, where avarice, lust, or envy can make any man an easy target for the machinations of the Chaos Gods. The Tau choose the good of their race over personal gain time and time again, making it far harder for them to be corrupted than the humans.
Why do you see so many human worshippers of Chaos? Because Man is weak.
I'm not saying the Tau can't experience these emotions, or possibly be drawn into Chaos' clutches, just look at O'Shovah. Without the presence of an Ethereal, who can say what has happened to the commander, save that he has forsaken the greater good for his own gain?
The Dark Gods are manifestations of the emotions of beings in the material universe (and each shows opposing aspects that aren't all bad), so the Tau's faint signature still would empower the gods even if it were to a shallow extent, correct?
The bravery, stoicism, honor and courage of the Fire Caste would lean them towards feeding Khorne, obviously, but Tau cultural values on a larger scale include hope for their future, constant learning, mercy after victory, trust in the Ethereals, and embracing change. This would lend them to feeding some other gods as well. So all in all, the Tau mostly give off emotions that would fuel Khorne, Nurgle, and Tzeentch. Who is absent from this list?
With the reading I've been doing, it would seem that the one god that the Tau have but a tenuous connection to is Slaanesh. Which, in the Eldar's desperate war against their orgy spawned starchild (along with the quote from Eldrad you presented above), may point to the Tau as some sort of Eldar experiment to use against Shim...
With their breeding programs and caste system, lust doesn't really come into play. Mating is to further the Empire's cause, and it is controlled. "Love" in Tau society seems more like utter respect and trust in your comrades, and the dedication of a group of lives to a united purpose (the Ta'lissera). How can Slaanesh corrupt something without the base animal desires man so readily displays?
If there is any more information about the relationship between the Eldar and Tau, I would be very interested. Probably should start a new thread though, as this has veered a bit from the original topic...