Ethereals, are they from Tau or are they alien cousins? maybe there could be fluff to find a ancient world explaining the trek of the Ethereals coming to Tau to unite the tribes?

Or Maybe the Ethereals were visited by a outside faction (aliens) who gave them knowledge and change there genetic structure to give them a ability of controlling/ persuading the tribes?
Is it fermones? or Psychic?

Humans have a great ability to adapt to their surroundings and that is why we have survived this long as a race, maybe the Tau are just even better at it and working together gave them the drive and the ability to leap great stages through technology?

Would we have been the same if it was not for division in land, language, views and beliefs?

People thought Galileo Galilei was a mad man in his time though he had great theories of science that today we know that are true, if we all followed, believed and were doing the same thing, to better ourselves just imagine what we as human beings could be doing today?

"after the ethereals left" when did they leave or have i missed somthing

they never left.

xenobiology, may give it a read... isit just about Tau? were can I find it? I remember reading something about the imperium having theories about it being pheremones but wasn't to sure if it was a fact within the fluff yet.

I want to do a little fluff with my army have a joint project with a group of eldar but I don't know how it work as my fluff knowledge on eldar lacks.

well eldar help and fight who every they want, they do whats best for them and will help anyone if it siuts them but are never reliable so, eldar and tau might fight chaous (or what ever) if they were close to an exodite (home world). so it could work yeah hope ive been helpful

i just did a torrent download of it. Xenobiology is about every alien in the game. If you can read the new eldar codex lots of fluff in there.

whats the addres for torent

just try piratebay.org and search xenobiology