I've been thinking heavily on this topic recently, and I thought I'd share my theory and see what others think. If you're interested in doing a thought experiment with this post, answer the following question before reading the rest of the post, and then see what you think of your answer after. I'd love to know, whether it influences your perspective or not.
Would Rand have been born on Dragonmount if Narg had killed him on Winternight?
Ok, on to the theorizing. I've seen a lot of lament recently regarding the assignment of ta'veren to Mat, Rand, and Perrin while the other critical characters like Egwene were not, despite being supremely important. This got me to thinking what the difference is between the two. I've also seen conjecture that Heroes of the Horn are always ta'veren or vice versa, and I don't think that's true.
The Wheel of Time turns and Ages come and pass, leaving memories that become legend. Legend fades to myth, and even myth is long forgotten when the Wheel spins its threads back out into the Pattern. The Pattern is mutable, and it's commonly believed I think among fans that each turning of the Wheel is different than the last. That even though this has all happened before and this will all happen again, what's constant is the themes, not necessarily the people.
Tarmon Gai'don represents a constant in the pattern. It culminates in an event which transpires outside of the pattern, outside of space and time as we know it. There was ever only the one battle with the Dark One for all the ages, all the times it cycled back through the Third Age. Every time, the Pattern must deliver the Dragon to the Bore so that the Champion of the Light can step out to face the Dark One. But that Champion, that Dragon, needn't be Rand al'Thor.
My initial thought on this was that of course it did, things happened exactly right for it to be Rand, it couldn't have possibly been anyone else. But that's not how ta'veren works. Ta'veren are the threads that the Wheel uses to correct itself, to bring the Pattern inline to where it needs to be. The tens or hundreds of thousands of years between each turning of the Wheel is a significant time for the Pattern to drift between hitting this constant, and people still have free will, meaning they're not driven by destiny. Unless they're ta'veren, or get pulled into a ta'veren's ta'maral'ailen. A hundred thousand years of free will is going to lead to a vastly different world each turning, even if all of the same themes are presented.
The ta'veren's job during the Age of Prophecy is to take that world and weave the threads together to get the correct pattern for Tarmon Gai'don. No doubt there are others through other ages who had different purposes. And their strength varies - Rand is more potent ta'veren than Perrin or Mat, and both of them moreso than Hawkwing was. But ta'veren aren't the people, they're the roles. People are delivered into the roles, and that's when the Pattern starts to swirl around them.
Here are some key things to consider:
-
in Baerlon, new images begin appearing to Min as people arrive. Nynaeve wasnt involved, but as soon as she arrived there were new omens - the pattern found a place for her.
-
Loial describes ta'veren as creating ripples in the pattern. Ripples don't necessarily need to move in only one direction. That said, I wouldn't bank too heavily on what a character thinks - but the Ogier do seem to know a lot about ta'veren, and this fits.
-
We already have a precedent for altering the past in-universe: balefire. We know, for a fact, that the True Source that turns the Wheel of Time is capable of altering the past to accommodate the present.
-
We see in Arad Domon that the pattern does so by vulgar coincidence. The spoiled grain just happened to be only in every sack they checked - so if they had checked one more sack it would have been spoiled, but since they didn't it wasn't. I refer to this as vulgar because it's so obviously bullshit that it got called out as bullshit by a character in the book - and Rand's response was to smile and blame ta'veren.
The pattern doesn't bank on one thread to become ta'veren from its start. It wove an intricate pattern and then spun in several threads. The one that best fit the pattern became ta'veren, and the other threads were allowed to go their own way. So for the Dragon's thread, the possible alternatives were Logain, Mazim Taim, and a nameless False Dragon who basically the pattern was just like "fuck you" and killed the second Rand proclaimed himself over Falme. I theorize that by fulfilling enough of the prophecy, any of those 4 could have become the Dragon Reborn - it was actually possible, for only them, to have claimed that destiny. Ta'veren would have provided.
If it had been Taim, we'd have found out something like: he was on Dragonmount during the Aiel War where he suffered some grievous wound that should have killed him but he channeled and healed himself, and his 'first breath' that killed Gitara Moroso was his waking in a fever as the Dragon Reborn. Rand was never born on Dragonmount, the stories Tam told were all true.
One other distinct power that ta'veren have is the ability to consciously alter the pattern. It's rare, but think of Mat with the Sea Folk in Ebou Dar, or Rand facing the Hall of the Tower. They exert an overwhelming pressure on those around them to bend their wills. That pressure can be resisted - both Egwene and Tuon resist.
And these are the things that make the ta'veren different from the critical players in the game. Egwene became the Amyrlin she did not because she's an unrecognized ta'veren, but because Rand needed the relationship he had with her to be exactly what it was and her to be who she became in order to help him win the Battle against the Dark One when she died and told him to let them die for what they believe. Her path was determined by her relationship with Rand, her proximity to his thread in the pattern. She was caught tight in his web of destiny. The pattern didn't swirl around her, she was just one of the most integral pieces of the pattern swirling around Rand. (Which, by the way, I've come to love Egwene after my last read through and I'm not tryin to diminish her at all)
My conclusion is that ta'veren is not just being really important and having an effect on the pattern that will echo for ages. Characters like Egwene, Lan, Demandred, are all greatly influential on the pattern for all of the subsequent Age if not longer. Ta'veren is being Schrodinger's Thread - the Pattern literally retcons you into place, twisting the past as much as the present, in order to bring the pattern back to the intended design - and in the case of the Last Battle that design has to culminate the same at every pass by the constant, which is why 3 ta'veren are used to shape it.