Destiny vs. Free Will

The third and last most prevalent theme in His Dark Materials is destiny vs. free will. From the very beginning, there are predictions and prophesies about Lyra's role and task in the world. Simultaneously, however, she is the most independent, "free-willed" girl in Oxford, always getting into trouble and doing her own thing. She constantly breaks rules and is a wild child. If anyone could change their destiny, it would be Lyra, but she didn't change anything. The prophesy was made that she would betray someone and it would hurt her, and that for her to fulfill her task, she must not know what it is. The prophecy comes true three times, and each time everyone thinks that that is the true prophecy in action. First, she betrayed Roger by bringing him to Asriel, but it allowed Asriel to open the next universe by severing his daemon. Second, she betrays Pan by leaving him on the shore when she travels to the land of the dead. Third, she betrays Will by leaving them each in their own worlds. Each of these events caused Lyra great pain; each she wouldn't have done if she would have known ahead of time; and each she realized was ultimately for the better.
The fact that Will met Lyra at all was such a slight chance, even just considering that they both met in a world other than their own that they just happened to find, albeit through very different circumstances. There is much more to consider what a small chance it was, that it would pretty much have to be fate.
Something fateful happened to me of which the statistical probability was so small we had to attribute it to destiny. My mom died of Huntington's Disease when I was 16, and I have it also. I met a young man, a student at MSU on the football team, who has a 50% chance of having it-- he hasn't been tested yet-- and his mom also died from it, a year ago. (You have a 50% chance of having it if one of your parents have it because it's a dominant gene.) HD is such a rare affliction that only 1 in 10,000 people have it. There are only 12,000 undergraduates at MSU. Just by numbers, I should have been the only one on the whole campus who had it. Even if by some ridiculous chance someone else had it, what were the odds that that person would be an English major, that that person would be the same age as me, be in the same classes with me, sit by me, and be my friend, enough that we figured it out? I've calculated the odds at 1 in 900,000,000,000 (that's 900 billion for those of you who lost count of the zeros). There was such a small chance that we have never got over our astoundment at meeting each other. And Lyra and Will had an even smaller chance of meeting. "Both of them sat silent on the moss-covered rock in the slant of sunlight through the old pines and thought how many tiny chances had conspired to bring them to this place. Each of those chances might have gone a different way. Perhaps in another world, another Will had not seen the window on Sunderland Avenue, and had wandered on" (491). Later on Will says that if he had been 30 seconds earlier or later, he would not have seen the cat walking through the window at all, and none of their adventures would have happened.
Also at the end, Xaphania tells Will that he has to live his whole life to do what he needs to do, and he tells her that he doesn't want to know because then if he did it, he would feel unhappy and obliging, and if he didn't, then he would feel bad. And she said, then you have finally acquired the first step of wisdom. Sometimes events happen, whether good or bad, and no matter how you try to avoid them, it happens anyway. Master Shifu in Kung Fu Panda said that "Many people's destinies are fulfilled while they are trying to avoid them."