So, I've seen three episodes of His Dark Materials, and it's a beautiful, monumental, wonderful adaptation, very close to the original text... And at the same time it's certainly not true to the Pullman Weltanschauung. I don't think it was the deliberate intention of the screenwriter, because Jack Thorne made a remarkable work, and "from-book-to-script" changes seem not only necessary — it's unavoidable in case of adaptations — but elegantly crafted. And yet...
And yet some of these changes betray him completely — he just doesn’t see the world the way Pullman sees it (and it's absolutely natural phenomenon, I don't see it that way either). The most notable case, probably, was in the recent episode, when Ma Costa told Lyra that she can be whatever she wants. This is the moral and magic spell of the XXI century, and I see the roots of that phrase and reasons to bring it in the adaptation. But it contradicts the book, and screenwriter doesn't even see it or doesn't pay enough attention. In the book, this scene is played differently, in much more unusual way and, more importantly, in full accordance with the rest of the book. Because the heart of His Dark Materials trilogy is the change from childhood innocence to experience — and the search for identity too.
Ma Costa had to remind her of a few things.
"You en't gyptian, Lyra. You might pass for gyptian with practice, but there's more to us than gyptian language. There's deeps in us and strong currents. We're water people all through, and you en't, you're a fire person. What you're most like is marsh fire, that's the place you have in the gyptian scheme; you got witch oil in your soul. Deceptive, that's what you are, child."
"I en't never deceived anyone! You ask..." There was no one to ask, of course, and Ma Costa laughed, but kindly.
"Can't you see I'm a paying you a compliment, you gosling?" she said, and Lyra was pacified, though she didn't understand.
One of the main themes of Northern Lights is the unavoidable course of nature. Lyra can't be who she isn't, but she can find out who she is. You cannot change your own nature, and although you are making your own way in life, you cannot become a person you're not: Lyra can't stop being Mrs. Coulter's daughter, panserbjorns can't become humans, witches in love can't become gyptians. This idea runs all through the trilogy, because it's part of author's Weltanschauung. And I'm so sorry that adaptation (not deliberately perhaps) kills this idea in favour of more popular and agreeable point of view.