“But there’s my mother. I’ve got to go back and look after her. I just left her with Mrs. Cooper, and it’s not fair on either of them.”

“But it’s not fair on you to have to do that.”

“No,” he said, “but that’s a different sort of not fair. That’s just like an earthquake or a rainstorm. It might not be fair, but no one’s to blame. But if I just leave my mother with an old lady who isn’t very well herself, then that’s a different kind of not fair. That would be wrong.

Philip Pullman. His Dark Materials Omnibus (Kindle Locations 17001-17005). Random House Children's Books. Kindle Edition.”