The irony of truth
Although people use shame to compel others to agree with their point of view, this novel exploits the ironic nature of truth, that it often involves completely disobeying what others want from you. For Lyra, this is so true, there is a staple image associated with it—the Alethiometer, which is an ironic indication that although things seem true on their face, there are dishonest motives mixed into their surroundings.
The irony of reality and mystery
Although many of the elements in this story are supernatural and mysterious, they happen within the realm of reality, and there are elements of regular human life spread throughout the story. The stories often take place in real places, and the police show up toward the end of the novel, a symbol for the unusual strangeness of daily life, which people take for granted.
The ironic missing hero
Lyra's disappearance leaves this novel with a big fat question mark as its ending. The position of Will is reminiscent of the reader's own dilemma—is Lyra gone forever or not? Will is left with her Alethiometer, which bodes darkly for her, but also it is a way of saying that Lyra has passed on her truth-finding abilities, hopefully not just to Will but to the reader as well.
The knife
There is an ironic knife that is useful to them in the same way the Alethiometer is helpful to them. It is ironic because the knife is not a sign of accomplishment, but of discernment. The way the villain's use truth is as a tool by which they can get what they want. If they can deviate from truth, they will, but that is why Will's knife is so helpful, because he can switch between points of view and contrast incoming information.
The irony of home and family
The only valuable part of this story is the love among the characters as they struggle against a fight they will eventually lose. They will become captured, as Lyra's situation shows, or they will become abandoned, like Will, or perhaps, like John, perhaps they will meet an early death. There is no promise given of freedom, privilege, ease, or even of life itself. Ironically, home and family is not just a respite from life's woes—it seems to be the only resource that is truly eternal, but Will must figure out how to piece that puzzle together, mourning the death of John and the disappearance of Lyra.
