When looking at ironies in Avi's Nothing but the Truth, one of the first areas to look would be the title itself. The idea of "nothing but the truth" is one of the basic elements of American jurisprudence and society. However, Philip does not come close to embodying any aspect of such an ideal. His manufactured story about Miss Narwin, the deception to his parents about both it and his lack of interest in track, as well as his willingness to continue the story when it is evident that people are being damaged as a result are aspects of behavior that are far from "nothing but the truth." An irony connected with this is that while he does all of this to run track, he transfers to a new school that does not have a track team.
Another irony that presents itself in the novel is that Philip is convinced that literature has no meaning. Philip believes that the written word is not important and does not contain relevance. However, it is the written word that ends up putting the entire story in motion when the media gets ahold of it and newspapers end up writing stories about what happened. The letters and telegrams that Miss Narwin receives confirm the power of the written word, something that Philip denies. The written word is also important because as the story spirals out of control, Philip can only confide in his journal. The written word is the only sanctuary for Philip as he realizes the full scope of his actions.
Miss Narwin experiences her own set of ironies at the novel's conclusion. She is suspended for following the rules. She has ended up becoming a shell of her former self when Philip comes in to ask for help. The course she wanted to take in order to make her a better teacher is now something that the administration ends up spinning as "remediation" for her "poor teaching." The entire educational system experiences ironic treatment. It is poised between educating children and placating a public that is looking to attack it. The superintendent says "People scream if the kids are not educated. Then they scream if you ask for the money to do it." This reflects the irony of American education in the public setting. While there is a desire for good schools and educated children, there is a resentment of education in the form of limits on financial commitments as well as a desire to challenge stakeholders in the school setting. A nation predicated upon democracy and one whose core value believes in "nothing but the truth" finds itself treating education in a politically expedient manner. This irony is something that settles on the reader over the course of the novel and at its conclusion.