Written in numbered paragraphs, Lyotard's book concerns a conflict that no court can resolve. A litigation can be judged because the parties share an idiom; a differend arises where the injury one party has suffered cannot be phrased in the language the tribunal accepts, so that the injured are stripped not only of redress but of the standing to testify.

The trap recurs throughout: prove the harm and it was mere damage, fail to prove it and the claim collapses. Denial of the gas chambers, the old paradox of Protagoras and his pupil, and the worker who can appear before the law only as the proprietor of labor-power are each read as versions of it.

What is required, then, is a new way of forming phrases and joining them. Lyotard assigns literature, philosophy and perhaps politics the task of inventing idioms in which the unphrasable can be put into phrases.