What do we know when we know the law? Not a set of rules or theories, but a set of practices that are at bottom practices of reading–reading the texts of the law, reading the world–and writing (including of course speaking), especially writing in news ways in the inherited language of the law. Legal knowledge is a writer's knowledge. It always has as one of its deepest themes the question of justice. These themes are explored through an examination of the Model Penal Code, which respect to which I ask what it would be like to learn this material with an eye to using it as a language of thought and argument. It is full of tensions and fissures about the most important matters, including its conceptions of justice and the purposes of criminal law, its central ideas of blameworthiness as a function of intention or state of mind, and its conception of proportionality. These can be seen as defects to be cured, or as reflections of irremediable tensions deep in our thought about these matters which it is a virtue not a vice of the Code to render explicit. To shift from legislative to judge-made law, I next examine Holmes's famous opinions in Shenck and Abrams, which I read in the light offered by the Model Penal Code, using that text to help define the criminal law issues presented in the two cases. This in turn helps define Holmes's achievement in these cases as a transformation of the criminal law, which leads to his constitutional doctrine. Finally, I analyze Brandeis's opinion in Whitney as an intellectual and rhetorical achievement of a different, and more extraordinary, kind. In all of these, the idea is to demonstrate how it is that legal knowledge is a writer's knowledge: for the drafter of statutes, for the composer of judicial opinions applying statutory and constitutional law alike, and for the lawyer thinking through and arguing a case.