We often lack clear procedures for assessing statements and arguments advanced in everyday conversations, political campaigns, advertisements, and the other multifarious uses to which ordinary language can be put. Critical thinking is a method for evaluating arguments couched in ordinary, non-formal language. Legal education should foster this argumentative skill as an ability to assess the open-end variety of arguments that may arise in legal disputes. I will argue that the ability of critical thinking helps lawyers to thrive even in legal cultures that are hostile to critical thinking. There is, therefore, a happy harmony between professional and moral reasons to teach critical thinking at law schools: it promotes epistemic as well as instrumental rationality.