Reasoning by legal analogy has been described as mystical, reframed by skeptics using the deductive syllogism, and called “no kind of reasoning at all” by Judge Posner. Arguments by legal analogy happen every day in courtrooms, law offices, and law-school classrooms, and they are the essence of what we mean when we talk of thinking like a lawyer. But we have no productive and normative theory for creating and evaluating them. Entries in the debate over the last 25 years by Professors Sunstein, Schauer, Brewer, Weinreb, and others leave us at an impasse: The ‘skeptics’ are too focused on the rational force offered by the deductive syllogism when they should attend to the kinds of arguments that can provide premises for deduction—exactly the work that legal analogy does. Meanwhile, the ‘mystics’ expect us to accept legal analogy without an account of how to discipline it. Using the argumentation schemes and critical questions of informal logic, this article constructs a theory grounded in philosophy but kitted out for action. Not skeptic or mystic, it is dynamic.