I outline a theory of deliberative debate, its distinctive features and the kind of normative criteria that may be posited for it in light of its distinctive features. Deliberative debate is a type of practical reasoning: ultimately it is not about what is true, but about what to do. From this follows several characteristics, primarily that there will normally be good reasons on both sides of an issue. I criticize prevalent conceptions of argumentation and outline an alternative, discussing contexts and varieties of deliberation and proposing normative criteria based on a citizen-centered view of the function of deliberation.