The article discusses how legal positivists can explain the normativity of law in a strictly legal sense, but not in a moral sense. It argues that the moral conception of law's normativity is more interesting from a broader perspective, but the strictly legal conception is more relevant to the study of law. The analysis shows that legal positivists can embrace the moral conception of the normative force of legal justification without contradiction. Overall, the article suggests that legal positivism is preferable to natural law theory in understanding the nature of law.