In this paper, I am going to deal with a logical relation between facts and norms. Humans both cognize some facts and take value attitudes to them. But what is a logical relation between these two activities of human thinking? I will focus on what it is for a fact to ground a norm. The normative beliefs that we ground on some facts ultimately always presuppose the acceptance of some normative principles that are no longer dependent on any facts. A full-blooded normativity is coming alive only from the position of participants in legal practice, and thus from within the practice. Ultimately, legal validity is not based on knowledge of a fact, whether normative or empirical. It is based on a practical stance of the acceptance of legal authority. Such an attitude is implicit in the day-to-day practice of human agents who use law without the need to thematise its normative grounds.