Abstract.  Philosophy is general and systematic reflection about what there is, what ought to be done or is good, and how knowledge about both is possible. Legal philosophy raises these questions with respect to the law. In so doing, legal philosophy is engaged in reasoning about the nature of law. The arguments addressed to the question of the nature of law revolve around three problems. The first problem addresses the question: In what kinds of entities does the law consist, and how are these entities connected such that they form the overarching entity we call “law”? The answer is that law consists of norms as meaning contents which form a normative system. The second problem addresses the question of how norms as meaning contents are connected with the real world. This connection can be grasped by means of the concepts of authoritative issuance and social efficacy. The latter includes the concept of coercion or force. The third problem addresses the correctness or legitimacy of law, and, by this, the relationship between law and morality. To ask about the nature of law is to ask about necessary relations between the concepts of normative meaning, authoritative issuance as well as social efficacy, and correctness of content.