The aim of this project is to write a monograph in which the naturalistic legal philosophy of Karl Olivecrona is clearly presented and critically discussed. There is no analysis of Olivecrona's legal philosophy as a whole - as distinguished from ever so incisive analyses of parts of his legal philosophy. Olivecrona's legal philosophy is of course highly relevant to contemporary debates in legal theory. At a bare minimum, the following topics will be considered: (i) Olivecrona's critique of the notion that the law has binding force, and the relevance of this critique to an idea that is popular among today's legal positivists, viz. that the law is normative in a non-trivial way; (ii) Olivecrona's own account of this so-called normativity of law, which is grounded in social facts; (iii) Olivecrona's view that legal rules are so-called independent imperatives; (iv) Olivecrona's analyses of the concept of a right, and the concept of declaration of intention; (v) Olivecrona's thoughts on the nature of court judgments and judicial discretion; (vi) Olivecrona's view on the relation between legal language and reality; (vii) Olivecrona's analysis of the relation between law, force, morality, and the state; and, (viii) the relation between Olivecrona's legal philosophy and the legal and moral philosophy of Axel Hägerström.