I have always been fascinated with the duality of human nature. One such version is the duality that has existed in legal theory or legal philosophy from the very beginning of our civilization, that between natural law and legal positivism. Both perspectives have certainly proven to be persuasive accounts of law, but it needs to be understood how their authors can be so different as to have such distinct approaches concerning the essence of law. In order to obtain an insight into people’s true nature, one needs to study psychology and I was very lucky to come into contact with Jung and his depth psychology. From amongst his enormous work in the field of analytical psychology, it was a particular typology that gave me at least a glimpse of understanding as to why people have such divergent views. This book has been in a state of either gestation or writing for more than 10 years. In order to make a general account of something, one needs to develop an overarching perspective that can only be properly established over a longer period of time. I have incorporated certain material from the following articles of mine, although with much revision and amplification: “A typological reading of prevailing legal theories”, Ratio Juris, No. 2, Vol. 27 (2014) (Chaps. 1 and 3); “The argument from psychological typology for a mild separation between the context of discovery and the context of justification”, in: Dahlman, C. (ed.), Legal Argumentation Theory: Cross-Disciplinary Perspectives, Dordrecht: Springer (2013) (Chap. 4); “Ideal Types of Law from the Perspective of Psychological Typology”, Revus, No. 19 (2014) (Chap. 3); and “Legal Thinking: A Psychological Type Perspective”, Dignitas, No. 49/50 (2011) (Chap. 2).