The Underlying Value of MacCormick’s Post-Positivism

Save for one key difference, Neil MacCormick’s institutional theory of a legal system closely parallels Hart’s positivist theory. Though MacCormick’s theory of a legal system looks very much like Hart’s positivist theory, he concludes that a central positivist tenet is false. He argues that, contra positivism, moral considerations are necessarily determinants of a legal system’s laws; for, on his account, radically unjust norms necessarily are not law. Thus, MacCormick’s theory presents us with a surprising juxtaposition – in his words, a post-positivist synthesis of positivism and natural law theory. In this essay, I examine whether it is possible to reach a natural law conclusion on the basis of what is traditionally taken to be a positivist foundation. I argue that MacCormick’s and Julie Dickson’s attempts (on MacCormick’s behalf) to do this are not promising. However, I also argue that MacCormick’s theory of law has resources for a more promising approach to this argument, and I attempt to mine these resources.