Grundnorms of the state. This theory has been severely criticised by theorists like Hart and Lord Lloyd, though others, such as followers of various schools of the future development of the United Nations, including Grenville Clark and Louis B. Sohn of Harvard, who have strongly endorsed it. See also Norm (social) Notes References Hart, H. L. A. The Concept of Law. 1961: Clarendon Press. Kelsen, Hans. General Theory of Law and State. 1949: Harvard University Press. Philosophy of law