Arguably his most important work, Principles of International Law was published after Kelsen's retirement from the University of California at Berkeley in 1952. It is an important synthesis of Kelsen's earlier work on international law and jurisprudence. Any contribution by Professor Kelsen to international law is always welcome. This certainly applies to the book under review. It represents an attempt-which must be regarded as wholly successful-to apply to international law, in an introductory text-book not necessarily limited to specialists, many of Professor Kelsen's basic doctrines in the field of jurisprudence. In preparing this book the author has drawn on many of his previous writings on international law, but he has avoided the danger of putting before the reader a mere compilation of fragments. The very arrangement of the book is stimulating in its boldness and unorthodoxy. ( . . . ) [It is] a model of precision and clarity and . . . a stimulus to thought. If for no other reason, this Introduction to International Law is an outstanding and fully successful attempt-of which there are but few-to present the entirety of the international law of peace within the framework of a jurisprudential system. --Hersch Lauterpacht, British Yearbook of International Law 29 (1952) 509, 513 Possibly the most influential jurisprudent of the twentieth century, HANS KELSEN [1881-1973] was legal adviser to Austria's last emperor and its first republican government, the founder and permanent advisor of the Supreme Constitutional Court of Austria, and the author of Austria's Constitution, which was enacted in 1920, abolished during the Anschluss, and restored in 1945. He was the author of more than forty books on law and legal philosophy. Active as a teacher in Europe and the United States, he was Dean of the Law Faculty of the University of Vienna and taught at the universities of Cologne and Prague, the Institute of International Studies in Geneva, Harvard, Wellesley, the University of California at Berkeley, and the Naval War College.
Hans Kelsen was an Austrian jurist, legal philosopher and political philosopher. He was the author of the 1920 Austrian Constitution, which to a very large degree is still valid today. Due to the rise of totalitarianism in Austria (and a 1929 constitutional change), Kelsen left for Germany in 1930 but was forced to leave this university post after Hitler's seizure of power in 1933 because of his Jewish ancestry. That year he left for Geneva and later moved to the United States in 1940. In 1934, Roscoe Pound lauded Kelsen as "undoubtedly the leading jurist of the time." While in Vienna, Kelsen met Sigmund Freud and his circle, and wrote on the subject of social psychology and sociology.
By the 1940s, Kelsen's reputation was already well established in the United States for his defense of democracy and for his Pure Theory of Law. Kelsen's academic stature exceeded legal theory alone and extended to political philosophy and social theory as well. His influence encompassed the fields of philosophy, legal science, sociology, the theory of democracy, and international relations.
La ONU funciona como una bisagra en la genealogía que va desde las estructuras jurídicas internacionales hacia las globales. Por un lado, la totalidad de la estructura conceptual de la ONU predica sobre el reconocimiento y la legitimación de la soberanía de los estados individuales, plantándose de este modo en el viejo marco del derecho internacional definido por pactos y tratados. Por otro lado, sin embargo, este proceso de legitimación es efectivo sólo en la medida que transfiere el derecho soberano a un centro supranacional real. No es nuestra intención aquí criticar o lamentar las serias (y a veces trágicas) insuficiencias de este proceso; en realidad estamos interesados en las Naciones Unidas y el proyecto de orden internacional no como un fin en sí mismo, sino como una palanca histórica real que empuja hacia delante la transición a un adecuado sistema global. Son precisamente las insuficiencias del proceso las que lo hacen efectivo.
Para aproximarnos más a esta transición en términos jurídicos es útil leer la obra de Hans Kelsen, una de las figuras intelectuales centrales detrás de la formación de las Naciones Unidas. Ya en 1910 y 1920 Kelsen propuso que el sistema jurídico internacional fuera concebido como la fuente suprema de cada constitución y formación jurídica nacional. Kelsen arribó a esta propuesta a través de sus análisis de las dinámicas formales del ordenamiento particular de los Estados. Los límites del Estado-nación, sostuvo, constituyen un obstáculo infranqueable a la realización de la idea del derecho. Para Kelsen, el ordenamiento parcial de las leyes domésticas de los Estados-naciones debe apoyarse necesariamente en la universalidad y objetividad del ordenamiento internacional. Esto último no sólo es lógico sino también ético, puesto que pondría fin a los conflictos entre estados de poder desigual y afirmaría una igualdad que es el principio de la verdadera comunidad internacional. Tras la secuencia formal que describió Kelsen, entonces, había un impulso real y sustancial de modernización civilizadora. Kelsen pensó, de un modo Kantiano, en un concepto de derecho que se volviera una “organización de la humanidad y [pudiera] en consecuencia identificarse con la suprema idea ética”.