The legal philosopher Hans Kelsen (1881–1973) is regarded in many circles as the quintessential figure in analytical legal philosophy, whose only possible rival in originality and scope is Jeremy Bentham. As with other legal positivists, Kelsen rejects morality as a criterion for legal validity. He parts company with other legal positivists in rejecting an appeal to social facts as undergirding the legal system. He is waging battle, then, on two fronts, which leads him to appeal to the Kant of the first
Critique
with an eye to a transcendental argument that will lend support to his nonnaturalistic view of the law. Along with his extensive work in the field of legal philosophy, Kelsen was active in the immediate post‐World War I period as one of the draftsmen of the Austrian Federal Constitution of October 1920. Here his epochal contribution was to establish centralized constitutional review, an institutional practice that was adopted by other European countries after World War II. Kelsen was also active in public international law and in political philosophy, where he defended political liberalism. A “Collected Works” of Kelsen's writings, projected to run to well over 30 volumes, is under way.