In the history of modern legal thought, Hans Kelsen has aroused more response–ranging from enthusiastic acceptance to vehement rejection– than any other jurist. He was born in 1881 in Prague. His prolific writings, spanning a period of nearly sixty years, have been published in 24 languages. Kelsen’s earlier work was devoted mainly to basic problems of law and the state; it is in this area that his theories have aroused passionate controversy. In his middle and later periods, his range of interests broadened, resulting in significant contributions to the philosophical and historical analysis both of political ideas and systems (such as democracy, parliamentary government, socialism, communism) and of such great political thinkers as Plato and Aristotle. His personal acquaintance in Vienna with Sigmund Freud combined with his lifelong interest in psychology resulted in numerous writings that examine the relation of psychology and social psychology to basic conceptions of law and the state. A student of religion and theology, Kelsen also examined some key conceptions of the state and of justice and natural law in the light of the Old and New Testaments. Finally, toward the end of his career he devoted a great deal of study to anthropology and early (“precivilized”) history, focusing his interest on the slow development of basic categories of thought, such as of causality in the physical world and of responsibility (or “imputation”) in the ethical realm. His investigations in this field were related to his persistent interest in the structure of the norm—above all, the legal norm, but also of the ethical and moral norm.
Among the early intellectual influences on Kelsen’s thought, Kant must be given first place, al-though it was Kantianism as renewed by NeoKantians like Hermann Cohen and Ernst Cassirer. Just as Kant had sought to establish, through his critical method, the possibilities and limitations of knowledge of the external physical world–leaving to the physical scientists in the various branches of learning the task of finding concrete knowledge –so Kelsen attempted to do the same in the field of law. Beginning with his first major work (1911a), Kelsen sought to develop a general theory of positive law as a system of fundamental categories and concepts, which would enable the practitioner (lawyer, judge, legislator) or the analyst (jurist, law teacher) of a particular legal order to attain a scientifically correct understanding of his subject matter. From Kant (and even more from the NeoKantians) Kelsen acquired a deeply felt sense of the importance of methodological purity: according to this view, the method of cognition determines the object of cognition. Since the “thing in itself” (Ding an sich) is unknowable, the object of cognition is logically “created” by the knowing subject. In this sense, the nature known to the scientist is nothing but an object of cognition “created” by the science of nature, a logically constructed system of functions and relations.
Kelsen attempted to construct a theory of law along Kantian lines which would enable legal science to come to grips with legal phenomena. However, whereas Kant confined his critical epistemology to natural science (treating law in his Metaphysics of Ethics), Kelsen sought to supplement Kant by constructing a normative epistemology, defining the nature and structure of the legal order and of a critical legal science. Cassirer’s main influence on Kelsen’s thinking lay in pointing the way toward resolving the age-old dualism between substance and function. In his pioneering philosophical books, Substance and Function; and Einstein’s Theory of Relativity (1910–1921), Cassirer emphasized the general tendency in modern science to dissolve traditional concepts of science– such as matter, force, energy, atom–into nonsubstantive concepts of relations, functions, and events. Similarly, Kelsen showed in his juristic analysis that traditional concepts like state, person, and similar substantive terms are nothing but reifications or personifications of relationships. The traditional problems of the relations between state and law, for example, are, according to Kelsen, insoluble because they are based on the false dualism of state and law: since state and (national) law are identical, the relations between them cannot be a subject of discussion. Likewise, the traditional problems of physical versus moral (or legal) person (such as the corporation) are based on the opposite false assumption of the identity of “person” in the physical-biological sense and “person” in the legal sense. Since, for Kelsen, “person” in the legal sense is nothing more than the sum total of legal rights and duties regulating human behavior, it makes no conceptual difference whether such legal norms define the behavior of one physical person or of many. The term “person” in the law thus never connotes a particular physical person but is merely a substantive reification or metaphorical personification of a complex of norms. Kelsen similarly resolved other traditional dualisms which are based on false premises, such as the dualism between law and administration, or between creation of the law (legislation) and finding of the law (adjudication).
In defining the meaning of law, Kelsen attempted to determine whether there is any one element common to all legal systems at all times and places and at every level of cultural development. Politically colored definitions of law invariably introduce substantive elements: thus, in a democratically oriented definition of law, a legal order is not “really” law unless a minimum of personal liberty is safeguarded. Similarly, to Marxist jurists a legal system that maintains private property in the means of production is not law, but naked bourgeois force. In his search for a conception of law that is based on scientific universality rather than on political particularism, Kelsen de-fined law in its most general meaning as an “ordering of human behavior” ( 1960, p. 31), as a “specific technique of social organization” ( 1961, p. 5). He emphasized the how (the function of law)—which can be universally valid–rather than the what (or contents of the law)—which cannot be so valid. However, other systems of norms (such as morality and religion) also seek to regulate human behavior. Therefore, Kelsen identified a specific characteristic of the legal method of ordering human behavior that both morality and religion lack: the element of physical force. Law is thus a coercive order of human behavior. Such an order can be (in its political orientation) liberal or totalitarian, capitalist or collectivist, but it is a legal order if it is a coercive order of human behavior. Kelsen, in his definition of law, thus dispensed with the traditional elements of justice, reason, or morality that so frequently were attached to the definitions of law as “the voice of reason” (Aristotle, the Stoics) or as an “ordinance of reason for the common good” (Thomas Aquinas). To introduce the criterion of justice or reason as a definitional element into the conception of law either serves the political purpose of legitimizing or sanctifying the existing legal system or of attacking it in the name of a “higher” law which is not realized in the existing system.
The constitutive element of law as a coercive social order is the “norm,” or the rule that some-body ought to act in a prescribed way. In Kelsen’s conception, legal norms always belong to the realm of the “ought,” although linguistically this may sometimes be hidden, such as in the phrasing of a criminal statute that a thief “will” be punished in such and such a way. Yet this linguistic inexactitude does not conceal the fact that the statutory legislator “is no prophet” ( 1961, p. 45) and is not predicting events but prescribing what ought to happen in a predetermined situation, such as theft. Kelsen stressed that the “ought” in the norm created by the legislator or in the legal rule has no ethical, moral, or natural-law connotations, but is merely a “functional connection” ( 1960, p. 109) or “mode of thinking” (1911 b, p. 6). Following Kant and the Neo-Kantians, he sharply distinguished the causal from the normative connection between two sets of facts or actions. The causal connection (whether in the physical or social sphere) is expressed in the formula: “If A, then B.” In the normative connection, the formula runs: “If A, then B shall be.” From the fact that something will be, one cannot logically deduce that it shall be, nor can one deduce from the fact that something shall be that it actually will be. He held that the modal, logical categories of the “is” and the “ought” are not susceptible of further definition or simplification, since they are basic categories of our mind. However, this axiomatic character of the “ought” applies only to its functional aspect; the content of the “ought,” that is, the content of a specific legal order, cannot be directly perceived or rationally discovered, since it is the result of acts of will.
The structure of the legal norm clearly shows its difference from the moral norm. A moral norm might run thus: “Thou shalt not steal” but, because the moral order is not a coercive order, it does not attach a punitive consequence to the act of stealing. By contrast, the structure of the legal norm (regardless of its linguistic expression) runs thus: “If a person steals, he ought to be punished by the competent organ or agent of the state.” The illegal act (crime or tort) is called by Kelsen the “delict” the consequence threatened by the norm in its second half is called the “sanction.” In Kelsen’s ingenious conception of the structure of the norm, the legal order is concerned not with human behavior that is in accord with the law but with behavior that is in opposition to it. The “ought” in the legal norm refers to the sanction to be applied to contralegal behavior–to the action prescribed for the state authority by the sanction. The contralegal (illegal or unlawful) behavior–the first structural half of the norm–is but a condition for the sanction. Kelsen emphasized that the condition on the basis of which the sanction ought to be ap-plied is not necessarily an act. A person may be punished for what he is, not for what he does. For example, when a totalitarian state imprisons or murders members of a particular social class, political entity, religion, or race; or when a nontotalitarian state imprisons citizens of enemy nationality resident in its territory at the outbreak of war.
By viewing unlawful behavior, the delict, as the condition of the sanction, Kelsen attained a double objective of analysis. First, he removed the last traces of natural-law or ethical criteria from the concept of positive law, since legally prescribed or permitted behavior is no longer posited or prescribed by the law as a positive command (in the sense in which this is done in morality or religion). Instead, legal behavior is “downgraded,” as it were, to the mere logical level of a condition; the behavior which according to the legal norm (of national law) ought to follow is the sanction of the state authority. Second, Kelsen’s structuring of the norm also enabled him to solve the problem, or apparent problem, of how a norm can be said to be valid in case of illegal behavior. “The delict,” Kelsen wrote, “is neither a violation nor a negation of the law. It is conduct determined by the law as a condition of the sanction, likewise determined by the law” (1952, p. 7). For this reason, Kelsen also objected to the usual formulation according to which a sanction is attached to certain types of human behavior because it is a delict. The more accurate way would be to reverse this formulation : a certain type of human behavior is a delict be-cause a sanction is attached to it. “There is no delict in itself” ( 1961, p. 51).
The relationship between the elements of the legal norm–delict and sanction–is called by Kelsen “imputation” (Zurechnung). Where as in nonnormative propositions (if A, then B) the principle of connection between A and B is causality, in the legal norm (if A, then B ought to be) it cannot be causality, since in actual fact A is not always followed by B (such as when a thief escapes legal punishment), or B may take place although A did not occur (such as when a sanction is imposed for an act which in fact did not happen and a person is punished for a crime he did not commit). Imputation thus does not connote the relation of a person and his action, but the relation between the sanction and that action. In the case of a child, for example, who has committed murder, this action can be “imputed” to him according to the principle of causality, but legally it cannot be imputed to him, because such action by a child does not entail a sanction.
The clarification of the difference between causality and imputation also enabled Kelsen to throw some new light on the problem of determinism and free will. Kelsen rejected the widespread view that man is subject to a moral or legal order because his free will enables him to break the chain of causality and establish a new chain of conduct. According to this hypothesis, man’s will is not the result of other causes, but only a cause which brings forth effects. Therefore, so this widespread view holds, if man fails to exercise his free will and to choose the right course of action, he is responsible for the moral disapproval or legal sanction attached to his morally wrong or legally delinquent conduct. Kelsen rejected this hypothesis of free will on the ground that every human action is causally determined, although our methods of knowing may not always be refined enough to ascertain the causes. Moreover, Kelsen pointed to the fact that the very establishment of a legal order influencing and regulating human behavior presupposes that human conduct is causally determinable, that is, not free. The function of the legal order (as of any normative order) is to induce men to be motivated by ideas and perceptions in accord with the conduct prescribed by the legal (or moral) order. If the legal order fulfills this function, men then “will” to do what they legally ought to do, and their so willing serves as a cause of their actions in harmony with the law. The legal order (like any normative system) is thus based on the supposition not of free will, that is, causal nondeterminacy, but of causal determinacy. On the latter supposition, if a person acts illegally, such a delict is imputed to him, or, more correctly, the sanction is imputed to his action (the delict). Kelsen also rejected the customary formulation according to which man is “imputable” (or legally responsible) because he is free, and substituted for it the opposite formula: man is free because he is “imputable,” because legal consequences–awards or punishments–can be attached to his actions. In this conception, freedom and causality do not exclude each other, since the legal order assumes the causal determinacy of human action and therefore prescribes that certain actions ought to be followed by corresponding sanctions. From a fundamentally epistemological viewpoint, too, there can be no contradiction between causality in the physical realm and freedom in a normative order (like law or ethics), for there can be no contradiction between a system based on the “is” and a system based on the “ought.” The proposition, “If A, then B,” is contradictory to the proposition, “If A, then not B,” but is not contradictory to the proposition, “If A, then B ought to be.”
The validity of the norm is most conspicuous in the case of illegal conduct. In a theft, for example, the norm against stealing does not lose its validity because the act of stealing has occurred, and the judge is required to apply the sanction against the delict. But even if the thief escapes and no judicial sanction can be prescribed, the norm still retains its validity. The validity of a norm thus does not imply that the conduct it pre-scribes is always followed but only that it has binding force. To know whether a specific norm is valid, we must therefore inquire in what way that norm is derived from other norms, since an “ought” can only be derived from another “ought.” Thus, the individual norm invoked by a judge against a thief is considered legal if it can be derived from a general statute prescribing sanctions against the delict of theft. If we ask why the general statute is legal, we find that it, in turn, can be derived from the legal authority of the legislative body. The legal validity of the body must again be derived from a norm: we find that under the constitution, the legislative body is authorized to make such general norms. In trying to discover the validity of the constitution, we find that it cannot be derived from any higher legal source since it is itself the highest legal source from which all other (lower) norms are derived. If the validity of the highest legal norm cannot be derived from another legal norm, it can only be derived from a nonlegal norm, or “basic” norm,” as Kelsen called it. This basic norm is pre-supposed to be valid but is not itself a norm of positive law. In brief form, the basic norm prescribes that conduct ought to be in accord with the constitution. Without such a presupposed norm conferring validity upon the constitution, the latter would have no legal character and the norms below the constitution–legislative, judicial, and executive–would have no legal character either, since a norm can be derived only from another norm.
The basic norm thus supplies the legal order with a principle of unity. It makes it possible to consider a human act as legally binding if it can be integrated into an entire system of norms, ultimately deriving its validity from the presupposed basic norm. However, although the basic norm is presupposed, it is not arbitrarily presupposed, for the legal order upon which the basic norm confers validity must on the whole be effective, although individual conduct may be contrary to the law. Kelsen applied here the principle of “cognitive economy.” According to this principle, physical laws are constructed under the postulate that the largest number of facts be explained by the simplest possible formula. Similarly, in the normative sphere, that basic norm should be presupposed according to which the largest number of behavioral phenomena can be subsumed under the legal order that seeks to regulate them. To assume the validity of British law in the United States after the success of the American Revolution makes it impossible to interpret acts of citizens or state organs as legal, since from the viewpoint of British law prior to 1776 such acts have no, or very little, legal significance.
The concept of the basic norm led Kelsen to the dynamic view of the law as hierarchically held together. In traditional legal thought, the main emphasis had been put on the difference between the creation of the law and the application of the law. This approach led, in Roman law countries, to a virtual identification of statute with law as such, while in common law countries the tendency was in the opposite direction–to identify law with judicial decision. In viewing the legal order as a hierarchical system that culminates in the highest norm, the basic norm, Kelsen dismissed the sharp distinction between law creation and law application. Most legal norms both apply and create law. The constitution itself applies a norm in relation to the basic norm but creates law in relation to the legislative process. The parliamentary statute ap-plies law in relation to the constitution but creates law in relation to the executive and the judiciary. The administrative or judicial organ applies the statutory law but creates administrative or judicial norms. Only the first and the last stages of the law are necessarily not dual in character. The basic norm as a presupposed norm is pure law creating, not applying any superior norm. At the other end of the legal system, the execution of the legal sanction in a concrete case is pure application of the law, without creating new norms. If, apart from the basic norm and the final act of law enforcement, every legal norm is both law applying and law creating, the higher norm appears as a frame within which several more specific lower norms may be created. The difference between the legislator and the judge is quantitative rather than qualitative. In the case of the legislator, the superior norm–the constitution–prescribes mainly the procedure of creating statutory law, although some determination of contents, too, may be included (such as a listing of fundamental rights removed from legislative interference). In the case of the judge, the superior norm–the statute–also prescribes the content of the frame within which he may move, but in either case the legislator or judge has discretion with respect to the manner of creating the lower norm.
The act of filling the frame of the superior norm is an act of will rather than of intellect, a political act rather than a cognitive act. In choosing one of the possible interpretations or applications of the superior norm–the constitution in the case of the legislator, the statute in the case of the judge– both legislator and judge act as politicians, not as logicians. This position of Kelsen was anticipated by Justice Oliver Wendell Holmes when he spoke of the fallacy “that the only force at work in the development of law is logic,” and went so far as to say that the alogical element is “the very root and nerve of the whole proceeding” (Holmes  1952, p. 180).
From the very beginning, Kelsen sought to demarcate his “pure theory of law” against two areas into which legal analysis has frequently been drawn: psychology and sociology on the one hand and ethics and politics on the other. Initially he rejected the possibility of a sociology (or psychology) of law, if law is to be conceived as a normative order. He later conceded that a sociology of law is possible, if the object of such inquiry is the “is” rather than the “ought.” The sociologist, for example, can legitimately investigate what social or economic motives or interests have induced a legislative body to pass a particular law, what motives induce persons to adapt their behavior to legal norms, or what social pressures or influences are behind judicial decisions. But, Kelsen argued, all such sociological and psychological analyses deal with causal phenomena parallel to the law, not with the law itself as a normative system.
The defense of legal analysis against the intrusion of ethical and political criteria appeared to Kelsen, particularly in the middle and later phases of his intellectual development, even more important than the defense against the intrusions of sociological methods into legal theory. The degradation of social science in the totalitarian systems of communist and fascist states strengthened Kelsen’s conviction that scientific investigation must be kept free from political intrusion in the form of particular value preferences, natural-law doctrines, conservative rationalizations, or revolutionary challenges of positive law. The theoretician or analyst of the social or legal order is not a social authority. His task is to understand society, but not to remake it politically. Analysis of the law–as of any other social institution–belongs to the realm of rational cognition, not to irrational political will. Rational cognition cannot, Kelsen argued, solve the problem of conflicting values, since values are subjective, based on emotional rather than cognitive factors. In numerous writings on natural law, Kelsen insisted that neither a rationalistic nor a metaphysical-religious natural-law doctrine has ever been able to formulate absolute values or universally valid principles of justice on which general agreement can be attained. Social progress, Kelsen held, consists in making the idea of justice relative: peace through compromise of conflicts of interest and of the values such conflicts reflect. Whereas absolute justice is impossible and its pursuit, if persistent, must result in great sacrifices of human dignity and even of human life, the relative justice of social (and international) peace is attainable and, if practiced, is socially less costly in terms of human life and dignity.
The position of philosophical relativism–both in the theory of knowledge and the theory of values –has often led to the charge that relativism is amoral or immoral, since it denies the possibility of demonstrating absolute standards of truth or value. Kelsen categorically rejected this charge in his farewell lecture, “What Is Justice×” given on his retirement in 1952, from the University of California, at which institution he concluded his formal career as a teacher. Relativism, Kelsen held, does not claim that there are no values but only that there are no absolute values, no one valid system. Relativism thus compels the individual to make his own choice between competing systems of values and prevents him from delegating his moral responsibility to a superior authority, be it religious or political. “The fear of personal responsibility is one of the strongest motives of the passionate resistance against relativism. Relativism is rejected and–what is worse–misinterpreted, not because it morally requires too little, but because it requires too much” (Kelsen 1957 b, p. 22). However, while Kelsen admitted he could not provide an answer that is absolutely true to the question “What is justice×” he did not hesitate to answer this question from his own viewpoint as a scientist. “Since science is my profession, and hence the most important thing in my life, justice, to me, is that social order under whose protection the search for truth can prosper. ‘My’ justice, then, is the justice of freedom, the justice of peace, the justice of democracy–the justice of tolerance” (1957b, p. 24).
Kelsen’s antimetaphysical position in his theory of knowledge as applied to his legal theory, combined with his relativistic, liberal value orientation in his political views, thus places him in the great tradition of modern thought that is identified with John Locke, David Hume, Immanuel Kant, and Bertrand Russell. The social sciences have, since the middle of this century, been engaged in a renewed effort to shed ideology as incompatible with science, since ideology is ideas in the service of interest rather than cognition. In his tireless struggle against the subservience of legal and political science to ideological, political interests Kelsen has made a lasting contribution to the growing process of establishing the social sciences as bodies of cognitive knowledge rather than as tools of political or ideological manipulation.
1905 Die Staatslehre des Dante Alighieri. Vienna and Leipzig: Deuticke.
(1911a) 1960 Hauptprobleme der Staatsrechtslehre entwickelt aus der Lehre vom Rechtssatze. 2d ed. Aalen (Germany): Scientia.
1911 b Über Grenzen zwischen juristischer und soziologischer Methode. Tübingen (Germany): Mohr.
(1920a) 1960 Das Problem der Souveränität und die Theorie des Vülkerrechts: Beitrag zu einer reinen Rechtslehre. 2d ed. Aalen (Germany): Scientia.
(1920b) 1923 Sozialismus und Staat: Eine Untersuchung der politischen Theorie des Marxismus. 2d ed., enl. Leipzig: Hirschfeld.
(1920c) 1929 Vom Wesen und Wert der Demokratie. 2d ed., rev. Tübingen (Germany): Mohr.
1923 Österreichisches Staatsrecht: Ein Grundriss entwicklungsgeschichtlich dargestellt. Tübingen (Germany): Mohr.
(1923–1957) 1964 Aufsätze zur Ideologiekritik. Edited with an introduction by Ernst Topitsch. Neuwied am Rhein (Germany): Luchterhand.
1925 Allgemeine Staatslehre. Berlin: Springer.
1926 Das Problem des Parlamentarismus. Vienna: Braumüller.
1933 Staatsform und Weltanschauung. Tubingen (Germany) : Mohr.
(1934) 1960 Reine Rechtslehre. With Supplement: Das Problem der Gerechtigkeit. 2d ed., enl. & rev. Vienna: Deuticke. → The final and most comprehensive statement of Kelsen’s “pure theory of law.” Contains a bibliography of Kelsen’s works.
1942 Law and Peace in International Relations: The Oliver Wendell Holmes Lectures, 1940–1941. Cambridge, Mass.: Harvard Univ. Press.
(1943) 1946 Society and Nature: A Sociological Inquiry. London: Routledge.
1944 Peace Through Law. Chapel Hill: Univ. of North Carolina Press. (1945) 1961 General Theory of Law and State. New York: Russell.
1948 The Political Theory of Bolshevism: A Critical Analysis. University of California Publications in Political Science, Vol. 2, No. 1. Berkeley: Univ. of California Press.
(1950) 1951 The Law of the United Nations: A Critical Analysis of Its Fundamental Problems. With Supplement. New York: Praeger.
1952 Principles of International Law. New York: Rinehart.
1955 The Communist Theory of Law. New York: Praeger; London: Stevens.
1957a Collective Security Under International Law. U.S. Naval War College, International Law Studies, Vol. 49. Washington: Government Printing Office.
1957 b What Is Justice× Justice, Law, and Politics in the Mirror of Science; Collected Essays. Berkeley: Univ. of California Press.
Cassirer, Ernst (1910–1921) 1953 Substance and Function; and Einstein’s Theory of Relativity. New York: Dover. → First published as Substanzbegriff und Funktionsbegriff in 1910 and Zur Einsteinschen Relativitätstheorie in 1921. The 1953 edition is a translation of both books.
Ebenstein, William (1938) 1945 The Pure Theory of Law. Madison: Univ. of Wisconsin Press. → An extensive revision of William Ebenstein’s Die rechtsphilosophische Schule der reinen Rechtslehre.
Engel, Salo (editor) 1964 Law, State, and International Legal Order: Essays in Honor of Hans Kelsen. Knoxville: Univ. of Tennessee Press.
Holmes, Oliver W. (1897) 1952 The Path of the Law. Pages 167–202 in Oliver W. Holmes, Collected Legal Papers. New York: Peter Smith. → First published in Volume 10 of the Harvard Law Review.
Lipsky, George A. (editor) 1953 Law and Politics in the World Community: Essays on Hans Kelsen’s Pure Theory and Related Problems in International Law. Berkeley: Univ. of California Press.
Verdross, Alfred (editor) 1931 Gesellschaft, Staat und Recht: Untersuchung en zur Reinen Rechtslehre. Vienna: Springer.
"Kelsen, Hans." International Encyclopedia of the Social Sciences. . Encyclopedia.com. (December 17, 2017). http://www.encyclopedia.com/social-sciences/applied-and-social-sciences-magazines/kelsen-hans
"Kelsen, Hans." International Encyclopedia of the Social Sciences. . Retrieved December 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/social-sciences/applied-and-social-sciences-magazines/kelsen-hans
Hans Kelsen was a European legal philosopher and teacher who emigrated to the United States in 1940 after leaving Nazi Germany. Kelsen is most famous for his studies on law and especially for his idea known as the pure theory of the law.
Kelsen was born in Prague, Czechoslovakia, on October 11, 1881. He studied at several universities, including Berlin, Heidelberg, and Vienna. He received a doctor of laws degree from Vienna in 1906 and began teaching at the school in 1911. He taught public law and jurisprudence at Vienna until 1930, when he moved to Germany to teach at the University of Cologne. There he taught international law and jurisprudence and served as dean for two years.
With the rise of the Nazi government, he left Germany and emigrated to Switzerland in 1933. He taught at the Graduate Institute of International Studies of the University of Geneva until 1940. He accepted a position as lecturer at the Harvard University Law School the same year, and relocated to the United States. Later in 1940 he accepted a teaching position at the University of California at Berkeley. He remained at Berkeley until his retirement in 1952.
Kelsen's pure theory of the law is fairly abstract. Its objective is knowledge of that which is essential to law; therefore, the theory does not deal with that which is changing and accidental, such as ideals of justice. Kelsen believed that law is a science that deals not with the actual events of the world (what is) but with norms (what ought to be). The legal relation contains the threat of a sanction from an authority in response to a certain act. The legal norm is a relation of condition and consequence: if a certain act is done, a certain consequence ought to follow.
In this theory a legal system is made of a hierarchy of norms. Each norm is derived from its superior norm. The ultimate norm from which every legal norm deduces its validity is the Grundnorm, the highest basic norm. The Grundnorm is not deduced from anything else but is assumed as an initial hypothesis. A norm is a valid legal norm only because it has been created according to a definite rule.
The theory is independent of morality. It does not matter which particular Grundnorm is adopted by a legal order. All that matters is that this basic norm has a minimum effectiveness: it must command a certain amount of obedience, since the effectiveness of the total legal order is necessary for the validity of its norms.
Kelsen received acclaim for authoring many publications, including General Theory of Law and State (1945), The Law of the United Nations (1950–51), Principles of International Law (1952), and What Is Justice? (1957).
He died April 20, 1973, in Berkeley, California.
"Kelsen, Hans." West's Encyclopedia of American Law. . Encyclopedia.com. (December 17, 2017). http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/kelsen-hans
"Kelsen, Hans." West's Encyclopedia of American Law. . Retrieved December 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/kelsen-hans