It is called a “pure” theory of law, because it only describes the law and attempts to eliminate from the object of this description everything that … - Hans Kelsen

Justice is primarily a possible, but not a necessary, quality of a social order regulating the mutual relations of men. Only secondarily it is a virtue of man, since a man is just, if his behavior conforms to the norms of a social order supposed to be just. But what does it really mean to say that a social order is just? It means that this order regulates the behavior of men in a way satisfactory to all men, that is to say, so that all men find their happiness in it. The longing for justice is men's eternal longing for happiness. It is happiness that men cannot find alone, as an isolated individual, and hence seeks in society. Justice is social happiness. It is happiness guaranteed by a social order.

By determining law — so far as it is the subject of a specific science of law — as norm, it is delimited against nature; and science of law against natural science. But in addition to legal norms, there are other norms regulating the behavior of men to each other, that is, social norms; and the science of law is therefore not the only discipline directed toward the cognition and description of social norms. There other social norms may be called “morals.” and the discipline directed toward their cognition and description, “ethics.” So far as justice is a postulate of morals, the relationship between justice and law is included in the relationship between morals and law.

The mark of Platonic philosophy is a radical dualism. The Platonic world is not one of unity; and the abyss which in many ways results from this bifurcation appears in innumerable forms. It is not one, but two worlds, which Plato sees when with the eyes of his soul he envisages a transcendent, spaceless, and timeless realm of the Idea, the thing-in-itself, the true, absolute reality of tranquil being, and when to this transcendent realm he opposes the spacetime sphere of his sensuous perception-a sphere of becoming in motion, which he considers to be only a domain of illusory semblance, a realm which in reality is not-being.