The legal discourse includes sentences that relate to the capacity to produce new legal entities and to the validity of the ensuing entities. In order to deal with these entities, legal scholars have to craft appropriate concepts. Kelsen’s initial individuation of the legal norm was based on the following scheme: “If certain conditions are met, then coercion ought to be used by the states’ organs”. Insisting on the mandatory character of norms, whose unique function is to create obligations, Kelsen considered that the other functions of legal sentences, like power-conferring, are merely apparent. They may be reduced to the obligation-imposing one if they are understood as mere fragments of norms properly so-called or, as Kelsen proposed in the Allgemeine Theorie der Normen, as indirect ways to impose obligations. But this posthumous book also offers another theory of power-conferring sentences, whereby these are understood as full-blown legal norms. On the one hand, this major change in Kelsen’s ontology of law is based on a shift from Kantianism to empiricism in his conception of legal science. On the other hand, it results from the unsuspected consequences of Kelsen’s adoption of Adolf J. Merkl’s Stufenbaulehre. Just like Merkl was led to distinguish between two kinds of norms, Kelsen was conceptually constrained by the internal dynamics of this conception of the legal system that was alien to his initial theory to revise his individuation of legal norms. Only at the end of his life did he seem fully conscious of the consequences of Merkl’s theory.