Far from a “psychological” interpretation of Bierling’s work, in this paper I defend the thesis that Bierling is a predecessor of the Pure Theory of Law. This thesis can be demonstrated through Bierling’s main thoughts, namely: Firstly, the central concept of the General Theory of Law is the concept of legal norm (normativism) understood as an act of will (wollen) (voluntarism) that expresses a duty (an ought to: sollen). Secondly, legal norms have a hierarchical structure (Stufenbau) in the legal order (system). Thirdly, the hierarchical structure of legal norms presupposes a basic norm (Grundnorm) as the last foundation of their validity (Geltung). Fourthly, the concept of acknowledgment (Anerkennung) is a psycho-social concept that is analogue to the Kelsenian concept of efficacy (Wirksamkeit). Fifthly, legal concepts, which are the concepts produced by legal Science, are formal concepts (legal scientific formalism).