Abstract

In line with the book On the Essence by Xavier Zubiri, this paper examines his metaphysical approach to the essence. The project explaines what is meant by the essence being unfounded, founding the rest of the notes, needing the non-essential or being closed. This reflection is carried out from two perspectives: the first considers the essence in itself and the second considers the relation of the essence with the rest of the notes. The analysis reaches its height with the characterization of the essential unity and the description of its function in the construct state. On the one hand, this project proves that the theory of substantivity must be crowned and sustained by the essential unity; on the other hand, it shows that the characterization of the essential subsystem and the constitutional system are not contradictory if we keep in mind the criteria used to assert their closure.