Abstract

Ontological categories form a network of ties of dependence. In this regard, the richest source of distinctions consists in the medieval discussion on the divisions of being. After a preliminary examination of some of those divisions, the paper pays attention to Roman Ingarden’s criteria for classifying the various types of ontological dependence. The following are the main conclusions that can be drawn from this exercise. Ingarden suggests that (1) the most general principles framing the categories of particulars are based on couples of mutually opposed principles; (2) the most general among these couples of principles appear to be based on three different types of modalities; (3) subsequent couples of opposed principles do not seem to require the introduction of further types of modalities, and (4) the overall typology shows that there are three spheres of being, respectively composed of ideal entities, real entities and intentional entities as contents of psychological acts.